Octane for ZZ4?
Thread Starter
Racer
Joined: Sep 2001
Posts: 371
Likes: 1
From: Nashville TN
Octane for ZZ4?
What octane are you running in your ZZ4? I'm running 93 with no ping problems ever with 12 degrees timing initial with 33 coming in at 2,600 rpm. In the interest of cheaper gas, is anyone running less?
Drifting
Joined: Jul 1999
Posts: 1,542
Likes: 43
From: Plano TX
Re: Octane for ZZ4? (stngry63)
I run the stock 1980 L82 rochester that came on the car that I now have the ZZ4 in. The point is that I have made no changes to richen the mixture to cover up detonation.
I did notice some detonation at part throttle with 91 octane with stock timing. If the heads had an EGR port, an EGR may have resolved this since an EGR valave helps reduce detonation at part throttle. I then went with a new vacuum advance unit that has less advance at part throttle and this eliminated the problem. I have yet to do a dyno run, but the engine stills runs great from a HP street motor.
Dave
I did notice some detonation at part throttle with 91 octane with stock timing. If the heads had an EGR port, an EGR may have resolved this since an EGR valave helps reduce detonation at part throttle. I then went with a new vacuum advance unit that has less advance at part throttle and this eliminated the problem. I have yet to do a dyno run, but the engine stills runs great from a HP street motor.
Dave
