Just ordered a JLT CAI through Lethal and wanted to get some opinions on which octane tune I should go with. I use 93 octane now since that is what the premium fuel in my area is rated at. The car is essentially a daily driver and it won't see track time at all. Am I right in assuming the 91 octane tune is just a safer tune? How much more HP would I gain with the 93 tune? Should I just play it safe with the 91 or is there really no risk on engine longetivity with the 93? Thanks in advance for your advice.
93 or 91 Octane Tune?
- Thread starter wjlane
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I'd go with the 93 if you have that in your area. Why wouldn't you? The 93 tune will be superior to the 91 tune.
Thanks for the quick reply. I'm wondering how much better is the 93 and am I putting the engine at any more risk than with a 91? I know I sound paranoid, but I just don't know enough about tuning to make an informed decision.
The gains you would see in the tunes with 91 vs 93 octane would be very minor. If you have 93 in your area, you would be safe using it with the 93 tune. If you are really concerned about say, bad fuel, you could run the 91 tune w/93 octane fuel for added safety margin.
The 91 tunes are mainly for guys like myself that only have 91 in my area that doesn't have ethanol mixed in.
The 91 tunes are mainly for guys like myself that only have 91 in my area that doesn't have ethanol mixed in.
I would estimate you would lose about 10 to 15 horsepower going with the 93tune.
I would lose power with the 93 tune or did you mean the 91 tune?
91 would give you a little area for wiggle room if you pick up bad gas... you cant always hear detonation.
Go with 93 the only things that may be different in the tune is like 1 or 2 degrees of timing anything else will be the same between the 2 gases. But either one is safe in my opinion I have been building mine for about 3 years now and it has thousands of hours on the dyno testing and seeing what works best what dont work and were you can push it.
Thanks for all the advice. I may just get both tunes and only use the 93 when I feel the need for a little more speed.
93 since it in your area...imo
91 tune. Sorry!
I bought my 08 with a 93 tune. In my area there is no 93 so off to the tuner. Car has a KB stage 3 and was putting out 700rwhp. We reduced timing at 3 different rpm levels and played with A/F ratio. On the 6th pull at 6200rpm car put out 680rwhp. So I only saw a reduction of about 20 horsepower and now have what my tuner called "A Very Safe Tune" With the Kenne Bell the car is a monster for just street driving and I can not tell any difference in the power or performance after the retune. I know we are talking about 2 different cars and horsepower output but my vote is stay as safe as possible so you can enjoy that car for a long time.
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Thanks for the info ram. Lethal says the GT500 has adaptive learning, meaning the car will adjust timing accordingly if the tune is 93 and either bad gas or 91 is put in. Still, I think I'll just err on the side of caution for now and go with 91. I can always get the 93 tune down the road if I want.
93...
Bringing an old topic up but have a similar question. I am looking into getting the new 127mm CAI by JLT. I have an older X2 tuner from a previous car and plan on using it.
1. I can get the JLT CAI and new tunes but only @ 91 octane tune. (They don't do higher than 91)
2. Or can get the JLT CAI and 93 tunes from another company but would cost $100 more.
Both are highly spoken companies and left out names since that is not really the issue.
Would the 93 tune be worth the $100 more? Also I can get 93 but it has 10% ethanol. Does the ethanol hurt/help? With the 10% does the 91 wash with me running 93 & the 10% ethanol?
1. I can get the JLT CAI and new tunes but only @ 91 octane tune. (They don't do higher than 91)
2. Or can get the JLT CAI and 93 tunes from another company but would cost $100 more.
Both are highly spoken companies and left out names since that is not really the issue.
Would the 93 tune be worth the $100 more? Also I can get 93 but it has 10% ethanol. Does the ethanol hurt/help? With the 10% does the 91 wash with me running 93 & the 10% ethanol?
interesting read... for future tunes on my ride.
The difference is about 10-15hp. I would do the 91 octane and play it safe. Never really know the quality of the gas you get or the actual ethanol level. If it is a daily driver the loss of 10hp won't matter. If you decide to run at the track add race gas then run the 93 tune
Is it bad to put Ethanol blended fuel into these cars? If so, can you explain why? I never have before in my old cars, but as I look to buy a 2011 GT500, I want to better understand this. Thanks.
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