Finally got back up o NC to make a comparison run between the old motor which I ran a best of 13.26 with and the new stroker. The best time I had was a 13.9@105 mph with a 2.30 60'. I actually had a 14 second run. Ive never ran a 14 second pass. What the F!$k gives. Is it possible that the machine shop honed to much out of the clinder and its causing me to loose power. I got over 130 when I didthe compression check. Can someone please give me some suggestions before I grenade this thing and sell it for scrap metal. Thanks

 

is it tuned/?

 

when you ran the car did it run bad at all heisatate, sputter anything? or did it run pretty smooth?

 

Assuming all is correct with your tuning. (I don't care for the 30# injectors your using). Did you put a convertor in to work best with the cam you have? What about the rearend? Gears, cam and convertor are of paramount concern when changing the power band.

You got to check some things. First how much power are you predicting you will put out? Check here http://www.smokemup.com/auto_math/fuel_injector.php

What is fuel pressure at WOT? Did you keep the lowsy in tank pump? if so ditch it. What about fuel pressure regulator? Is the old one still there? Does it have a hole in the diapragm?

With higher compression you need more powerful spark? what did you do with ignition? What fuel are you running? At 11:4 to 1 it's important.

By the way WTF is a desensitized knock module? I know what a knock module is.

just trying to help

 

Wicked-When I first did my stroker, I was getting a TON of knock retard at WOT, my engine is virtually identical to yours. The increased compression required less timing. I also have an LT4 knock module on the way as well, as the hotcam makes for a noisy valvetrain, possibly causing false knock. Get a scanner and take the car for a WOT run. I was only seeing 12 degrees advance at WOT. You will need to get this taken care of for a nice horsepower gain.

After you're done fiddling with the timing, you should still get to a dyno and find out where your air-to-fuel ratio is. Between this and the timing it is very possible to have 75-80 horse on the table.

When I first built this motor, I was only trapping 105 as well. I quick chat with Drop Top Steve, and he pointed out that cars like ours should be trapping 113-115. Time for some tuning!

 

well, i dont know about the knock thing

I'm probobly pushing a bit over 11:1 on 91 octane without ANY knock whatsoever and I have HUGE exhuast leaks. Make sure your not really knocking. I also have a much bigger cam so my dynamic compression will be lower.

As far as the105 trap,
I just got a program from Bryan @ pcmforless to keep the car alive- nothing performance oriented at all. My *** and street races tell me i'm trapping 110+ on stock heads and intake box.

My buddies C4 ran a 107mph run and he flipped the nitrous on in 4th gear. Racing me he flipped it in the middle of 2nd and we were dead even from 60- 120. And my intake box and heads are stock.

Hope this gives you a bit to compare and contrast.

 

Well...my scanner does!!! Since my combo is very similar to Wicked's, I think there is a good chance he is in the same boat.

 

your car shouldn't be knocking-
what CR?
timing?
fuel?

 

I think it could be a combo of a lot of things now that you guys mention it. Guess Ive still got a lot of work to do. As for the knock sensor, i put a resistor in between the drk blue wire of the knock sensor and the computer. Im running 93 octane always but my ignition seems to break up under high RPM. Think my opti is taking a dump also. Thinking about going to an LTCC setup. Also still runnig stock compuer program and gears. No converter its an M6. thanks everyone

 

Traction ? Were you spinning ?

I'm heads, cam, intake, exhaust, stock bore. My first run of the season was 14.8 at 107 mph. Look at where your car is falling off before looking to the engine. Compare your 60" times and stuff from your previous run with the stock engine.

-Shannon

 

Most cars with increased compression do NOT require the amount of timing dialed in at the factory...soooo..when the steep advance comes in combined with the high compression equal knock counts which equal timing retard. False knock is also a factor in cars with aggressive valvetrain ramps.