I have mpt right now. 89 prx because 89 octane was in the tank. I'm low right now and will mix 91 when I can get 89 as low as possible. Once I run the mix down, I will fill up with 91 and switch to 91 prx.
I still would datalog/check your tune if I were in your shoes regardless of who you're tuning with. Your car isn't the one at MPT's dyno and there could be some tweaks that could make all the difference in the world. See this starting from post #26: http://www.mustang6g.com/forums/showthread.php?t=54648&page=2 Every car is different and there are too many variables between vehicles. That would mean every reputable tuner on this site who has customers who datalog are doing something wrong (which I highly doubt) if they could just have a "one size fits all tune" for a list of mods and be done with it (of course that's not how it works). If you have 6 months of free tuning updates (which should be free for life IMHO for n/a vehicles as most tuners do it) you might as well use it. Datalogged tunes are way better than a canned/base tune (even if the tune you have now is significantly better than stock). Datalogging is doing it right the first time and prevents you from swapping back and forth between tunes. It might really help your 1/4 mile times.
It's true, datalogging might help, I can't deny that. But I feel that would be pretty much min/maxing for like 0.1-0.2 sec. I'm rather certain that my problem is with the basics of launching and shifting. I will have someone else run my car on Friday and use that as a benchmark.
It can be more than that once it's dialed in. But I will agree it's a combination of things that need improvement and the same could be said for anyone who is at the drag strip practicing. I do believe the traps should be better with a tuned car (even on lower octane). That is where the datalogging part comes in if your traps do not increase after this experiment.
