Hello i have a 2004 ralliart with a AEM cold air intake, cat-back exhaust, and a rrm piggy back ecu. I was wondering if i should be running 93, 91 , or 89 octane gas? Right now i am running 93 octane. The car seems to idle a little rough every once and awhile. Would 89 octane fix my rough idle with the piggy back ECU? Also is it safe to run 89 with a piggy back? Thanks everyone.

 

It depends what kind of tune you have really, if the tune is for 93 only you shouldnt be running any less than 93. If you run 89 octane and you start beating on the car youll get some knock. However, if youre tuned for 89 octane and you put in 93, its not exactly gonna be helping or hurting anything really.

 

how would i find out what tune my roadracemotorsports piggy back ECU is set to?

 

you would need to hook it up to a laptop. I'm not sure what connector you would need. I'm assuming some sort of I/O connector cable.

 

Call rrm !!! I'm prettty sure their piggys are tuned to 91 if I remember right. But like I said call them.

 

rrm would be happy to help! like lancer said, call them up!

 

i called them. They recommend 91 octane. I will run this tank of 93 out and start using 91 octane. Thanks everyone.

 

Man I love being right but it pisses my wife off , lol...

 

lol

 

glad you got it figured out !