tuned for 93 octane, but moving to 91 only area.

[henrysan]

running a garrett 50 trim with full supporting mods, currently tuned for 93 octane at 21 psi. will be moving and only 91 octane available at stations. e85 is available but not sure if ready to make the switch. will the car be ok for a while with just lowering boost to run 91 or would a re tune be mandatory?

 

[horizontalkev]

I live in an area with 91 tops, with NO ethanol. You should atleast lower boost.

 

[gofer]

A 50 trim running 21psi is right where I'd expect to see boost levels on 91oct, the thing you should be concerned about is timing advance and AFR's.

 

[Pipnorcali]

Every car is gonna be a lil diff. But I lower mine around 3-4psi on 91 piss water

 

[BurrowZ]

I'd just tune more conservatively for the 91 in the meantime. Lower timing advance and maybe a little easy on the boost. Just until you switch you E85. Yes, you really want to switch to E85. You'll wonder why it took you so long to do it.

 

[henrysan]

alright thanks guys!

 

[boostle]

Look around for pump 100 and add 3 gallons to each tank when you fill up. It's annoying but at least you have the correct fuel until you retune it.

 

[Lou98GSX]

get meth injection

 

[braden26]

Meth injection will solve your problems for sure. We only have 90 octane in Alaska so quite a few people go the meth route.