1MoorTym

How many of you are using a ZZ4 with the stock chip? I've rebuild my 89L98 to ZZ4 specs (cam and valve train) and wonder how its going to perform with the stock programming. I'm keeping the TPI setup, but added an Accel base, 23# injectors and removed the pre-cats.

I know for maximum performance the chip should be replaced, I'm just looking for any gotcha's with the stock programming before I fire it up.

h rocks

1Moor, with a mass airflow car, you might be surprised how well it adapts. I'm not an expert in this area, but you may want to try the following: disconnect the battery for five minutes if it's not already been off for a while. Start it up and see if it will idle on it's own. Even if it's rough, let it run for another five or so. Next, go drive it for at least 20 miles until it learns how you want to drive it. See what you've got, then make your next decision. PS. I presume that along with the big base, you also installed the runners? If not, it will be a very limiting factor. I ran a ZZ4 race car on a roadcourse a month ago, and it had Brodex heads along with the cam and headers and stock base and tubes. It just ran out of air at 4900. With that cam, heads, headers, it should have easily pulled to 5500 or more with a big base and runners.

18carfan

I'm running a stock chip in my '85 with a ZZ3 right now. It runs fine really. MAF cars adapt a lot better to engine mods, especially in non-WOT, closed loop conditions. I believe that I'm running a bit lean at WOT though. The headers appear to have gotten hot a few times and that's the direction I'm headed to take care of it. I agree 100% with h rocks on the limiting factor of the TPI intake setup. My intake setup is stock except for the SLP runners and the ZZ3 simply runs out of breath at around 4800 RPM. I know for a fact that the ZZ engines will pull hard well past that. It does pull strong on the low-end though just like a TPI setup should. I haven't put a lot of time into modifying the MAF chip. I've spent a lot of time tuning and learning about MAP systems more and have put off any mods to my car until I convert it to a MAP setup. I do have a chip that Craig Marcho has set me up with to try in the meantime though. I hope to get to the track soon to see what difference it makes. Anyway, you should be fine starting off with a stock chip. It will probably surprise you how adaptive the MAF setup actually is just like h rocks said. Good luck1! -Jeff

1MoorTym

I actually left on the stock runners because from everything I've read/heard, the base is the biggest bottleneck in the system(followed by the runners). Besides, the runners are easier to replace later.