I'd hazard to guess that even you as the 87 octane campaigner will not feel the power difference between 87 octane and 91 octane. True, the lowest safe octane will produce the most power, I would not however, recommend 87 octane to anybody with a forced induction car, the gains are negligable and the risks are phenomenal.

 

PureSephiroth =

 

how am I "owned"? I'm right and if you don't realize that, then you don't know the first thing about fuel.

 

Its alright, you aint gotta lie to kick it.

 

this issue of using less octane fuel is kinda funny. My friend has a cobra and he does the same thing. He leans his out so the power numbers go up. Well you can't get away with this on a rotary because you will blow a rear apex seal in a heart beat. Piston motors are a little more forgiving rotarys are NOT

 

That whale pic is awesome. I bet it smells like flowers...
Stock DSM engines, n/a eclipse motors are pretty reliable

 

if you don't ping you don't ping. people like to make ridiculous general claims like "you can't use 87 on a turbo vehicle". Bullshit. it all depends on whether or not its pinging. you can get away with low octane on a rotary just like you can on a piston motor. You can NOT get away with detonation on a rotary like you can on a piston motor. But if its not pinging then don't needlessly increase the octane. That's retarded.

 

Jesus Christ man!!! Here's a little trivia- what do alot of guys with modded turbo motors do when at the track? Well, they tweak and tune. What categories of tuning do you think fit here- tire pressure, a/f ratios, weight, timing, BOOST! If you up the boost, you increase the pressure in the combustion chamber. Upon increasing said pressure to a certain point, the danger of premature detonation looms. Now, using you vast knowledge of fuels that is PERFECT and CORRECT in all ways [/sarcasm], you should be able to conclude that to reduce the chance of premature detonation under increased boost, one must run a fuel with less likelyhodd of detonation EXCLUDING fuels with octane ratings of 87, 89, 91, 92, and 93. The higher the octane, the more boost you can run safely. Of course, like all things, there is a limit to this, and said limit FAR surpasses that which 87 octane can support. Use some common sense man.

 

Running the highest octane you can get on the track and upping the boost as much as you can (for the track ONLY) is the stupidest thing in the world. So many people do it and it's so ******* retarded. What exactly does that prove? Well it proves what you COULD do if you wasted a bunch of money on high octane fuel all the time. What does it NOT tell you? It doesn't tell you **** about what you run from a day-to-day basis on the street. Say you run a 12.5 by running higher octane and upping the boost but run a 13.2 with normal octane and normal boost. Are you going to go around saying you have a 12 second car? You shouldn't, because you can only do that with race gas.

People should run at the track what they run on the street, otherwise it's pointless information and knowledge unless you plan on running race gas all the time. I'd much rather know what I run ALL the time on the street rather than knowing what I COULD run at the track once in a while.

 

no ****. doesn't change the fact somebody simply said, "run 100 octane". That's dumb advice.

so here's a bit of trivia for you:

RUN THE LOWEST OCTANE YOU CAN WITHOUT PINGING.
If he has the boost high enough that he needs 100 octane, then great. But guess what. If he doesn't need 100 octane and uses it anyway, then he will be slower. Isn't that like, obvious by now? or do I have to keep beating it into your thick skull for you to understand?

 

I still say to run 100 octane. Telling someone to run low octane on a boosted car is truly the dumbass advice

 

But, if he leaves everything as is when running at the track like he does on the street, why run 100 octane? I mean, if he's upping the boost obviously it'd be a good idea with no other tuning. But if boost is staying the same, and it's already properly set up and tuned to handle that boost level with 91/2 whatever octane, what's the point in the 100?

 

the factory mazda manual instructs to use 87 octane on all US Turbo II's. That is a boosted car. Do you know more about fuel than the engineers at Mazda?

 

didnt he race allready?
who won?

 

I was just thinking the same thing...

 

pump gas and 2 AFC and boost controller settings, everyday driving/race.

 

yea but like i said a million times before, this car isnt stock

 

I would like to know the outcome also.

Please post.

 

Sorry for the delay guys, unfortunately the race has been postoned till the 9th. I found out that I have to do a few things to my car to make it pass the tech inspection.

I have a question related to the high octane vs. low octane issue. I agree with dDUB that running race gas at the track and upping the boost won't tell me much about how fast I am at the street, but I really want to beat that GSX. So, If I do put race gas in how much can I up the boost? Is there like a rule or something to follow? (i.e. 1 psi increase/ 3 octane increase). I don't want to just turn up the boost till I knock, I just want an estimate of how much I can plan on increasing the boost when running race gas.

 

I just got back from a cruise with some friends down highway 74. I decided to turn my boost up a little bit and see what would happen. I set the boost to 15psi and went for a run on the freeway. I got on the throttle quite a bit, and still haven't seen any signs of detonation. It was hard to watch my boost and my A/F meter, but from what I could tell, even at 15psi my guage was still reading full rich.

Do you guys think I am pushing the engine too hard? I've read that the engine can't take much more than 14 psi, is this true?

 

puuuuuuuuuuuuuuuuuuuush it:P

 

the engine can take plenty more than that as long as it is tuned properly. what octane were you using when you drove it?

just saw that you are on the stock turbo. the 14psi you've heard is probably all the stock turbine can take. They start to lose efficiency up there anyway.

 

take it to a dyno and find out. Pay 70 bucks for 3 pulls to find out what you can do on race gas or pay 1500 for a rebuild to find out what you can't run.

 

You have to watch your intake temps when you run that much boost on the stock turbo and intercooler. You will blow your motor no matter how much fuel you throw at it. I run 14 psi on the stock turbo and TMIC and have logged the intake temps with my Haltech...the numbers are kinda scary after about 5 seconds of constant boosting. Be careful.

 

Great info, but if I was on the freeway would I still have to worry about high intake temps? It seems like there would be enough air movement through the IC to keep the intake temps down. I also don't think that I'm at full boost much longer than 5 seconds when not on the freeway. I don't usually go that fast on the streets.

If 14 psi is the most the stock turbo can handle, is it even worth running race gas at the track? I'm pretty sure my pal with the GSX is planning on using 100 octane on race day and upping the boost, won't this put me at a disadvantage?