HELP new Corvette Z06 tuning issues

[TriPinTaZ]

I would check to make sure your O2 sensors are plugged into the correct sides 1st.
Common mistake on C5 header installs that produce the same symptoms you described.

[EC_Tune]

Not in this application: 2006 Z06
But a good point for others with C5's. Not sure how you could cross the front o2's though as their way too short. Rear o2's it's possible though.

[Redline MS]

EC,

Thanks for the info. I am expecting a to have the LS7 sofware by the end of the week and look forward in seeing some of the different parameters used in the LS7.

Do you happen to have a stock LS7 file that I can view in V2.0 sofware or do I have to have the new cable?

I will also use your config. files! Thanks

Howard

[EC_Tune]

Horist's site has at least one or two

[Redline MS]

We'll got the software so I have the file!

I have been logging some data for the last couple days and see that the LTRIMS in Bank 2 are always 5-7 % off from Bank 1. Bank 1 is around -3% to -5 % and Bank 2 is -6 to -9% consistently. I would think that regardless of the headers, both trims should be equal. What I am wondering is if this the cause of this light surge. I have installed countless number of headers and never had an issue but not to say this couldn't be the first. As a matter of fact I always torque the bolts and spark plugs to ensure they are right.

This condition is only at light cruise. The minute you tip in it's gone until you are cruising again. Anything else relevant that I can log until I get the car back on the lift to inspect? It most certainly is isolated to the passenger bank.

Thanks

[EC_Tune]

The 06 ECM is very aggressive chasing fuel around. IIRC the older LT1's would always have one bank richer than the other (as an example). So I'm not too surprised to see differences come and go with throttle position. Dynamics inside the intake change with RPM, TPS & MAP as well.

[Redline MS]

It wouldn't have been much of an issue but since I'm chasing a drivability problem its seems to be something I am homing on to. I wish I had the software before the header change as it would have made it easier to determine if the change in trims on the back was there before.

This surge thing is wierd since the only thing modified on the car is the headers and tires/wheels. Part of me still thinks this started when the wheels/tires went on the car! The rear tire is slightly larger then the stock and I know has effected the traction control system and enabled at high speeds a function called "engine drag control". The PCM plays with the brakes/throttle when you lift at high speeds (over 120) and high decel. The difference in tire size is causing the PCM to think the rear tires are spinning on decel and tries to control the car. Neat feature but wondering if it is still active and causing this surge. When you disable the traction control it is does stop the EDC from happening but who knows what else GM has dialed into these cars.

What other PIDS would be relevant to catch a fuel issue at part throttle cruise? Can't dynamic air but checked vs. maf flow or something to determine error? I want to rescale the MAF at low hrtz. but after seeing the difference from the two banks I though it would make it worse.

Appreciate your help.

Howard

[505hp]

Sorry for the stupid question but what is "CAI"?

Thanks
Mike

[Screamn03]

Sorry for the stupid question but what is "CAI"?

Thanks
Mike

Cold Air Intake (the air intake ducting up to the throttle body, not the actual intake manifold).

[EC_Tune]

The rear tire is slightly larger then the stock and I know has effected the traction control system and enabled at high speeds a function called "engine drag control".

Howard

You can re cal the rear tire size n/p. that *should* eliminate the EDC problem. The 06 speedo cal is in tire turns per mile.

As to the surge. CAI's can or will cause this on an `06 Z06. I fought like he$$ with one and finally the owner said get rid of the CAI and the problem went away immediately. Wasn't worth the 2 HP it gave him over the stock intake. All the exhaust systems I have tuned on the 06 Z06 have caused no problems at all as of yet. (Kooks 1 7/8" long tubes & metal matrix cats)

The sampling MAF's on the `06 Z06 can give you major headaches if you create turbulence in the intake system. Just ask Rune... I think he's still trying to sort out the problem.

[Redline MS]

Well I finally got some alone time today at the shop so I strapped the Z down on the dyno.

Turned off the COT and adjusted the WOT fueling so the WB was reading 12.7 from 2K and started to lean in to 13.00 from 5500 and up. Wasn't to impressed with the gain from the stock 11.7 but today is pretty hot and humid. I started to play with the timing a bit as well. I knocked the IAT vs. load down in the first three columns (86 to 113 degrees). Picked up a small amount at top end.

I copied the high octane to the low and added 3 degrees just past peak torque and up to redline. Picked up some KR and went back to stock timing table.

Maybe it was just a bad day today but didn't no matter what I did it really did phase this thing. Coolant temp on all pulls was the same as well as oil temps but these motors seem to hold heat for quite a while.

As a note I have a stock intake system and AR headers.

I also changed the tire size for the new tires and it seems like the speedo does not agree with the scanners reporting of speed. Don't they get it from the same place?

[SSUte01]

Without hijacking this thread. I also have the same issue with the speed in the scanner not matching the cluster.

Are there any other ratios/multipliers that influence the scanner's speed interpretation.

[EC_Tune]

Might want to send a data log to Chris at hptuners for him to look over in his "spare" time... Haven't personally noticed the speedo/cluster difference. But then all but one of the Z06's I've tuned had stock tires.