Ok, I bought my 1992 vette with a 383, and an LT4 hotcam. The shop that built the motor recommended a bigger cam, and sold me a 232/242, .565.575 114 LS cam, based on a very expensive computer program's recommendation. I installed the cam, and paid for a chip from PCMforless.com. Prior to the new cam, the car made 370 RWHP.

I just lost to a stock O2 Z06. It wasn't even close. The guy pulled me probably 5 car lengths in third gear. It's a buddy of mine, so I know its stock. When I had the hotcam and the old tune, I was door to door with him. This is the 2nd attempt by PCMforless.com to tune the car. The first tune, the car had cam surge so badly it wasn't even driveable, and had way less power. This time, the surge is better, and it has more power, but the surge still makes 25 mph in 3rd gear an impossibility. Does anyone know of a way I can communicate what needs to be done differently with the tune to Alvin at PCMforless? I don't have any data logging equipment, and the only Dyno shop in the area charges $135 for a friggen pull with a wideband.

Any idea's?

BTW, I am about 4,500 ft. above sea level.

 

sounds like your timing is way off. But, if you want it to run right u need a dyno pull and data log to figure outs wrong. Otherwise you are just guessing.


i dont understand how you say the you were door to door with the same Z06 before the new tune. And no the new tune is more powerful and you lost by 5 cars?

It makes me think your buddy was either toying with you the 1st time you raced or hes installed a N20 kit that he didnt tell you about.

 

Your misunderstanding him. With the hotcam he stayed with him. With the new cam and 1st tune the car was weak. With the new cam and the 2nd tune the car is stronger, but it still can't keep up with the Z06

 

Maybe I wasn't clear. What I am saying is that the tune from PCMforless.com is way off.

Is there anyway I can find out what needs to be done to bring the tune up to snuff without any data logging or a wideband session? I all ready paid for a chip that supposed to be "on the money." I don't want to shell out more $$$ than I all ready have.

 

WEll now that I understand more my "GUESS" would be too much fuel and not enough spark advance. But you REALLY need a wideband dyno to find out.

 

Second vote here for getting it on a wideband. Otherwise you'll be guessing and chasing numbers.


Tails

 

I can adjust y A/F ratio at WOT with my AFPR. My A/F ratio was on the money with the hotcam. I have tried more fuel, and less fuel via AFPR with no real results.

I need to know the timing tables and things like that. All a wideband session will net me is the A/F ratio at WOT. Not enough to get a comprehensive tune.