Near Stock v. OFT Stage 2 Dyno

[s2d4]

Originally Posted by Fast_Freddy

When has that ever stopped you?


No, I think you nailed it. His MAF needs to be re-scaled and the ECU needs a lot of time to learn those big fuel trim changes caused by the exhaust mods. Although the OP only questioned the possibility that his engine might have been too cold on the post-tune pulls, your assumption that it definitely was too cold must surely be correct since it is your assumption.


Bravo.

MAF scaling is useless, fuel trim and AVCS learning are for pussies, go WOT on a cold engine is bad ass.

[s2d4]

Originally Posted by DarkSunrise

One thing I noticed upfront was that my IAM started off around 0.88, but quickly rose after that. Not sure how long it's been that way.

FLKC @+6700rpm
FBKC @ low rev and high/low load.

I would change out ignition advance/kc learned and change to Oil temp/IAT, or run 91 tune on 93 if you have no access to E85, but that's because I hate seeing knock.

[troek]

subd for a good mystery

[DarkSunrise]

Originally Posted by s2d4

FLKC @+6700rpm
FBKC @ low rev and high/low load.

I would change out ignition advance/kc learned and change to Oil temp/IAT, or run 91 tune on 93 if you have no access to E85, but that's because I hate seeing knock.

Yeah it also looks like I'm running richer than the commanded AFR and the knock around 6700-6900 RPM is a bit worrisome.

There's an e85 station about 30 minutes from my house. Wouldn't want to drive there all the time, but I could fill a 5 gallon container every few weeks and create an e20 mix.

I wonder if the e20 mix would eliminate the detonation (effectively 95 octane) and lean out the AFR by about 3-4%. Could be a way of killing two birds with one stone, no?

[wparsons]

Originally Posted by 904FRSlow

I just reflashed my car last night. I got to 50 miles today and was told by my friend that 50 is fine.

How much does your friend know about tuning, or how the fuel trims are set?

Originally Posted by 904FRSlow

I drove 50 miles below 4k rpms. It feels pretty normal driving now so should I be good if I go WOT?

Actually log the STFT and LTFT over time, you'll quickly see that 50 miles is nowhere near long enough for them to fully stabilize unless the tune is VERY good (specifically, the MAF scaling is bang on).

There's no danger in going WOT before the trims have stabilized, the ECU will keep adjusting to hit AFR targets

[BuBlake]

Originally Posted by DarkSunrise

@steve99 @BuBlake

Did six 3rd-gear pulls tonight on the highway. Would love to know what you guys think:

http://www.datazap.me/u/darksunrise/...e?log=0&data=1

One thing I noticed upfront was that my IAM started off around 0.88, but quickly rose after that. Not sure how long it's been that way.

Definitely running rich. It's not "pegged rich"(<11.25:1) so one MAF rescale would probably do the trick. My guess is that letting the headers warm up a bit, rescaling the MAF and maybe even trying a 91 tune will net 5-10 more hp. You're probably making more HP right now than you were on the dyno.

Then again, maybe your stock ECU tune was just a freak of nature? lol

[DarkSunrise]

Originally Posted by BuBlake

Definitely running rich. It's not "pegged rich"(<11.25:1) so one MAF rescale would probably do the trick. My guess is that letting the headers warm up a bit, rescaling the MAF and maybe even trying a 91 tune will net 5-10 more hp. You're probably making more HP right now than you were on the dyno.

Then again, maybe your stock ECU tune was just a freak of nature? lol

Cool thanks I'll try the MAF rescale and hopefully that'll lean out the AFR a bit.

[s2d4]

Originally Posted by DarkSunrise

Cool thanks I'll try the MAF rescale and hopefully that'll lean out the AFR a bit.

If it's not pegged rich, it may be worth err on the less lean side due to cooling properties. Since you are already knocking flkc in high rpm.
Which is why looking at oil/air temps could help narrow it down.

[steve99]

Originally Posted by DarkSunrise

@steve99 @BuBlake

Did six 3rd-gear pulls tonight on the highway. Would love to know what you guys think:

http://www.datazap.me/u/darksunrise/...e?log=0&data=1

One thing I noticed upfront was that my IAM started off around 0.88, but quickly rose after that. Not sure how long it's been that way.

Ok somewhere before that log started were knock events that dropped your IAM below 1 , it was most likely lower rpm high load knock in 1500-3500 area as @s2d4 said.

once you iam drops ie ecu pulls timing across entire rpm range reducing power.

you can see a couple of instanced of fbkc of -2 degrees.

your also pulling another degree flkc even with timing reduced by iam of 0.9.

yes as @BuBlake and other said your running richer than ol fuel over 6000 and its flat lined at 11.25 which is about the limit of the reading of the 02 sensor so it may be even richer.

think you have two problems maf way off top end likey aftermarket intake ?? and you have a batch of crappy 93.

try some different brands of fuel this is likely why header tune is not performing as the header tune runs more advance than stage 1 tune and due your iam drop and still knocking the ecu has pulled that ectra advance that give you power , coupled with running rearly rich above 6k

yep maf scale and better batch of fuel shouls sort it, fuel trims look fairly good so exhaust leak unlikely

[Thorpedo]

Just FYI..

Every time I do a dyno pull (or do aggressive driving) right after I change the tune my I get knock and my IAM drops a TON. The only way I can drive aggressively without losing timing advance is to give my car significant amount of time to learn the trims. If I flash a tune and drive ~80kms to my typical autocross meeting area then it is usually fine.

Just an example, my car made 175whp before my header, fp/op, and OFT. After I installed all this stuff I went back and flashed my car on the dyno. Even though I went through the proper startup procedure my IAM immediately dropped to 0.8. A few runs later it was at 0.6 and I made ~160WHP (which really got all the VW guys laughing lol)

On the drive home As the car learned the trims IAM came back up, and once it was at 1 no matter how hard I drove it it would not drop below one.

[DarkSunrise]

Originally Posted by steve99

Ok somewhere before that log started were knock events that dropped your IAM below 1 , it was most likely lower rpm high load knock in 1500-3500 area as @s2d4 said.

once you iam drops ie ecu pulls timing across entire rpm range reducing power.

you can see a couple of instanced of fbkc of -2 degrees.

your also pulling another degree flkc even with timing reduced by iam of 0.9.

yes as @BuBlake and other said your running richer than ol fuel over 6000 and its flat lined at 11.25 which is about the limit of the reading of the 02 sensor so it may be even richer.

think you have two problems maf way off top end likey aftermarket intake ?? and you have a batch of crappy 93.

try some different brands of fuel this is likely why header tune is not performing as the header tune runs more advance than stage 1 tune and due your iam drop and still knocking the ecu has pulled that ectra advance that give you power , coupled with running rearly rich above 6k

yep maf scale and better batch of fuel shouls sort it, fuel trims look fairly good so exhaust leak unlikely

Thanks very much! My intake is stock other than a K&N drop-in, but as you said, my MAF scaling looks off. I'll try playing with that, find some better quality gas, and re-dyno.

Originally Posted by Thorpedo

Just FYI..

Every time I do a dyno pull (or do aggressive driving) right after I change the tune my I get knock and my IAM drops a TON. The only way I can drive aggressively without losing timing advance is to give my car significant amount of time to learn the trims. If I flash a tune and drive ~80kms to my typical autocross meeting area then it is usually fine.

Just an example, my car made 175whp before my header, fp/op, and OFT. After I installed all this stuff I went back and flashed my car on the dyno. Even though I went through the proper startup procedure my IAM immediately dropped to 0.8. A few runs later it was at 0.6 and I made ~160WHP (which really got all the VW guys laughing lol)

On the drive home As the car learned the trims IAM came back up, and once it was at 1 no matter how hard I drove it it would not drop below one.

Yeah that sounds exactly like my situation. My IAM is back up to 1.0 now so that's good. I'm hoping I can find some better quality gas too, as that seems like it might be an issue.

[steve99]

Originally Posted by DarkSunrise

Thanks very much! My intake is stock other than a K&N drop-in, but as you said, my MAF scaling looks off. I'll try playing with that, find some better quality gas, and re-dyno.



Yeah that sounds exactly like my situation. My IAM is back up to 1.0 now so that's good. I'm hoping I can find some better quality gas too, as that seems like it might be an issue.

if your intake is stock its suprising the maf is out that much, is that filter oiled ? might be worth cleaning maf sensor.

[DarkSunrise]

Originally Posted by steve99

if your intake is stock its suprising the maf is out that much, is that filter oiled ? might be worth cleaning maf sensor.

Sounds good - I'll try to clean it tonight before my track days tomorrow.

[Fast_Freddy]

Originally Posted by s2d4

MAF scaling is useless, fuel trim and AVCS learning are for pussies, go WOT on a cold engine is bad ass.

If you say so.