I am working on my 95 corvette LT1 running 9lbs of boost on a heavy moded 355ci. Car drives good until I step on it then car starts skipping or acts like it's skipping.
I have been working on this problem ever since the supercharger was put on. I have got it to run better by lowering the timming and richening it up but I would like to know if I am on the rite track. I am running about 25 to 27 degrees WOT timming and my %change to AFR at WOT is at 25%. Is this common where I have the timming and % change to AFR for a moded supercharged car? Any help is appreciated.

 

Aso if anyone running about 9lbs of boost and 10.5 to 1 compression could show me there timming tables it would be appreciated. This is driving me nuts

 

Well, I have a 1997 camaro OBD2 PCM running a Procharger D1 with a 383ci displacement. I use Carputing.com version 2.2 software. I run an intercooler with meth/ h2o, and, run timing @ 34* @ > 100kpa map. I tried low timing (24*) and, the LT1 did not respond well for me. I aquired a Dynojet WB AFR O2 sensor that helped me tune the car for closed loop, and, WOT mode. The two (2) WOT modes were PE vs. rpm, and, PE vs, Temp. I zeroed PE vs. Temp and only use PE vs, rpm mode. It works well for me now. I am running about 12.8 afr @ WOT mode with boost. Hope this helps. B.

 

Don't zero pe vs temp without adding the fuel back in to the pe vs rpm mode. Or just keep it the same all across the warm operating range of the car.

 

Thanks for the reply guy's. I left PE Vs Temp stock. I guess Im just shooting in the dark without a wideband. Anyhoo, what are your %change to fuel/air ratio Vs. RPM at WOT set too so I can get an idea if I am way off or not?

 

Fuel pressure is good. I added a MSD 6AL. I thought it might be a problem with the spark, no luck. Although I wasn't sure how to wire it because there diagram that shows how to wire a dual connector coil shows four wires. Mine has three and the colors of the two don't match with the diagram. So I wired it up like they show it but without the one wire. So I'm not sure about the wiring but it's got spark. I also have a new opti on it so I don't think thats it.
Come on guy's help me think??

 

Put in a couple new plugs and do some plug cuts. See what that tells you.

 

Log it and see.

 

Plugs look alot better than they were. Light tan color.

 

I have loged it and it is still showing some knock retard. Should I give it more fuel? My timming is down to 25 degrees at WOT although it is around 35 degrees before I push the peddle down. I can't tell what the AFR is but the O2 mV are between eight and nine hundred. If you would like to take a look I can e-mail a log to you. I would appreciate it.

 

Most blown small blocks make max power with 25 degrees or less. So, I doubt it's a timing issue. What ignition are you runing? It may be blowing out the spark. Are the wires in good shape? Try closing up the plug gap.

Rich

 

I am running the MSD 6AL with the stock opti. Autolite 103 plugs and a good set of taylor 8mm wires. My plugs are gaped at 35 thousanths. Should I go down to 30 thousanths?

 

Probably not the problem but worth a try.

Rich

 

A new problem has showed up. I am popping fuses to my electric water pump. Man, one thing after the other. I am assuming it has somthing to do with the MSD put I'm not sure what. Do you guys have your MSD's hooked directly to the battery? Thanks