In a big dilemma about heads/piston choice for turbo setup...

Originally I was going to sell my LE2 heads and get a set of trickflows for the new turbo combo going into my car with the 383. I was going to run them as cast for a while then port them down the road. Now that I've been looking around I'd really like to upgrade to a set of AFR 227s down the road, which would require me to keep my stock castings for now. These castings are no slouch at 274cfm compared to the trickflow as cast 25x. I know the car will make more power on the stock ported casting over the trickflow as cast, but should make more power on the ported trickflows, and even more power on the AFRs. The problem I'm having is I dont know what I should do. If I stick with the stock casting (i measured them 52cc) I'm going to need a -39cc dish piston to get me to 9-1. If I use those same pistons with an AFR 76cc head I'm at 7.4-1, and TFS 62cc chamber I'm at 8.22-1. If I stick to my stock castings and -31cc piston, I'm at 9.64-1, using TFS heads later would yield 8.8-1, which is where I want to be, and AFRs would put me at 7.8, too low. Now I dont know how much can be taken out of either the AFRs or TFS heads to get the chamber size down, been searching and seeing a lot of different numbers thrown around, then hearing that going too small on the chamber of the AFRs will screw the shape up, ah I dont know what to do :confused:

This is going to be the setup: my same forged bottom end (eagle crank and h-beams), with JE low compression pistons, Bret's cam, realquick's hotparts, and most likely a pt76gts. Looking to make 800-900whp when it's all said and done, but will settle for lower numbers now. There are just so many ways to go about this it's driving me nuts.

Selling your ported stockers will cover the price of porting the TFS, see that was easy.:D


David

Selling your ported stockers will cover the price of porting the TFS, see that was easy.:D


David
Haha, no it will cover the price of the heads as cast setup with springs and what not. I cant afford to have them ported if I want this beast running in the next couple months for racing weather.

It will still go faster with the trick flows because you can run more boost, have them ported later.


Flow numbers do not tell the whole story about a head and how it works on an engine.

David

It will still go faster with the trick flows because you can run more boost, have them ported later.


Flow numbers do not tell the whole story about a head and how it works on an engine.

David
That's all I needed, just a little reassurance I wasn't making a mistake, cant wait to get it running :D

TFS for the win....

Although cylinder head choice is always an important factor, it's not as important on a forced induction motor as it would be on a normally aspirated or nitrous motor. The ability to rid the motor of exhaust gasses (ie proper cam choice and an exceptional flowing exhaust system) play a crucial role in engine power when boost is applied. The fact the the turbo/blower makes its own wind will in many ways make up for the lack of a "perfect" cylinder head. Choose the cylinder head/piston combination to achieve the c/r you want and go from there. As FASTFATBOY stated, you can always have more headwork done in the future.

Don't make the mistake of comparing power production of 2 sets of heads based on peak flow. We have seen almost no correlation (within reason) between peak head flow and horsepower.

Mike

Don't make the mistake of comparing power production of 2 sets of heads based on peak flow. We have seen almost no correlation (within reason) between peak head flow and horsepower.

Mike
So you're saying that the TFS heads can have the same potential as the AFR 227's?

So you're saying that the TFS heads can have the same potential as the AFR 227's?

Depending on who ported each set... then they could be equal.

Aim for 8.5:1 if possible to run decent boost on pump gas.... if the TFS heads get you there, then I'd do it.

Jon

So you're saying that the TFS heads can have the same potential as the AFR 227's?

Could be, but we wouldn't know for sure without putting them on the dyno. Low-lift flow tells allot too. Compare flow at .200 - .300 lift.

Mike

Depending on who ported each set... then they could be equal.

Aim for 8.5:1 if possible to run decent boost on pump gas.... if the TFS heads get you there, then I'd do it.

Jon
-31cc dish on TFS will put me at 8.79, you think I should go lower than that?

-31cc dish on TFS will put me at 8.79, you think I should go lower than that?

I think thats fine!