How many lbs of boost and gasket thickness?
 

I am a noob to FI. But I've read a decent amount to better understand FI for some years now. Its 97 LT1 M6. I know the gurus here are going to lay it on me, so here it goes: I ran across a unbelievable deal on craigslist. Its a new garrett 70mm turbo with all the new plumbling, intercooler etc for dirt cheap. My question is how many lbs of boost should I run?

Now, the thing is the motor was built for NA, but when I asked about CR last year many of you said that my CR was too low and just keep it that way til im ready to boost. Well, I think the time has come. This is my first turbo setup and I have a good understanding of turbos and how they work.

The motor is still on the engine stand out of the car. My CR currently is 10:8, with the thickest non-copper gasket I can get around 10:2 CR. Now they do have a copper gasket thats .080 thick and that would put me around 9:89 CR but I've heard from many people that copper gaskets will leak quicker and re-torquing them down would be b**** in a 97 T/A. My other question is will a .066 head gasket kill my quench? Or is it not as important as NA?

My current cam has a 110 LSA and I am trying to find something with at least a 114 LSA and I can get my ECU retuned for free. There are just some technical things that I do not know that maybe yall can help me out with. What do you think?

Help LOL!

what kind of fuel?

Whatever works best. E85 or 93....

E85 is king. You can get away with a lot on e85.

On E85 you could probably leave your compression as it is and boost 8-10psi without issue (with intercooler). On 93 you would really want to get under 10:1. Preferably under 9.5 and using a REALLY thich gasket is a really bad bandaid. New pistons or bigger chambered heads are really a must.

Quench doesn't really matter for FI. It's a min max thing for N/A to get the mixture to burn better.

Your current cam will bleed of a lot of boost with 30* of overlap.

The pistons are forged -16 dished. So basically, its ok that my current CR is 10:8 and I'll just have to run E85 with the current .040 head gasket? So if I jump to let say .060 gasket is that still considered a bandaid? Thanks for the input!

Hey! Anybody else have any input on this?

I just did the calculations and a 383 with a 0 deck with a -16 cc piston .040 gasket and a 62cc head comes to 10:1 and a .060 gasket puts it at 9.6:1 so unless you have some small chamber heads, I don't know where you are getting your numbers from.

You have in your sig TFS 215 heads. Did you port them? Trickflow doesn't make an out the box LT1 215cc head except for a SBC and an LS1

The heads were ported, and the CC is 55 on the heads. So the gaskets I just measured earlier today was .056 which is .048 compressed. So my current CR is 10:6. I wish they were 62CC at this point..............

Sell the cam and heads and use that money to buy a more boost friendly top end. Problem solved.

Almost 11 to 1 and 17 psi. E85 is magic fuel. Acually I made my best power at e68

Wow........ Almost 11:1 and 17psi??? Thats great! I will be running E85 as well. Now, how much RWHP were you putting down? Im thinking with 10:6 I could get away with 14lbs but that is with not pressing my luck too hard and tune the s*** out of it.

Yep that is a easy problem solved but, I dont have the time to wait around to see who's going to purchase my heads. Nor spend the money trying to purchase new 1's. I would get the heads CC'd out to bout 62CC if that was the case but time is the issue here. New turbo cam already on the way.....

Well if you're gonna pull the heads to have them CC'd out that's time and money as well. I don't think you'd have much of a problem selling the heads you have as long as you price them reasonably. Or just keep the compression where it's at and run E85. Good luck either way bro...