Difference between 91 and 93 need help!

[roush123]

I just got into a 2003 cobra my first cobra actually and its currently tuned to run on 93 octane. I've been running 91 in it but haven't drove it much cause of whether and I don't know if I'm leaning the engine out so much that in hurting it? Being from Kansas the amount of gas stations that actually sell 93 are few and far between. Anyone have any suggestions on a place to get 93 or a place to take it that's relatively close to Kansas to change the tune for 91? Not sure what to do need help!

 

[98 Saleen Cobra]

How much boost and what is the timing at?? Typically you can just pull 2-3 degrees of timing out and it'll be fine. But if you're running like 19psi I would highly recommend lowering boost regardless of how much timing you pull

 

[roush123]

Curently running a conservative tune at 17lbs of boost not sure the timing

 

[roush123]

2.3 L wipple 3.0 pulley
Nx wet 100 shot
10 in air intake
Accufab throttle body
Bassani o/r x pype
Bassani as cat back
Ba3000 maf
60lb injectors
Fore return fuel system w/ walbro gas342
Black gord ford heat exchanger
Spec clutch
Fidanza flywheel
26 spline input shaft
H&R race springs
Steeda subframe connectors

Here's a mod list... I just bought this car already set up like this so not sure where he had it tuned he was from Iowa and had it tuned to 93 since Kansas doesn't sell 93 very many places I'm trying to figure out the best way to figure get it setup right for 91

 

[svtshadow]

good call on getting the tune for 91oct. In my book $5000>$500!

 

[roush123]

good call on getting the tune for 91oct. In my book $5000>$500!

Yes sir now to find a place to do it any suggestions?