Go with Low Z injectors (72lbs) and the Low Z box. It will idle like stock and leave you a ton of room for more power, and trust me, you will crank it up. Its like crack....you have to have more after the first hit .

Jose

 

AlexA, if this is the case then get a turbo .........unless changing pulleys is fun for ya.

 

I hate you guys. I thought I'd be happy with 400rwhp...it feels so slow now.

Low Z injectors it is.

I was thinking about traction on the street, so full boost at a low RPM would be silly...I just want to be sure I will get at least some form of boost (even if it's 3-4psi) before 3000 RPM.

-Alex

 

You hav to remember, at 500rwhp+ romping on it from 2k and revving it to 3krpm where it hits full boost will be very quick (like a second).

 

A friend of mine sees 3-4psi at 1400rpm with his T72. You shouldn't have a problem building 5-6psi below 2000 rpm with a T-76.

 

Ok, I'm convinced - it's the PT-76 GT-S.

Now, what compression ratio should I shoot for? Depending on the head chamber size, I can go anywhere from 9.3:1 - 10:1. This would be with an AFR 220.

-Alex

 

9.3:1 (I am guessing due to lack of enough piston -cc you are stuck huh). Keep it as low as possible to keep it pump gas friendly.

 

These are the pistons :

http://161.58.59.82/pics/pulling_hea...3/DCP_1836.JPG

For now, I can only guess there size. I want to say -10cc. They are JE SRP pistons from about 2001.

-Alex

 

Look like my -31cc pistons (or atleast -24cc). Way more than -10cc...

 

-24cc you think? Wouldn't match up with the setup...my CR would be really low.

4.03 x 3.875, 4.125" gasket bore, .055" gasket thickness, -24cc pistons, 58cc heads (best guess), .005" deck clearance = 9.5:1 CR

The motor is MORE built, so I assume he would shoot for about 11:1. I think -31cc would be a dedicated FI piston. I might have to pull the heads again and measure the deck height, piston area, and heads. Any idea how I can measure the pistons while in the block? Clay and water??

-Alex

 

Here are my -31cc pistons...look similar huh? Your s appear to have a little less dish when you see the cut for the exhaust valve (probably the -24cc). If you had -10cc, it would just be reliefs for the valves, not the big dish.

 

There are more pictures in that directory. Here is a close up before I cleaned them with WD-40 :



I want to say they look about half the depth of your pistons, but I'm not sure. Maybe a -15cc is a better guess? When I looked at a JE PDF catalog, they showed there non-FI inverted dish pistons were about -14cc.

-Alex

 

If anyone can take a stab at the CC of the pistons above, please let me know!

-Alex