With the rising price of fuel, who's still running race fuel and why? Does the higher octane really make a difference to justify the cost? Do I need to reprogram the ECU to handle race gas?
Race vs. Pump Gas
- Thread starter NSXAMG996TT
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If your engine is stock, you won't get any added benefit from 100+ octane race gas. I've tried it. It won't hurt anything (except your wallet) but it won't give you any added benefit.
What about using lower/regular octane gas (not that I would)? Any decrease in performance or harmful issues?
Performance will definitely decrease, but the ECU is designed to adjust the timing to prevent damage to the engine. Given the possibility of poorer fuel economy, it's not wise for economic reasons - any decline in mileage will offset the cost savings - but if you're stuck somewhere where regular fuel is your only option to get where you're going, you can do it.
There are exotic fuels and fuel additives that will make stock engines run faster. In fact, one of the old prime forum members started up an effort towards racers using pump gas because of the advantage exotic fuels and additives give to the Spec Miata racers who were using these exotic fuels and additives. http://plainoldgas.com/faq.html
Re: Here's the short answer
listen to your engine builder. If it's Honda; read the owner's manual; if it's Shad, take notes.
We Mazda rotary racers only blend in some race gas to bump up the octane above 92 on hot days if we're concerned about detonation from a hot/lean condition. Running 87 or 89 octane would not be advisable for those reasons at least. There's other reasons, but I'd probably fumble the explanation of those if I tried.
listen to your engine builder. If it's Honda; read the owner's manual; if it's Shad, take notes.
We Mazda rotary racers only blend in some race gas to bump up the octane above 92 on hot days if we're concerned about detonation from a hot/lean condition. Running 87 or 89 octane would not be advisable for those reasons at least. There's other reasons, but I'd probably fumble the explanation of those if I tried.
Ken, obviously I haven't tried the stuff - But, the POG effort has moved on to other cars besides Spec Miata'a to other racers who drive essentially stocker/spec engines. Not trying to argue about race fuels, etc., but if the person who started the POG thing thinks there is a clear advantage in using the exotic fuels, he knows what he's talking about. As to stock NSX engines, I don't know why they would somehow be subject to not benefitting. Who knows though...
I think the stuff that the Miata guys use now costs upwards of $45.00 per gallon. See "SR1" on this page. And it looks like they have something to fit for just about anything...
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To beat a dead horse...
High Octant Gas NA = No use except in maybe extreme conditions like 120F outside air temp + high engine load.
High Octane FI = Adds some level of safety. Higher Octane cools the combustion chamber and less chance of pinging and detonation. Opns the ability for a more aggressive tune.
I run a mix of 92/100 on my FI car every now and then.
High Octant Gas NA = No use except in maybe extreme conditions like 120F outside air temp + high engine load.
High Octane FI = Adds some level of safety. Higher Octane cools the combustion chamber and less chance of pinging and detonation. Opns the ability for a more aggressive tune.
I run a mix of 92/100 on my FI car every now and then.
Re: What's really important
There are some who believe the VP gas that they buy in 55 gal barrels is a more consistent, predictable product than what we get from the neighborhood gas station. Those are the same guys who have a nitrogen bottle in their trailer. :wink:
Everyone has to obsess about something. Me, I'm still fussing with the design of my custom lime green floor mats that I'm going to order from Hrant.
There are some who believe the VP gas that they buy in 55 gal barrels is a more consistent, predictable product than what we get from the neighborhood gas station. Those are the same guys who have a nitrogen bottle in their trailer. :wink:
Everyone has to obsess about something. Me, I'm still fussing with the design of my custom lime green floor mats that I'm going to order from Hrant.
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Did anyone bother to look at what I linked, or are you just going off the same information I also believed until recently? Or have you actually used some of the $45 per gallon oxegenated fuels, or have first hand experience in a race with someone else using it while you get left behind? If you look at the exotic fuels, they are not necessarily higher octane.
No matter...
Even on cool days (like in the 80's), I've noticed a big difference in using ~96 octane blended fuel over the standard 93 stuff here.
Not any power that I can feel through the butt dyno, but above 7000RPM's to redline, the engine runs sooooo much smoother.
Not any power that I can feel through the butt dyno, but above 7000RPM's to redline, the engine runs sooooo much smoother.
I did that for a few tanks thinking the same thing. I made it to the dyno and lost 10-12 hp till redline. It's a waste of money unless your F/I or tuned for it.
Was it the proprietary MacAttack blend with 30% more aromatics and synthetic lubricants though? :wink: All the neighbors think I'm nuts mixing gas out in my cul-de-sac with a fire extinguisher nearby. I just tell them it's weedkiller.
I would like to do some dyno testing like you've done, but I was using my formula when I did the 109.4MPH pass in the 1/4 mile (should have been 111MPH) in my stock '92?
Now, I could see where you run too high of octane and your computer can't advance the ignition enough to take advantage of it. In that case, yes, you would lose power with the higher octane fuel. Without an OBDI monitor though, it's pretty much trial and error for me on my stock computer to find that limit.
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I ran a 165.3 mph pass in the 1/4 with my stock 2000 using 93 oct + 2 shots of Saki, one of grandpa's Nitro Glycerin pills, a bottle of Jaegermeister and a medium size rock of crack. :biggrin:
Give me a break!
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Dude, when I have an engine in another vehicle that alone is worth more than twice the value of my NSX, I tend to study what is burned through it.
One day I thought I may as well try some in the NSX and it seemed to like it.
BTW, I do have gas with 20% nitro in it, but that's for the RC vehicles. Sometimes I really get creative with those mixes.
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It doesnt necessarily cool the combustion chamber. It is just less prone to ping and det because it ignites at a higher temperature. and has a much smoother burn.
It's important to remember that octane is not a measure of energy contained in the fuel. Instead, it's a measure of anti-detonation of the fuel.
Sorry to dredge this up but I just stumbled on it and felt compelled to respond.
As some have correctly stated, octane is there to prevent bad things that reduce power and potentially damage the engine, it is not there to “add” power. BIG difference, but not one the octane-boost marketers like to advertise. Technically, you want as many molecules of power yielding molecules as you can get, which means the lowest octane your car can operate with safely because the octane additives displace some of those fuel molecules.
As emphatic as it sounds, and common as the belief is amongst many of the more knowledgeable car people, this statement is absolutely incorrect. I have tested and proven it on the dyno with an essentially stock Miata engine, and have observed the same test on other cars. I assure you that the NSX would respond similarly.
Someone above hit on the key, which is oxygenated fuel. VR SR1 in particular is specifically formulated to pass SCCA tech yet yield additional HP over any street or typical race fuel. The mixture provides additional oxygen during combustion which allows the burning of more fuel, much like boost but without the pressure. It is most effective in “restrictor plate” limited engines which have artificially choked intakes and are therefore oxygen starved, but even with the best intake available and no filter at all, a Miata makes more on SR1, just pouring it in the tank. Tune the mixture and timing for it and you get still more. Not much mind you, we only make 110 – 125 at the wheels to begin with, but that's why just an extra five or six HP is the difference between keeping up with the pack or not even being able to hold a draft. And that's why we started the PlianOldGas (POG) movement. (By the way, the primary additive in SR1 is easily spotted by looking at the plugs. In just a few dyno pulls the ground electrode turns snow white with a hard crust. Not like a super lean mixture, really white and hard.)
I can afford the exotic fuels if that's what it takes to compete, but a lot of people can't or won't, and amateur racing just doesn't need this extra and pointless expense. At first it was yet another advantage for the deep pockets “in the know”, but once it was exposed and most of the front runners started buying it, the advantage was gone but the expense continues. And, perhaps more important, those who can't afford it or won't run it are just that much further behind and more disillusioned with racing. That's one of the many reasons our car counts are falling off.
There is also a significant health and environmental issue with exotic fuels, and especially the home-brews. I know my eyes and sinuses have burned and watered when following certain cars running wild stuff, and corner workers hate it. SR1 is not like that because it's formulated within strict rules, but a lot of the other stuff is nasty.
As some have correctly stated, octane is there to prevent bad things that reduce power and potentially damage the engine, it is not there to “add” power. BIG difference, but not one the octane-boost marketers like to advertise. Technically, you want as many molecules of power yielding molecules as you can get, which means the lowest octane your car can operate with safely because the octane additives displace some of those fuel molecules.
As emphatic as it sounds, and common as the belief is amongst many of the more knowledgeable car people, this statement is absolutely incorrect. I have tested and proven it on the dyno with an essentially stock Miata engine, and have observed the same test on other cars. I assure you that the NSX would respond similarly.
Someone above hit on the key, which is oxygenated fuel. VR SR1 in particular is specifically formulated to pass SCCA tech yet yield additional HP over any street or typical race fuel. The mixture provides additional oxygen during combustion which allows the burning of more fuel, much like boost but without the pressure. It is most effective in “restrictor plate” limited engines which have artificially choked intakes and are therefore oxygen starved, but even with the best intake available and no filter at all, a Miata makes more on SR1, just pouring it in the tank. Tune the mixture and timing for it and you get still more. Not much mind you, we only make 110 – 125 at the wheels to begin with, but that's why just an extra five or six HP is the difference between keeping up with the pack or not even being able to hold a draft. And that's why we started the PlianOldGas (POG) movement. (By the way, the primary additive in SR1 is easily spotted by looking at the plugs. In just a few dyno pulls the ground electrode turns snow white with a hard crust. Not like a super lean mixture, really white and hard.)
I can afford the exotic fuels if that's what it takes to compete, but a lot of people can't or won't, and amateur racing just doesn't need this extra and pointless expense. At first it was yet another advantage for the deep pockets “in the know”, but once it was exposed and most of the front runners started buying it, the advantage was gone but the expense continues. And, perhaps more important, those who can't afford it or won't run it are just that much further behind and more disillusioned with racing. That's one of the many reasons our car counts are falling off.
There is also a significant health and environmental issue with exotic fuels, and especially the home-brews. I know my eyes and sinuses have burned and watered when following certain cars running wild stuff, and corner workers hate it. SR1 is not like that because it's formulated within strict rules, but a lot of the other stuff is nasty.
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I'm saying VP1 and oxygenated fuels by others such as ERC will produce more power than POG, or most popular race gas such as VP 110 or 116, in stock engines. I would not assume that is as beneficial, or even safe, in true no-limits NA race engines. It's also much more expensive, because they can get it.
OT, but interesting given the current pump prices.
Is REGULAR (87 octane) or Midgrade (89) OK to use in the NSX ? Other than reduced performance, are there other downsides ?
Specifically, application is for an NA1 OBD-I (Pre 1995) NSX.
EDIT: found this linked thread - http://nsxprime.com/forums/showthread.php?t=108214
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ROFL! I wont get into this, cause i can see it going downhill FAST! but octane is NOT the issue/reason.
If you like, i can post up SEVERAL dyno charts of our Race gas (yes 1 is leaded, the other is unleaded) where we get up to 10 RWHP (or about 7%) with just the fuel. Granted most you car guys are really into spending the $25.75 a GALLON for it either..lol
I notice HUGE improvement in throttle response and hp in my stock NSX with just Sunoco GT 260+ unl 104. It really works well and is unleaded. The R-tech Prov1 we use in our AMA bikes is over $25/gal but not meant for my NSX since its leaded and only 86 motor octane.
Flame on.
you guys CRACK ME UP!
PLEASE someone donate a day at a Portland area car dyno (i only got a 1 wheel dyno) and ill bring my stock nsx (only intake and muffler) and run it on 92 oct. then we will put in the Rtech Prov1 and i bet $$ i not only get OVER 10 RWHP but the increased throttle response will be huge. But again, read my other post, most dont want to run leaded gas nor pay $25/gal but i get for free, so ill donate the gas and my own car even. You guys are thinking of crap fuel like "trick 110" or other $5/gal stuff made for big block chevy's and such.
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