I've got a zz4 crate engine with a decent cam in it. How much HP have you TPI guys squeezed out of your system? I hear the TPI system is limited but how limited is it? I sure dont need 400hp, especially when a complete TPI system is going for a few hundred on ebay.

 

My 89 IROC has a stock block and heads, flat top pistons, minor porting on heads and intake, 212/218 cam, TES headers and a custom chip and I got 237 RWHP.

 

The ZZ4 with a carb gets 355hp, from the information I gathered, adding a STOCK TPI to any carb tested engine, reduce the horsepower by 30. There is a good web site on this try this My 85 Z28 and EPROM Project this guy did 13.6 in the 1/4

 

I'm moving this to the TPI board, since this has nothing to do with an alternative port intake, but rather an althernative to the L98 long block.

-- Joe

 

I hope there is a problem with your engine, because that number seems really low. What kind of dyno was it? Dynojets seem to read high, while the others read low. We have a CA member with stock untouched heads and cam, Edelbrock intake and runners, and SLP 1 3/4" headers making 260 RWHP on a Dynojet. The car has gone 13.95 in the 1/4.

To the original poster, please use the search. There are a thousand posts on putting TPI on a ZZ4. My own result was 13.23 @ 107.50, and 318 RWHP, 419 RWTQ thru a T5.

 

running the stuff in my sig ..without turbo . It got me 251/318 to the wheels with no tuneing. Just the ZZ4 cam and the intake stuff with SLP headers.

 

Here is an example for carb. reference.Stock zz4 with 650DP and 1 5/8 headers.

271rwhp
368rwtq


You need to upgrade at least the base plate and runners to get the full potential of the zz4 or run a stealth ram.

 

Be avised that the 355hp zz4 crate with a carb is dynoed at the flywheel and not the wheels and under the best conditions. But yes the carb version will do better from breathing through a better intake. So if you go with a high flow intake and large runners you will see about the same results, but with instant control of fuel and spark though a laptop.