Hello-
Just got a '83 RX-7 track car street ported 12-A, looking for input on how far to
advance ignition timing safely. Also thinking about NOS.(!!!)
Thanks,
John

 

it depends on a lot of things, air intake temp is a big factor as well as other things that can affect this. start with 25 degrees btdc and see if you can go more. i woudl suggest going to a dyno to see where the car is happy.

 

100 Octane Race Fuel- Cold Ram Air
Thanks,
John

 

for me at 2300 ft elevation 26 degrees went pop at the top when she got a little lean. 24 is a good place.

-Trent

 

you popped an na?
how lean is a little lean?

 

i don't know why, but that's just funny to me right now.

 

run 25 degrees no split. get yourself the analog Westech egt gauge and mount the probe 6 inches from the exhaust flange at the engine. tune the jets for 1750 degrees F in top gear at the end of the longest straight.

as per Roger Mandeville. i ran this setup on my 12As for 6 years SCCA Nats and the Runoffs. we ran pump gas w it and made 259 flywheel hp thru a restricted to 38 mm twin choke weber downdraft.

obviously this is NA. i have no clue as to NOS.

howard coleman

 

On a n/a rotary, I run 24 degrees BTDC on the leading, with pump gas. I used 87 and 89 octane with a street port 12A engine, and 93 octane with a higher compression 13B motor PP motor.

100 octane race gas will make less power than lower octane gas on a 12A n/a rotary. N/A rotaries like fast burn (low octane) fuel.

 

Thank you for your input-
We have been running 1550 F EGT, thinking we were lean. On piston motors, we would be looking for 1250 F.