aode08

"tune" if by hand -carb.

EFI 5.0 = Chip and Laptop, with dyno. It doesn't take the ecm that long to start changing the injectors pulsewidth to try and stay within the programmed ratio from the factory.



Dont know what you have in plans for the car as far as mods in the future, but this typically will cost you about $450 , so do it at the right time.

67mustang302

Whatever makes you go fastest down the track without damaging the engine. You could run lean and make the best power, but run hot, and eventually burn up the pistons and/or exhaust valves. Also it never hurts on a street car to tune a tad richer than it needs as a safety margin for the occasional fuel batch that's lower octane than rated(this happens a LOT). You'll never notice the 5hp you lose top end on a street car for the wider margin of safety.

94StinkinLincoln

im going to kill the mis info now...some cars, yes N/A cars, will make more power at 9.5:1 than 13.5:1

i personally will not run my n/a car more than 13:1 WOT just for saftey and parts life.

without a tune i was in the 15's, thats not good wot.
cruise i wont go over 15:1 b/c any more than that stuff is getting hot.

HACKGT350

ok there is a lot of right and wrong info in here. 14.7 is stocheometry like stated above. 14.7 is the point where engines run the cleanest emissions wise atleast for NOx. most new cars are running 16, 17-1 now a lot of toyotas and hondas are running 18 which is pretty scary and this is all for gas mileage but is increaing NOx but no one cares about that anymore. a performance n/a car like our mustangs should run about 12.5-1 at wot which a tune. stock we will be around 13, 14-1 at wot with out hurting the engine going higher at wot will start hurting the engine. forced induction you want it to be 12-1 or less but not so much that the engine runs like crap this is where all the tuning comes into play. every engine will run different so every engine wont run best set at the same setting