Digital Tuning Octane Question

[blk97gt]

Hi I have a 97 gt with PI intake/cam, UD Pulleys, BBK CAI, MAC catback, and I had a question about custom tunes. The car is currently set up to run a 93 octane tune (I have a SCT Tuner with a custom tune from American Muscle) and was wondering how much of a difference the 93 octane tune really makes compared to 87 octane. Any suggestions?

 

[chasM]

Well, coincidenally I got an SCT tuner with a rear end package last May for my 2000GT. I tried everything in the book to get the 87 octane tunes to run my car, but they were terrible. Then I tried the 91 octane tune with prem gas and was shocked at how well it worked. I still use the 91 tune but have it modified for regular gas. For me I had no choice but to do it this way. I get good MPG too
My car is stock so YMMV, but if in difference do you mean power? I have not dyno'ed my car, but there is a very noticable difference in how long I can smoke the tires using premimum gas and the unmodified 91p tune.

 

[84Ttop]

the difference in the tunes should be mostly timing based. less total timing with the lower octane fuel to prevent spark knock and more timing with the premium fuel for more power

 

[blk97gt]

I was wondering if it was really worth the extra $$ to run premium over 87, but from the way that it sounds it is! I plan on using my car as a dd this summer, so I wasn't sure if I would be alright running an 87 tune to save some $$ or if its going to be a lot better to stick with 93.

 

[sneaky98gt]

On a stock-ish N/A car, there is some difference, but it's really not much. I'd say maybe 8-10 rwhp and 12-15 rwtq. Enough that a keen SOTP meter could tell a difference, but not enough that you could really tell it if you didn't know about it. 25 degrees of temperature difference will make more difference in power.