i got ahold of a local member that had a HP tuner so i could scan for KR. well low and behold i am at around 6* at WOT in 2nd gear.....this made me ....well now i am thinking i am either going to ditch the idea of getting winter rims and tires and put that money towards getting a new PCM so i can keep my warranty and a dyno tune. if i dont get the PCM and tune then i will have to learn how to drive without a heavy foot and still get the rims and tires....put yourself in my shoes and what would you do? anybody know where i can get a core PCM from? also would an 06 PCM from a GXP work on my 08?

 

I run an AlkyControl progressive alcohol system in my Grand National. It lets me run 22 lbs of boost on 91 octane pump gas with ZERO KR. You may want to look into something like that for your car. If you want more info, just PM me.

 

Well, now we know why your traps were low at the track. I would check to see if it's false kr first. One of the ways I used to check, was to pour unleaded race gas in the car and the re scan. If the kr was still there, that would tell me that the kr was falst since you won't have true kr with race gas. With you having the aftermarket downpipe, it's a good possibility. The computer will pull your timing when it sees kr, so you're losing power. If it's true kr, you might be a little too lean, in which case a good custom tune would fix it and net you more power. Let us know how it works out!!

 

lose your intake. every time I have opened up my intake path, the mixture has gotten more lean. Go back to stock and retest. when you are ready to tune, reinstall the aftermarket intake.

 

first steps are going to be cleanin the filter MAF and throttle body.....i also found a leak where my DP was welded on so i am hoping this is all causing the KR.....if the exhaust is hitting in other places would this cause KR? i will rescan after this is all done.

 

Two things.
I wouldnt do a tune yet. I have never seen a big gain from a tune, usually around 5-8hp at the wheels. So go with some other stuff first before you do a tune. Like rockers and stuff.
Second, the dealer can not tell you have a tune on the stock computer. It shouldnt void your warrenty if you tune that one.(if they dont know)

 

tonight i clean the air filter MAF and TB....tomorrow it goes to the exhaust shop cuz i thought i heard a leak by the DP...i am hoping that these will reduce the KR...from what ive been told i am running really rich so if this doesnt help when i scan next week i will be looking for a stock air box and taking off the CAI.

i thought if the dealer hooked up their tech 2 they would be able to tell if you had tuned the car???

 

My rad fan went and ive been waiting patiently for 2 weeks for my "tuner guy" to find his cable which got lost in the mail. In the mean time i keep pushing back the apointment making me look all soo retarded haha.

 

took it to the shop and no exhaust leak....the car is running better since i cleaned the air filter MAF and TB but i wont have my scanner stuff til next week....back to the drawng board.

 

I am not sure about the tech 2 thing.

 

Yes... in some cases you can tell if the ECM/ TCM has been tuned at the dealer. All program updates and orignal software have ID numbers and serial numbers along with the date it is uploaded into the hardware. When you tune with HP tuners and enter your custom program it saves it as an update and the new date but will retain the original authorization number. This is how a dealer can tell. Also if you have a major issue and the ECM/TCM took a snapshot because of a stored code you can check and see the torque output and if it is significantly higher than the stock output it is usually obvious that the car has been "played with". GM has been getting a bit more strict on this stuff because people are upping the boost on new duramax's and blowing them sky high.

 

Also heard that some of the newer pcms are going to have a key turn counter.. that way if you have a car that you DD or drive regularly, and you bring it in with warranty work and it only has 4 key turns on it, they'll know the pcm has been swapped out..

 

tune before rims. its more important.