1FZ and higher octane fuel technical discussion... (3 Viewers)

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Shaun,
I don't think you understood my point. I don't expect to solve it or come up with an answer. I just enjoyed the level of conversation. Kind of like two guys at a bar drinking some beers wondering some things and not coming to a resolution, but enjoying the conversation.

Kind of like wondering what cdan thinks when he is looking at my avatar. Is he thinking "handsome devil", "Damn thing still hasn't washed off" "Damn that Hants White" or "Why do I copy that damn Canadian" Unless he tells us we won't know.

I am supercharged so I run Premium anyways.

So yer saying that this is just chat, I know I know I already got that! :D :flipoff2: :D
 
I did some knock testing when I was evaluating my MAF housing. I have the auto enginuity software so it could be recorded. What I would do is place the tranny in 2nd start mode and take off at the bottom of a hill full throttle. I never saw the timing retard under those conditions running 87 octane gas.

I have always been under the impression that our ECUs don't advance the spark past a preset value and only retard the spark if needed. But I have not tried to prove that either way.

Rick, not arguing about anything, just asking about it but even in 2nd Start Mode, won't the kickdown switch engage if you go full throttle from a stop? I guess I've never tried that - the only times I've used the 2nd Start Mode is on really icy streets. This might be a good way to dial in one of the highest load situations you can get. :cheers:
 
Shaun,

I am supercharged so I run Premium anyways.

Okay now all kidding aside, some questions that will help with the overall understanding on this subject (which I admit I'd love to learn more on)

1. Why do you run premium specifically? (May be many different reasons)

2. Have you ever purposely tried to run something less than that with the SC?

3. If so what was the result?


I really was serious by the way when I suggested trying to come up with a measurement methodology here. If we started with that and everyone more than less followed that methodology we really might get closer to some truths with regards to premium vs regular in our rigs. In the meantime, I'd like to learn better specifically from you SC'd guys what yer observations are, if it is mandated in the owner's manual that you use the premium, if anyone has tried something lower and what were the results. Thanks. :cheers:
 
So yer saying that this is just chat, I know I know I already got that! :D :flipoff2: :D

Not Chat. Its tech talk with no outcome like arguing over the theory of evolution. In some places it might be chat, but chat here is down a few levels in the did you shave body parts kind of discussion.

Okay now all kidding aside, some questions that will help with the overall understanding on this subject (which I admit I'd love to learn more on)

1. Why do you run premium specifically? (May be many different reasons)

2. Have you ever purposely tried to run something less than that with the SC?

3. If so what was the result?

When I ran mid grade the truck did not perform as well. Mid grade from Bradley cause a mil light with the knock sensor code.

My BMW also says Premium. I ran a tank of regular (By mistake) and it ran like crap with a mil light coming on and my having to restart it to get the engine to run right. Would work ok at easy speed increases, but when I punched it the problem happened. Went back to premium and no issues since.

I am use to Premium being on the right hand side of the pumps, at this gas station it was in the middle and I wasn't paying attention, thus the mistake.
 
Rick, not arguing about anything, just asking about it but even in 2nd Start Mode, won't the kickdown switch engage if you go full throttle from a stop? I guess I've never tried that - the only times I've used the 2nd Start Mode is on really icy streets. This might be a good way to dial in one of the highest load situations you can get. :cheers:

2nd start means just that and no matter how hard you press the accelerator it won't down shift. I was looking to put the greatest load on the engine and what I saw was a smooth increase in timing as the RPMs increased, no jumping around at all.
 
2nd start means just that and no matter how hard you press the accelerator it won't down shift. I was looking to put the greatest load on the engine and what I saw was a smooth increase in timing as the RPMs increased, no jumping around at all.

Hmm, I'll havta play around with that then! I'll probably get greater peak boost numbers there than I would while already rolling and flooring it. :cheers:
 
Not Chat. Its tech talk with no outcome like arguing over the theory of evolution. In some places it might be chat, but chat here is down a few levels in the did you shave body parts kind of discussion.



When I ran mid grade the truck did not perform as well. Mid grade from Bradley cause a mil light with the knock sensor code.

My BMW also says Premium. I ran a tank of regular (By mistake) and it ran like crap with a mil light coming on and my having to restart it to get the engine to run right. Would work ok at easy speed increases, but when I punched it the problem happened. Went back to premium and no issues since.

I am use to Premium being on the right hand side of the pumps, at this gas station it was in the middle and I wasn't paying attention, thus the mistake.


Well, that's good to know and with all that in mind maybe the FI guys should gracefully bow out of this conversation alltogether; I know that I'm not willing to throw MIL's and have rough running conditions, etc. just to measure if there are any differences in economy or power. Perhaps with combinations of careful driving practices, scangauges and such we can come to the proper conclusions about economy and power differences on NA versions. For me, other than knowing that I can ONLY use premium, I can't make comparisons heres. :cheers:
 
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.
 
I havn't stepped down to regular on either of my trucks and wouldn't. However I have recently run some mid grade through my present rig with no issues. Although I don't plan on doing it again it might be the fuel delivery problems that are inherint in the 93 in comparison to the 97. I still run premium though just for my peace of mind.
 
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 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.
 
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.
 
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.
 
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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.
 
Come on out to Colorado and enjoy our regular 85 octane - 87 is midgrade here! Something smells in Denmark.

Yea, and premium is 91! :cheers:
 
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.
 
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.
 
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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.
 
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.
 
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!
 

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