Fuel mixture to rich

Mike Gaskins

New Member
New at this game. Former big block gearhead. Took the GN to Dyno yesterday. I have green injectors, upgraded fuel pump, 3" down pipe, K&N cold air, 3 xtra rows on Intercooler, adj. fuel reg. Last yr car ran 8.21 on stock tires. Dyno showed max hp of 267.7 @ 4600 rpms with max torque of 368.6 at 3200 rpm. Air fuel ratio maxed 17+ at 2700 rpms, then started to bottom rapidly below 10 throughout the run. Don't know if these #'s are good or not. Tried to turn the fuel pressure down to 35lbs from 40lbs with no luck. Big block guys have no clue on what is going on and neither do I.

Somewhere in the 11.3 to 11.7:1 range is what you should shoot for. This works well for me on the street w/ 93 octane. Too many times too much fuel is thrown at a TR to try and cover up knock rather than going for a correct tune and reasonable boost levels. With race gas and higher boost you can sometimes go leaner. You still need a scan tool so you can carefully tune to this range w/o knock. Good luck.