How Does My Tune Look?

[Zero4488]

So I've been tuning for about a year now with a handful of happy customers. Every car I've done has been easy...I mean real easy....except my car. I've been having a problem with my car breaking up at high rpms under the load of 2nd and 3rd gear (th400). It started with a professionally done tune and I've been trying to narrow it down. I just want to make sure it's not something I'm over looking in the tune itself. I have a log aswell with it breaking up at the top of 3rd gear. Barely noticable in the log but it is there. Also I apologize but my wideband wasn't logging but the narrowband mV are spot on....also was wondering if someone could check and see if their is a reason I can't run alot of timing in my car? It's a stock bolt on 2001 LS1 F-Body and every other car I've tuned can run alot more timing than I do....any input on that would be great aswell....

-Dave

[Throttle]

is that autometer fuel pressure reading correct it says 25 PSi on my scanner log

[Zero4488]

is that autometer fuel pressure reading correct it says 25 PSi on my scanner log

No the sensor is not hooked up...fuel pressure holds roughly 55psi WOT....disregaurd reading in scanner....

[Throttle]

kinda need a wideband reading for WOT.

[gsegse]

your IDC more than 80%

[Throttle]

your injector duty cycle is borderline if not to much,i think your to AFR is lean and your VE map is rather rough but hey what do i know.??

[Zero4488]

your injector duty cycle is borderline if not to much,i think your to AFR is lean and your VE map is rather rough but hey what do i know.??

Everything is very rough I'm still trying to figure out this issue I'm having...as soon as the problem is worked out I'll be smoothing out the VE and the AFR's are set lean...I've tried richening them up with no success.....

-Dave

[WS6FirebirdTA00]

You add a lot more timing on other cars you tune? I hope this isn't true. Your VE table looks very high (and screwy in spots).

Step one: Tune VE and other tables correctly
Step two: Worry about your issue

If you have issues in your tune, how could you expect to diagnose an issue? Get it strait first and then go from there. You have way too much timing in there IMO for a 241 headed car.

[Zero4488]

You add a lot more timing on other cars you tune? I hope this isn't true. Your VE table looks very high (and screwy in spots).

Step one: Tune VE and other tables correctly
Step two: Worry about your issue

If you have issues in your tune, how could you expect to diagnose an issue? Get it strait first and then go from there. You have way too much timing in there IMO for a 241 headed car.

My timing tables we're done by ECS and I have not added timing since all I've done was adjusted my VE accordingly....as for my issue, it has been an on going problem. Telling me my tune is screwy isn't answering my intial question. As for smoothing the VE I will get to that in due time. In your opinion what AFR's and max advance should I shoot for?

-Dave

[Zero4488]

Also when you say my VE looks alittle high are you talking about WOT conditions or across the MAP? When my wideband does decide to log I am within 1-2% A/F Error....

-Dave

[WS6FirebirdTA00]

You asked for feedback on your tune, so I answered your initial question. You have spots in your VE table that are almost 20% jumps. Yes, the values are WOT read high. If this were me tuning, I would verify that there wasn't something else messing with the reading like a bad calibration, leak in the exhaust, etc. Just looks high to me for just a bolt on car.

Target AFR should be ~12.8-13.0 across the board (I would use 1.14 in the PE table) and for the timing I would not run it higher than about 22º in WOT areas.

[Zero4488]

You asked for feedback on your tune, so I answered your initial question. You have spots in your VE table that are almost 20% jumps. Yes, the values are WOT read high. If this were me tuning, I would verify that there wasn't something else messing with the reading like a bad calibration, leak in the exhaust, etc. Just looks high to me for just a bolt on car.

Target AFR should be ~12.8-13.0 across the board (I would use 1.14 in the PE table) and for the timing I would not run it higher than about 22º in WOT areas.

Target AFR's come in at 12.6 and ramp up to 13.0 and go alittle richer right before redline. I'll try cutting back on some timing. Also I'm curious to why I'd go so low on the timing when stock it's pratically 25* and I've seen stock firehawks at 28*. Going back to the calibration, the Wideband is good, I've compared it to sevral others. Exhaust is all sealed. What else could possibly throw it off? Also this issue started last February, my car was tuned by ECS last June. While on the ECS tune this issue started. Could it be computer related or is it mechanical?

-Dave

[WS6FirebirdTA00]

Yes, some stock cars are at 28º, but look at the years. The '99-'00 heads (853 casting) may like a little more timing than the '01-'02 heads (241 casting). The heads are different so you can not assume they would be the same timing. The VE may be high depending on the temp you calibrated it in and how close your IAT is to ambient.

[Zero4488]

Yes, some stock cars are at 28º, but look at the years. The '99-'00 heads (853 casting) may like a little more timing than the '01-'02 heads (241 casting). The heads are different so you can not assume they would be the same timing. The VE may be high depending on the temp you calibrated it in and how close your IAT is to ambient.

IAT temp is ambient give or take a *. Also the car in question is the same year as mine...but thats not gunna help me lol. So besides what you've already mentioned could anything else be out of whack?

-Dave

[WS6FirebirdTA00]

What plugs do you run and what gap? Have you logged misfire counts to see if it is a specific cylinder? Normally I see three things if it breaks up, too much fuel, bad plug or loose plug wire.

[Zero4488]

What plugs do you run and what gap? Have you logged misfire counts to see if it is a specific cylinder? Normally I see three things if it breaks up, too much fuel, bad plug or loose plug wire.

NGK TR55 at 45. When I try to log the misfire nothing comes up. I'll give it another try. This is driving me nuts. Could it be a problem with the IDC? I mean 28.8's with bolt on's should be fine right????

-Dave

[Zero4488]

you need to take your base file and start from scatch..

so your saying start with a stock VE and Spark map?

-Dave

[WS6FirebirdTA00]

Don't start with a stock VE, timing you can start with stock though.

The injectors should be OK, but may be borderline. What is the IDC?

Careful closing up a TR55 gap to 0.045", that is a huge jump in the air gap on a plug that normally is in the 0.055" area. If it were me, I would be running a TR5 copper plug around 0.042-0.045". Their factory gap is 0.038" but the most parallel alignment is just over 0.040". I had randomly seen issues on the TR55 when trying to close the gap up a lot.

[Zero4488]

Don't start with a stock VE, timing you can start with stock though.

The injectors should be OK, but may be borderline. What is the IDC?

Careful closing up a TR55 gap to 0.045", that is a huge jump in the air gap on a plug that normally is in the 0.055" area. If it were me, I would be running a TR5 copper plug around 0.042-0.045". Their factory gap is 0.038" but the most parallel alignment is just over 0.040". I had randomly seen issues on the TR55 when trying to close the gap up a lot.

I'll try the timing as for IDC it was roughly 85%...which I've people saying anything after 80% is pushing it...but why would my IDC be so high with just bolt ons?

[WS6FirebirdTA00]

All bolt on cars I have tuned are around there, it is quite typical. With 85% though I would not believe that is causing issues. Good practice is to go larger at 80% (depending on who you talk to). If you were over 100% it would be more suspect.