100 Octane

[jeff4946]

Originally Posted by E.T.

This has been discussed in numerous threads. People will say there is no performance boost, but it has been proven that timing is being pulled when using 87 in our V6's. This equates to a loss in power. It was also shown that timing was not pulled when running 93.

The manual states: use 87 octane or higher. Many members have reported that the engine seems to run better/smoother with the higher octane. Not sure about the diff. (if any) between 93 and 100 octane.

Edit: here's one discussion--

http://www.camaro5.com/forums/showthread.php?t=111580

Your engine is tuned to run 87. I would like to see that proof it pulls timing... that doesn't make sense... and the difference between 93 and 100 octane is Av Alkylate in the blend, not Motor alkylate. Higher octane, better vapor pressure... and probably a ton of Toluene, and Butane

[brantley847]

Originally Posted by jeff4946

Your engine is tuned to run 87. I would like to see that proof it pulls timing... that doesn't make sense... and the difference between 93 and 100 octane is Av Alkylate in the blend, not Motor alkylate. Higher octane, better vapor pressure... and probably a ton of Toluene, and Butane

Sir, don't be ridiculous...

Don't you know? A friend of a friend's grandmothers cat was eating out of a bowl of food a local dyno shop and noticed a 5 hp increase in when utilizing 93...the cat returned to his liter box and conducted an exact replica of the dyno results in the liter mix. The owner of the cat ran to his cousin's house with the liter box to show him the results of his sister's boyfriend's Camaro.

It is a mystery that not one single person can provide a graph ...but I believe in miracles, sir.

[jeff4946]

Originally Posted by brantley847

Sir, don't be ridiculous...

Don't you know? A friend of a friend's grandmothers cat was eating out of a bowl of food a local dyno shop and noticed a 5 hp increase in when utilizing 93...the cat returned to his liter box and conducted an exact replica of the dyno results in the liter mix. The owner of the cat ran to his cousin's house with the liter box to show him the results of his sister's boyfriend's Camaro.

It is a mystery that not one single person can provide a graph ...but I believe in miracles, sir.

AHHH .... clear as mud! Makes perfect sense now. I too, read that thread, and it is a bit off. Turns out ,we have a good idea of what we do for a living... but I'm sure ,never the less, I will be wrong. Thanks for that though. It was very comical.

[anthonyj9h]

Originally Posted by Russell James

Go into your bathroom and start flushing $20s.

Same end result.

The LLT is calibrated for 87.

that made my day

[E.T.]

Originally Posted by brantley847

Sir, don't be ridiculous...

Don't you know? A friend of a friend's grandmothers cat was eating out of a bowl of food a local dyno shop and noticed a 5 hp increase in when utilizing 93...the cat returned to his liter box and conducted an exact replica of the dyno results in the liter mix. The owner of the cat ran to his cousin's house with the liter box to show him the results of his sister's boyfriend's Camaro.

It is a mystery that not one single person can provide a graph ...but I believe in miracles, sir.

Here you go. There are probably some dyno charts on the forum as well, but I'm not going to search for them all. Obviously if this much spark retard is required when running 87, the car is not using its full potential. If the V6 was for meant for 87 only, it would say "use 87 only" in the manual. Sure, it'll run just fine, but it's less than optimal. It's great that this engine will run on 87, and of course GM will use this as a selling point; but many members have felt differences with higher octane, and have also gotten better MPGs.

Originally Posted by scrming

bottom right hand corner is the "spark retard". With 87 octane you can clearly see the spark retard is very active!



with non-ethanol 93 octane, the spark retard basically stays at ZERO!

Here is another nice synopsis:

Originally Posted by KMPrenger

Oh boy, not this topic again. Here it is in a nutshell...

Car will run fine on 87, but theres proof out there that the car seems to pull more timing with the lower octane fuel.

Using 91 or higher has shown to lessen the amount of timing pulled which should result in the engine running a bit more to its potential. Will you be able to tell the difference? Who knows, some say they think the car sounds smoother or feels more responsive, while some say that while they agree it may be better for the car, its too little to notice. I lean more towards that 2nd camp, and yes I try to run higher than regular graded fuel.

[brantley847]

Originally Posted by E.T.

Here you go. There are probably some dyno charts on the forum as well, but I'm not going to search for them all. Obviously if this much spark retard is required when running 87, the car is not using its full potential. If the V6 was for meant for 87 only, it would say "use 87 only" in the manual. Sure, it'll run just fine, but it's less than optimal. It's great that this engine will run on 87, and of course GM will use this as a selling point; but many members have felt differences with higher octane, and have also gotten better MPGs.

I cannot watch the video, Is the car in the video an SS or V6? Are we comparing an SS recommended at 91 or a V6 at 87? I didn't say the car would not run, possibly more efficient at 93. However the power or "boost" claims are ridiculous. No one has shown anything more than "I felt the car was running with a higher efficiency. MPG comparisions IMHO are just as bad. Unless you are running the same exact route everyday with the exact same wait or idle time at each red light then it is not proven either...

I have yet to see a dyno comparision, but I would be open to seeing it if it actually exists.

I don't honestly believe GM would make a vehicle, state the level recommended is 87 and subsequently force your vehicle to run less than full potential when the simple fix is just having you place a higher grade in the vehicle. We are not talking about GM restricting power or tuning a vehicle lower than its capabilities...we are talking about a simple fix of purchasing a higher grade. Why not say 87 required, 91 recommended?

[jeff4946]

So why would you run a higher octane with nitrous, if you WANT timing retard? I would like to see the mods on this car. Our test engines are set for specific octanes and must run to a certain proficiency before product is released for sale. Cheap Gas? Ethanol? If an engine is designed for a certain octane, it is tuned to that octane... period.

I am betting this car is tuned, and is not updated for ethanol.

[brantley847]

Originally Posted by jeff4946

So why would you run a higher octane with nitrous, if you WANT timing retard? I would like to see the mods on this car. Our test engines are set for specific octanes and must run to a certain proficiency before product is released for sale. Cheap Gas? Ethanol? If an engine is designed for a certain octane, it is tuned to that octane... period.

I am betting this car is tuned, and is not updated for ethanol.

STOP MAKING SENSE!!!!

[mpiper]

Originally Posted by jeff4946

So why would you run a higher octane with nitrous, if you WANT timing retard? I would like to see the mods on this car. Our test engines are set for specific octanes and must run to a certain proficiency before product is released for sale. Cheap Gas? Ethanol? If an engine is designed for a certain octane, it is tuned to that octane... period.

I am betting this car is tuned, and is not updated for ethanol.

Jeff,
I also work for an oil refining company, so your earlier points are dead on, no arguements on anything about fuels. But you're using old school carberator logic on a direct injection, highly ECU-managed engine. I've gotten slammed by that myself several times since I got the Camaro. Last Hot Rod I had was a 79 v8 with NO computer controlls whatsoever. I'm still trying to get out of my late 80's performance mindset and get used to the new world of computer controlled engines.


However; The 3.6 has a knock sensor. The engine ACTIVELY trys to add timing to max mileage/power. Once the sensor detects a knock situation, it backs off the timing for that RPM. Therefore, it adds timing to ANY octane rating. 91 allows more timing, 93 even more. Is there a max? Possibly. I don't know. Here is what I DO know:

With 87 Octane, running a data log shows timing starting at 11 and going all the way to 40 and dropping down to 20 and up again. it is the most uneven, ugly graph you've even seen. running 89, the drops were fewer and farther between, but still occured. Running 93 I had the timing start at 11, run up to 40, drop to around 36 and stay there, no further drops, except when RPM range shifted. I tested 91 later, when weather was much warmer. Seemed pretty much like 93, only was around 34 that the timing hung instead of 36. No idea if the difference was the temperatures, the octane, or both.

So, yes, I've tested the "myth" of 87 being the best gas. It's "Busted." 87 is 100% SAFE and effective with the advanced fuel/timing management this Bosch ECU has. But it is NOT the best. Based on my tests, anything 91 or better should see a smooth, consistent timing curve that follows engine RPM just like it should. For best budget, run 87, for best Mileage/Power run 91+

[jeff4946]

O no... defiantly not saying the best gas to run. I run 91, and I only run it because nitrous requires it... I am pointing out that as far as manufactures go... they built this car on standards and specs too, and as it might get a little out of the 91/93, that the car with waste some of the carbon and deposit it in your exhaust components, therefore the 87 is better for the life span of your car. 93 is an octane giveaway, and 100 is just going to do damage on a stock engine. I would still bet if this was a pull on an ethanol enriched gas, that the results are skewed. If not tuned for it, it will throw you off.

[jeff4946]

Originally Posted by brantley847

I cannot watch the video, Is the car in the video an SS or V6? Are we comparing an SS recommended at 91 or a V6 at 87? I didn't say the car would not run, possibly more efficient at 93. However the power or "boost" claims are ridiculous. No one has shown anything more than "I felt the car was running with a higher efficiency. MPG comparisions IMHO are just as bad. Unless you are running the same exact route everyday with the exact same wait or idle time at each red light then it is not proven either...

I have yet to see a dyno comparision, but I would be open to seeing it if it actually exists.

I don't honestly believe GM would make a vehicle, state the level recommended is 87 and subsequently force your vehicle to run less than full potential when the simple fix is just having you place a higher grade in the vehicle. We are not talking about GM restricting power or tuning a vehicle lower than its capabilities...we are talking about a simple fix of purchasing a higher grade. Why not say 87 required, 91 recommended?

That is funny, because everytime you bring up a v6 tune, every tuner out there will tell you with a straight face" there are no gains to be had... gm did an excellent job of getting everything out of this engine", and yet this just proves that wrong.

[i007spectre]

I usually put in 87 but last time i used 89, so far I cant tell any difference.

[DarkObsession]

Originally Posted by E.T.

Here you go. There are probably some dyno charts on the forum as well, but I'm not going to search for them all. Obviously if this much spark retard is required when running 87, the car is not using its full potential.

Unfortunately, I can't really see anything in that video so it's impossible to tell what we are looking at and what the numbers are.

KR is only going to show up at WOT; if it shows up while you are idling or under mild acceleration, then you have bigger problems than what octane of fuel to use.

Generally speaking, timing is only useful information at WOT as well if you are talking about how much power you are making. What I'd like to see is the following:

V6 - bone stock. Scan at WOT with 87 octane and show spark advance (timing) and KR (spark retard).

That would probably be sufficient to see what exactly is being hurt/helped with 87 octane but then of course it would be nice to see what the car does with 93. That said, if the first scan shows timing ~15-18 and 0 KR, I doubt that 93 octane would make any difference.

My personal opinion is that by running higher octane in a V6, you are flushing twenties down the toilet as someone else said but I don't have any data to back that up.

[brantley847]

Originally Posted by jeff4946

That is funny, because everytime you bring up a v6 tune, every tuner out there will tell you with a straight face" there are no gains to be had... gm did an excellent job of getting everything out of this engine", and yet this just proves that wrong.

I have never heard anything about V6 tunes or their results, I never mentioned anything about tunes. I figured were speaking specifically in reference to STOCK V6 vehicles and their difference between higher grade comparision for 87 and 93. I assumed that was only way to make a fair comparision for the OP.

What I mentioned was, we don't know which vehicles have been tuned or which vehicles have been modified when other members continue to reference dyno results etc...