From what I have heard, you are supposed to shift at when you hit redline on the tac because that is were the power curve peaks out....

Since I have put mods on my car, I have noticed that it is really pulling strong to redline, and I think it would also pull strong a little ways through it from what it feels like now.

I was wondering would modding your car push the peak HP curve up the RPM scale some, or is it just a bad idea period to shift beyond redline.

Originally posted by MechanisM
From what I have heard, you are supposed to shift at when you hit redline on the tac because that is were the power curve peaks out....

Since I have put mods on my car, I have noticed that it is really pulling strong to redline, and I think it would also pull strong a little ways through it from what it feels like now.

I was wondering would modding your car push the peak HP curve up the RPM scale some, or is it just a bad idea period to shift beyond redline.

Well when i race i shift rite before it hits redline. I guess thats where all your power is at. Not sure though. I just shift there to be safe.

the redline is their to warn you that you are reaching the highest RPMS for the cams to control the valves. if the RPMs are too high, the valve springs are too weak to close the valve & thus will hit the piston during rotation. this is called floating valves, & causes bent valves. sometimes the OEM tach is off by 200-300 RPMs, & that's why ppl use aftermarket tachs for accuracy.

IMO, goto the track & do a few passes; the timeslips can tell you alot. try shifting before & after the redline to see where the best RPMs are for power. getting a dyno test will also help you see where the power curve is, therefore you can use that as a guide to find the best shift points w/ the track times.

also cams with high lift need tighter springs... my lift isn't high so I retained the use of my stock springs and it does well at 7,500, the stock rev limit is @ 6,200. The stock peak power was @ 5,500.

Originally posted by A20A1
also cams with high lift need tighter springs... my lift isn't high so I retained the use of my stock springs and it does well at 7,500, the stock rev limit is @ 6,200. The stock peak power was @ 5,500.

So your engine is stock and its redline is 6,200 but you turn it 7,500?? The car actually holds together after doing that over a period of time?

Maybe I didnt understand what you said; also I dont know your mods.

I'm not saying thats impossible, I am just curious. I sure want to know what you did to get your motor to turn 7,500 *jealous*:D

yeah the motor if fine... I had to get an aftermarket tach (autometer) for precision and adjustable red line and a Air fuel ratio guage (autometer) just to see if I'm getting a rich mixture @ high rpm's.

I have changed my camshaft with a hot racing regrind from Colt cams.

I've posted the cam specs on my web site.

I've changed my old keihin carb to a weber 32/36 downdraft.
good thing about carbs is that you don't need a cpu to controll them so I dumped my cpu which also housed a fuel cut switch that acted like a rev limiter.
I also just recently ported my intake manifold, and boy did it open my car up.
2.5 cat back... still waiting on light speed headers.

I don't have many new pics on the web site.
:)

there are other mods here and ther I just don't know them off the top of my head.