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Finally got my car on the rollers today, same place that did my baseline dyno run with the car naturally aspirated. The car put down 162 rwhp and 185 rwtq with Metric Mechanic exhaust and a TCD CAIS being the only derivations from stock. The car had 233k miles at the time.

Today, with the TCDs1 kit and TCD exhaust running near 10psi peak at peak boost, it threw down 256 rwhp and 311 rwtq in fourth gear just after turning 240k miles on the odometer. Normally I'd be ecstatic about numbers like those, as they are quite good. However, there is definite room for improvement on the horsepower end, as the motor goes pig rich starting at 5k rpm. The car also has a slight misfire (noticeable only for the unsteady line on the dyno chart) starting before that in the rev range.

AFR was healthy between 11:1 and 12:1 (started at just above 11:1 then trended upwards towards 12:1 as rpm increased), then right around 4800-5000rpm it nosedives to 10:1 and stays there until he got out of it at about 5600 rpm. This same behavior was replicated identically on three seperate pulls, one of them in third gear instead of fourth.

On the wideband around town, cruise AFR is perfect, and boost AFR was good as far as I could tell, but second gear disappears awfully fast, and I don't have enough road to watch the AFRs all the way through third, let alone fourth at high rpm. The rise on the FMU is currently dialed all the way back (has been for a while) with a restrictor the signal line. The interesting thing about this is it gains about a half to three quarters of a pound of extra boost (goes from 9psi to 9.5 or a touch more) right at the point where it goes rich, so I'm wondering if it has something to do with the FMU, but I'm not sure.

Anybody else run into this kind of high rpm over-fueling when tuning?

Oh, and sorry, but at this point there are no graphs to show.

Jeremy

[Edit by Jeremy on [TIME]1127842369[/TIME]]

Jeremy,

I think you have ~10-12rwhp to gain when you lean it out. The torque number is really healthy. I'll post the sheet tomorrow when I get it.

Todd


[Edit by TCD on [TIME]1127416275[/TIME]]

Todd said tit. I'm telling

solid numbers. that's alot of torque!!! keep it coming!

[QUOTE="Jeremy"]Finally got my car on the rollers today, same place that did my baseline dyno run with the car naturally aspirated. The car put down 162 rwhp and 185 rwtq with Metric Mechanic exhaust and a TCD CAIS being the only derivations from stock. The car had 233k miles at the time.

Today, with the TCDs1 kit and TCD exhaust running near 10psi peak at peak boost, it threw down 256 rwhp and 311 rwtq in fourth gear just after turning 240k miles on the odometer. Normally I'd be ecstatic about numbers like those, as they are quite good. However, there is definite room for improvement on the horsepower end, as the motor goes pig rich starting at 5k rpm. The car also has a slight misfire (noticeable only for the unsteady line on the dyno chart) starting before that in the rev range.

AFR was healthy between 11:1 and 12:1 (started at just above 11:1 then trended upwards towards 12:1 as rpm increased), then right around 4800-5000rpm it nosedives to 10:1 and stays there until he got out of it at about 5600 rpm. This same behavior was replicated identically on three seperate pulls, one of them in third gear instead of fourth.

On the wideband around town, cruise AFR is perfect, and boost AFR was good as far as I could tell, but second gear disappears awfully fast, and I don't have enough road to watch the AFRs all the way through third, let alone fourth at high rpm. The rise on the FMU is currently dialed all the way back (has been for a while) with a restrictor the signal line. The interesting thing about this is it gains about a half to three quarters of a pound of extra boost (goes from 9psi to 9.5 or a touch more) right at the point where it goes rich, so I'm wondering if it has something to do with the FMU, but I'm not sure.

Anybody else run into this kind of high rpm over-fueling when tuning?

Oh, and sorry, but at this point there are no graphs to show.

Jeremy

[Edit by Jeremy on [TIME]1127404877[/TIME]][/QUOTE]

You cant tune the car in 1st or 2nd gear, period. It will not run as you would think, theres not enough load on the car to get an accurate read on AFRs. You have to use 3rd gear at least, and perferable 4th. Dont tune in 2nd, trust me. If you can't get the road to do it, use a dyno to get ~85% of the way there.

Your #s are spot on. The torque will run ~45-60lb-ft more than hp on the stock M30-34s. Look forward to seeing the chart. Fix that rich conditions, you will like it.

RussC

question, how come jeremy is making so much more torque than hp and on my motor (the slightly larger b35) i am not making nearly that large of a difference in torque. when we stopped the dyno at 5k, i had about 20 pounds more torque than hp. i also noticed this on todd's e28 back last year. any rhyme or reason to this.

[QUOTE="gol10dr1"]question, how come jeremy is making so much more torque than hp and on my motor (the slightly larger b35) i am not making nearly that large of a difference in torque. when we stopped the dyno at 5k, i had about 20 pounds more torque than hp. i also noticed this on todd's e28 back last year. any rhyme or reason to this.[/QUOTE]

Dont try to read too much into his #s yet, the AFR is too rich. With that said, the differences in cam, head profile will figure into the differences. Plus, theres the difference in dyno, atmospheric condtions and the cycle of the moon can effect dyo #s.

I guess we need more info on the exact setups also.

RussC

[QUOTE="gol10dr1"]question, how come jeremy is making so much more torque than hp and on my motor (the slightly larger b35) i am not making nearly that large of a difference in torque. when we stopped the dyno at 5k, i had about 20 pounds more torque than hp. i also noticed this on todd's e28 back last year. any rhyme or reason to this.[/QUOTE]

This is totally typical of the differences between s stock m30b34 and m30b35. Being more efficient your b35 cyl head and cam continues to flow and make upper rpm HP. The b34 motor and cam do not.

sounds sweet man...if u want, i can help u read your afr's while u floor it in 3rd, 4th gear
or just setup a video camera and record the gauge as you fly down the highway at 3am

sorry officer, i was just testing my afr conditions
do you know how fast you were going son?
um lemme see, WOT in 4th, 6000rpm, 3.64 final drive, prolly 110 or so
license and registration. now!
*burnout + dixie horn, drive away fast*

Here's the graphs.

Hp and torque. Baseline in blue, turbo run in red. Peak numbers are a little off what I claimed originally. Apparently they use STD corrections and old software in the shop. See how nice it spools?



Hp and AFR. The dip in AFR at high rpm on the baseline begs the question if this is a problem unique to my car. Not sure what it could be though, injectors were swapped, AFM is completely re-calibrated, main fuel pump has less than 5k miles on it. Fuel pressure gauge setup will hopefully get here today and I'll know more.




[Edit by Jeremy on [TIME]1127842424[/TIME]]

Jeremy,
Your NA AFRs are hosed to start with. So just using the FMU will still give you bad AFRs. I don't understand whe the NA AFRs are soooo LEAN ~0 ~0

Your NA AFRs should be at least under 14:1 by 2krpm, and in the 13s by 2.5krpm. Your so lean, your giving some hp away for sure. Your boost AFRS are just following the NA curves, are are giving som hp there also.

Your FI runs are ungodly rich, you sir need some tuning time, and not in 2nd gear. Um, if you have the WBO2, didn't you use it to log during the dyno pulls And they need some tweaking. Since the NA has the same issue, it's definately an issue with something else in the system besides the turbo equipment. What software are you runing?

In my paticular case, I tried tuning in 2nd gear, can't do it. My car ran way rich, leaned it out. First run under a 4th gear load, way lean. You may be having this issue also. Also, if your using an FMU, the start pressure setting, the big top screw sets the point where the pressure starts rising. you may need to get that farther in to start the fuel pressure rise in the vacum to boost transition. Most cars, like the documentation say, run lean in that area.

RussC

I really can't account for the early leanness. It's almost as though the operator wasn't going WOT until like 3k rpm, but the O2 sensor should've kept it at or near stoich before that. I really don't know what's causing the early leanness (16:1@ 2800rpm ~0) or the late rich condition. We're guessing something funky in the fuel pressure or AFM at this point. I'm going to get a fuel pressure gauge on there soon and hopefully narrow it down.

New graph, all in one. I'm still getting used to WinPEP.

Early leaness seems like a lazy O2 sensor or delayed single not representative of the mixture at that rpm. Sensor is in the tailpipe.
Todd

[QUOTE="TCD"]Early leaness seems like a lazy O2 sensor or delayed single not representative of the mixture at that rpm. Sensor is in the tailpipe.
Todd[/QUOTE]

Sample dilution? That occured to me with that big 3 inch exhaust . . .

Question: Does anyone know for sure if a device like an LM1 can be hooked up to a Dynojet for dyno runs in place of the tail pipe sniffer? Seems like a better way to do it than logging the run on the LM1 and trying to match the two up later. The LM1 does have a couple of output channels . . .

Jeremy

[QUOTE="TCD"]Early leaness seems like a lazy O2 sensor or delayed single not representative of the mixture at that rpm. Sensor is in the tailpipe.
Todd[/QUOTE]

Umm, even with a "lazy" O2, theres no way it would read that lean, even with a tail pipe sensor. I've never had or seen that kind of leanness @ WOT with a ball park tune NA engine. The tail pipe sensor should be "reasonably" close due to the fact that @WOT, the large amount of exhaust gas overwhelms the catalyst reactions, and gives a close AFR. Does the DynoJet delay O2 readings Ive not heard this.

RussC

[QUOTE="Jeremy"]Question: Does anyone know for sure if a device like an LM1 can be hooked up to a Dynojet for dyno runs in place of the tail pipe sniffer? Seems like a better way to do it than logging the run on the LM1 and trying to match the two up later. The LM1 does have a couple of output channels . . .

Jeremy[/QUOTE]

The LM-1 has two output channels, a narrow and a wide. You could use the WB output to go into the DynoJet. But I don't know if the dyno has this capability.

RussC

russ, please email me (gol10dr1@aol.com). we need to speak immediately.