My R was tuned on Chrome with 93 octane pump gas. I'm not sure how "safe" the tune is for the A/F ratio, but it was done professionally, and done the right way. The guy that had the car before me is who had it done, and it runs like a champ.

Fast forward to me owning the car now, and where I live, there is only 91 octane at the pumps. The car is very quiet, so I cannot hear pinging, but just to be safe, I've been using bottles of octane booster every tank of gas.

My question, is this an ok thing to do for now? Just keep using the octane booster? If so, what's a good brand. Keep in mind, I don't want to add a 20 dollar bottle of booster to every 30 tank of gas, so I've been going a little cheap with the 5 dollar bottles. Also, if a bottle treats up to 21 gallons of fuel, what do you think about pouring in half of it every tank. That would save a little money that way.

Anyway, I know that I need to get the car re-tuned, but shops are far and few between here. So it's gonna be a while. Any suggestions? I also have the stock ECU, I suppose I could just put that in the car, and then the knock sensor would take care of the timing for me. Maybe I should just do that. The Chrome tuned ECU is a P28, so it doesn't look for knock.

 

if im correct octane booster really not needed. there isnt that much of a difference between 91 and 93 if im correct if not correct me

 

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if that is the case, that's awesome. I hope so. I just don't want to hurt the car. It has a Spoon crate motor, and the compression is 11.6:1 I believe? Higher than stock. It has stock ITR pistons, but a Spoon head gasket.

 

you will be fine with 91 then. i have a friend that has the same setup and he runs 91 runs great

 

91 octane is the min rating, it most likely is a little higher. A lot of tests show 91 to be closer to 93. You could always go out and by a five gallon bucket of 101 race gas and add a gallon to each tank fill up, should be slightly cheaper than the "cheap" octane boosters, with more reliable, predictable results.

 

how much hp are you making? what has been done to the car?

 

it makes 190 to the wheels. Stock exhaust and intake. Tuned on Chrome. The bottom end of the engine is untouched, but the head has cams, and valves, etc. And the head gasket which raises the compression.