Disappointing dyno results w 71mm atmo. Any Ideas?

[BBottoms]

Mine was still climbing when I let off so it hadn't maxed yet, but I knew it was close. I've got elite stage 1 springs, pushrods and up-pipes so other than the potential to over speed the turbo I shouldnt have to worry too much about BP, correct?

 

[SVTDiesel]

Sorry for the derail, but how do we find the EBP on the DashDaq? I have looked and did not find it>

 

[BBottoms]

Sorry for the derail, but how do we find the EBP on the DashDaq? I have looked and did not find it>

No idea. I've got a LiveWire.

 

[Jeff@Spartan]

Sorry for the derail, but how do we find the EBP on the DashDaq? I have looked and did not find it>

It's listed as:

EP - Exhaust Back Pressure (absolute)

It's under Ford Specific PID's

 

[InnovativeDiesel]

Your truck is probably making great power. Depending on how the Mustang was calibrated and how the truck was dyno'd, the numbers can fluctuate considerably. Put it on a dynojet 224xlc, 248c, or 248h, and make a pull in overdrive. You'll get numbers that will calculate very close to track times.

 

[BBottoms]

Your truck is probably making great power. Depending on how the Mustang was calibrated and how the truck was dyno'd, the numbers can fluctuate considerably. Put it on a dynojet 224xlc, 248c, or 248h, and make a pull in overdrive. You'll get numbers that will calculate very close to track times.

Yeah, that's what I'm gathering from this thread. Looking around for a diesel shop with a dynojet but there aren't any close to me unfortunately. SPARTAN (the user) has been advertising the Deep South Shootout with a 248c but that's a long haul (650 miles round trip) even at $50 for 3 pulls.

Anyone know what kind of dyno Bean's runs? I've heard it's a little high but I'm going to there event anyway next month.

 

[08BIGRIG]

I belive Beans has a Dyno Dynamics Dynometer. That is a good dyno and it can tell you what your truck would make on a dynojet by selecting the correction factor for dynojet in the settings. It will get you very close to a dynojet number. When I ran mine on a dyno dynamics it was only 3 hp off the dynojet after correction facrtor.

 

[Jeff@Spartan]

I've just never liked how long they hold trucks at WOT on their dyno. When I was up there last winter, I thought 2 or 3 trucks were running away on the dyno but it was just how long they were holding them. I know some others agree with me on that as well. Numbers seem to be pretty accurate for the most part although I have seen some pretty low 6.4 tune/intake/exhaust numbers. It happens with all dynos though.

 

[B585Ford]

Mine was still climbing when I let off so it hadn't maxed yet, but I knew it was close. I've got elite stage 1 springs, pushrods and up-pipes so other than the potential to over speed the turbo I shouldnt have to worry too much about BP, correct?

I am not an expert, but to the best of my knowledge, that is correct. The HP turbo specifically.

 

[Lowdown89]

The only experience I have with dyno's in person is bill at PHP other than that just watching videos online, but I was always under the impression that you should get it to where it doesn't downshift once you actually start the run... I watched a few videos throuroughbred posted and in almost every video they romped hard on the the truck then it downshifts and they kept going. I'm assuming this is why the graphs I have seen from that Dyno aren't a smooth curve like other sheets I have seen. I may be totally wrong and it is ok to run them like that just seemed a little weird

 

[Super Diesel]

I was at the Thoroughbred Diesel dyno event too - and my graph looks worse that that! I'll be re-dynoing at Bill's shop, and hopefully hitting up a guy's shop somewhat nearby to run the truck on his DynoJet. It'll be interesting to see what the numbers are.

If your numbers are low (which I suspect they are).... I wonder if mine will be too... mine shouldn't be too much lower (if any).

 

[BBottoms]

I was at the Thoroughbred Diesel dyno event too - and my graph looks worse that that! I'll be re-dynoing at Bill's shop, and hopefully hitting up a guy's shop somewhat nearby to run the truck on his DynoJet. It'll be interesting to see what the numbers are.

If your numbers are low (which I suspect they are).... I wonder if mine will be too... mine shouldn't be too much lower (if any).

Yeah, I knew you were pretty happy with your numbers and weren't expecting any higher results. The 6.4Ls that ran the stock class seemed pretty close to what was expected as well. There were a few other guys that didn't seem happy with their numbers though so maybe they just weren't loading some trucks well. I did think letting the trucks downshift was weird, but being my first dyno even I didn't want to question them about it. In retrospect I should have requested that they keep it in 5th. Even if it didn't give any higher numbers at least the graph would have been useful...

I'm really wanting to go to Spartan's Deep South Shootout on Nov 3rd since they are running a DynoJet 248, which sounds like the standard by which all others are judged. There should also be a few other similar set ups there to compare numbers with. Its a 650 mile round trip though so I'm not sure if it's worth it instead of just going to Beans Diesel's event and hoping for the best. I'm happy with how the truck runs, but if there's a problem I want to fix it.

Track numbers still rule, so I need to do that too soon.

 

[Jeff@Spartan]

I was at the Thoroughbred Diesel dyno event too - and my graph looks worse that that! I'll be re-dynoing at Bill's shop, and hopefully hitting up a guy's shop somewhat nearby to run the truck on his DynoJet. It'll be interesting to see what the numbers are.

If your numbers are low (which I suspect they are).... I wonder if mine will be too... mine shouldn't be too much lower (if any).

Mo's Speed Shop November 3rd oke:

 

[Super Diesel]

Mo's Speed Shop November 3rd oke:

Haha, don't worry Jeff - I'll be there! I'm going to get a dyno tune from Vivian, that way I can prevent the truck from shifting once I get into 5th gear. Still sucks about Hunter's Performance.... that was a nice shop.

 

[Jeff@Spartan]

Haha, don't worry Jeff - I'll be there! I'm going to get a dyno tune from Vivian, that way I can prevent the truck from shifting once I get into 5th gear. Still sucks about Hunter's Performance.... that was a nice shop.

Should be a lot easier to prevent this time around. They shouldn't start the run until 70-75 MPH since it's on a Dynojet. Yeah....I really wanted to host it there but I think it's going to work out really good at Mo's. They have a ton of space like Hunter's and they seem really excited about putting it on.

 

[Super Diesel]

I'm really wanting to go to Spartan's Deep South Shootout on Nov 3rd since they are running a DynoJet 248, which sounds like the standard by which all others are judged. There should also be a few other similar set ups there to compare numbers with. Its a 650 mile round trip though so I'm not sure if it's worth it instead of just going to Beans Diesel's event and hoping for the best. I'm happy with how the truck runs, but if there's a problem I want to fix it.

Track numbers still rule, so I need to do that too soon.

You should come to the Deep South Shootout! I made the loooooooong round trip to come up there to Thoroughbred! I got your lunch if you come!

It's always cool to meet up with other Powerstroke enthusiasts.

 

[BBottoms]

You should come to the Deep South Shootout! I made the loooooooong round trip to come up there to Thoroughbred! I got your lunch if you come!

It's always cool to meet up with other Powerstroke enthusiasts.

I'm really considering it, just need to convince the other half that I really do need to drive to Atlanta for a 2nd dyno in a month, haha.

 

[Gearhead]

Ran the truck at Thoroughbred Diesel's dyno day yesterday and put down 566/1081, which is a bit disappointing for a 71mm Elite atmo and my mods. I've been anticipating putting down 650 +/- 25 whp based on others with similar set-ups (Spartan - 641hp, jdgleason - 673hp, Dustball8504 - 621hp, Dozer - 652hp). I IN NO WAY DOUBT THE 71MM CAPABILITIES as there have been too many good results. It has to be something with my truck.

Truck has 71mm Elite atmo turbo, AFE Intake, 4" down pipe and exhaust, Elite CAC pipe, Flo-Pro EGR Delete and intake elbow, 6.0 manifolds and Elite Up-Pipes, Elite stage 1 valvetrain, AirDog and I was running Gearhead's Race tune. It also has a nearly new HPFP (6k miles) and rail pressure on WOT runs holds ~24.5ksi. I can hit 49 psi boost on the street pretty easily.

Unfortunately I didn't get to do any data logging during the run and they had staff running the trucks so I'm not sure what boost or anything else it hit. They had the exhaust piped outside and i was standing right next to the truck when they ran it and it sounded good. No weird noises or obvious/noisy 100-hp boost leaks. Flashlight inspection under the truck shows no black/sooty places around the up-pipes or manifolds. Filter minder didn't get sucked in.

Their dyno is a Mustang Dyno. I know a DynoJet is preferred, but it is what it is. The dyno graph did look a little funny, it wasn't real smooth like I'm used to seeing. The Corrected and Uncorrected numbers were very close because of the weather (mine was 564/1077 corrected). There were several other 6.4s that ran the stock class with only exhaust/intake/tuners that put down 550ish, so I'm fairly certain the dyno was accurate. There were some torque numbers on a few trucks that seemed squirrel-ly, but most people seemed happy with their results.

Everything seems fine with the truck to me in DD conditions. No CEL and no funny stuff happening. Unfortunately I've never drove another stock 6.4L, more or less a mild-build, so I don't have much to go on with the butt-dyno. The only thing I've noticed is the TC seems to be stalling out a little high, but once it locks up it seems solid and I've never noticed any slipping. Unfortunately I don't have anything to monitor TC slip with at the moment to make sure.

Any ideas? Things to check? I'm going to make a boost leak tester today to make sure I don't have anything leaking and get some WOT data logs on the AutoEnginuity to make sure nothing is obvious.

It looks like the truck was shifting before the power peaked....

 

[Gearhead]

Did a few data logs this afternoon. Rolling into WOT, without a downshift. I did two runs with very similar numbers. Max numbers in 2nd run just before let off were:

2989 rpm
85.9 psi abs EBP (71.2 psi gauge)
52.7 psi Boost
1396 deg EGT
~24.66 ksi FRP (170 mPa)

EBP and EGT were still climbing at let off. FRP had no problem maintaining throughout.

I don't want to be that guy that says "It's not my truck, it's the dyno" but at the moment I'm leaning that way....

Is there anything that can cause a loss of power while still maintaining data like this?

should have taken it up to 3500 rpms or better....

 

[BBottoms]

It looks like the truck was shifting before the power peaked....

Agreed, and now I know better. You would think a diesel shop with their own dyno would know better how to run the dyno and the trucks.

should have taken it up to 3500 rpms or better....

That would be somewhere around 130mph, haha. I wish there was a way to lock out the OD on these trucks. I was also starting to worry about the EBP since it was pushing 72psi gauge when I let off. What's your opinion on a practical limit with a stock HP turbo and stage 1 valvetrain?