He351ve stand alone Arduino controller code for 2nd Gen Cummins

[Vais01]

I have seen several hx40 maps, but none that match the flow specs that holset gives (67-69lb.min) and none that extend beyond 107k.

The HX Super 40 is much higher than a normal HX40. Also the compressor housing A/R ratio on the HE351VE is a bit different. It flows just a few Lb/min better from my understanding.

I'm still working on getting the compressor map.

[Vais01]

Just from the reference sheet the HX40 (possibly more with the HX Super 40) can flow between .53 Kg/sec to .54 Kg/sec which equates to 70-71 Lb/min of air flow.

[Me78569]

Yep the only maps I have seen were from the hx40 not the super 40.

[Vais01]

So if this is remotely accurate(it has to be to work on a 6.7 Cummins)

Here are 2 links.

Shows a compressor map of the HX Super 40.

http://www.myholsetturbo.com/upgrades.html

Gives you course specs.

http://www.myholsetturbo.com/40appnotes.html

[Vais01]

From what the turbo calculator says a 6.7 Cummins at 500 ft of elevation running 35 PSI of boost out to 3400 RPM will require 85.2 Lb/min of airflow. This being said your turbo should be capable of this when all the parameters are set correctly. Your definitely on the right track.

What will hinder the turbos ability to yield these results is the restriction of the turbine and the housing. I have seen better fuel economy and reduced EGT with my Borg Warner 62/68/.80 than with the VGT due to the way the turbine side of the turbo flows. Geometry of the turbine wheel will dictate how it flows and responds along with the A/R ratio of the turbine housing.

Example the 68mm turbine wheel on my particular turbo has two configurations. The first is a flat blade or flat tip however you see it. The second being a J-Cup or a cupped tip blade. The flat tip is faster responding than the J-Cup, while the J-Cup flows better with a bit less response.

So in my case with a 14cm divided turbine housing and the flat tip turbine provide great response and good flow characteristics. If I wanted even faster response from the turbo a 12cm divided housing may be used but can become a restriction at higher RPM. The best way to mitigate this is to use the J-Cup turbine wheel with the 12cm turbine housing this will yield the fastest response and great flow.

I say all this to basically point out the point of restriction is the flow characteristics of the turbine housing with the vane position. So as we agreed earlier that the sweet spot is between 12cm and 14cm the turbo can be modulated from those positions to create the best overall outcome.

Keep up the good work and keep us posted.

[Vais01]

A quick side note the HX40 and HX Super 40 shafts are notoriously weak but this has been addressed in the HE351VE.

[Me78569]

That map doesn't really make sense to me when compared to the specs in the other link.

 

850cfm is equal to what? 60ish lb/min?  are they spec'ing it within the highest efficiency island only?

 

But then the pressure ratio of 4.5 would mean the turbo was pushing nearly 50 psi?

 

 

Mass flow means what? it can't be lb/min can it? if so then it flows a bunch more than anyone thinks it does.  Everyone says the super will flow 70ish lb/min but that map shows it flowing nearly 90 lb/min.  Again doesn't make sense.  I just don't see the he351ve flowing 85 ln/min without blowing the compressor apart.

 

I am assuming that the top speed line on the map is ~130k? maybe?  

 

 

I really wish holset would just publish good maps haha.

 

Maybe I am reading it wrong?

[Vais01]

That map doesn't really make sense to me when compared to the specs in the other link.

850cfm is equal to what? 60ish lb/min? are they spec'ing it within the highest efficiency island only?

But then the pressure ratio of 4.5 would mean the turbo was pushing nearly 50 psi?

Mass flow means what? it can't be lb/min can it? if so then it flows a bunch more than anyone thinks it does. Everyone says the super will flow 70ish lb/min but that map shows it flowing nearly 90 lb/min. Again doesn't make sense. I just don't see the he351ve flowing 85 ln/min without blowing the compressor apart.

I am assuming that the top speed line on the map is ~130k? maybe?

I really wish holset would just publish good maps haha.

Maybe I am reading it wrong?

Pressure Ratio changes with air density so at higher altitude it is different than sea level.

Also it states over 850 CFM but does not include an exact figure. The bottom portion of the map is Lb/min of airflow which is directly in line to the calculated value for the 6.7 Cummins at 500 feet pushing 35 PSI of boost while turning 3400 RPM.

There are no official efficiency percentages or islands on the map. From my understanding is as long as you remain in the area on the map you should be at worst case 65% efficient.

Yes the top speed seems to be 130,000 RPM on the HX Super 40. I do not have an official speed for the HE351VE. The HE351CW would be the closest to compare with because they share turbine wheels from my understanding but the compressor housing and wheel I do believe are different. (HE351VE compressor = HX Super 40 VS HE351CW compressor = HX40.

[Me78569]

so according to that map then the he351 flows nearly 90lb/min then right? even though it would be at %65 efficient and turbo speeds of 130k ( assuming that is the top line)

 

That's way beyond the 69 lb/min most spec the super hx40 at.   Just doesn't make sense, but I guess if holset says mass flow is lb/min then the map says nearly 90 lb/min.

 

Humm. 

[Vais01]

so according to that map then the he351 flows nearly 90lb/min then right? even though it would be at %65 efficient and turbo speeds of 130k ( assuming that is the top line)

That's way beyond the 69 lb/min most spec the super hx40 at. Just doesn't make sense, but I guess if holset says mass flow is lb/min then the map says nearly 90 lb/min.

Humm.

The line is deceptive but I do believe 85-87 Lb/min is the capability of flow from the turbo.

The HX Super 40 is that high. The HE351VE uses that compressor I'm almost 95% certain. My data sheet shows .54 but only on the HX40 the HX Super 40 has a different compressor wheel and housing.

Yes I do believe the maximum capacity is 85-87 Lb/min at a maximum boost near 40 PSI with a 65% efficiency when achieving those numbers. That is like you said on the far tail end on the far right of the compressor map.

Edited September 8, 2015 by Vais01

[Vais01]

Completely off topic but can you walk me through the picture posting process for my BHAF thread?

[Cowboy]

That's my thought as well, but he's been working on this for months so I'm sure he's got it figured out much better then I do.

 

I always thought that having a EGT gauge post turbo would be the best way to find the correct vain position while cruising.  To much drive pressure, and they get hotter, to little boost and they get hotter.

 

I just realized this is not true, this would rule out the drive pressure adding "artificial" heat to the exhaust, however with DP comes Boost.  So if you have the same amount of heat, with more boost (flow) there is overall more heat energy going into the exhaust.  

 

I went on a trip here this weekend, and found two interesting facts.  

 

1st, it is crazy easy to hit 1.4:1 Boost:DP with the stock turbo, just lug the crap out of it at 1200 RPM.    Otherwise boost is about 1:1.1 throughout the RPM range/load.

2nd, the IC works crazy well, engine input temps going down the highway are maybe a couple *F above ambient, while the pre-intercooler temps are steady at 170-200*F.

[Vais01]

I just realized this is not true, this would rule out the drive pressure adding "artificial" heat to the exhaust, however with DP comes Boost. So if you have the same amount of heat, with more boost (flow) there is overall more heat energy going into the exhaust.

I went on a trip here this weekend, and found two interesting facts.

1st, it is crazy easy to hit 1.4:1 Boost:DP with the stock turbo, just lug the crap out of it at 1200 RPM. Otherwise boost is about 1:1.1 throughout the RPM range/load.

2nd, the IC works crazy well, engine input temps going down the highway are maybe a couple *F above ambient, while the pre-intercooler temps are steady at 170-200*F.

Drive pressure cam be as high as 2.0:1 without hurting the HE351VE. Holset does state 1.5:1 as safe. Also the HX35W 12cm turbine housing wastegate only controls 1 of the 2 volutes so if you measure drive pressure on the rear volute the pressure will seem normal while the front volute will be over 1.1:1 when the wastegate opens.

This is another reason the HY35W was used on the auto transmission trucks because the wastegate is nearly always open and the turbine housing is a single volute.

[Cowboy]

When I say 1.4:1, I meant 10 psi boost, 6 psi drive pressure.  I read the pressure from the front runner.  The wastegate on mine doesn't start to open until exactly 35 psi, or 33 psi at the intake plenum.

[Vais01]

When I say 1.4:1, I meant 10 psi boost, 6 psi drive pressure. I read the pressure from the front runner.

That makes a small difference haha.

[Me78569]

Is 10 psi boost with 6psi drive even possible?   

[Vais01]

Is 10 psi boost with 6psi drive even possible?

It could be if cruising on the interstate.

[Me78569]

Humm interesting I suppose the effective leverage arm of the turbine is different compared to the compressor. 

[Vais01]

Humm interesting I suppose the effective leverage arm of the turbine is different compared to the compressor.

That is correct. The A/R ratio determines the exhaust flow velocity through the volute which acts against the turbine wheel. The turbine wheel then becomes the point of restriction for a brief period until the shaft speeds up and begins creating boost.

After that the drive pressure rises incrementally according to boost pressure. On a VGT you can alter the A/R ratio thus producing boost at low speed and high speed without the unnecessary high drive pressure.

[Cowboy]

That is correct. The A/R ratio determines the exhaust flow velocity through the volute which acts against the turbine wheel. The turbine wheel then becomes the point of restriction for a brief period until the shaft speeds up and begins creating boost.

After that the drive pressure rises incrementally according to boost pressure. On a VGT you can alter the A/R ratio thus producing boost at low speed and high speed without the unnecessary high drive pressure.

This is while lugging it at 1200 rpm.  The explanation is simple.  The turbine runs off exhaust volume, heat is artificial exhaust volume,  if you have enough heat, the turbine will get enough energy out of the exhaust to drive the compressor without the need of as much back pressure.

 

Turbos have the possibility of running more boost then drive pressure easily.  The problem is we want quick spooling and high flowing... so the turbine is setup for the higher RRM's while the housing is sized for the lower RPMs.  I was looking at some dyno logs earlier, a 2000+ hp engine was making 90 psi of boost on a single turbo with 70 psi of drive pressure, EGT's were sub 1200 (I'm sure they had plenty of water injection).