Terminology

Before I can begin writing an article explaining turbochargers, terminology must be learned. Here is a list of the more commonly used turbocharger terms:

Compressor - Essentially a fan that spins and compresses air within an enclosed area (compressor housing). In order to allow the air to compress and build pressure within the housing, the fan must be spun at certain rpm levels.

Compressor Housing - Housing that encloses the compressor. Pictured is a compressor housing.

Compressor Map – A map that allows the ability to plot compressor pressure ratio vs. engine airflow. An “island” shape is created on the plot showing where the compressor is efficient.

Compressor Efficiency – Compressors efficiency is the ability to produce lowest possible temperature from the compressor air. When air is compressed heat is generated, at certain range of speeds of the compressor rotation the heat can be keep to a minimum. This is what is known as “being in the efficiency range of a compressor” Higher efficiency, lower outlet temperatures. Highest possible efficiency of compressors are 78~82%. Lower outlet temperature=lower intake air temperature. Lower intake air temperature=more dense mixture of air=more oxygen available in the combustion to burn. The greater amount of oxygen present with fuel provides more energy. More energy=more heat=more torque=more power.

Compressor Trim – The trim of the compressor refers to the squared ratio of the smaller diameter divided by the larger diameter multiplied by 100 of the compressor wheel. The smaller diameter of the wheel is known as the inducer, and the larger diameter of the wheel is known as the exducer.

Compressor Families – Beyond compressor trim levels there is compressor family of wheels. In the Garret turbo line of older technology compressors there is T22, T25, T3, T350, T04b, T04e, T04s and T04r families. In each family there is trim levels to the family. Although there is a 60 trim in both the t3 and to4e family wheels, the main difference is the inducer diameter of the wheels. The trim is only a ratio of the exducer/inducer, so while the inducer size of the compressor wheels are vastly different, the ratio between the exducer/inducer remains constant since it’s the comparison between the exducer to inducer size.

Turbine – A fan that uses exhaust energy to rotate. The rotation of the turbine is transmitted through a shaft that is connected to the compressor. Faster the turbine spins, faster the compressor spins. Compressor uses the rpm translation through the turbine/compressor-connecting shaft to compress air at the rpm level that dictates compressor flow.

Turbine Housing – Housing that encloses the turbine wheel. Turbine housing size affects the ability of the turbine to transmit rpm to the compressor wheel. Smaller turbine housing, quicker spool up due to quicker translation of rpm’s to compressor. Trade-off is increased low-end response for less high-end response from turbocharger. Picture below is a turbine housing.

Turbine Trim – The trim of the turbine refers to the squared ratio of the smaller diameter divided by the larger diameter multiplied by 100 of the compressor wheel. The smaller diameter of the wheel is known as the inducer, and the larger diameter of the wheel is known as the exducer.

Turbine Families – As with compressor families, there is turbine families. The most common evidence of the turbine families is the t31, t350 and t04 wheel used in the t3, t3/t4 turbos sold on the market. Precision offers the t31, aka stage 3 blade in their smaller line of sport compact series turbochargers. The t31 comes in two different trim levels the 69 and 76 trim. The t350, aka stage 5 blade comes in two different trim levels as well, 69 and 76 trim. The t31 will spool faster than the t350 due to the physical size differences (t31 being smaller). The smaller the trim level the quicker spool, but less top end. Essentially you are changing the turbine pressure ratio when you are selecting the family and trim level of the turbine wheel you are using. The larger family and trim level you choose the more power the turbocharger will produce at the expense of lag. As with the compressor trim levels both the t31 and t350 have the 69 and 76 trim levels, which are not the same. The turbine trim is the ratio of the exducer compared to the inducer size of the turbine wheel, since its only a ratio the size of the inducer/exducers are completely different.

Turbine Map – A map that allows the ability to plot turbine expansion ratio vs. engine airflow. An “island” shape is created on the plot showing where the turbine is efficient.

A/R – Ratio of the area of the compressor/turbine housing to the radius of the compressor/turbine wheel. In order to find out the A/R of the compressor or turbine housing select a point where the compressor/turbine housing begins and measure the cross-sectional area at that point. Cross sectional area is A=P*(Radius)2. Next step is to measure the distance between the center of the area and the center of the compressor/turbine wheel, this is the radius measurement. If you choose a different point on the compressor/turbine housing and remeasure the area and radius, you’ll find that it stays constant. This is due to the housing getting constantly smaller in diameter as it gets closer and closer to the compressor/turbine wheel.

When you upgrade from a .48 to a .63, or .63 to a .82 A/R you are essentially increasing the area of the housing. Increasing the area increases the amount airflow to the turbine wheel. The smaller area of the smaller turbine housing builds pressure quickly and transmits this pressure to the turbine. The pressure gives the turbine enough rpm’s to allow the compressor to compress air at lower engine speeds (less engine speed, less airflow from engine). The trade off is that pressure builds up quickly in the housing to obtain quick spool up, but the pressure quickly becomes to great and backpressure builds up. The backpressure is the restriction that limits shaft speed of the compressor, and as the rpm increase (engine airflow increases) the torque curve begins to drop off due to the volumetric efficiency of the engine decreasing. Think of the turbine housing sizing as increasing/decreasing inlet pressure to the housing in order to gain low end, midrange or top-end response from the turbocharger. The smaller turbine housing wont carry the torque curve to a high rpm, limiting the amount of peak whp. Excellent low-end and midrange gains are felt through smaller housings.

Compressor/Turbine Mismatch – When “matching” a compressor and a turbine you are seeking to balance the turbine characteristics to the compressor characteristics. When you increase the size of the turbine wheel you are decreasing the pressure ratio of the turbine, essentially decreasing the shaft speed connecting the compressor/turbine. When pairing a larger turbine wheel to a small compressor wheel, the smaller the compressor wheel the higher the rpm the wheel has to be spun at to compress the air. This becomes a problem in that the smaller compressor cannot generate adequate shaft speed to compress air. The same can hold true when pairing a huge compressor to a small turbine wheel. The larger compressor needs less shaft speed to compressor airflow, but the smaller turbine wheel will spin at a much higher rpm level that is what is necessary. The result is crossing over the choke or surge line on the compressor map (this will be explained in part 2 of this article). Note the two different compressor maps, one of a 60 trim t3 compressor wheel, the other a t64 compressor wheel.

Part 2 will explain compressor and turbine maps, and all the terminology that goes along with topics.

The A/R in a relationship that is obtained when dividing the interior area of the turbine where the inner walls are found, through the turbine housing radio from the center to the tongue as the illustration indicates.

A/R values are expressed as .35, .47, .68, .84, 1.00, 1.15, etc.

A small A/R indicates a small interior volume in the small turbine and a large A/R indicates a greater volume.

At a minimum A/R the motor's response is produced at small revolutions per minute but at high revolutions we will not achieve an adequate caudal. We should always find a compromise between achieving the lowest response possible and have enough caudal at high revolutions. The picture below is for reference:

As stated, the turbine housing A/R is the cross sectional area of the turbine housing divided by the distance from the center of that cross section to the center of the wheel. This makes sense if you look at the graphic.

If you take for example, the area in A1 and divide it by R1, you will have found the A/R for this turbine housing. Each cross section and radius have the same proportions so the A/R will be found by using any cross section/radius.

What is the Trim of a turbo and how is it calculated?

Each turbine wheel y compressor wheel model generally have the same turbine diameter (highest diameter), but different steps (lowest diameter). Each type of step (trim), has different blowing characteristics.

[*]TRIM values are expressed as 45, 50, 55, etc... and can only go from 0 to 100. A value of 100 means Dp = Dg

[*]A large TRIM indicates a large turbine diameter.

[*]A TRIM of 55, gives 10% more caudal than a TRIM of 50.

[*]TRIM is used in the same way for turbine wheels as for compressor wheels.

[*]TRIM is calculated through the following formula.

TRIM = ( Dp / Dg )² x 100

Si Dg = 50 mm y Dp = 35 mm

TRIM = ( 35/50 )² x 100 = 49

What are the different flanges and what are the sizes?

[*]All most all of your turbo head units come with the flanges described below. The T3 housing is the smallest and flows the least, with the T6/Thumper flange being the biggest and flowing the most. The flange plays a role in spool up, backpressure...etc. The rule of thumb here is use the largest flange you can possibly fit. Of course this will be limited by what headers you use, since most are pre-fabbed and come with a flange already, and under hood space will also be a limitation.

[*]Basic T3

[*]Basic T4

[*]Basic T6

There are several different kits and filters available for assisting Cummins Turbo Diesels to breathe more efficiently. The following are some of my personal findings when considering and using BHAF’s (Big Honkin' Air Filter).

Firstly, there are air filters on the market that are washable and re-useable. These air filters also claim to prolong the life of the air filter and save money. I have found this claim to be invalid. When a air filter is washed it puts unneeded wear on the media and eventually creates holes in it. These holes in turn allow the passage of dirt. Another issue of washable air filters is they need re-oiled once washed. Most people over oil these air filters, which causes the turbo to pull oil onto the compressor wheel. Once the turbo wheel gets dirty it can cause damage to the turbo.

Here is typical results of using washable media filters like K&N air filters. What I want you to take notice to is not the amount of oil but I want to to pay attention to the grit and dust stuck to the turbo housing. If this filter is doing its job this dirt and grit should not be present at all in the turbo.

Here is my turbo after 195K miles and using the BHAF (Big Honkin' Air Filter) since 50K miles (145 total miles) and only on my second filter in 9 years.

There are several good qualities when considering a BHAF (Big Honkin' Air Filter) or similar air filter. The first quality is it is a completely sealed unit. Being completely sealed there is no way for dirt to pass through the air filter into the engine. The second quality of a BHAF (Big Honkin' Air Filter) is it is roughly 3x bigger than a stock panel air filter. Being bigger allows more air to enter the engine unrestricted. The third quality of a BHAF (Big Honkin' Air Filter) is the media used in it is a dry paper element. Dirt will not stick to this type media, thus almost eliminating the potential of premature plugging.

An accessory to consider with using a BHAF (Big Honkin' Air Filter) is the Outerwear for it. The outerwear is and works as a pre-filter for the BHAF (Big Honkin' Air Filter) It will protect the filter from heavy dust and water, as well as prolongs the life of it. The outerwear is also washable.

I have been very happy with my BHAF (Big Honkin' Air Filter) as I now have 109K miles and 5 years on it, and it is just now starting to show dirt.

Listed below are the different part numbers used for a BHAF’s:

You can find a BHAF at

Vulcan BHAF Link

Amazon BHAF Link

How to test the filter minder

BHAF (Big Honkin' Air Filter) Life in Idaho

Taking A Closer Look At K&N Filters

As for the life of a BHAF (Big Honkin' Air Filter) I've gotten up to 130K miles and 6 years and still never pulled the filter minder down. But started thinking I'm pushing my luck so I change out the filter at 130K miles and 6 years of back country dirt roads and forestry roads.

As you can see the filter minder still hasn't moved...

Heat Shield Template for The BHAF (Big Honkin' Air Filter)

Here is the template for the heat shield shown in my pictures above.

Alternate BHAF (Big Honkin' Air Filter) Part Number

This is copied from smokey burnouts at
http://www.cumminsforum.com/forum/98-5-02-performance-parts-discussion/65116-bhaf.html#post643174

Well this is just info for all who might be interested:

NAPA BHAF (Big Honkin' Air Filter) number is: 2790, which most of us know and is priced at about $70-75
But i got a NAPA 6637 which is a very large filter for only $54...might save some folks some cash...and it fits on the factory hose!!!

Mopar1973man... 6637 is another you can add to you list of filters

BHAF_Template.doc

Common areas for  leaking

1. intercooler boots

2. intake shelf gasket

3. grid heater gasket. 

Steps:

pressurize the system, to ~ 5- 10 psi using the setup in the above video > next use soapy water in a spray bottle to soap up the intake track.  start at the turbo and work your way to the intake side of the engine.  Spray and watch for bubbles in each area.

Enjoy.

Compressor Efficiency and More

by Khiem Dinh

Compressor efficiency is a term thrown around whenever people mention forced induction, but what does it really mean? How does it affect an engine's performance? And what role does air temperature play in all of this? The cool thing about thermodynamics is that we can explain effects with equations. Using basic compressor equations, we'll put some numbers to the affects of air temperature and compressor efficiency on compressor power requirements and air temperature increase.

Some fundamental compressor equations are below.

I like working in SI units because doing calculations with English units sucks! So, mass flow rate is in kg/sec, the average constant specific heat value for air I used is 1.007 kJ/kg*k, and k for air is 1.4. The specific heat of air actually varies with temperature, but the change is basically nothing within the range of temperatures we're using, so I'm assuming a constant value. After calculating all the values in SI units, it is a simple conversion to English units. The table and chart I generated assumes: air inlet temperature of 298K/24.85C/76.7F, and 100% compressor efficiency (isentropic compression).

Looking at the chart and table above, it becomes very obvious that increases in mass flow rate and pressure ratio require more power. Also, the graph shows lines of constant power. For a given compressor power, you can get a lot of flow and little pressure ratio, a lot of pressure ratio and little flow, or somewhere in the middle. To get a feel for what the numbers mean in the real world, we'll use 2.0L 4-cylinder engine as an example.

Automotive engines of this displacement and cylinder count will make roughly 500hp with a mass flow rate of 50lbs/min and a pressure ratio of 2.75, or about 25psi of boost. Looking at the table, a 100% efficient compressor would require 51.1hp! Looking at the compressor map for a GT3076, it shows a compressor efficiency of ~72% at this point. So the actual power requirement becomes 71hp. A GTX3582 has a compressor efficiency of 77% resulting in a power requirement of 66.4hp. That extra hp required over a 100% efficient compressor ends up as extra heat in the air. More efficient is better!

The other variable in the equation that's very important, but many people seem to neglect in the practice of building turbo cars, is the temperature of the air going into the compressor. Many people have the misconception that performance is unaffected because the intercooler will cool the air enough regardless of the air temp going into the turbo. What they are neglecting is the fact that compressor performance improves with cooler air. Said another way, it gets worse with taking in hotter air. Using values of 50lbs/min and a PR of 2.75, the table below shows compressor power required, change in temperature of the air (Delta T), and the exit temperature of the air based on the inlet temperature of the air.

Hotter air in equals mo' hotta air out! Takes more power too. Translation? Laggy turbo.

Notice that the hotter the air going into the compressor, the more power is required to compress it. Also, the increase in the air temperature is greater. Of course, this results in the final temperature being even hotter. I think comparing air inlet temps of 77F and 122F is reasonable; 77F being ambient air temp and 122F being the temp if you ingest air from the engine bay. So by sucking up the hotter engine bay air instead of cooler air from the front of the car, the compressor power required increases by 4.3hp, or about 8%. The difference in the temperature coming out of the compressor is a toasty 60.1F making the intercooler work that much harder.

Of course, there's no such thing as a perfect compressor, so let's see what happens with a 60% efficient compressor; this is often where the tuner industry operates as they try to squeeze as much power as possible out of turbos. Looking again at 77F and 122F inlet temps, the power and temperature differences are now 7.1hp and 70.2F!

Crappy compressor efficiency means supa dupa hotta air! You could boil an egg on it. Mo' laggy too.

So now we know how crappy compressor efficiency and sucking in hot air increase the power required of a compressor to move and squeeze air. But where does that power come from? A supercharger gets it off the crankshaft of the engine and a turbocharger uses a turbine wheel in the exhaust. If you go by old school nomenclature, what we call a turbocharger was referred to as a turbo supercharger. So basically a special type of supercharger with a turbine wheel to get work out of the exhaust. Anyways, we like turbos because they use otherwise wasted energy. Going back to the very first chart, a perfect compressor doing 100lbs/min at a pressure ratio of 4 would need almost 150hp. Given the option of taking that from the engine crankshaft or the exhaust energy, we'll take the exhaust energy. That's the reason why pretty much every diesel engine and the majority of gasoline engines use turbos instead of superchargers. So does the turbo engine make 150hp more than the supercharged engine? The answer is no because the turbine wheel and turbine housing create back pressure in the engine reducing its volumetric efficiency. But a turbo engine will still make significantly more power than a supercharged engine given the turbo is properly sized.

Sizing of the turbine wheel is important so as to get the maximum efficiency from it. Our worst case scenario of the 2.0L engine, 60% efficient compressor, 50lbs/min mass flow rate, 2.75 PR, and 122F air inlet temperature requires 92.4 hp of shaft power from the turbine to drive the compressor wheel. A 100% efficient turbine wheel would need to get 92.4 hp worth of energy out of the exhaust. However, like compressor wheels, there’s no such thing as a 100% efficient turbine wheel.

Throw in some moderate turbine efficiency and you end up needing a lot of exhaust power to spin a compressor.

Plugging in a value of 60% for turbine efficiency, we can see how much energy needs to be pulled from the exhaust based on the temperature of the air going into the turbo. The difference in power required going from 77F and 122F is a lag inducing 11.9 hp, or about 8%.

So what have we learned? Maximizing compressor and turbine efficiencies reduces the exhaust energy required to get a turbo going. Sucking in colder air instead of hot air also makes compressors happy. The final conclusion to all of this is that math is cool, stay in school!

Another simple enhancement that doesn't cost a bunch of money is straight pipe the exhaust. Beware in some states it is illegal to be without a muffler. Now in some states, a turbo is considered a muffling device. Some people think it just too loud. I will admit that without the muffler in place is it louder. I've been told that my truck can be heard up to a mile away.

Now besides the noise and legal stuff. The bonus to straight piping the exhaust is that the engine can breathe easier. It will reduce the pyrometer temperature, increase horsepower and torque, and increase your fuel mileage.

Basically, all you need to do is measure how long the full muffler assembly is and get a piece of 3" exhaust pipe and maybe a new set of clamps. Once you got the pipe have them expand the ends so they will fit over the existing pipe. So now when you do this you going to have to fight a little to get the old muffler and resonator off. I used a torch to heat the clamp spots up to get the muffler assembly off. Then slide in your new pipe and clamp it down.

I've welded in some re-bar hanger to mount back in the rubber hanger on the frame to help hold the pipe up.  

This Article covers the effect of being at higher altitude in a Turbo Diesel powered vehicle.  The princples work the same on a Cummins 24v vs common rail and powerstroke or duramax.   

First thing we need to look at why altitude plays a role.  We need to remember that at sea level there is about 14.7 psi of pressure in the air you breath.  You can figure out this number by doing some basic math seen below.

I am gonna quote some wiki info from https://en.wikipedia.org/wiki/Pounds_per_square_inch to show how PSIA is caluclated

"

The pound per square inch or, more accurately, pound-force per square inch (abbreviations: psi, lbf/in², lb_f/in²,lbf/sq in, lb_f/sq in) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:

1 psi =  =  ≈ 6894.757293168 N/m²

Therefore, one pound per square inch is approximately 6894.757 Pa.

Now converting the psi to standard atmospheres:

1 atm =  =  ≈ 14.69594877551 psi

Therefore, 1 atmosphere is approximately 14.696 pounds per square inch.

Pounds per square inch absolute (psia) is used to make it clear that the pressure is relative to a vacuum rather than the ambient atmospheric pressure. Since atmospheric pressure at sea level is around 14.7 psi, this will be added to any pressure reading made in air at sea level. The converse is pounds per square inch gauge or pounds per square inch gage (psig), indicating that the pressure is relative to atmospheric pressure. For example a bicycle tire pumped up to 65 psi above local atmospheric pressure (say, 14.7 psia locally), will have a pressure of 65 + 14.7 = 79.7 psia or 65 psig.^[1][2] When gauge pressure is referenced to something other than ambient atmospheric pressure, then the units would be pounds per square inch differential (psid).

"

and a pretty graph

 Now as we all know there is less air the higher in altitude you go.  But the real question is how much does it really matter?  I mean the turbo compresses air anyways so does a little less atmospheric pressure really matter?  

Well the answer is yes absolutely it matters.

A lot of people say that when you have a NA engine it matters a ton but on a turbo engine it isn't as big of a deal.  While that is somewhat true we can see below that turbo engines also suffer a good deal.

So using the below you can see in the "PSIA" column the atmospheric pressure at a given altitude. As expected we see about 14.7 PSIA at 0 feet. If we look down the chart we can see at 3000' altitude you should have 13.17 psia or about 1.5 psi less than at sea level ( 14.7 - 13.17 = 1.53 psi).  Now lets step up to 7000' were a lot of us Rocky Mountian guys live.  The PSIA at 7000' is ~11.34 or about 3.5 psi less than at sea level ( 14.7 - 11.34 = 3.36 PSI)

Well those numbers are all fine and dandy, but what does that actually mean?   

So lets think of this in laymens terms and just add the PSIA to the overall boost on the gauge IE: if your gauge reads 30 PSI you actually have 44.7psi at sea level ( 30 Psi + 14.7 psia = 44.7 psi). 

Lets say now that you are sitting idle at a stop light. At sea level sitting at a stop light you have a total boost of 14.7 psi ( 0 psi from the turbo + 14.7 psia = 14.7 psi). 

Lets do the same with 3000' At idle you now only have 13.17  psia at idle.

And at 7000' you have a whooping 11.34 psia at idle.

So in order for the guy at 7000's to have the same boost as the guy at sea level the turbo will need to create that extra 3.5 psi.  

So to sum it up the guy at sea level has the same amount of boost going into the engine at idle as the guy at 7000' when his gauge is reading 3.5psi.   So you can think about this all in terms of, How long does your truck take to make 3.5 psi worth of boost?   The time it takes for your truck to make that boost is how much quicker the guy at Sea Level will spool.  Right off the line the guy at sea level is already "spooling" 3.5psi worth of boost compared the the guy at 7000's altitude.

You could also think of it as if you lined 2 trucks up and told them to drag race, but told one driver that he could brake boost to 3.5psi while the other truck had to leave the line at idle.    It is easy to see which truck will leave the line quicker.

As we can see this means that the turbo will have to work harder when it is at a higher altitude. From a stop the turbo at 7000' is automatically at a 3.5psi disavantage to the guy at sea level.  

Not only does altitude have an effect on Off idle performance, but it also has an effect on the upper end of the turbo map.  The turbo has a map that shows how much air it will flow.  How To Read Turbo Map

So we need to consider that the in order for the turbo at 7000' to make 30 psi on the boost gauge it will actually have to make 33.5psi of boost.  Fine and dandy right?  What's another 3.5 psi worth of boost on a diesel right? Well if we consider that each turbo has it's limits that it flows air, we know that while the turbo at sea level might be efficent at 30 psi of boost, the turbo at 7000' might be out of it's map when the gauge hits 30psi as it actually has to create 33.5 psi total pressure.   The turbo at 7000' altitude will become inefficent 3.5psi sooner than the turbo at sea level.  

If we use the rule of thumb and say every 10psi of boost is worth 100 hp at the crank we say say that a truck at 7000' will make roughly 35 hp / 70tw less than the same truck at sea level if the turbo is kept within the same map both times.

Numbers are fine and dandy, but lets see some proof to back all of this up.

First the spec's on the truck.

- 2000 ram 2500 24v Cummins

- 3.55 rear end 47re tranny

- 7x.009 DFI vco injectors

- 235/85/16 tires

- Quadzilla tuner ( turned off for the videos)

Here are some Videos.

 0' altitude

 I was unable to ge ta video of this, but I can say that smoke output was pretty much 0 at sea level I would say the DFI 7x.009 injectors were Less than a stock truck with a timing box with no canbus fueling.  You can see the difference between 2000' and 7000' so keep that in mind.

2000' Altitude

7000' Altitude

As you can see the difference is HUGE.  

So to sum up everything.  Altitude plays a HUGE role in how your turbo diesel runs.  A truck at Altitude will smoke more, build boost slower, run out of boost faster AKA It's map.

So what can we do about it?  Truthfully, Nothing.  You need to build your truck with this in mind.  If you live at high altitude you might not want the same turbo that you would at sea level.

At the time you turn the ignition key to the ON position the PCM/ECM looks at the IAT (Intake Air Temperature) temperature and determines if the manifold is cold enough to need pre-heating. Typically this occurs when temperatures are below 55-65*F. You'll notice that the battery voltage will fall slightly more than normal during this time that the WAIT TO START light is lit. Once started the grid heater will continue to cycle on and off to maintain proper manifold temperature. There are 2 grid heater elements. The PCM/ECM will determine if one or both elements will be used.
Here are the times and temperatures you should see.

When temperatures are below 0*F it’s suggested to cycle the grid heater twice to help aid in starting. Block Heater use can offset intake temperatures, since the block will warm incoming air.

Grid Heater(s) - Power Requirement

Starter – Power Requirement
350-700 Amps
(Depends on temperature and oil viscosity)
Alternator Output
120 Amps

As in anytime you start the vehicle and grid heaters are active it will take longer to recharge the batteries. So be sure to run the engine longer to ensure the batteries are charged back up. Typically about 10-15 miles is a enough distance to re-charge the batteries in arctic cold temperatures.

Both grids on will provide a heating temperature of 500F as proved in the video.

When the grids heater(s) are running, you can tell when both or just one grid is running. You hook a voltmeter up to any point on the truck and measure exact voltage. In the video, you can see voltage drops to 11.75V, indicating that both grid heaters are running. When the voltage slightly releases to 12.20V, one of the grid heaters has stepped out. That grid heater then also steps out and regular charging voltage of over 13V is seen. Only one grid heater is needed after the initial dual grip operation to keep intake temperature up, so then you can see only one grid turning on and off with every time it drops to 12.4V.

Driving at low speeds can make the grid heater stay on seemingly endlessly as the cold air is driven into the engine at a high rate with the grids failing to heat it up to the temperature that the grid heater(s) turn back off. You have to get the RPM and engine load just right, it also has to be during the state that you haven’t turned the grid heater cycling phase off (going over 20mph). Basically, you might be going 15mph up a hill and the grid heater will cycle on and instead of turning off the next second like normal, the threshold temp is never met and the grid will stay on for a seemingly endless time. Like I said, the conditions have to be perfect in order for it to do it. Just an interesting tidbit.. It is surely hard on the alternator and batteries.

The grid heaters will then shut down when you go over about 20mph, retain sufficient intake temperatures, or shut the engine back off. The grids typically run about 3 minutes while idling, cycling on and off to maintain temperature, and finally canceling the cycles.

Grid Heater Relays

There are 2 grid heater relays, one for each grid heater. Each are ran by the ECM individually. The green wire on each of them is ground. The yellow and red wires are for each unique relay and serve as the positive lead that goes to the ECM. Upon being sent positive voltage, the relay energizes and the grid heater turns on.

This article is for the standalone controller / tuner needed to control a Holset HE351 ve He351 VGT turbo from a 6.7 Cummins.   This controller will help you tune the holset he351ve vgt turbo for your truck.  It is is %100 open source you can tune the turbo in any manner you like.  It will take some trial and error to tune the holet he351vgt, but the pay off is worth it.  The he351ve really shines when it comes to low end power and having a flat torque curve.  

 He351ve Airflow Specs

The reason for wanting this turbo comparted to another aftermarket turbo are,  Increased flow over a hx35 turbo ( 60lb/min to 69 lb/min) built in Exhaust Brake functions, Cheap turbo cost, fast spooling, and good mpg's if you have it tuned right.  For a 5.9 Cummins the he351ve makes a great towing turbo for hp levels up to 500.  It will be hot at 500hp but it is possible, not recommended, but possible.   

This should also work for He451 ve vgt or other Holset variable Geometery turbos. 551 431 turbos

There is a certain amount of DIY needed to get this setup on your truck.  You will need to learn the arduino system, how to wire it, power it, etc etc etc.  

Basic Video

Here is a Video of the basic code and how it works with the VGT turbo

If you read through this and have ANY questions, feel free to Post to the Ongoing thread covering the progress on this project  You can Find the Forum Link HERE 

Parts:

Here are the list of parts that are used.  you can void the code to use one or all of the sensors, but this list is for everything.

Arduino uno: http://www.amazon.com/Arduino-Board-Module-With-ATmega328P/dp/B008GRTSV6 $25

Canbus Shield:  http://www.amazon.com/CAN-BUS-Shield-Compatible-Arduino-Seeeduino/dp/B00NQVH666 $40

Exhaust/boost sensor 0-100 psi:  http://www.auberins....products_id=271x2 if you want to control the turbo on both exhaust and boost.  $56 a piece and they come with 3 wire pigtails.

Potentiometer push pull 10k linear: Mouser Link  $15

Momentary on button switch: havent picked one up yet that I like.  Currently using a computer button.

Wire: 16 gauge should be fine 100' should be enough, ensure to get good quality wire

Connectors: I used 2x DT06-12SA and 2 x DT06-12PA along with all hardware, ebay link

LCD Screen: I used a 4x20 screen with a I2C adapter.  Searching EBAY should find you one.  Click link to see search.

Turbo Connector 4 pin: Mouser Connector Link 54200410-B   Pins 10762770

Turbo RPM Connector: Mouser Connector Link PN: 282087-1

Software:

You will need to download the Arduino program: Arduino - Software

You will need the libraries that I use.  You can Download them all from My Google Drive

Download the Canbus library: Dropbox - CANLibrarymaster.zip (thanks to Farm828)

download the LCD Library: Dropbox - LiquidCrystal.zip

Download the Freqmeasure library https://www.dropbox.com/s/yv98sgdllckc9z4/FreqMeasure.zip?dl=0

Download the Timer library https://www.dropbox.com/s/xa0lxny0pftdi6h/Timer-master.zip?dl=0

Basic starter Code downloaded here: Dropbox - HE351VE_Control.ino (thanks to Farm828)  This is the code from CF without my changes

You can edit the code by voiding the sensors "//" you are using in the right section, defined.

My code has changed significantly from the above.  

How to Connect everything

I will go into some detail here. 

First basics of the arduino uno and cabus_ shield.

Arduino boards allow you to "stack" shields onto it via the pins on the outside edge of the board.  Each Pin on the arduino and shield correlate to the Pins the code below.  You can think of the Arduino as a Small computer and the Shield as a device to perform another specific task, like WIFI or Audio or in this Case Communicate on a Canbus Network.  Stacking the shield onto the Arduino allows the arduino to talk in Canbus.

First is the Arduino Uno                                                            Next is the Can bus Shield that you stack on top

Together they should look like this.  notice how they are connected, stacked on top of each other with the pins from the shield extending into the Arduino board.

Each Shield will use some pins so your code must take that into consideration.  Just as an example the can bus shield might use pin 10 and 11 ( I dont remember off the top of my head) so in your code you can't address those pins outside of the canbus shield use.

Next you will need to connect all the wires to the sensors.  I used some weather proof plugs to make my arduino detachable from the rest of the wiring harness.  You will need to figure out a way to connect your harness to the arduino.  I used a shield to do this like this.

Now for actually connecting the wires from the sensor to the board you will need

3 wires for boost

-5v

-Sensor return ( pin A0)

-Ground

3 wires for Drive

-5v

-Sensor return ( pinA1)

-Ground

3 wires for Pot

-5v 

-Sensor return ( pin A2)

-Ground

1 wire for TPS

-Sensor return ( pin A3)

2 wires for PotSwitch

-Ground return ( pin D2)

-Ground

2 wires for EBSwitch

-Ground return ( pin D9)

-Ground

4 wires for LCD screen

-5v 

-Ground

-SCL ( Pin A5)

-SDA ( Pin A4)

2 wires for The turbo Shaft speed input

-positive signal ( goes to the 9924 chip)

-Neg signal ( goes to the 9924 Chip)

-Output from pin 7 of 9924 chip to pin 8 of the arduino.

Here is an example from www.Arduino.cc of how to wire a simple pot/sensor. you can see 5v. ground, and the sense return going to pin 2

Keep in mind some shields provide more 5v outputs and grounds than others. You can splice the grounds together and run them into one or a couple grounds on the arduino.

The Code

He351ve Boost/Drive Controlled 

My basic code is as follows for controlling the he351ve using boost and drive..  You can change it / use it / do whatever you like.

You can download the tab'd version of the boost controlled code HERE  Keep in mind that it is VERY easy to overspeed the he351ve turbo.  Holset rates the turbo to 130,000 rpm.  Using the code below I was seeing speeds of up to 160,000 rpm.  ENSURE you tune the turbo for your fueling.     I found that it is nearly impossible to manage the turbo efficently without using shaft speed so I do not recommend driving the turbo on this code.  You will run into egt issues, you will run into shaft speed issues.  

the boost map code is no longer updated so the version that is hosted is what you get.

I have noted in the code as much as I could,.

The basic run down for what this code allows is. 

- During normal driving it will allow you to choose from 3 different boost maps, performance, daily, and Economy by using the pot, with the switch off, to have low/mid/high input from the pot.  Vein position is managed by the boostmap until 30 psi is hit.  after 30 psi boost the program will switch over to DPmanage and it will attempt to keep drive pressure at 50psi ( defined by code "maxexhaustpressure")  which keeps drive to boost ratio within check, 40psi boost theory max 50 theory max drive 40psi/50psi gives a ratio 1.25:1.  the HE351 turbo seems to like a high ratio on the lower end.  I see ratio of 2:1 all the time until boost is above 20psi, then it starts to level off and come down closer to 1:1.

- Turning the pot switch on allows you to manually set the vein position as long as throttle input is below %25.  If you turn the pot all the way to 1000 value ( turbo is limited to positions 40-970) it will lock the turbo %100 open regardless of throttle input.  You can use the pot to set the turbo position to small and allow for fast warmup.  

- Exhaust brake will work provided pot switch is off and throttle input is below %5  it will try and keep EB pressure at 45psi per the code.  If pressure increases to above 45 psi it will slowly open the veins.  

 He351ve TURBO RPM based Controller Code

Thanks to hakcenter at lilbb.com I have edited my code to include his turbo shaft speed controller for the turbo.  It is smoother and more refined than using the boost/drive to control the vanes. You will not run into EGT issues or shaft speed issues using this code. You can download the code in the attached zip ** versions after 1.11 are for the arduino mega so if you are using an arduino uno ensure you use version 1.11

This requries you add a 9924 chip to your controller to count rpms.  I highly suggest you visit www.lilbb.com and look at his controller shield for the arduino if you want a more out of the box controller. 

Additional Parts

Umax 9924 Chip: Mouser link

Pullup Resistors 10k: SparkFun Link

You can find the documentation for the 9924 HERE, Click "Data Sheet"

Chip:

Pins:

Basics on wiring for A2 Mode:

1 vr+ ( turbo +)
2 vr- ( turbo -)
3 NC ( not connected)
4 GND 
5 GND

10 +5v
9 GND
8 NC
7 IO8 + 10k + 5v pullup 
6 GND

Top left is 1, Top right is 10
Bottom left is 5, Bottom right is 6

 

He351ve Shaft speed Controller with ODB interface

In my quest for a better controlled turbo I have decided to interface with a pretty cool OBDII interface.  It is $39.99 shipped and should plug and play into your arduino.  It converts the Canbus info into serial signal that can be read by the arduino via the library that was created for the device.  You can find it Arduino OBD2 reader

You will plug this into your vcc, gnd, tx, and rx pins of the arduino.  Due to the age of the cummins there is a limited amount of info that can be used, but it does read RPM, TPS, Coolant, and IAT ( I think) maybe some other stuff, but I am not sure.

The biggest perk to this is you can now use Engine RPM in your code to increase the vane size at higher RPMS while keeping the turbo responsive down low.  

You can download the code in the attached zip

This code is still Beta so use at your own risk.  

Spool speed with the He351vgt.

I went to about %35 throttle at about 8-9 seconds into the video.

If you found this helpful please shoot a donation my way.  Everything I do is to help support the community.

Thanks

-Me78569

he351.zip

There seems to be a lot of miss information on this topic, so I'm going to help clear it up some.

First off what do the numbers mean, for instance a 56/60/12?

The First number is the Diameter of the Compressor Inducer in Millimeters, in this case it's a 56mm compressor wheel.

The Second number is the Diameter of the Turbine Exducer in Millimeters, in this case it's a 60mm turbine wheel.

The Third number is the exhaust housing size in cm², I'm not going to go into this, but generally speaking, bigger equates to laggier down low, but more power up top.

There can also be Letters at the end like 'W', that gives us more information about the Turbine housing.

• 'W' Stands for wastegated.
• 'D' Stands for Devided.

With that newfound information, lets get started.

WH1C (56/60/12WD)

The WH1C is found on 94 and some 95 Cummins, it is basically identical to the HX35 except it has a V-Band Compressor housing.

The Turbine housing is a 12CM housing, is divided and has an internal wastegate.

HX35 - 8 blade (56/60/12WD)

The 8-blade HX35 is found on 95-98 12 Valve Cummins.  You can normally tell them apart because the wastegate canister is mounted on the turbine housing, where as the 7-blade's wastegate canisters mounts on the compressor housing.

The Compressor is a 8 Blade 56/82 wheel.  Due to the larger exducer, this wheel is not interchangeable with the 7-blade design. 

The Turbine is a 12 Blade 60/70 wheel

The Turbine wheel has the older 'straight blade' design, they spool faster but don't flow as well.

The Turbine housing is a 12CM housing, is divided and has an internal wastegate.

HX35 - 7 blade (56/60/12WD)

The 7-blade HX35 is found on 98.5-02 24 Valve Cummins.  You can normally tell them apart because the wastegate canister is mounted on the compressor housing, where as the 8-blade's wastegate canisters mounts on the turbine housing.

The Compressor is a 7 Blade 56/76.5 wheel.    Due to the smaller exducer, this wheel is not interchangeable with the 8-blade design.  

The Turbine is a 12 Blade 60/70 wheel

The Turbine wheel has the older 'straight blade' design, they spool faster but don't flow as well.

The Turbine housing is a 12CM housing, is divided and has an internal wastegate.

HY35 (54/58/9W)

The HY35 is found on '00-02 24 Valve Cummins with an Automatic Transmission.

The Compressor is a 7 Blade 54/76.5 wheel

The Turbine is a 12 blade 58/65.5 wheel

The Turbine wheel has the newer 'curved blade' design, they flow better, but don't spool quite as fast.

The Turbine housing is a 9CM housing, is undivided and has an internal wastegate.

HE341 (56/58/9W)

The HE341 is found on '03-04 24 Valve Cummins.

Most HE341 Compressors are a 7 Blade 56/76.5 wheel.  Very few have the smaller HY35 54/76.5 wheel. 

The Turbine is a 12 blade 58/65.5 wheel

The Turbine wheel has the newer 'curved blade' design, they flow better, but don't spool quite as fast.

The Turbine housing is a 9CM housing, is undivided and has an internal wastegate.

HE351 (60/58/9W)

The HE351 is found on 04.5-07 5.9L 24 Valve Cummins.

The Compressor is a 7 Blade 60/84.5 wheel

The Turbine is a 12 blade 58/65.5 wheel

The Turbine wheel has the newer 'curved blade' design, they flow better, but don't spool quite as fast.

The Turbine housing is a 9CM housing, is undivided and has an internal wastegate.

This is from Borg Warner's Website.

Operation

Exhaust gas pressure (drive pressure) and energy drive the turbine, which in turn drives a centrifugal compressor that compresses the inlet air (boost pressure), and forces the air into the engine through the intercooler and plumbing. Since heat is a by-product of this compression, the air must pass through an intercooler to cool the incoming air and maintain power and efficiency. Increasing air flow to the engine provides:

• Improved engine performance
• Lower exhaust smoke density
• Improved operating economy
• Altitude compensation
• Noise reduction.

The turbocharger also uses a wastegate, which regulates intake manifold air pressure and prevents over boosting at high engine speeds. When the wastegate valve is closed, all of the exhaust gases flow through the turbine wheel. As the intake manifold pressure increases, the wastegate actuator opens the valve, diverting some of the exhaust gases away from the turbine wheel. This limits turbine shaft speed and air output from the impeller. The turbocharger is lubricated by engine oil that is pressurized, cooled, and filtered. The oil is delivered to the turbocharger by a supply line that is tapped into the oil filter head. The oil travels into the bearing housing, where it lubricates the shaft and bearings. A return pipe at the bottom of the bearing housing routes the engine oil back to the crankcase.

 

The most common turbocharger failure is bearing failure related to repeated hot shutdowns with inadequate “cool-down” periods. A sudden engine shutdown after the prolonged operation will result in the transfer of heat from the turbine section of the turbocharger to the bearing housing. This causes the oil to overheat and breaks down, which causes bearing and shaft damage the next time the vehicle is started. Letting the engine idle after extended operation allows the turbine housing to cool to normal operating temperature.

Mopar's Notes: You should allow your pyrometer to fall below 300°F before shutdown. If you don't have a pyrometer I highly recommend you purchase a pyrometer gauge and install it. There is also turbo timers that allow the driver to turn off the ignition and lock up the vehicle. The engine will continue to run for set time and then shut down. These add-ons will extend the life of your turbo greatly.

Turbo Inspection Procedure

Visually inspect the turbocharger and exhaust manifold gasket surfaces. Replace stripped or eroded mounting studs.

1. Visually inspect the turbocharger for cracks. The following cracks are NOT acceptable:
Cracks in the turbine and compressor housing that go completely through.
Cracks in the mounting flange that are longer than 15 mm (0.6 in.).
Cracks in the mounting flange that intersect bolt through-holes.
Two (2) Cracks in the mounting flange that are closer than 6.4 mm (0.25 in.) together.

2. Visually inspect the impeller and compressor wheel fins for nicks, cracks, or chips. Note: Some impellers may have a factory placed paint mark which, after normal operation, appears to be a crack. Remove this mark with a suitable solvent to verify that it is not a crack.

3. Visually inspect the turbocharger compressor housing for an impeller rubbing condition (Fig. 25). Replace the turbocharger if the condition exists.

4. Measure the turbocharger axial end play:
a. Install a dial indicator as shown in (Fig. 26). Zero the indicator at one end of travel.
b. Move the impeller shaft fore and aft and record the measurement. Allowable end play is 0.038 mm (0.0015 in.) MIN. and 0.089 mm (0.0035in.) MAX. If the recorded measurement falls outside these parameters, replace the turbocharger assembly.

5. Measure the turbocharger bearing radial clearance:
a. Insert a narrow blade or wire style feeler gauge between the compressor wheel and the housing(Fig. 27).
b. Gently push the compressor wheel toward the housing and record the clearance.
c. With the feeler gauge in the same location, gently push the compressor wheel away from the housing and again record the clearance.
d. Subtract the smaller clearance from the larger clearance. This is the radial bearing clearance.
e. Allowable radial bearing clearance is 0.326mm (0.0128 in.) MIN. and 0.496 mm (0.0195 in.) MAX. If the recorded measurement falls outside these specifications, replace the turbocharger assy.

 

For those wanting a switched grid heater, here is how to do it on a 12V from 1989 on up to 1997. The 1998+ trucks throw a code (P0380 and P0382) so for those with that system, you will have to just disconnect the leads that go to the grid heater itself. When winter comes, just reconnect them.

The reason for doing something like this is because the truck will run the grid cycle if you run into the store or something and this is not necessary and is a load on the batteries and alternator, so why have it when it’s not needed during these scenarios.

The controversy begins when you use it as a selector switch as to if you want to use the grids at all at a said temperature. The truck will start fine down to 32F and below that it will still start fine but is much happier with the grids. The problem is, this is very hard on the engine when it has to start with nothing but the heat of combustion. The temperature at which this degradation occurs is unknown but it’s a safe bet to say that 50F and below should be using the grid heater. The grids will still cycle up to 60F, but I think that last 10F is a buffer zone that is up to you.

Why use the grid heaters at all?

If you choose to remove the grid heaters or disable them, there are a few consequences of that action. All I will tell you is that starting it cold with no grid heater will make it hate the cold. My truck started up with no smoke, on the first crank, with no grid heater at 0F when I first bought it, this was even at 250k miles. The next year, it was starting the same, but I HAD to use the grid heaters. Don’t push your luck with them, use them every chance you get.

What about my batteries?

Driving short distances in the winter is the worst thing ever. Your grid heaters are going full blast on the morning start and your battery is getting killed. It will last a little while, maybe a week doing these cold short driving stunts. After a week, you really need to drive it for a long distance or charge the batteries using a battery charger or even exchange them with another vehicle that drives long distances.

Hooking up the switch

On the driver’s side fender well, there are the 2 grid heater relays. They control the 2 grid heaters individually. The positive wires (orange and yellow) are controlled by the ECM and are what turns the grid heaters on and off. There are 2 other wires that are green (one on each relay). Those are the wires you want to tie together and put a switch in between the ground source and the relays, thereby making the relays have no ground when the switch is off and having ground when it is on. This way, the grids will work exactly the same as stock when the switch is on. It is also easier as you only need to run one wire from the 2 relay grounds, to the switch in the cab, and then any good ground inside the cab.

In this video, you can see the grid heaters being switched on and off, the ECM continues to cycle, it doesn’t know that they really aren’t cycling. This allows you to turn the switch off and if you turn it back on and the ECM is still signaling the relays, they will work when you turn the switch back on without anything knowing the difference. The clicking is the switch being turned on and off, you can see the voltage drop when the grid is on.