Highest Octane For Stock ECU??

Shunya

I'm gunna try to list things on the back of my head now..
1.8L>2.0L Bore, Camshafts, Cam Gears, Pistons, Rods, Valve Springs, Fuel Pump, Fuel Rail, Injectors, Port Matched, Port & Polish, Ecu.... etc...
too much to list on my track car.

Izzoh

It's not a bad thing. You said you did internal work which probably raised your compression ratio that rasied ratio usually will cause a car to Ping (detonate) running lower octane (87,89,91) rated gas. Running 94 will allow you to take advantage of the mods that you did to your engine by tuning.

Higher Octane dosen't increase HP/TQ it just helps to keep Pistons from coming out the side of the block or through the oilpan by helping reduce Knocking and Pinging. Tuning is where you get your HP from.

bigaudiofanat

I agree, if your car was made for regular than you burn regular. I mean yes in my civic I have ran a few tanks or premium with a fuel injector cleaner and a few times on race night but there was no real reason for it. If it takes a certain kind of gas that is what you should use. End of story.

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37Z

104 Sunoco race fuel on a re-tune!!

Blown32

Apparently this is one of those subjects that you can beat to death.As I said in my last post there are those that insist race gas will make more power in the Z because they just don't know any better.
The 370Z in stock form is NOT going to make more hp with race gas instead of the recomended fuel by the manufaster.Plain and simple!
Some know the real deal and others are lost.It is a shame that these gimmicks catch some and they waste there money!
So anyone advertising any different are looking to draw attention,don't know what they are talking about or looking to make a buck on the public that just isn't familiar with the performance world.
As for the additional 14 hp on just race gas with a stock 370z is pure bull at its best!
Guys in the race world spend thousands of dollars to gain every little bit of hp to have an edge over there competiter but a stock motor with premium fuel versus race gas is a waste of money!No advantage power wise unless its been modified with the compression raised to the point it will detonate on pump fuel!
As to the oxgeanated fuel that is a whole different type of fuel.The first post if I recall was about higher octane fuel.

bullitt5897

I agree with some of the above statements. The only times I saw tat race gas helped was when the cars were modified. My s2000 loved 112 octane it would eat it up. I also had close to 10K worth of work done in the power department. You will know that you are gaining power when it takes the engine less time to hit redline! I ran 112 for about 2 months till I destroyed a racing test pipe from T1r... thats right I destroyed it! S2000's are known for hot exhausts but with the racing gas I cracked and disintegrated all of the welds in the test pipe it literally fell apart. I have it as a trophy in my shop and had T1r send me a brand new one saying it just fell apart one day.

But any way like others are saying if your car is not tuned to use high octane you will loose throttle response and power. I had an emanage ultimate that allowed me to adjust everything for my fuel and performance parts and I saw a good 17hp increase by going to 112 octane. Be safe with your fuel the stuff can get dangerous for you and your engine. I have 10 gallons of experimental race gas thats close to 120 octane and if you get it on you it evaporates instantaneously... some pretty cool sh1t!

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Hi-TecDesigns

I had some flanges welded to my S's test pipe so I could wrap it in the stock cat heat shields... it lasted about 6 months before I started hearing this ringing noise. Took me another 6 months before I tracked it down to the test pipe. when I took it off, two of the four brackets had ripped holes in the tube wall. Looks like the heat was just so bad it affected the stainless surrounding the welds. Pity.

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semtex

YouTube - XXX Race Gas gains 14whp on stock 370z

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import111

Wow, look at how much leaner it ran with the race gas. I wonder if that is due to the way the gas is burned or if it is the ECU's doing.

Mercennarius

The gains were made because of the oxygenated fuel, not because of the octane difference. Oxygenated fuels have a lower power stoichiometric and thus you have to run a richer AFR mixture then non oxygenated fuels to compensate. While oxygenated fuels will reduce gas mileage they are able to produce more energy during the combustion process.

semtex

Whatever, forgive me if I don't take your word for it. In any case, this still disproves the claim that race gas produces gains only if cars are modified.

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"There are no small accidents on this circuit." -- Ayrton Senna
316.8whp & 248 ft/lbs (Dyno Dynamics) | 319whp & 256 ft/lbs (DynoJet) (04/23/10)
Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf.

Mercennarius

Its not the octane that makes the difference though. You only need high enough octane to resist preignition, anymore can't help you.

semtex

And how do you know this definitively? How can you be 100% certain that higher octane didn't account for at least some of that 14whp gain? Understand, I'm not saying you're wrong. What I'm saying is that I don't know for sure one way or the other, because I have yet to see any proof. I just see a bunch of people making claims, but I see no tests to verify one way or another. What I'd like to see is a video similar to the one IP did, showing someone dumping in non-oxygenated 100-octane fuel in. If the dyno reads 0 gain, then I'll be convinced that higher octane doesn't do anything, because that's actual evidence/proof. Let me put it this way. I wouldn't accept someone's claims that mod xyz produces huge gains without seeing proof in the form of dyno results. I doubt many of us would, right? So likewise, I'm not going to accept anyone's claim that xyz produces zero gains without the same kind of proof. As far as I'm concerned, until there is proof one way or the other, the question hasn't been definitively answered and all positions are conjectural. Also, just to be clear, I did not post that video with the intent of offering it as proof that higher octane produces gains. We obviously can't say that because the fuel they used was oxygenated. My intent was only to refute the claim that race fuel in general will produce no gains in the 370Z unless the car is modified for it.

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"There are no small accidents on this circuit." -- Ayrton Senna
316.8whp & 248 ft/lbs (Dyno Dynamics) | 319whp & 256 ft/lbs (DynoJet) (04/23/10)
Stillen G3 CAI, CBE, Pulley / F.I. LTH / GTSpec Ladder Brace / Setrab Oil Cooler / UpRev-tuned by Forged Perf.

USNA94

This is spot on and 100% correct. Operating your car with anything higher than required to prevent knocking is just wasting your money. Octane rating does not relate to the energy content of the fuel. It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner. Octane is not something you add to a fuel, it is just a rating on a fuel's resistance to preignition (knocking). Certain additives are added to the fuel to increase the octane rating. Until the 1970's, Tetra-ethyl lead was that additive (hence leaded gas) but has been since replaced by MTBE as the additive used for health and environmental reasons.

A fuel with a higher octane rating can be run at a higher compression ratio without detonating. Compression is directly related to power, so engines that require higher octane usually deliver more motive power. Engine power is a function of the fuel, as well as the engine design, and is related to octane rating of the fuel. Power is limited by the maximum amount of fuel-air mixture that can be forced into the combustion chamber. When the throttle is partially open, only a small fraction of the total available power is produced because the manifold is operating at pressures far below atmospheric. In this case, the octane requirement is far lower than when the throttle is opened fully and the manifold pressure increases to atmospheric pressure, or higher in the case of supercharged or turbocharged engines. Many high-performance engines like the Z's are designed to operate with a high maximum compression, and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor which detects knock, and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

While working on my undergraduate degree (mech eng) I took a course on internal combustion engines and my professor was an expert in this field. I clearly recall him telling us that using a higher octane rating than required was a waste of money. He suggested that if your car did not ping or knock while going up an incline or hill (where this usually presents itself first) then you were fine with your current octane rating. We even had a lab where there was a Ford V-8 on a test stand hooked up to a dyno that we ran tests on comparing power versus different variable such as fuel mixture and octane rating. Our tests showed that there was no appreciable increase in power when using a higher octane rated fuel but there was definitely a decrease in power when using a lower octane rated fuel at the higher end of the RPM spectrum.

Now, would you like me to prove that Force=mass x acceleration or are you going to take my word for it?

import111

Then why with the oxygenated fuel does the car run a lot leaner?