giff

Anyone been able to succesfully advance the timing on a TPI motor? I read a road test on my 91 formula that said they were retarded a few degrees from the factory.

same article said that although you can't override the "computerized" timing you can still successfully advance initial timing for hp gain.

anyone had any luck with this?

giff

Berlinetta00

Try changing the springs out of the distributor as well as turning the distributor housing (if possable)

-Berlinetta00

jwfirebird

iTrader: (2)

the springs set how fast the timing advances. i wont matter if you rotate the disributor, the computer will compansate.

AJ_92RS

There aren't any springs on a CC dist. It's all electronic.

You can advance the base timing. The only correct way is to take it to the strip and keep advancing by 2* at a time. As long as your MPH gets better keep going. Once your MPH drops, back it off 2* and your set.

The reason is once the engine starts knocking, the ECM will retard the timing until the knock sensor doesn't sense any knock. Once it does, you've gone too far, and it will retard the timing as much as 20* to get rid of the knock, and your MPH will drop.

You can't really use your ET because as power goes up, you may lose traction, and your ET will drop.

jwfirebird

iTrader: (2)

i never fooled around with my car when it had a computer but, i have with my truck and if you use a timing gun you can watch the computer change the timing right back if you rotate the base.

Tim Burgess

Adjusting the base timing by turning the distribuor, or by using an MSD adjustible timing module, as I use for my nitrous system, will offset the entire spark curve by the amount of adv or ret that the base timing is offset by. The computer will not compensate for an adjustment in base timing. It uses lookup tables in the PROM to determine total spark adv based on RPM and vacuum.