Hi there,

My car is a 1989 Pontiac TransAm GTA 350ci TPI (165 ECU). We've been burning and optimising our own PROMs for a few years with good success. I'm wondering what we should use as a base for the new ZZ4 Crate engine we are installing.

Should we use:-
1. Stock 1989 GTA bin.
2. Stock 1989 Corvette (Aluminium Heads) bin.
3. My own custom burn we were using on the original L98. The other modified intake parts, ported plenum, Lingenfelter runners, Throttle Body, headers etc are all being transferred to the new Long Block.

We are aware that no matter what base is used that it will need to be optimised but are looking for opinions on what is the best base, particularly for the run in period.

The main worry is the difference the ZZ4 cam makes, along with the higher compression ratio, to the fueling and timing the engine will require.

Many thanks for any help you can offer.

DrG

 

http://www.eecis.udel.edu/~davis/z28/index.html

 

Run the camaro/bird bins.

Never been a fan of all the timing stuffed into the vette bins.

Most stuff I've seriously played with ended up with a lot less timing than the vette version

later
Jeremy

 

Agree. Actually, I generally find the Vette (especially the ARAP bin) needs a major haircut in the spark tables. I find it better to just add spark (if necessary) to an F-body bin.

 

I would start with your latest custom burn and go from there. Both engines are 350s, right. Be carefull to data log immediately and hold off from going it WOT until you have more confidence in your Eprom. To be on the safe side at WOT, you could add a few % to the fuel when the ECM in in PE mode.

 

Thanks chaps,

I think I'll start with the custom modified bin I was using with the original modified L98 and just carefully datalog and adjust to suit.

Doc, both are 350's. Both have L98 heads, original steel, ZZ4 aluminium. It's really the cam and the compression ratio that re different.

Any more suggestions/points are welcome gentleman.

 

Well the new ZZ4 crate engine is in and running. I'm doing some gentle run in miles on the above mentioned custom bin. I'm not using high revs or putting the engine under high load and it's running really well.

I'll keep things updated once I'm logging/burning.

 

Just curious, would you have used the vette bin if you had aluminum heads?

 

No, too much timing IF you want to keep the knock count and knock retard down. I find the excess timing ends up causing the Knock Sensor to pull more timing to end up with less "effective" timing than if you just had less timing in the spark tables and didn't "irritate" the Knock Sensor too much.

 

Thanks bud!