Anyone dyno with and without BHAF ?

[AH64ID]

You have a 180° thermostat right? Max temp is 212°, so I would say that if you can hit 215°, or even 210°, a fan is needed. Only 1 or 2 times have I come within 5° of my max allowed temp, 225°.

[ISX]

Actually 195. They screwed up and gave me the 5.9 V8 gasser one but somehow it fits perfect and all that temp swaying crap is fixed so I couldn't ask for more. I put in a digital water temp gauge at the back of the block (where it is OEM) so I could see exact numbers. So much nicer than guessing between 140-190-230. It still stays around 180 though so I'm not sure if gasser thermostats open early or if it has to do with the probe location or what. I thought it must gaine 15F or something going to the front of the head to the thermostat but that would mean the 180 cummins thermostat would also have the same 15F drop and the OEM gauge would have shown 165 which it sure didn't unless it's way off. I never had the OEM one in with the digital gauge.

[AH64ID]

I wonder if gasser thermostats are rated full open? I couldn't even begin to guess what the max allowed temp would be. Odd that it doesn't swing, the Cummins thermostats are supposed to, it's normal. The Cummins thermostats are cracking temp, so a 180° should run 180° ±3° going down the road.

[ISX]

Someday I'll get a thermal imaging monitor and see what is really happening

[AH64ID]

I took a photo on a recent camping trip, but can't find it, of my IAT's pre and post turbo. I don't recall the exact numbers, and hopefully will find the photo, but the pre-turbo temps were 30-40° hotter than post turbo, and even more than that above ambient. It was slow speed towing, which is where I think the BHAF will decrease power the most. I will try to find it, I think it was a good example of how hot the underhood temps get.

[Mopar1973Man]

You got to remember there is a gap running along the edge of the hood where air blows in over the top of the BHAF on the 2nd Gen's like my last RV run to Heyburn Park in Plummer, ID I was seeing roughly 30-35*F offset from outside. The only time IAT crawled up in temp was crawling through towns at 20-25 MPH. The most I've every seen on IAT was 148*F. But that was while crawling around Lewiston,ID at 25 MPH in city streets.

[AH64ID]

You got to remember there is a gap running along the edge of the hood where air blows in over the top of the BHAF on the 2nd Gen's like my last RV run to Heyburn Park in Plummer, ID I was seeing roughly 30-35*F offset from outside. The only time IAT crawled up in temp was crawling through towns at 20-25 MPH. The most I've every seen on IAT was 148*F. But that was while crawling around Lewiston,ID at 25 MPH in city streets.

I doubt you get that much cold air from the gap in the hood, in fact if the fan is running or there is decent airspeed I bet the air flow all but stops, or goes out. Like I have mentioned I don't think that the IAT on a 24V is representative of the actual temp, as you have stated it's greatly effected by the coolant passage adjacent to it. There is a reason it was moved for the CR. Flat cruise out IAT's should be ±5°, and they aren't. At least the IAT's show different, but I bet the air is the same.

[ISX]

I think there is a different issue going on. The intercooler drops the temp but is the turbo working harder (and less efficient) if it is fed hotter air.. I think the IAT would mask this since the intercooler gives the illusion that the turbo is working fine, though it could be working like crap but since the intercooler is good at it's job it easily masks the issue. Like I said though, I see 25F over ambient max but I have no shroud, no battery, no overflow tank...no nothing, so it could be a completely different story for someone with those still in. I have also hear the stock intercooler is only good enough for stock values and begins to fall on it's face after that. Being the heat really comes on when you get above "stock levels", a high turbo intake temp could make a big difference in how well the turbo does it's job. I think of it like my boost controller I made. If the turbo is fed hot air, you can still get enough flow to show the restriction of 30psi, but you are working against the wastegate and EGT's are pretty high. Leave the wastegate shut and now you can get to 30psi with ease and the EGT's are nice and happy. So the analogy is that a hot intake air turbo is "fighting a wastegate" whereas an ambient temp air temp is working with the "wastegate closed". This isn't really noticed if you have never done it. I mean 30psi up a 7% hill might mean 1200EGT with X load. But what if you could do 25psi with everything the same and be at 1100EGT....thats what my wastegate thinger did for me. The same thing could be true with the ambient temp stuff. I swear my EGT's went down when I ripped everything out and if the turbo intake really does get to 100F with all of it in, then I could see the EGT drop being legit.

[Mopar1973Man]

Hang on a second gang. We keep discussing racing or WOT values of intake temperature and such. Most of us have daily drivers that don't tow and drive sensibility at posted speed limits. Like myself here locally the speeds are 55-65 MPH respectively. I might be at 15-20% of throttle, 600-700*F EGT, and 2-8 PSI of boost. Ok. So how much is heat going to effect it? Not much being there is little to no compressor heat generation, intercooler is way big enough at those values to handle that little bit of heat. Ok. So now a WOT passing operation which last at the most 30 seconds so it not exactly perfect but we don't drive WOT operation like racing/dyno operation as a daily driver. Like trailer towing yeah I got some good serious grades around me but never had extreme intake temps even with the stock IAT placement. I don't run 30-35 PSI climbing grades more like 20-25 PSI tops which is still close to stock values. Even pulling over Whitebird I was geared down took my time looking at 1,000*F at about 20-25 PSI of boost. My highest IAT was 148*F ever but still within the +40*F normal for offset vs. outside temp. But that was being foolish and climbing in too high of gear and pushing. Yes now if your in the racing/dyno game them YES. I fully agree you have to highly consider the intake temp, boost pressures, and everything else because it does have a huge impact of performance out. But back to the daily driver. Which I keep looking at my ScanGauge II which is now calibrated to my +50 HP injectors (only off 0.5%) I'm seeing 23-26 MPG for my daily travels. So does high intake temps (120-140*F) hurt MPG performance? No. Not that I'm seeing with empty truck daily travel going to and from McCall, ID and other local towns.

[ISX]

You're avoiding the issue If a little cold air intake could mean the difference between maintaining whatever speed and having to decrease before the engine melts, then I think it's worth looking into further. As for the hills and stuff. On my way to this one place I ride dirt bikes there is an alternating passing lane. There is always a line of semi trucks going up dead mans hill at 35mph (in a 65) and it just happens to be a passing lane but to pass them all you can't slow down from 65. It is a steep longgg hill and I am pushing 25-30psi doing 65-70 to pass them all with EGT's hovering around 1000-1100. However, without my boost controller thing holding the wastegate shut it would only be at 20psi and I would need more fuel since I don't have as much boost and my EGT would show it. I'm not about to drive down to 25mph following those semis up 50 miles of identical steep hills. That is actually where I get the 25F over ambient temp on my BHAF, up that hill.. If I was 100F over ambient up that hill, would it be the same as not having my boost controller thinger as well? Thats what I want to know. I don't want to build it for everyday flat ground running, I want it to be efficient doing that as well as up that damn hill. I have it all set perfect to where I can do whatever I want under 1200F at this point, but I don't know how much my "open flow under hood" design has helped it. Like I said though, taking all that crap out did seem to help my EGT's, I just cant prove anything since I don't have solid figures. But I think AH64 does.

[Mopar1973Man]

That where we differ... I don't worry about holding speed limit up a grade I don't mind slowing down to take my time. That where on the racing side you would be looking into the intake temps and such. But I don't race. Even in stock form back in 2004 when I bought my gauges... No Edge Comp, factory cold air air box, no injectors, etc. I was still able to pass over 1,400*F with a trailer in tow climbing 7% grades. I could push the coolant temp well up into the 210-215 area without thinking but that is racing foot mashed to the floor trying to tow over a grade in fully stock form. So again it comes back to daily driver, racing and extreme end would be full abuse. I've try putting back on the stock box and looking for change in intake temps or EGT's there is none for me. I don't see any changes in IAT or EGT's at all between stock cold air and BHAF once again in daily driver. But again I don't drive with 30-35 PSI of boost for miles but only in short burst. I typically only see 2-8 PSI so like I said before I don't generate huge amounts of turbo heat like you would with you foot planted to the floor for several miles pulling a grade. The only time I tend to get a bit abusive to the truck is during fire calls I do run 70-75 MPH roughly in a 65 MPH, I do pass vehicle planted to the floor and can see EGT's cresting 1,200-1,300*F but once again short burst and it drops back to 800-1,000*F and still hauling down the pavement to the fire call. This could be a cold start in the middle of the night. So to go from dead cold no warm up and hauling at 70-75 MPH yeah just a bit abusive. Even the bigger Cummins 400 I drive that weighs 65,000 pound in stock form if driven too hard in the wrong gear can really make that coolant temp rise up fast. It's also turbo charged non-intercooled no gauges either boost or pyro but I can bet that EGT's are high as hell if you try to mat the throttle going up a steep mountain road racing as seen by the coolant temp. Once again I grab a gear that has a good power level for the load and hold the R's at about 2K and let her climb at her own rate not try to force it to speed up and grab another gear that might be just too tall for the load. Again another sign of racing again. But again dump the 4,000 gallons of water (33,360 pounds) now you can race up the canyon roads almost 2 gears higher than loaded. All based on load.

[AH64ID]

That where we differ... I don't worry about holding speed limit up a grade I don't mind slowing down to take my time. That where on the racing side you would be looking into the intake temps and such. But I don't race.

And that's why you have a hard time in these conversations, you don't ever put your truck in a scenario where you would see a difference. Racing doesn't have everything to do with it, I see the highest IAT's at 20 mph on steep back roads (where I know you tow as well) and that's the kind of scenario where the turbo is going to be working harder than it has to. You run your mods for mileage and don't use the power, so it's really hard to discuss power application with you.

Even in stock form back in 2004 when I bought my gauges... No Edge Comp, factory cold air air box, no injectors, etc. I was still able to pass over 1,400*F with a trailer in tow climbing 7% grades.

Seems too hot for a 2nd gen, are you sure it was a stock motor? Maybe it came with some injectors? I'd hate to see how hot you could get it now. Even with the crazy hot emissions tuning the 04.5-07's only run about 1450° full tilt and a VP truck runs a lot more timing (thus cooler EGT's).

I could push the coolant temp well up into the 210-215 area without thinking but that is racing foot mashed to the floor trying to tow over a grade in fully stock form.

Well within limits for the 190° thermostat.

So again it comes back to daily driver, racing and extreme end would be full abuse.

How is using your power, within all parameters (boost/egt/coolant/etc) in normal operation range considered abuse?

I've try putting back on the stock box and looking for change in intake temps or EGT's there is none for me. I don't see any changes in IAT or EGT's at all between stock cold air and BHAF once again in daily driver.

This is all with the stock IAT sensor on the 24V, which even you have pointed out reads a high number based on location. It's not going to give you correct enough information for a comparison. In addition low power driving won't make much difference, as the underhood temp is low and airflow thru the engine bay is decent. Aside from fuel economy, there are very few gains noticed from any product in a cruise scenario. If you change air filters and get a noticeable change during cruise then either your old filter was plugged, or the new filter flows a lot more and I would question it's filtering abilities (as we discussed in a separate thread). Airflow is so low that you won't see a difference until you put a load on the motor.

[Mopar1973Man]

Once again there is the difference. I'm not out for full blown race to the the top of the hill. I am looking for fuel Economy. Fuel is expensive for me up here compared to you AH64ID.

How is using your power, within all parameters (boost/egt/coolant/etc) in normal operation range considered abuse?

So to go from dead cold no warm up and hauling at 70-75 MPH yeah just a bit abusive.

Start cold and go to heavy throttle usage in a cold state no warm up at all. Like I said just a wee bit.

Again here is a difference again. I'm looking for longevity and efficiency so it outside my normal usage. I consider it a abuse.

Well within limits for the 190° thermostat.

I like to leave so buffer room while towing. Because there is time like I learned of the years that once it starts to over heat you might be stuck driving another 5-10 miles to fine a safe spot to pull over. Without a trailer no problem. But I never allow the engine to put in a spot where I could but caught with a safety issue of stopping or possible damage the engine getting to safety. Once again difference between us. Already had this happen with another vehicle this why I won't do it.

You run your mods for mileage and don't use the power, so it's really hard to discuss power application with you.

That is correct. But it goes to show IAT do have effect for better MPG numbers though. Once again different goal. When I'm reach higher average than your are I guess I found a sweet spot that way. 200K work of logs and 17.89 AVG. Your avg MPG 15.3. Your high is 21.5. My high 26.12 MPG (Hand Calc'ed). I looking after a different performance than both you and ISX.

http://www.fuelly.com/driver/AH64ID/ram-3500

Power performance I will highly agree with both of you! YES, you need colder air for high power or racing applications for controlling EGT's. I will not argue that point.

[ISX]

Who is talking about racing or flooring it? This is about improving turbo efficiency really, which in turn improves engine efficiency..isn't that your goal?I am never floored, not even close, the engine would melt. Hence the reason we are talking about turbo intake temps lowering EGT's. If they are lower, I wouldn't go faster, but it would make me feel better doing 100F lower up that hill at the same speed. The engine would be more efficient since the turbo was working better, mileage would be up....now you see why I want to hear AH64's proof on the matter. This has nothing to do with racing. This has to do with making the power our trucks already have more usable and more efficient.

[Mopar1973Man]

Who is talking about racing or flooring it? This is about improving turbo efficiency really, which in turn improves engine efficiency..isn't that your goal? I am never floored, not even close, the engine would melt. Hence the reason we are talking about turbo intake temps lowering EGT's. If they are lower, I wouldn't go faster, but it would make me feel better doing 100F lower up that hill at the same speed. The engine would be more efficient since the turbo was working better, mileage would be up....now you see why I want to hear AH64's proof on the matter. This has nothing to do with racing. This has to do with making the power our trucks already have more usable and more efficient.

I'm stuck with my turbo because of the exhaust brake. So I can't change the efficiency of it. As for the 24V's they are a odd duck. Doesn't work that way. As far as measurements and results I'm seeing. Still and all I'm way above the efficiency average of most 24V owners. But still both you and AH64ID are two different series of engines with way different mods even between the three of us. Now if this conversation would be a little more fair if all of us has 24V truck completely stock and started comparing notes. Now the playground would be level and fair. Comparing oranges, apples and peaches isn't working. Once again 24V only... Once again why is MPG fooler showing increase with not just me but most all others? Viable mod that actually works. Why is it during cold weather even during the summer MPG is down? (40-50*F outside temp) Why is it that during warm or hot weather MPG's are up? (90-110*F outside temp) All I got to do is get up early in the morning driver ot New Meadows and day break and get 3 MPG lower than if I got up later and let the Meadows area warm and now gain it back why is that?

[AH64ID]

Start cold and go to heavy throttle usage in a cold state no warm up at all. Like I said just a wee bit.

That's not within parameters. Min coolant temp for full power operation is 160°F.

One thing we haven't mentioned in the turbo/IAT efficiency issue is that the more temp the intercooler removes the more heat is put into the radiator. That means that even thou the IAT may be dropped down to a good level the radiator may be reviving air that is much hotter than needed, and now you are running into potential cooling issues.

Again here is a difference again. I'm looking for longevity and efficiency so it outside my normal usage. I consider it a abuse.

All of my mods are for efficacy and longevity, so I wouldn't call it abuse at all, it's called using it and building it with matched parts. If you cannot go WOT without running too hot then you have mismatched parts, and I do not think that is a recipe for longevity.

I like to leave so buffer room while towing. Because there is time like I learned of the years that once it starts to over heat you might be stuck driving another 5-10 miles to fine a safe spot to pull over. Without a trailer no problem. But I never allow the engine to put in a spot where I could but caught with a safety issue of stopping or possible damage the engine getting to safety. Once again difference between us. Already had this happen with another vehicle this why I won't do it.

I find it just a little bit rude at the assumptions you have made in this thread. I am not even sure how you can come to the conclusion that I disregard safety or possible engine issues. Simply because I understand operating ranges, min/max limits, and have a truck with matched parts to tow with does not mean that I disregard safety. When I am working my truck the hardest I have the family on board and all of my modifications, decisions, and driving technique are geared around them not sitting on the side of the road.

I have never been on a road where there is a 5-10 mile stretch where you cannot pull over or slow to to let things cool if needed (shouldn't have to with matched parts).

Just because you feel you need to impose a lower limit than Cummins does NOT mean that anyone else operating in the acceptable range is disregarding safety.

When I'm reach higher average than your are I guess I found a sweet spot that way. 200K work of logs and 17.89 AVG. Your avg MPG 15.3. Your high is 21.5.

Your right, truck use has NOTHING to do with it....

My truck hasn't had but one empty tank (no trailer/haul/etc) since March, so when you use your truck as a truck the average drops. I also have DD so the truck really only gets used for work/play which has a higher fuel consumption by default. My average has dropped several mpg's since I bought my commuter car, despite the fact that my truck is more efficient than it was when I was using it as a DD.

Yes my best is 21.5, but that was also at 70+ mph (tank average speed was 70.7, with some town driving) with a bed full of hunting gear (~9,500lbs).. what did you report you get at 70?

Power performance I will highly agree with both of you! YES, you need colder air for high power or racing applications for controlling EGT's. I will not argue that point.

I guess the big difference is I prefer a matched motor, one that you can go WOT and not watch the pyro like a hawk except maybe on the hottest of days at elevation. It is very possible to have matched parts, lots of power, and be fuel efficient.

I'm stuck with my turbo because of the exhaust brake. So I can't change the efficiency of it.

Not true.

Why is it during cold weather even during the summer MPG is down? (40-50*F outside temp)

More air resistance, colder more viscous fluids, etc

Why is it that during warm or hot weather MPG's are up? (90-110*F outside temp)

Opposite of above answer.

Once again why is MPG fooler showing increase with not just me but most all others? Viable mod that actually works.

Simple, the ECM will adjust the timing based on IAT. The timing for higher IAT's is more optimal than the timing for lower IAT's. The difference is probably emissions based, as any decrease in potential mileage is generally attributed to emissions requirements.

I'm not trying to throw stones (other than the safety comment), it's just simple observations on how things work.

- - - Updated - - -

Once again there is the difference. I'm not out for full blown race to the the top of the hill. I am looking for fuel Economy. Fuel is expensive for me up here compared to you AH64ID.

Last few times I have been thru Riggins the fuel has been cheaper than down here...

[Mopar1973Man]

what did you report you get at 70?

But once again that was a short burst down the interstate which I never use. Also could I ask if you could repeat that again? Get the same MPG numbers and with the same load. I will admit I've seen rare high MPG's like I noted in my logs. Even ISX has seen the same thing too. Rare but do happen. So what I look at is the typical average.

That's not within parameters. Min coolant temp for full power operation is 160°F.

Correct that why I said a bit of abuse.

One thing we haven't mentioned in the turbo/IAT efficiency issue is that the more temp the intercooler removes the more heat is put into the radiator. That means that even thou the IAT may be dropped down to a good level the radiator may be reviving air that is much hotter than needed, and now you are running into potential cooling issues.

Very true. After seeing ISX finding on the turbo discharge temps and the what the intercooler has to expel I would say you absolute correct there too. But no cooling issues unless pushing excessive with heavy load in too high of gear. Yes. I will agree at this point you need the colder air to over come the weight/load issues.

All of my mods are for efficiency and longevity, so I wouldn't call it abuse at all, it's called using it and building it with matched parts. If you cannot go WOT without running too hot then you have mismatched parts, and I do not think that is a recipe for longevity.

So very true this why I will not upgrade more than I have. I'm at my limit. But like I stated before I got go WOT with totally stock truck and still see 1,400*F EGT's towing. So even in stock form it was mis-matched. Never said you abusing yours. Just stated it was the far extent would be abuse. Not throwing stones either.

I find it just a little bit rude at the assumptions you have made in this thread. I am not even sure how you can come to the conclusion that I disregard safety or possible engine issues. Simply because I understand operating ranges, min/max limits, and have a truck with matched parts to tow with does not mean that I disregard safety. When I am working my truck the hardest I have the family on board and all of my modifications, decisions, and driving technique are geared around them not sitting on the side of the road. I have never been on a road where there is a 5-10 mile stretch where you cannot pull over or slow to to let things cool if needed (shouldn't have to with matched parts). Just because you feel you need to impose a lower limit than Cummins does NOT mean that anyone else operating in the acceptable range is disregarding safety.

Once again...

Already had this happen with another vehicle

Not my Cummins. Also I never said anything about you. Just experiences I've had and how I handle hauling heavy loads and how I leave margin for safety. Nothing about your driving style. And no it wasn't meant to be rude it just I factor in road, trailer, etc but more. After this happened in the past.

Not true.

About the turbo ok. Asking politely how could I change my current turbo to be more efficient without replacing both turbo, exhaust brake, cam or head studs? Seriously scratching my head on that one? Just to be clear I'm not trying to be rude to anyone just I look at things from efficiency angle and less from power performance angle. This is a heck of a debate though. So. Let me back up a second why does Wild & Free say it perfectly ok to run +150HP injectors against a stock HX35W turbo? Once again racing application. That for sure not matched... I'll have to find the thread.

More air resistance, colder more viscous fluids, etc

Don't really buy that too well. Once the vehicle is warmed up so is all the gear train too. It warm to the touch as well. Wind drag change I will admit air does become more dense but I'm pretty sure it's not going change that drastic. ISX do you have a formula for wind density, temperature vs. drag coefficient. I would love to see if this is actual a truth how much lost there is to wind drag vs. temp.

[AH64ID]

Correct that why I said a bit of abuse.

But that doesn't answer my question. What is abusive about operating withing the proper parameters?

About the turbo ok. Asking politely how could I change my current turbo to be more efficient without replacing both turbo, exhaust brake, cam or head studs? Seriously scratching my head on that one? Just to be clear I'm not trying to be rude to anyone just I look at things from efficiency angle and less from power performance angle. This is a heck of a debate though.

There are turbo's that keep the stock exhaust elbow, and thus your exhaust brake. Unless your breaking 40 psi I do not believe studs are required. A Cam isn't needed either, especially on a 2nd gen. You can get a slightly larger turbo that will increase flow, decrease discharge temp, and free up the exhaust for better low throttle efficiency. You would need a 4" exhaust thou.

Don't really buy that too well. Once the vehicle is warmed up so is all the gear train too. It warm to the touch as well. Wind drag change I will admit air does become more dense but I'm pretty sure it's not going change that drastic. ISX do you have a formula for wind density, temperature vs. drag coefficient. I would love to see if this is actual a truth how much lost there is to wind drag vs. temp.

I can tell you from my experience in the air that air temp plays a much larger role than most people give it. I personally believe that most of the winter fuel mileage drop is from air density. A 10°F change equals a 2% shift in aerodynamic drag, or a 1% fuel economy shift. Until your warmed up each 30° below operating temp constitutes a 1% fuel economy loss, for oil and coolant. One thing I found in recent research is that chip-sealed roads (common around here) provide the worst fuel economy of any improved surface, up to 45% more rolling resistance than polished concrete. Just looking at those numbers it's easy to see how a cold summer day can show you a decrease in mileage just based on temperature alone. None of that data talks about the increased drag from cold tires, transmission, transfer-case, and axles. In winter it takes my truck more than 30 miles to get the drive-train and engine oil to operating temp, even if the engine is hot.

[Mopar1973Man]

There are turbo's that keep the stock exhaust elbow, and thus your exhaust brake. Unless your breaking 40 psi I do not believe studs are required. A Cam isn't needed either, especially on a 2nd gen.

Nope. During the time of hose clamp vs. turbo I asked around to a bunch of vendors about upgraded turbo with my exhaust brake. No one had a upgrade for me at the time nor any suggestion of turbo that would fit the Jacobs brake. That's why I still have a stock turbo. Everyone suggested I ditch my exhaust brake then I could upgrade. But to keep it I have to keep the HX35W turbo.

One thing I found in recent research is that chip-sealed roads (common around here) provide the worst fuel economy of any improved surface, up to 45% more rolling resistance than polished concrete.

Not going to argue that you are 100% correct.

Just looking at those numbers it's easy to see how a cold summer day can show you a decrease in mileage just based on temperature alone.

Still not quite willing to believe it yet... (personally). So from -20*F to 110*F net me 24% loss. Well maybe seem a bit steep... Food for thought. Some of my basis of the warmer air idea. Also looking at ISX without a fan and warmer temp he creates. http://www.dieselpowermag.com/tech/general/0708dp_1997_dodge_ram_3500_dualie_cummins/viewall.html

[dorkweed]

Ok guys............I call for a group hug, now!!!!