Hey Guys I am new to the TPI systems. And well long story short I am converting a 85 TA into a 87 GTA for my sons first car. A father son project if you will. Well, I have rebuilt the original motor and had to bore it 30 over. I put forged aluminum pistons with CR of 9.7 Now I am wondering should I go back with the 22 pound injectors or what. Any advice here and some guidance would be greatly apprcitated.
Thanks Mickey

 

It's really impossible to say without knowing the rest of the setup. What heads are you running? Cam? Intake/runners/plenum?

Basically, are you doing anything to the engine that will increase it's airflow by much? If so, then more fuel will be needed to match, which could mean higher flow injectors. If not, then 22 pounders will probably be fine. You can always bump the fuel pressure up a little if a tad more flow is needed, provided that you install an adjustable fuel pressure regulator.

You might look into a set of Bosch design 3's, even if you do wind up staying with 22#. They have a better spray pattern than the stock multecs, and can be had relatively cheap. Here's one example:
http://cgi.ebay.com/ebaymotors/LS1-I...item4143e90a0e

You can tell the design 3's by the really narrow injector body. I run bosch design 2s in my car, but 19#, since it's a 305. They're still better than the stock multecs, but the design 3's are supposed to be better.

 

Hey Mickey,
if you are not going to be making any other major changes to what you have now then the 22lb injectors will be fine. We like the bosch design lll's hands down, we receive nothing but positive feedback on them. The bosch lll's are a little shorter than the stock injectors so we have developed a newer version that completely takes care of the fitment issue (length). We sell them for $160 for the set of 8. Look at the attached pic and you will see what i mean.