Inabj2

Theres no interesting topics on this subject so I had to bring this back from the dead.

I had trouble passing emmissions. high nox readings. So I retarded timing to about 3 degrees btdc. This is the point where the car is drivable to about 5300 rpms. Anything more retarded then this... Car does not drive well. It drove this way for less then 10 miles since I dont think its good to drive it like this.

It originally was at 10 degrees btdc.

I advanced timing to 15. And holly molly what a difference it makes! Feels as fast as when my nissan was retarded to 10 degrees (normal is 15. again for same reasons.)

I wonder if I can do more then that..

There is a very noticeably difference between 10 and 15 degrees. And still no hesitation or missfires or anything to indicate or knocking at 91 degrees.

tjcetanyan

I would like to know if anyone has any more information on this topic. Can the timing be advanced more than 15 degrees, or is this the limit on a GE block. I would be interested in finding out how much people have advanced/retarded timing and their gains/losses.

Soarer.jzz

Most cars shouldn't be taken past 15 deg or so. mainly because the valves will start to lope and it will not idle unless you are holding the gas or adjust the throttle cable to do it for you. you would also need to take off your rev limiter to get the full benefit of the timing advance. think of it like you are moving you power band up and down with the advancing and retarding. the more advanced you get the higher you can effectively revv. But you will have loads more torque if you retard it a bit. just be aware that you can easily float your valves this way unless you have higher rated springs and supporting mods. If you are running n/a with bigger cams and lots of valve work and have a higher revv limit. then maybe take it up to 20-22. even then only if it is a track car. if not then take it back to 10-12 for DD. IMO