Matt's tuning fun

[matt5112]

Mod list:

- L36 block 80 something thousand miles.
- L67 top swap with unknown miles on the heads. Never checked for flatness, cracks, or anything else. Probably not good.
- gen III blower with a mildly ported outlet. I know... Gains are found on the inlet, not outlet.
- L67 TB with a mild port, that magically hasn't affected the MAF table much. Did a bad job most likely. Working on another.
- Gen III WBS 2.25" intercooler. Too tall, blower and fuel rail eat the hood yet I'm stock ride height, no spacers.
- Yella Terra 1.9 RR's with L76 springs/LS1 retainers. Great mod. Didn't feel any difference at all. Drives exactly the same.
- Speed daddy headers with a 3" non-high flow cat welded in. Leaky speed daddy flex still in place. AEM wideband is about 6 inches after this leak. Good idea right? At least its on the top half of the pipe.
- Maremont "performance" 2.25" crush bent to 1 7/8ths inch crush bent catback. Very quiet. Sure its hurting them performance numbers.
- Short ram intake with a very oversized air filter. Going from old small K&N to new oversized amsoil filter (dealer was terrible) resulted in PCM adding another 2% fuel at WOT. Driver foglight has ducting running into the engine bay right beside the air filter.
- 3.4/3.6 ZZP MPS Boost is good.

For those who REALLY care: 180 t-stat, TR6 spark plugs side gapped at 0.045".

Saw an HPT for cheap, decided it would be a good way to spend spare time.

Car has been tuned by Will previously.

Had it tuned to 11.0 AFR on the 3.4 pulley, 16* of timing, not much knock to worry about.

After a week the car would add fuel at WOT bringing it down to 10.2 AFR.

Had it touched up. Still occurred.

Added half a percent to the below 5000 Hz MAF table and it seems to be doing just fine in that regard.

Next step was trying leaner. Got it to 11.3. Still experiencing KR at 16* solid advance.

Tried a 3.6 pulley and 17* advance with the same results.

Went back to Wills 7000 Hz + maf settings for a solid 11:1 AFR and the 3.4 pulley.

tried 15 -> 16 -> 17* timing advance. Still didn't like it, the 15 helped out in the mid/high 4000's rpm. Yet the 17 up top the motor didn't like at all.

Threw the 3.6 back on with 16 -> 17 -> 18 timing advance.

Heres some of that fun:

http://i88.photobucket.com/albums/k1...2/1186f7ca.png

Note I can't seem to get the WB AFR to log properly. Sometimes its bang on, others its not.

[whiney]

Mod list:


Note I can't seem to get the WB AFR to log properly. Sometimes its bang on, others its not.

I don't know how to get it bang on either, mine at idle would read perfect with each other and then at wot my tables show like 12.2 and watching the gauge its like 11.0-11.3?

[matt5112]

Yeah.... slope of 2 and intercept of 10 is what is supposed to be correct, but 9.5 intercept seems to be the best fit for idle ranges.

At WOT I'm not sure. Last run suggested it was reading correctly, yet why it would run 11.0 on the last run, yet 11.3-11.4 earlier makes no sense to me when fuel trims are the same and so were the ambient temps.

One thing that has me lost is that apparently scaling injector IFR's is wrong. Guessing based on what its rated for then scaling it upwards with MAP kPa is wrong.

Only correct method is to find data on injectors then insert that.

Heres just the chart with IMG tags:



Ran a cylinder balance test, did terribly. Replaced the spark plugs and it all seems to be within 3% of each other.

Injectors seem to shut off after long pulls like that. That can't be good right?

Boost levels:

3.4 pulley

4400-5000 RPM: 6.53 - 7.54

6000 RPM: 9.14 - 10.30 psi

3.6 pulley

4400-5000 RPM: 6.2-7.54 psi

6000 RPM: 9.2-9.72 psi

Not much change, but then again, different ambient temps, intercooler core blocking the intake etc.

IIRC I saw roughly a 1.5 PSI drop when installing the core and sticking with the stock pulley.

[Z34Phoenix]

if the injectors seem to turn off after time... did you look at the PE_rpm_vs_time table? it if leans out after a while then that could be the cause... that or could it be the fuel pump cant keep the pressure up? what is the injector pulse width? is it close to being static?

as for scaling the injector IFR's your right its not recommended... i have heard that some to it so that commanded AF matches their wide band... but if you have the wide band on the car just look at it...i would never trust commanded when you can look at the actual AF.

[matt5112]

Can't keep up when the car is coasting?

Time table is zeroed out so its easier to calibrate the MAF.

[Z34Phoenix]

maybe try and add fuel towards the end?

[matt5112]

See the picture above?

Where I'm coasting down from the 1/2/3 gear pull?

MAF Hz drops right down. If I added fueling there it'd simply screw up cruising and my idle.

[Z34Phoenix]

sorry i've never used what ever program that is... im used to looking at the data in eddies table modifier. is that an HP tuners thing? ok looked it all over and its making sense now...

Maybe im not understanding the question....
if your off the gas and coasting the maf would drop down because the throttle is closed and only minimal air would be going thru the IAC.

[matt5112]

The question simply is: Why do the injectors shut off when coasting from high speeds.

[Tuner-Extraordinaire]

DFCO.

[Z34Phoenix]

i was about to ask what DFCO but it is "deceleration fuel cut off" makes sense that they would shut off as you are costing, the throttle is close so no more air is coming in. the trany turning will keep the engine spinning so you still have vac... its just using the engine to slow the car down.

im wondering if there is a table in there that controls off throttle AR? i have seen some with very high AR's could be something to look into... or for # of injectors to disable? something like that. we may have the table after all

[darkhorizon]

dfco is a mess if you start doing weird tuning stuff... You can edit some of the values in TinyTuner.

A normal car with 60# injectors should never have issues with it.

[darkhorizon]

One thing that has me lost is that apparently scaling injector IFR's is wrong.

I have suggested that scaling the maf is wrong... I leave the maf table stock (stock to whatever maf is on the car) when I can and tune in PE and injector.

[matt5112]

It seems the good deal on the 42.5's was really a curse.

And porting your TB is bad idea period.

Sticking with the 3.6 and stepped timing for now.

Its a little slower, but theres typically 0-0.5* KR versus 0-1.5* on the 3.4.

Next step is sorting out those wonderful heads.

[matt5112]

Tried 12.0 AFR for fun.

It works. Very little KR if any. Doesn't make the car any faster or slower though.

Threw the 3.4 back on and went for 11.7.

Haven't got a good pull in yet.

[matt5112]

That was a no go.

Plenty o' KR.

Bought a magnaflow catback.

Sounds poopy.

But with a 3.6 pulley, 11.7 AFR, 17*, it felt slower than with the stock catback.

So I threw the 3.4 on and had a go at it.

Same AFR, same timing, no knock. That being previously impossible.

[darkhorizon]

a catback "upgrade" resulting in a horsepower gain is probably a fluke.

[matt5112]

Have to say, it seems that way now.

[matt5112]

Interesting thread:

ClubGP Message Forum troubleshooting

Namely:

You don't need that kind of timing with high compression. It's really doing you no good. I personally would stay around 15, with 17 max. The advanced timing only helps out speed up the combustion in a low compression situation; you have that part taken care of. High compression cars also will like a leaner mix, but you obviously will have to watch this closely. It might be a good idea to be watching EGT's to optimise your tune. I have a feeling you have a volume problem with your fueling. Have you done a pressure test during a WOT run? Generally these type of problems only happen during a long WOT run, and show up at the top of 2nd and through third.

[Nicksupercharged]

Nice tuning.