1FZ and higher octane fuel technical discussion...

[reffug]

Originally Posted by lathamb

I know that mine knocks all the time except when its really cool outside or when I run 93 octane. I think, however, that this is more by the design of the oil companies. Most every vehicle I get into these days knocks on regular (87 octane) fuel. Even some really new cars that should not have significant carbon buildup. This is why I speculate that 87 ain't really 87 anymore.

I would disagree unless we get model specific. I reguarly drive a 2000 honda civic as well as an 07 Accord and both would run on sewer water and not care. Just 02.

[Atoyot1031]

Originally Posted by Romer

I do know another guy with a SC who uses midgrade with no issues. It could have been the quality of the midgrade I got. It's worth the 10 cents extra agallon to me to not worry about carbon buildup and knowing the engine runs better.

My friend, mountjoy_99, who was at CM08 with the champagne '97 is also SC'd (that's just how we roll in A-town), but he's always run his on midgrade, and doesn't complain. I know mine runs better, and I've only used premium in the short time I've had it, but there are many other factors (I'm bored out, have a better/different exhaust, I'm cooler, etc.) so the comparison is definitely not equitable.

[lathamb]

Originally Posted by reffug

I would disagree unless we get model specific. I reguarly drive a 2000 honda civic as well as an 07 Accord and both would run on sewer water and not care. Just 02.

Said most, not all. I think hondas were designed to run on sewer water.

[overhanger]

Originally Posted by lathamb

I know that mine knocks all the time except when its really cool outside or when I run 93 octane. I think, however, that this is more by the design of the oil companies. Most every vehicle I get into these days knocks on regular (87 octane) fuel. Even some really new cars that should not have significant carbon buildup. This is why I speculate that 87 ain't really 87 anymore.

Come on out to Colorado and enjoy our regular 85 octane - 87 is midgrade here! Something smells in Denmark.

[turbocruiser]

Originally Posted by overhanger

Come on out to Colorado and enjoy our regular 85 octane - 87 is midgrade here! Something smells in Denmark.

Yea, and premium is 91!

[FirstToy]

Originally Posted by Brian894X4

There is definately a limit on how much the stock ignition can compensate for knocking. Stock 1FZs find themselves knocking all the time, if the temps are hot and they are towing uphill or they have carbon deposits. To me this is evidence that there isn't much margin of error on 87 octane even on a stock engine.

brian,
I don't see a 'margin of error'. fuel either detonates or it doesn't. If it doesn't, than you are wasting fuel. If it fires early, than you get knock.
In fact, if it is closer to early detonation, that tells me the engine is pretty efficient.
Of couse then it goes to whether it is taking away power but again, even if it were, it is inconsequential - just imo.

Have you ever wondered why the 1FZ can so easily be turboed or supercharged with minimal or no changes to the computer and ignition mapping systems, yet yeild significant increases in power? I sure have. Same for the Toyota 3RZ and 5VZ and 2UZ, all modern Toyota designs from the same or later era than the 1FZ. All with factory supercharging options, with minimal or no changes to the engine management system and a factory backed warrenty. I think the explaination is the wider mapping parameters with the engine management systems of these engines and Toyota's complete confidence in their anti-knocking system.

But this is just my theory.

The 1FZ is a large displacement, high torque motor w/ 9:1 compression. It responds well to forced induction because it's a pretty big, low stressed 6.
But realize that many toyota v8's and i6's as well as domestic v8s do really well w/ forced induction
I feel it's the nature of the engines and not so much something to do w/ stock knock sensors or characteristics (altho i understand the ecu management is very important to forced induction)

Just my thoughts- I am thinking of this from stock engine perspective. maybe it's wrong but these are my feelings on it. I know once the discussion goes to forced induction, it's a whole new ballgame.

[Brian894X4]

The points you're bringing up have a lot to do with survivability durability of the 1FZ when supercharged. What I was talking about is the ability to add a supercharger and not modify the engine management system in any way that I'm aware of and still allow the engine and entire system to be factory warranted and smog legal on top of that. There may be other engines that you can turbo or stick a supercharger on without changing the timing, ECU or anything else, but how many of them will be factory warrentied and still pass smog in all 50 states? Seems to me the engine managment system in the 1FZ must have some serious adapting abilities.

BTW, I ran a tank of 92 for the first time this weekend and I was surprised by the results. No major seat of the pants difference. Scangauge is inconclusive, since I can't compare direct apples to apples. But I did notice some major mileage improvements. But this was just one tank. It's not conclusive, but enough to make me to want to keep trying it and see it if the results are consistent.

[PDoyle]

Is it true with the 10 % ethanol additive in gasoline today there is no need to use fuel injector cleaner ?
If so, there must be less and less carbon deposits as we drive with this ##it in the gas tank.

[overhanger]

I've been under the impression that with ethanol, there would be no need to ever add a gas drying additive but I wouldn't think it would do much to clean up carbon deposits.

[FirstToy]

Originally Posted by Brian894X4

The points you're bringing up have a lot to do with survivability durability of the 1FZ when supercharged. What I was talking about is the ability to add a supercharger and not modify the engine management system in any way that I'm aware of and still allow the engine and entire system to be factory warranted and smog legal on top of that. There may be other engines that you can turbo or stick a supercharger on without changing the timing, ECU or anything else, but how many of them will be factory warrentied and still pass smog in all 50 states? Seems to me the engine managment system in the 1FZ must have some serious adapting abilities.

BTW, I ran a tank of 92 for the first time this weekend and I was surprised by the results. No major seat of the pants difference. Scangauge is inconclusive, since I can't compare direct apples to apples. But I did notice some major mileage improvements. But this was just one tank. It's not conclusive, but enough to make me to want to keep trying it and see it if the results are consistent.

The TRD SC has very mild boost. I don't necessarily think that means anything about a special engine management system. If anything, it seems that a more archaic or simple system would allow for big tolerances.
A more complex system would pick up finer degrees of flux right?

it is very interesting, brian, I hope you keep going with your thoughts. You think very differently than me!