Any one running with 100 octane?

[captainzorg]

I wanted to see how many (if any) of you guys are running your cars with 100 octane. I filled up the other day with it. I havent driven it much to notice any difference. There is only one place I know of in my area that sells it. It is pretty expensive (4.59 per gallon) to be exact.

[Dev]

Where in NH did you fine 100oct..are you in Loudon?

[captainzorg]

Nashua, Exit 6 Broad st...SUNOCO

[gosox2003]

i have noticed a decent amount of type-r's in and around mass.

i live outside boston and am picking up my itr this weekend. (first one stolen). any itr gatherings in NE?

[AdamF]

Running a higher octane than is recommended by the manufacturer will generally not yield any performance gains, and can sometimes lead to decrease in performance. The octane rating on gasoline is directly proportional to how long the the fuel burns in each combustion cycle. Sometimes people will call low octane gasoline "quick gas" as it burns more quickly than higher octane fuel, which on high compression engines can lead to pre-ignition. Running 100 octane fuel I would imagine could lead to incomplete burn on engines that are not properly configured for it. I could be wrong on that last point, so feel free to correct me.

Nonetheless, I think it's highly doubtful you'll yield a sigificant increase in performance through use of 100 octane gasoline.

[Chris N]

What AdamF said is true.

If you don't have higher compression, it won't make a difference. How high of compression is needed to see an effect with 100 octane or higher? I'm not exactly sure, I'd say at least 12.5:1 or so.

[ballsoutracecar]

ITR have a high compression, 10:6:1 US / 11:1:1 AUS

ive only ever since brand new (now 20,000 KM) used Octane 98. If there was a hundred, i'd use it.

With the right engine, & i KNOW the ITR B18C is a worthy contender.

Why do you think the JDM are that little more powerful than ours. They are able to better tune their engines because they get 100+ octane piece of piss from the pump and can better tune the car knowing they have the efficient fuel to cope.

I can now see why you guys have lower compression, because i come across alot of ITR owners who use Octane 92 or lower in their ITR. You should know better than that.

Another bonus, the higher the octane, the cleaner your fuel, the more reliable and longer lasting engine will be as it wont clog up or anything because of crappy, watered down dirty dirty fuel.

Another bonus, cleaner fuel emissons.

[Dave-ROR]

ITR have a high compression, 10:6:1 US / 11:1:1 AUS

That's not "high compression" imo.

ive only ever since brand new (now 20,000 KM) used Octane 98. If there was a hundred, i'd use it.

There is no reason to. It is a waste of money.

With the right engine, & i KNOW the ITR B18C is a worthy contender.

With 13:1 compression..

Why do you think the JDM are that little more powerful than ours. They are able to better tune their engines because they get 100+ octane piece of piss from the pump and can better tune the car knowing they have the efficient fuel to cope.

I guess the different ECUs, slightly higher compression and better header have nothing to do with the 2 crank hp difference.. it must be that higher octane gas this whole time.

I can now see why you guys have lower compression, because i come across alot of ITR owners who use Octane 92 or lower in their ITR. You should know better than that.

a good, clean 91 octane is fine for 10.6:1 compression. 93 is most common and is perfectly fine.

Another bonus, the higher the octane, the cleaner your fuel, the more reliable and longer lasting engine will be as it wont clog up or anything because of crappy, watered down dirty dirty fuel.

Another bonus, cleaner fuel emissons.

That depends sooo much on the fuel used more than the octane. As for emissions, all 100 octane is a 10.6:1 compression USDM integra will do is kill the cat faster since it wont be burning enough fuel.

[ballsoutracecar]

good points.

11:1:1 is high imo for a stock production motor.

regardless higher octane is cleaner and imo a better fuel.

if you guys had higher octane fuels readily available at a reasonable price i'm sure you all would be using it.

Regardless, fuel is a BIG reason you dont get JDM.

Quote
[I guess the different ECUs, slightly higher compression and better header have nothing to do with the 2 crank hp difference.. it must be that higher octane gas this whole time. ]

well thats why they get these better parts, because they have got Better fuel.
Fuel does not add power, I know this, if you read correctly i never said higher octane makes more power but it gives the engine more tuning capabilities with more efficient results. imo anyway.

[Type R 98]

Quote
[I guess the different ECUs, slightly higher compression and better header have nothing to do with the 2 crank hp difference.. it must be that higher octane gas this whole time. ]


yeah the only reason the motor's better tuned in japan is cause of the octane level difference from usdm type R's .. better gas allows them to make a healthy running motor with more compression, requiring new fuel maps (which is why u got another ecu for) and a better flowing (2.5" piping).

[Dave-ROR]

yeah the only reason the motor's better tuned in japan is cause of the octane level difference from usdm type R's .. better gas allows them to make a healthy running motor with more compression, requiring new fuel maps (which is why u got another ecu for) and a better flowing (2.5" piping).

Actually, the exhaust is 2.25" on the JDM ITR I do believe (could be wrong). The header collector is 2.5" A JDM ITR header alone on an otherwise stock USDM ITR will make more power than a stock JDM ITR.

100 octane on 11:1 compression is retarded. You can run 12:1 easily on 93 with no predetonation issues at all on 16 degrees base timing. Hell I'd do 12.5:1 on 93 with normal base timing, then have a different program for race gas (and much more advanced timing).

If I could get 100 octane here for 20 cents a gallon cheaper than 93, I'd still buy 93.

[Type R 98]

JDM is 2'5 pimping Front to back

[AdamF]

Is 98 octane gas leaded? I've never seen it anywhere here in California, only 103 which *is* leaded as far as I know. If it *is* leaded, I certainly wouldn't be running it in the car all the time.

Anyhow, what octane does is increase the length of time the fuel burns. If the burn time exceeds the length of the combustion cycle, you will not fully burn the gas and thus *lose* efficiency. Also, further lengthening the time of the burn I would assume yields extra heat, so you're burning up your exhaust system and especially your cat while you're at it...well that is if the unburned hot gas doesn't do it first.

Octane, as far as I know, isn't even measuring the presence of octane in gasoline. I believe it measures the amount of dimethyl heptane with respect to other isomers present. Lower "octane" gasoline isn't watered down, it just simply does not have the same concentration of dimethyl heptane. There is nothing intrinsically inferior about 93 vs. 98 octane gas quality wise. Quality is determined by the purity of the refinement process...you can get 89 octane fuel that is of higher quality than some other company's 91 octane.

Running 98 octane, all you're doing is burning a hole in your pocket, probably burning a hole in your cat, and likely lowering the performance of your car. You'd have to raise your compression to probably 13:1 or so or use some outrageously aggressive timing to make the engine truly *compatible* with 98 octane fuel. People run 91-93 octane fuel in their ITRs because that is what they are *designed* to run on. Using much higher octane than reccommended by the manufacturer is not only costly, it could very well be damaging to the vehicle.

I would gather you'll continue to use 98 octane fuel, but I feel sorry for whoever buys the car should you decide to sell it some time in the future.