Hpnatized9

iTrader: (3)

Hello all,
I have a question about my current tune. I run a single turbo set up at 8.5 lbs boost on 93 pump gas pushing a little under 400 whp on the DD. I am considering taking it to the track and running 100 octane race gas. Will I be safe, or should I have an alternate tune specifically for the higher octane? I have an HKS boost controller with two settings currently, so this should not be a problem switching between the two if advised. Just curious if anyone has had issues with running 100 on a 93 tune. Thanks for any input.

str8dum1

iTrader: (11)

perfectly fine.

Italianjoe1

iTrader: (6)

no problems, but if you're not tuned for it, why run 100oct?

str8dum1

iTrader: (11)

the track is not normal driving conditions. everything gets hotter than normal, so its very prudent to run higher octane than you are tuned for to play it safe.

Hpnatized9

iTrader: (3)

Thanks all for the input. As the post after yours sums up what I have heard, race gas is a wise choice for fuel under track conditions. Guess in the back of my mind, I am liking the idea of more power. Of course that addiction has cost alot of members in here dearly. So I will be alright with my current tune with the 100 octain. So with my second setting, would I be correct in saying that I can only have better runs with a tune dedicated to the 100? And for my primary tune staying the same with daily driving with pump?

binder

iTrader: (8)

If you change the tune for 100 octane you will be pushing more power on your car and risking more.

Race gas generally has a similar specific gravity as pump gas so the map won't be off much (if any) so your 93 map will work fine with just added piece of mind that it won't detonate when the car heats up like st8 said.

Goo$e

iTrader: (9)

I got a question about race gas as well...

I have a tuned map for 91 and also a tuned map for 100 race gas. Now, if my tank is full of 91 oct and I want to switch to 100 oct...and use the 100 oct map...do I just stay on the 91 oct map until my low fuel light comes on...then fill the car up...let's say 2 gallons of race gas. Then drive the car until the low fuel light comes on again, then switch to the race gas map and fill up the car with race gas and then I can put it down?

str8dum1

iTrader: (11)

going from 93 -> 100, you want the tank as empty as possible. Going the other way doesnt matter at all.

binder

iTrader: (8)

yep, fuel light coming on leaves like 2 or 3 gallons in the car. If you're only adding 2 gallons of race fuel then you're only a 50/50 mix.

Best thing is to undo your return line or your feed line and run the pump. To get the most out it's best to have the drivers side of the car up in the air.

Goo$e

iTrader: (9)

Alright...so I get the fuel tank totally empty and run out of 91 gas. Then switch to the race fuel map and put the race fuel in and drive normally for say 10-20 miles and then good to go?

ashtrojan2008

iTrader: (1)

dumping in race gas in won't make more power, theoretically it will make less power on the same tune/boost/ etc because there is less energy in it. So if you are going for power, leave the 93 in. For added safety under track conditions, 100 is a good idea. But i wouldnt recommend putting race gas in and turning up the boost without tuning.

Ross

Brett@AwesomeZ

If you have a return fuel system you can just pop that return line loose and plumb it into a gas can, run the engine until you've drained as much as you want.

Neat trick for going to car shows too since they require you to have less than 1/4 tank. That way once you're done you can put that gas right back in the tank.

Goo$e

iTrader: (9)

I don't think you are getting what I am trying to say. I have a full tune on 91 oct AND a full different tune using 100 oct. I didn't say anything about turning up the boost. I'm not turning up the boost. Switching between my maps. Map 2 for me is 91oct only low/high boost and map 4 is full race gas map. Understand?

andre12031948

I use 93 Sunoco. I did what every Tom, Dick & harry did/does. I took 2 runs, then added a couple of gallons of 100 octane. Saw no difference. It was that simple. Got my answer & now I'm saving money.

str8dum1

iTrader: (11)

why would you see a difference without advancing the timing to utilize the additional octane. unless you dont understand what octane does/means.

athenG

iTrader: (2)

lol.. I guess Tom, Dick and Harry didnt explain to him why they were using 100oct. gas...

andre12031948

Too much timming may cause engine pinging(can damage engine) higher octane or retarding timming will help.
I don't want to touch my timing, because car is running almost to perfection. Just wanted to see if higher octane would help. My top H.P peak is long & flat. That keeps me longer at the h.p peak when shifting. Advacing my timming might give me a couple of more h.p. but at a higher rpm. & will change my H.P curve.

Barnabas

iTrader: (15)

running the higher octane gas will keep your problems down when temps go up and reduces the risk of ping when racing. But no it wont gain you more power without tuning to it.

ashtrojan2008

iTrader: (1)

i wasn't answering your question. I didn't even see your post. I was talking to the OP. He didn't say anything about different tunes. I can read.

anyway to you.. like stated basically its ok for you to run the 100 on your 93 map and not ok for 93 on your 100 map so i'd just get it low, put in a good bit of 100 and run it for a bit and go ahead and switch over.

ross

Hpnatized9

iTrader: (3)

All great stuff. Thanks for all the suggestions. I think the third post I mentioned 2 tunes, but that is neither here nor there. 100 doesnt do anything for the power without a proper tune for it, but will help protect my engine under the stress. It is Ok to run 100 on a 93 tune, but not vice versa. I think that is what I will do, a primary tune for the 93 at 8.5 and a 100 tune for the second setting that I never use (6 psi low boost tune - drive it like I stole it) Thanks all