Tuning for a 3.5" pulley upgrade

[mechguy]

Guys I need your help.

I have an 03 GTP with headers, 3.5" pulley, A104 plugs, and HAI.

Running on a tuned PCM but was getting a lot of part throttle KR, so I bought a DHP PT to rectify this.

I scanned up to the point of 3 or 4* KR and loaded that into Eddies Table Modifier, along with a stock MAF table. It spat out my new MAF table which I exported to DHP and flashed to the PCM.

I think the table modifier primarily bases off of LTFT, and I have no wideband. I know that narrowband sucks. If I mod further a wideband would be purchased.

Anyway, seem to get at least as much KR now as before.

So here's where I need the advice:

1. For those mods, should I be bothering with a MAF tune?

2. Found a 2001 GTP bin file for similar mods. Should I use the AE enrichment table from this? It's quite different from stock. Then put the MAF table to stock?

3. Is this table modifier program legit?


Really just looking to get this chit going....it's been hectic over here.

[Z34Phoenix]

ok... using eddies table program and generating a new MAF is just going to level your fuel trims. if your trims are Zero at WOT already then running another maf tune again wont help. if you go to the table section and view where in the graph the KR is. then use another tab and plot O2 values. look where the KR is and if you see that your fuel is going lean where the KR is then you need to go into your PE and add more fuel for that rpm section. if your rich and still have KR then you need to go to the spark table and pull timing for the same cell your having KR at.

hope this helps

[matt5112]

And if that fails, you're like me

[mechguy]

Alright, have a look at some sections of my scan. I've done several LTFT tune/scan iterations. Still a lot of low throttle KR, and LTFT doesnt look bad.

[mechguy]

Thought I should add that timing is stock at the point of KR.

[darkhorizon]

Fueling is most likely not the issue here (unless its too much fuel, which is unlikely).

The RPMs are quite low, and you are putting quite a bit of load on the motor at low rpms... I would consider looking at the octane of fuel you are running, and see what your torque converter is doing.

Your PE entry looks ok as it is dumping into fuel about when the boost comes on, but there is always KR there... I would also suggest looking at your case learn and or DTCs for hidden knock sensing codes.

[Juanmiguel]

fueling looks good, you're using stock timming, but still a lot of KR. I would look in to the torque management section (max torque allowed) and AE enrichment as you say. But I would first download the DHP 1.0 file for your model from the powrtuner site and start from there, it already has all those items covered for a basic 3.4 setup.

[darkhorizon]

no torque management does not show up as KR... Please stop spreading that rumor.

AE also has no effect on things like this... AE operates at such a small level when when "cranked up" you will never see it effect anything.

This KR is mechanical, no amount of tuning is going to fix it unless you try tossing a ton of fuel at it (although your injectors look to be at 50% already, which seems to be stupid rich for 2psi of boost.

[mechguy]

Well I put the MAF table back to stock, and PE AFR back to 11.7. I'm going to run this for a few days before flogging it to re-evaluate. I did allow more TCC torque if that should matter.

Fuel is 91 octane and not changing that. I see that injector PW appears high. I'm thinking of playing with the injector flow vs MAP. Also, AE is turned way up as per DHP V1.5. So initial injector flow is large.

So if no progress is found then a 3.8" pulley goes on.

[Maximum Gnarnage]

As stated before i'd be looking and your torque converter lock-up release settings. Scan TCC duty cycle and pay attention to kr relative to duty cycle to identify if that's causing your knock. . . go from there

[darkhorizon]

Try rolling onto boost with the gear selector in 2.

Also as I said before, AE is not going to do much for fueling. If you want to lean things out use PE not your injector constants. PE is the only adjustment your pCM needs to add or subtract fuel in PE.... and it works very well and is extremely easy to adjust.

[mechguy]

Try rolling onto boost with the gear selector in 2.

Yeah, I've done quite a bit of 2nd gear checking. Usually KR begins with any boost, even in 2nd.

Also as I said before, AE is not going to do much for fueling.

If I understand correctly AE is an additional initial fuel dose compensating for PID lag. After this it does nothing.

PE is the only adjustment your pCM needs to add or subtract fuel in PE.... and it works very well and is extremely easy to adjust.

That is what I do for PE tuning. I haven't spent much time with PE tuning yet because of sub PE KR. I was getting KR at 15% throttle.

I'll try to grab a 2nd gear scan and post that.

To the suggestion of releasing TC lockup earlier in throttle, I agree to a point, but not to the point of it releasing every time you hit resume accel in cruise control.


Thanks for suggestions guys.

[Hixc]

can you hear the knock? got a vid? does it knock in Park while rolling on the throttle?

[darkhorizon]

Lower PE entry if you are getting knock at 15% throttle...

But hell if you have KR at low throttle, there is just some issues you need to sort out mechanically.

[mechguy]

Well finally some positive progress.

I'm using the much scaled back injector flow of a DHP V1.5 tune. Looks like she was a rich knocker. I actually don't know why having the injectors slowed down is necessary for my mods. The LTFT's are still a little more off than necessary, but a MAF tune should help that.

Some PE knock remains, but I have yet to try the V1.5 settings for that. I'm quite confident they will help.

Will report back. So far so good.

[mechguy]

A lot of PE knock now. I've tried from 11.4 through 12.3 commanded AFR and it all knocks. Hmmm.

[mechguy]

Even when 02 shows 924mV.

I thought PE tune would be easy. AFR and timing, that's pretty much it.

And timing is stock.

[matt5112]

Well if the injector tables are on and the MAF is on, you can zero out the PE vs RPM vs Time until about 10-13 seconds then richen to keep it safe.

Car should maintain a fairly consistent AFR.

[Tuner-Extraordinaire]

Some like an AFR that richens with time however. i wouldn't 0 it all the way.

[matt5112]

Stock is fun

Its 12.x base minus a point or more depending on time and engine speed.

Too much inconsistency if you're trying to dial the maf/injectors in.