My car is an '86 IROC, and I replaced my driveshaft with an aluminum one from an '89 IROC. I can feel the difference in rotational mass. However, I noticed that my engine seems to be knocking quite more often when accelerating. Does installing an aluminum driveshaft have any impact on ignition timing? I just wanted to ask before I start fiddling around with the timing. Please advise. Thanks.

 

how exactly can you feel the difference in rotational mass?

 

The knocking must just be coincidence. The driveshaft change should not affect engine performance.

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FORMULA 350 TK
Southern California 3rd Generation F-Body Organization©

 

Thanks Tom. I'll just go ahead and play with the timing until I get it right. Someone
told me to check the knock sensor too. The car has 200 thousand miles and never changed.

Larry: To answer your question, the car just "feels" lighter when I accelerate. I haven't really had the chance to experience if it makes a big difference in performance because of the pre-detonation.

 

R U sure that your are not feeling lighter because of less money in the wallet.

A person's "butt" can detect a 2-3% difference in acceleration, but the only way you can objectively tell is quarter mile times.

I guy in high school ran a 20.8 in a v-6 Bobcat (took third place in high school drags out of a field of 500, luck phu˘ker!). He rebuild that POS v-6 (~$800, I told him to V-8 it), and thought it was so much faster.

He ran the car again in High School Drags and best time was 21.1.