Race Gas...

[Che'_Moderator]

Yes because that statment was directed completely at you. Nice attempt to jab.

You have only made 1 statement of use in this tread.

"Excess octane results in less mileage and HP but whatever"

#1 Can you please produce any proof of your statment that you get less HP and less milage from octane? (never heard about this before and honestly intrested)

#2 How can you prove that it's excess octane, when you dont know what setup someone is running? (not everyone is stock)

The only place I can see higher octane then 91 give less milage is sunoco 94 here in Canada because it contains 10% alcohol. Whist it does give higher octane it also delivers worse milage due to alcohol buring up to 30% more to produce the same energy. I don't see how going from 87 to 91 will create worse milage since with better fuel you'll get a cleaner burn with higher timing which equates into less fuel needed to make the same power since the T5's a specificlly designed for higher octane fuel. They are not 8.1 compression and do not run low boost. 10 PSI pretty high for a stock car.

3#Have you EVER hooked up and datalogged the OBDII timing logs with 91 vs 94 or 91 vs 116? Do you have results? Time slips one with and with out? what was your setup?

Bascially all i'm saying is the lazy 1 line answer you gave is a load of horse dung without knowing the whole story.

Anyone planning on using race gas USUALLY has the boost on on their car which means they PROBABLY will gain something power wise.

I have a datalogger on several cars. I am on my way out so I do not have time but if you are interested look up the BTUs of different grade fuels. Of course needlessly high octane will help any car if you are comparing 91 octane with sand in it to 120octane thats clean. Less octane = more combustible.

[GT2]

Yes because that statment was directed completely at you. Nice attempt to jab.

You have only made 1 statement of use in this tread.

"Excess octane results in less mileage and HP but whatever"

#1 Can you please produce any proof of your statment that you get less HP and less milage from octane? (never heard about this before and honestly intrested)

#2 How can you prove that it's excess octane, when you dont know what setup someone is running? (not everyone is stock)

The only place I can see higher octane then 91 give less milage is sunoco 94 here in Canada because it contains 10% alcohol. Whist it does give higher octane it also delivers worse milage due to alcohol buring up to 30% more to produce the same energy. I don't see how going from 87 to 91 will create worse milage since with better fuel you'll get a cleaner burn with higher timing which equates into less fuel needed to make the same power since the T5's a specificlly designed for higher octane fuel. They are not 8.1 compression and do not run low boost. 10 PSI pretty high for a stock car.

3#Have you EVER hooked up and datalogged the OBDII timing logs with 91 vs 94 or 91 vs 116? Do you have results? Time slips one with and with out? what was your setup?

Bascially all i'm saying is the lazy 1 line answer you gave is a load of horse dung without knowing the whole story.

Anyone planning on using race gas USUALLY has the boost on on their car which means they PROBABLY will gain something power wise.

Put some 110 race gas in your lawn mower and see how good it runs! Seriously, like crap.

Many years ago when I had a race shop, I sold ERC leaded race fuel. Some of the oval track street stock guys (stock engines) started buying fuel from me and then started complaining that thier cars ran like dirt. I tryed to explain the excess octane thing to them, and tryed to get them to re-jet and add timing but thick skulls prevailed and I just quit selling fuel to them!

[zazzn]

Put some 110 race gas in your lawn mower and see how good it runs! Seriously, like crap.

Many years ago when I had a race shop, I sold ERC leaded race fuel. Some of the oval track street stock guys (stock engines) started buying fuel from me and then started complaining that thier cars ran like dirt. I tryed to explain the excess octane thing to them, and tryed to get them to re-jet and add timing but thick skulls prevailed and I just quit selling fuel to them!

I would but it doens't have a turbo charger, nor do I run high compression.

If the engine is running 18 psi and you are on the stock intercooler, stock turbo and you don't think the engine is retarding some timing. Then you guys are on another planet or the ecu isn't agressive at all.

[hawks25]

I've used GT100 with my base mapped RICA and have gained 3-4 mph in the 1/4 consistently.

...if I'm pinging, then just about everyone else that is running an 17-18 psi base chip/MBC is too.

Have to back up zazz on this one. Higher octane is not beneficial is when the compression ratio and timing advance remain the same. That scenario is not applicable here.

[Che'_Moderator]

Then you guys are on another planet or the ecu isn't agressive at all.

Of the A/F is 10:1 at WOT ;)

[ppcgm]

It is screwy. Have never seen 87 suggested for 13k+ RPM

It's all a matter of tuning. Your engine needs what it's setup to run best on. I used to drive a four thousand pound '76 Dodge Royal Monaco with a 360 cubic inch V8 that would blow anything Porsche could build right off the road on 125 octane leaded racing gas. But the cars we're buying now wouldn't know how to burn that stuff. They're not jetted for it or timed for it. And even these smart injection systems and electronic ignition boxes can't compensate for that big a difference in fuel volatility.

If it's any consolation, all these little "fart cars" with the stupid sounding exhaust are frying their valves and burning pistons because most of them haven't been retuned for the change in back pressure and they're running way too lean. They won't be making that "rude noise" for long. So now you can smile at them when you hear that idiotic racket.

[SkyWriter]

If it's any consolation, all these little "fart cars" with the stupid sounding exhaust are frying their valves and burning pistons because most of them haven't been retuned for the change in back pressure and they're running way too lean. They won't be making that "rude noise" for long. So now you can smile at them when you hear that idiotic racket.

heh, i saw/heard one with TWO can's yesterday. it sounded twice as lame.

[zazzn]

Of the A/F is 10:1 at WOT

But all manufactures make the cars pretty rich under boost, especially turbo cars if that’s what you are trying to say.

Also the extra fuel helps to stop detonation by cooling the charge.

Until someone actually hooks up the ODBII scanner and does the test I was discribing above then we'll never know but it sounds like hawks did and found out that was indeed pulling timing. (what I gather form his post)

[Che'_Moderator]

But all manufactures make the cars pretty rich under boost, especially turbo cars if that’s what you are trying to say.

Also the extra fuel helps to stop detonation by cooling the charge.

Until someone actually hooks up the ODBII scanner and does the test I was discribing above then we'll never know but it sounds like hawks did and found out that was indeed pulling timing. (what I gather form his post)

There are probably a hundred plus people here with that information. At stock boost levels it depends a lot on abmiant temp. In a tuned engine with decent AITs its not an issue either. The only time I am seeing huge improvements is:

1. Race built engines, maybe 4 here on the site

2. When its a bandaid solution for some half asssed mod thats buggering something up, probably 1000 plus of those here.

[zazzn]

There are probably a hundred plus people here with that information. At stock boost levels it depends a lot on abmiant temp. In a tuned engine with decent AITs its not an issue either. The only time I am seeing huge improvements is:

1. Race built engines, maybe 4 here on the site

2. When its a bandaid solution for some half asssed mod thats buggering something up, probably 1000 plus of those here.

Sorry i'm lost hundreds of people with what infomation? According to my personal experiance boost has always been pretty consistant at 10 PSI regardless of AIT's. Here in toronto we get 34+ c weather and in the winter -20... It's always been right around 10 PSI, so form my personal experiance your statement is wrong.

AIT's are always an issue not matter how good the tune, if the AIT's are too hot you will detonate if your boost is too high and don't have enough octane to fight pre ignition.

I don't know what you consider a huge improvement, but if you are talking 100whp no... You won't see that gain on the stock turbo on race gas vs pump without nitrous or something.

But maybe 40-50WHP is deff possible.

I haven't done the math on the stock turbo but i'm almost 100% sure that the stock turbo is probably inefficent atfter 13-15 psi. Meaning you'll create alot of heat and less HP for each pound of boost. While you will not gain as much you WILL still gain.

All that extra heat form the inefficent turbo will make the engine pull timing to stop the engine from blowing it's self to may peices. Enter race gas. having the octane to allow for hotter IAT's without detonation now means #1 don't need as rich so you don't detonate #2 can run higher boost.

So again... Race gas WILL give an improvement depending on your situation.... at 18 PSI with a upsolute chip I would think you would gain something but nothing crazy maybe 10-20 HP.

But if you where running 20-25 PSI on the stock turbo and race gas you would probably see a gain of 40-60 WHP.

Che not taking a stab just wondering, have you ever tuned a car with race gas and without. (Regardless if it was a supra engine, s70 ect.) I know form my experiance that with and without is like having a NA vs turbo.

For the original poster, I suggest you read up on this subject via Google and made your own decision, and if you decide to go one way post why and most of all post any results!

[Fudge_Brownie]

Won't the "stock" turbo be quite the heat pump at 20-25psi? You can still gain 40whp? Really...

[Che'_Moderator]

Sorry i'm lost hundreds of people with what infomation? According to my personal experiance boost has always been pretty consistant at 10 PSI regardless of AIT's. Here in toronto we get 34+ c weather and in the winter -20... It's always been right around 10 PSI, so form my personal experiance your statement is wrong. AIT's are always an issue not matter how good the tune, if the AIT's are too hot you will detonate if your boost is too high and don't have enough octane to fight pre ignition.I don't know what you consider a huge improvement, but if you are talking 100whp no... You won't see that gain on the stock turbo on race gas vs pump without nitrous or something. But maybe 40-50WHP is deff possible.I haven't done the math on the stock turbo but i'm almost 100% sure that the stock turbo is probably inefficent atfter 13-15 psi. Meaning you'll create alot of heat and less HP for each pound of boost. While you will not gain as much you WILL still gain. All that extra heat form the inefficent turbo will make the engine pull timing to stop the engine from blowing it's self to may peices. Enter race gas. having the octane to allow for hotter IAT's without detonation now means #1 don't need as rich so you don't detonate #2 can run higher boost. So again... Race gas WILL give an improvement depending on your situation.... at 18 PSI with a upsolute chip I would think you would gain something but nothing crazy maybe 10-20 HP.But if you where running 20-25 PSI on the stock turbo and race gas you would probably see a gain of 40-60 WHP.Che not taking a stab just wondering, have you ever tuned a car with race gas and without. (Regardless if it was a supra engine, s70 ect.) I know form my experiance that with and without is like having a NA vs turbo. For the original poster, I suggest you read up on this subject via Google and made your own decision, and if you decide to go one way post why and most of all post any results!

BMW and Volvo are both tuned for 110 and 94. Both are so far from stock its not even funny. I am not argueing you will not make more HP if you tune for it on a purpose built engine. What I am argueing is on a stock car at 10 psi 110s is going to give up HP. Even on a modest built, most of the tunners have the trim so fat, and Volvo compression is so low, it does not even matter. No matter what tune lower octane always has more potential energy and will get better MPG all things being equal. Re: 20-25 psi on a stock turbo, if you are doing that you have bigger issues than race fuel.

Won't the "stock" turbo be quite the heat pump at 20-25psi? You can still gain 40whp? Really...

Stock turbo on a stock block at 20 psi is going to be ~260hp. Race fuel is not going to put you north of 300 so no.

[steve s]

Stock turbo on a stock block at 20 psi is going to be ~260hp. Race fuel is not going to put you north of 300hp so no.

aww man, chuck, why u gotta ruin the party :P

[zazzn]

Won't the "stock" turbo be quite the heat pump at 20-25psi? You can still gain 40whp? Really...

Yes it will be a huge heat pump but you'll gain something even but don't expect the world

BMW and Volvo are both tuned for 110 and 94. Both are so far from stock its not even funny. I am not argueing you will not make more HP if you tune for it on a purpose built engine. What I am argueing is on a stock car at 10 psi 110s is going to give up HP. Even on a modest built, most of the tunners have the trim so fat, and Volvo compression is so low, it does not even matter. No matter what tune lower octane always has more potential energy and will get better MPG all things being equal. Re: 20-25 psi on a stock turbo, if you are doing that you have bigger issues than race fuel.Stock turbo on a stock block at 20 psi is going to be ~260hp. Race fuel is not going to put you north of 300 so no.

Being tuned for 94 and 110 I find hard to believe, but i'm not saying your wrong because I simply don't know. Just wondering where you got the info regarding the tune.

I think we agree that stock car at 10 psi doesn't need race gas but the argument here was a chipped car, with a exhaust, and other bolt on mods or possibly more as thats what the initial poster was asking and i still stick by my comments that you will gain if you lean out the car that is running 18 PSI form the stupidly rich 10:1 ratio that I keep seeing from all these "tuned" chips and run some race gas in the tank.

I believe the T5 is 8.5:1 which is a normal ratio for turbo cars.

As for the stock turbo I made 244 WHP though an auto with a 10:1 a/f there is 15-20 HP right there in the A/F + add another 5 PSI of boost I think the car could post some suprising numbers....

I'd say the biggest diff here is that I cam from a supra background which didn't have ECU upgrades which means we tuned everything via piggybacks and standalone's and had specific tunes for our cars which suited our car's enviornment ect. VS the generic tune form the chipped cars which run stupid rich and don't post the best numbers.

Seeing that I had no fuel management on my s70 (btw i'm not talking 850 turbo here talking about 16t) I think it's very possible to get **close** to 300WHP.

[Che'_Moderator]

Being tuned for 94 and 110 I find hard to believe, but i'm not saying your wrong because I simply don't know. Just wondering where you got the info regarding the tune.

Seeing that I had no fuel management on my s70 (btw i'm not talking 850 turbo here talking about 16t) I think it's very possible to get **close** to 300WHP.

Ok you are right. My IPD chip in the S60 must not be a 110 tune. It is only lightly modded but I really did not see any reason to run 110. And my 850, which has run several 12 second 1/4s, must lso be under 300hp. I am really just basing my Volvo insight on the 5 Volvos I owned in the last 10 years which are all pretty much stock.