Short update - made a pre-empted trip to the chassis dyno.

Started working on a low octane (89) tune in case I ever get stuck in the boonies again with crap gas.

Tune and exhaust differences (to shut the thing up) -200HP @8 psi from last round 3 years ago. Drop the exhaust at the bottom of the down pipe and add 2* timing added +110HP @10 psi and lots left to go. total timing is just 12* under boost. (420 rwhp)

So back to trying different exh. configs that 1) flow well enough & 2) are quiet enough to keep me sane.

Have another day booked soon - this time with 94 octane in the tank - we'll add in timing and be back to the numbers from 3 years ago. Then add more boost.

Last will be to tune on M100 which is finally working.

Last edited by efi-diy; 05/24/13 03:04 AM.
51 GMC 4.2 turbo
Can't solved today's problems using the same technology/thinking that created them