So one of my planned winter projects is to take my 03 up to Function Tuned for a dyno tune (Uprev).
It is basically a dedicated track car, but I don't trailer it. I drive it back and forth from the track (VIR), about a 4 hour drive.
My question is, should I get the tune done for 100 octane gas?
Does it make a significant power difference?
Are there any significant down sides? (apart from the inconvenience - they sell 100 octane at the track, but i hav'nt seen it for sale any where else).
Any advice appreciated!

 

You can buy 100 low lead at your local FBO at the airport. We get people coming in all the time to put it in their race cars or old motorcycles.

 

I had a kid with an srt4 tell me he needed 100ll for a dyno run. He would mix half tank of 100ll and halph premium. i asked hm to text me the results and he clamed to have gained... drum roll please...
20tq and 40hp.

100ll has Lead wich gunks up your injectors and cats.

 

Tune with the same gasoline you will be driving.

 

It's readily available in unleaded. Leaded gas will kill the O2 sensors prior to causing any of your above issues. 100oct for turbo cars allows more timing and boost w/o detonation. His results are pretty typical for the slight additional detonation resistance (octane).

In my car I have run 100-104 a few times and it has offered no additional value in the 1/4 mile. When I run that gas I typically add 2 degrees to base timing (work my way up from 0(additional)). The only real benefit for an NA car is if your ecu is already pulling timing, etc. Unless the car is tuned for that additional octane via more aggressive timing (throughout not just base timing) you will see little if any benefit. Plus, at 10 bucks a gallon for 100-104 unleaded, it is hardly cost efficient.

 

Did you ever get the 100 octane tune? I'm tuned for 100 octane and we saw about a 7rwhp increase over my 91 tune. With the Osiris, you can run 91 to drive to/from events, then switch maps to the 100 tune and load her up with 100. 100 octane is $6/gal here versus ~$3.50/gal for 91, so I figured it was worth it (271rwhp/252rwtq).

 

if you drive to the track, then fill up there, how do you know what the mixture's octane truely is?

 

I'm not tuned for the ragged edge on 100 octane. That said, the two tracks I frequent the most are of well-known distances, so I can pretty easily whittle down the stuff in the tank to just a few gallons, then top off with 100. At the worst case, 5 gallons of 91 with 15 gallons of 100 produces a mixture of ~98 octane.

Sidenote: I usually leave it on the 100 octane program. It's certainly not a 91 tune, and I believe ZCG tuned the WOT portion at higher RPM for 100 so that me cruising around on the street at partial throttle / lower RPM is fine.

 

that makes sense and will work perfectly fine as you do it.

sad thing is someone will tune it to the limit on 100 then go take half a tank of pumpgas and add 100 adn wonder why their engine blew. lol

 

True. Then we must have faith in the knock sensor. . . If money was no object with the tuning, I'd have a drag racing program for 100 (aggressive) as well as my current "moderate" 100 program for road course driving along with the 91 for commuting long distances, but that is not the case.

 

If you're looking to pick up more power on race fuel and have access to it try tuning with an oxygenated fuel. VP's MS109 is pretty amazing stuff when properly tuned for it. Definitely going to produce better results than a common 100 octane fuel.

 

Based on teh comment he doesn't have access except for what's on the track therefore if he was going to jump through hoops to get ms109 why not just run the q16 that's oxygenated and have a higher octane?

I run ms103 in our racebikes. Oxygenated fuels are awsome but i'd never run that in my car because it's a PITA to do a full tank drain then re-drain after the race and go back to pumpgas. There is no way i'd just leave it in the tank and burn it off on the street for it's cost. Now in our pure race bikes it's no big deal cause it takes 1 minute to drain a tank.

 

Yeah, that's an entirely additional cost. I run Q16 in my 300ZX TT for drag racing at $12/gal, but I burn way too much fuel at the track in the 350 to justify that kind of cost for fuel. Paying for 100 octane is enough as it is!

 

Dont run AVGAS it is not benificial to you at the altitude your car is running at but I am no expert. Run the mixtures from VP ive tuned on awsome gas MS109 and Q16, C16 leaded with mix 91 unleaded. I have different tunes based on fuels running with huge timing maps.

 

what are you talking about? what does altitude have to do with anything? 100 octane is 100 octane on the earth's crust or in the stratosphere. The car is tuned at the altitude it will be driving at so there isn't an issue.

I don't see how octane has anything to do with altitude. You do know planes are up a lot higher than his altitude and it doesn't change the 100LL that's in their tanks.