Hmm...higher octane?

[fierodeletre]

DI works very similarly to a diesel engine, in that it has a vastly more powerful fuel pump in order to atomize fuel into a cylinder near top dead center of the compression stroke. Main differences of course being that it's injecting gasoline and that it has a spark plug in there too to initiate combustion. There is virtually NO chance of detonation, because the cylinder is not compressing fuel/air mixture, it is compressing air. Compressed air doesn't detonate. Timing retardation to avoid detonation is now more a function of the ECM's fuel injector timing than it is cam phase. This means a lot of good things: 1, that you can run ridiculous CR with crappy 85 octane gas. 2, if someone were to boost this engine, intercooling is less mandatory, as the atomization of fuel into the hot, extremely high-pressure combustion chamber at near TDC has a remarkably effective cooling effect.

To be more on topic though, Premium gas doesn't contain more energy than regular. It just has a lower flash point, meaning you can compress it in an air mixture to a higher point without it detonating. This why the LS3 recommends premium. The 3.6 DI doesn't care what it burns because the fuel doesn't enter the combustion chamber until the air in that chamber has completed almost all of its compression. People get the idea in their heads (understandably) that premium gas = go faster because typically higher performance engines have required premium, this because of higher compression ratios. (higher CR = more performance per displacement)

Premium will most likely have little to no effect on performance in the 3.6l VVT DI V6. Now, boosting, on the other hand...

[Beelzebubba]

Originally Posted by headpunter

the direct injection engine doesnt benefit allot from changing the octane because it injects the fuel directly into the cylinder right before the apex of the cylinder stroke so it. so there is no threat of detonation.

Awww beat me to it!

[Vash]

Is there any info on estimated city MPG?

[CamaroSpike23]

Originally Posted by Vash

Is there any info on estimated city MPG?

5mpg....



yes im serious...


about you using the search function...

[Vash]

Originally Posted by CamaroSpike23

5mpg....



yes im serious...


about you using the search function...

Hey you don't have to be like that. It's a discusson forum and we are talking about fuel. I am just trying to get a better picture of the engine.

[CamaroSpike23]

Originally Posted by Vash

Hey you don't have to be like that. It's a discusson forum and we are talking about fuel. I am just trying to get a better picture of the engine.

not trying to be an ass to ya, just making a point. instead of posting the same questions over and over and over and over and over and over and over and over and over and over and over, we have the little search button that will lead you to the threads with these topics already being discused. and its not all aimed at you, there's plenty more others that are doing it every day lol.

[Mblock66]

I used to be in the business of tuning (for subarus) and going from say 87 or 89 to 91 or 93 isn't going to get you very much. There just isn't a ton of room there to increase timing. Especially with the crap CA91 gas california and a few other western states get. That stuff is garbage so the cali cars will never make the same power (safely) as in say NJ or Texas.

Now if you start mixing Torco into your tank that is another story. with 32 oz of Torco in NJ 93 octane it brought a 4 banger turbo up to about 100 octane mix. Which on the dyno cars would go from 280 HP to about 310. Again that is allowing more timing and boost without knock. So when you are only moving 2 points of octane you might get like 5-7 HP on AN ALREADY TUNED CAR.

The reason the G8 sees 40 HP is because the car isn't opimized from the factory for racing. It is a mix between MPG and performance and reliability. You can tune ANY car from the factory with a nice ECU only gain.

So simply tuning the G8 for the same gas (say 87) would get you 20-30 Hp. Then tuning it for 93 octane would get you another 5-7 HP. Then from there you only have room to make more power as you add mods. But there is always a gain from tuning an ECU.

My guess is the new V6 will be putting down about 265 HP at the wheels. Tune it back fro ECU maybe 280-285 and for premium 290 TOPS at that wheels

The V8 will dyno about 385-390 at the wheels (vettes have seen 400). Tune the car for 93 again since it already requires it and you will maybe see 405 at the wheels.

Im not sure how well NA cars take to tunes b/c there is a benefit to boosted cars in tuning. NA cars can't "turn up boost" to make more power. You can only adjust AFR's and lean out the car to a safe point then you are really done.

[Tomash]

Oh hey, has this question in my head for a while and this topic seems perfect for it.

The thing is, in Europe there're two types of gasoline and both pretty hi-octane, that is 95 and 98.
New cars for european market (since about 1995 or earlier) have engine systems able to distinguish between the two (or somehow detect octane number of fuel) and thus burn 98 more efficiently, giving the engine a bit more kick (dynamics, that is).

My question is, could Camaro also do it (behave better on 98)? Or is it made specifically for american market dominated by 87-93 octane gasoline and thus won't distinguish a 95 from 98, having same performance and feeling on both?

[GTAHVIT]

The computer has fuel maps that determine how to handle the diferent octane levels. I'm not sure if the US Cars will have an Octane map for levels that high. But a reflash will allow them to be added if needed.

[Vash]

Aye it should have it already built in to the ecm. When I was young and dumb in the 80's and had my 78 I would put super or Howell Racing Fuel 104 thinking it was better. All it was doing was fouling my plugs.

[MajorTom]

The guy who talked about subarus has the right idea. You can get a few hp from tuning to run on a higher octane, but not that much. I've heard that the G8 is an exception because it was basically an LS2 in disguise ready to run 91 and have the same 400hp. But that's even a bit questionable.




I think the Camaro V6 is going to be cool, but I think some people are overestimating it and thinking it's going to be able to run 12s for 25k. That'd be great. But it's obviously way optimistic. You should really do some real research before getting your hopes up. Stop believing what you hope is true and start believing what is likely to be true. I hope a V6 Camaro whoops a Mustang GT, but it's not likely to happen. It'd be the ultimate burn, but let's be realistic.

[CamaroSpike23]

Originally Posted by Tomash

Oh hey, has this question in my head for a while and this topic seems perfect for it.

The thing is, in Europe there're two types of gasoline and both pretty hi-octane, that is 95 and 98.
New cars for european market (since about 1995 or earlier) have engine systems able to distinguish between the two (or somehow detect octane number of fuel) and thus burn 98 more efficiently, giving the engine a bit more kick (dynamics, that is).

My question is, could Camaro also do it (behave better on 98)? Or is it made specifically for american market dominated by 87-93 octane gasoline and thus won't distinguish a 95 from 98, having same performance and feeling on both?

well, the thing is with gasoline in places other than the US, it is rated differently. In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from our own... So, like every other measurement system it seems that everyone else uses a different scale than we do, but unlike most other instances where we have had the good sense to create different units of measure in this case we all use the same name...
Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating... Interestingly, to further complicate things it would seem that our own AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number... So, to recap our methodologies for measuring gasoline's octane rating are different, but share some common elements...
So, with the commonality of RON in mind a good rule of thumb is as follows, multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent.

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that are subjected to substandard 91 octane.
91 AKI Octane (US measure) = 95.5 RON Octane


http://en.wikipedia.org/wiki/Octane_rating

Originally Posted by Vash

Aye it should have it already built in to the ecm. When I was young and dumb in the 80's and had my 78 I would put super or Howell Racing Fuel 104 thinking it was better. All it was doing was fouling my plugs.

did you have a vacuum advance on the dist? or did you add timing to it when you would run the higher octane fuel?

[Tomash]

Thanks for the explanation, CamaroSpike!

[Supermans]

Originally Posted by CamaroSpike23

well, the thing is with gasoline in places other than the US, it is rated differently. In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from our own... So, like every other measurement system it seems that everyone else uses a different scale than we do, but unlike most other instances where we have had the good sense to create different units of measure in this case we all use the same name...
Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating... Interestingly, to further complicate things it would seem that our own AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number... So, to recap our methodologies for measuring gasoline's octane rating are different, but share some common elements...
So, with the commonality of RON in mind a good rule of thumb is as follows, multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent.

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that are subjected to substandard 91 octane.
91 AKI Octane (US measure) = 95.5 RON Octane


http://en.wikipedia.org/wiki/Octane_rating






did you have a vacuum advance on the dist? or did you add timing to it when you would run the higher octane fuel?

Learn something new every day..