Trying To Build A Low 10 Sec. Ride

[pac663]

First of all I'm not looking for a Cent vs. KB discussion:p I have a 90mm MAS that will run into a 70-75mm TB. The KB@17-19 psi will flow into the new bottom end and pistons through a set of AFR 185 heads. The cam might be tricky because of CA. smog laws. To keep the motor together I'll be running 98-100 octane with water injection. The car will weigh approx. 3275-3300#s. OK, lets here it.

Thanks

[Simi Stang]

What is your suspension set up like? As long as you set that up properly, for drag racing...and some sticky tires...You could pull 10s. Not sure about low 10s...but maybe.

[pac663]

Tokico drag struts, stock front springs,stock rear springs, Tokico 5 way shocks, sperical adjustable upper CAs, height adj. lowers with sperical on the axle side, 6 point roll bar, subframe connectors, 28x9x15 ET Drags. To run 20 psi, what CR pistons should I be looking for?

[jonnyk]

More octane wouldn't hurt. I would go around 8.5:1 compression. You're gonna have a hell of a time hooking up that kind of torque...your timeslips will all be in the chassis.

[Mustang_289]

Hey pac663, I'm curious...

Our 88GT project car my son and I are building, we just put an x303 cam in with Typon intake. My son has done a lot of research on heads and he wants the AFR 185s.

I noticed in your post that you're running the 185s, we've been told by AFR tech support that we need to notch our pistions. Just curious to see if you're running a stock bottom-end, and whether or not you notched your pistions.

AFR said with the amount of lift, notching is required.

[pac663]

I ran them on with the stock pistons for over a year without any problems. After the heads were surfaced then the valves started hitting at least 2 pistons. I have since taken them off until I can build a motor for them.

[Mustang_289]

This is encouraging, we really want the AFR185s as my son did the research and their kick butt heads. We're not ready for a stronger bottom end at this time money wise, we're just trying to step up performance on the top end with stock bottom.

My son picked out the X303 cam, Typhoon Intake, and AFR185s. Got the Xcam and Typhoon intake installed, after we converted to mass air. Motor loses power in the 4K rpm range with the radical cam installed. We believe it's the stock heads that are causing the problem with lose of power. Maybe a floating valve with so much lift on stock heads.

need to fix this problem, didn't want to buy AFR165s and then buy the 185s when we're ready for the new motor. After reading your post, sounds like we can chance going with the 185s on a stock bottom end?

[pac663]

Not with that X303 cam. I have the stock .444 lift cam. If you put the 185s on with that cam, you will ahve problems.

[Mustang_289]

Thanx for the info, I guess we're back to our delima - we want the 185s, but need to do something to fix our lose of power caused by our current config without buying two sets of heads. One for now, 185s when we get our bottom end crate motor with notched pistons.

[jonnyk]

Maybe look into a ported small valve head? It will cost a bit more but then piston/valve becomes less of an issue, and you can still move a lot of air with a 1.90 sized valve.