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· Not Anymore.
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IreiMember said:
always try to stay with what oem specs are and what they reccomend. the rating on fuels is nothing other than a ping rating. absolutely nothing will ever happen if you use 87 it may not burn as clean as 91 obviously. but as far as power gains lol please... thats like saying puting in 110 octane in a car with a compresson ratio of 9:1 is gonna make it faster LOL .


as far as your specific problem goes it could be many things and to many for me or anyone else on this forum to speculate on. it sucks any way u slice it especially for a new car.

gl


Irei
Is your argument saying that you will get the same power on 87 as 91 or that 91+ will make more power. A 350Z will NOT make the same power on 87 as it will on 91, the ECM will retard the timing.
 

· Whoa...
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NickZac said:
Is your argument saying that you will get the same power on 87 as 91 or that 91+ will make more power. A 350Z will NOT make the same power on 87 as it will on 91, the ECM will retard the timing.
yea, just cxause you lose power by going down on octane rating(because of retardation by the knock sensor) isnt the same as saying you will gain power by going up...
 

· ZPOOLNZ
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IreiMember said:
always try to stay with what oem specs are and what they reccomend. the rating on fuels is nothing other than a ping rating. absolutely nothing will ever happen if you use 87 it may not burn as clean as 91 obviously. but as far as power gains lol please... thats like saying puting in 110 octane in a car with a compresson ratio of 9:1 is gonna make it faster LOL .


as far as your specific problem goes it could be many things and to many for me or anyone else on this forum to speculate on. it sucks any way u slice it especially for a new car.

gl


Irei
Do you know anything? From reading your posts I can assume that you don't. A 350Z will NOT make the same power on 87 if anything the ecu will pull timing and go into limp mode. If you don't know what your talking about don't give incorrect information that could cause problems for other users.
 

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IreiMember said:
always try to stay with what oem specs are and what they reccomend. the rating on fuels is nothing other than a ping rating. absolutely nothing will ever happen if you use 87 it may not burn as clean as 91 obviously. but as far as power gains lol please... thats like saying puting in 110 octane in a car with a compresson ratio of 9:1 is gonna make it faster
If its a turbocharged car, it will........ ;) Why have race gas, then, by your way of thinking.....
 

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lol james its obvious you dont know crap about engines. yeah ok i guess your right you will loose 1 hp if you choose 87 over 91 sorry i stand corrected.



race fuel is for race engines (yes people in the business call these engines not motors)with high compression. hince the need for higher octane fuels..... as far as posting false information. james im not the one who picks eveyrones postings apart on this forum. sorry i live in the real world if that offends you sorry get a life. no need in feeding ppl full of bull crap


oh and for someone who is so quick to point out faults maybe you should read up about some of the things "you claim to know about" id really like to know what your background is with the Z car or any car for that matter


Irei
 

· Not Anymore.
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BlankgazeX said:
yea, just cxause you lose power by going down on octane rating(because of retardation by the knock sensor) isnt the same as saying you will gain power by going up...
This is true...I guess I worded that awkwardly. The car will not be making its full potential because of the knock sensor (I assume the Z has one) will retard timing. Dyno graphs will show this on Spec Vs which use 87 while dynoing. Their graphs look somewhat like a richtor scale.
 

· ZPOOLNZ
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IreiMember said:
lol james its obvious you dont know crap about engines. yeah ok i guess your right you will loose 1 hp if you choose 87 over 91 sorry i stand corrected.



race fuel is for race engines (yes people in the business call these engines not motors)with high compression. hince the need for higher octane fuels..... as far as posting false information. james im not the one who picks eveyrones postings apart on this forum. sorry i live in the real world if that offends you sorry get a life. no need in feeding ppl full of bull crap


oh and for someone who is so quick to point out faults maybe you should read up about some of the things "you claim to know about" id really like to know what your background is with the Z car or any car for that matter


Irei
I've built/building a Z31T, worked on Z32s, I have been around and worked on the 350Z; I have been around/in development of parts for the 350Z. I know all of the guys that design parts at Crawford, and many of my friends own 350Zs. If you think all you will lose is 1hp your dead wrong. The ecu will pull timing to the point where the car is not making any power; and just trying to avoid detonation. Now I have a life the thing is everything I have read that you posted is incorrect. Unless you know what your talking about don't post because I will continue to correct you so you don't cause problems for someone that reads your posts.
 

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IreiMember said:
race fuel is for race engines
Wrong. Race fuel is useable on all engines. I noticed a definite difference between running 91 octane pump gas in my car, and running 104 race gas in it. NA engines are mostly the ones that don't require an increase in octane, unless you increase the compression ratio and/or the valve lift. Turbo engines, when you increase the boost, you effectively increase the compression ratio.
I've also learned the problems of running low octane in a higher octane required engine. My motorcycle requires 91 octane. I attempted to run 85 in it, and the pinging was painfully obvious. I promptly drained the tank and put the proper grade of gas in it. And this was in a carburated 15 year old motorcycle. Modern engine electronic controls will cause massive loss of power when low octane fuel is sensed by the knock sensor and the 02 sensor. You can't argue with the facts, and those are.
It used to be that running too low a grade of fuel, in older engines, simply caused the head gaskets to blow, due to knocking, and other major problems. Now, thanks to modern technology, we don't have those problems any more, the effects are simply seen as a loss of power as systems compensate for the low grade. So people no longer seem to see the severity of the situation , as they may have 20 years ago before modern electronics.
 

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lol ok james here we go. read the posts i write(and i mean the whole thing not just parts you like to pick out)

ok perhaps if you dynod your car with 87 octane im sure you would see that 91 will surely put up better numbers. (not by a whole lot though)

now as far as your timing retarding, yes to some degree you will have some retarding but not to the extreme like your thinking and this is why.

lets assume for the sake of argument that our new 350z has a compression ratio of 9:1 putting in what the oem recommends which im sure is 91 is always the best solution. however its not a requirement.

o2 sensors senses the fuel mixture and tells the ecu to change the fuel mixure if need be. (via exhaust)

knock sensor senses the vibration in the antifreez in your block, which then controls the timing to stop a knock if one should come about before something bad should happen

it would take a really low octane fuel to cause an engine to knock and retard its timing. this is a brand new engine keep in mind. so its effeciency is gonna be way high unless there are other problems that we dont know about. (an old tired 10 year old engine would probably prover otherwise)

i will agree if a knock does occur there will be substantial power lose of course.


Higher Octane fuels in low compresson engines will not produce more power PERIOD!

im looking at all data as we speak and will post some more precise data as time permits.

Irei
 

· ZPOOLNZ
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10.3:1 is the compression on the 03-05 VQ35DE found in the 350Z (minus the 05 track and 35th anniversary). The engine doesn't exactly have "low" compression. In every thread you have come back saying you will have proof. The fact is you do not. You continue to post B.S. that could cause problems for other users. In fact thus far you have not posted one piece of useful information. So sit back for awhile and absorb some knowledge before you start posting. That way you won't post the wrong information.

I have noticed you know nothing about the engine managment on any car. And since you know NOTHING about Zs and especially the 350Z please stop trying to act like you know everything. The engine will pull timing and ALOT more then you are letting on. You act like it won't effect anything when in reality it DOES. Please you have NO experience with the car. I'm sick of telling you over and over again your wrong.

And 100 octane will help on the 350Z it cost to much to be practical, but dynos have shown a 7rwhp gain from running 100 octane gas. Also low octane has caused pinging in the Z33. Performance gains aren't exact, but people have slips showing a .3 second difference between 91 and 100 octane in the 1/4 mile.
 

· Whoa...
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NickZac said:
This is true...I guess I worded that awkwardly. The car will not be making its full potential because of the knock sensor (I assume the Z has one) will retard timing. Dyno graphs will show this on Spec Vs which use 87 while dynoing. Their graphs look somewhat like a richtor scale.
not to mention what would happen if the knock sensor crapped put... major engine knock and leading to fuct pistons...
 

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BlankgazeX said:
not to mention what would happen if the knock sensor crapped put... major engine knock and leading to fuct pistons...
Blown head gaskets, too. Depends on the engine. Some engines, such as the 4G63, simply melt the pistons before the headgasket goes. I have personal experience with that..... ;)
 

· Power FC Z32
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IreiMember said:
lol ok james here we go. read the posts i write(and i mean the whole thing not just parts you like to pick out)

ok perhaps if you dynod your car with 87 octane im sure you would see that 91 will surely put up better numbers. (not by a whole lot though)

now as far as your timing retarding, yes to some degree you will have some retarding but not to the extreme like your thinking and this is why.

lets assume for the sake of argument that our new 350z has a compression ratio of 9:1 putting in what the oem recommends which im sure is 91 is always the best solution. however its not a requirement.

o2 sensors senses the fuel mixture and tells the ecu to change the fuel mixure if need be. (via exhaust)

knock sensor senses the vibration in the antifreez in your block, which then controls the timing to stop a knock if one should come about before something bad should happen

it would take a really low octane fuel to cause an engine to knock and retard its timing. this is a brand new engine keep in mind. so its effeciency is gonna be way high unless there are other problems that we dont know about. (an old tired 10 year old engine would probably prover otherwise)

i will agree if a knock does occur there will be substantial power lose of course.


Higher Octane fuels in low compresson engines will not produce more power PERIOD!

im looking at all data as we speak and will post some more precise data as time permits.

Irei
We are talking about the Z33, right? The ECU from the factory is tuned to 91 octane and the Z33 compression is 10.3:1 (fact) not 9:1. Have you noticed that it is very hard to make power on these cars? The reason is that Nissan has tuned the Z33 to it's optimal and why it's important to put in high octane gas. Anything less will drop your HP considerably and I'm not talking 5 hps (there is a reason the variable timing is used in this car). You won't find a dyno comparisions of octane difference because it's a waste of money and know one in there right mind would subject a $30+K Z to that kind of abuse.

Originally Posted by IreiMember
"Higher Octane fuels in low compresson engines will not produce more power PERIOD!"

I hate to say it but this statement puts you in the John.. A Z32 has a compression of 8.5:1 and when this car came out the octane rating in Cali was 92 and when they switched over to 91 octane people with JWT ECU's went into safety boost. What does that tell you?? If you have some knowledge of how a car works this is telling you octane does count.

If you do have data please post it I do have a open mind?
 

· Not Anymore.
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♣Zen31ZR♣ said:
Blown head gaskets, too. Depends on the engine. Some engines, such as the 4G63, simply melt the pistons before the headgasket goes. I have personal experience with that..... ;)
I've seen it!!! (crap, my buddy was pulling bad knock on his heavily modded 4G63 with 93 octane).
 

· Whoa...
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Spongerider said:
Ok show me the fact, I'm waiting? But if your word is fact then you really need to go to the 300zxclub because that kind of baby talk belongs there.
ok idiot, run 87 in your car, but dont tell other peole to, because you are too ignorant to realize IF THE KNOCK SENSOR FAILS A 350Z WILL BECOME SERIOUSLY FUCKED UP WITH 87 OCTANE GAS! and like i said, you lose power with lower octane BECAUSE of the sensor, is that what you are disputing? or are you disputing my statement you WILL NOT gain power from higher octane?

its a high performance car, use high performance gas... god i went through with this shit in the qr section with spec V's, some dumb ass is gonna have 100 people fuck up thier cars to save 30 cents at the pump...

in the end, if your car says 91, run 91, 87 will hurt it, 100 wont help it, use what is recomended...
 

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BlankgazeX said:
ok idiot, run 87 in your car, but dont tell other peole to, because you are too ignorant to realize IF THE KNOCK SENSOR FAILS A 350Z WILL BECOME SERIOUSLY FUCKED UP WITH 87 OCTANE GAS! and like i said, you lose power with lower octane BECAUSE of the sensor, is that what you are disputing? or are you disputing my statement you WILL NOT gain power from higher octane?

its a high performance car, use high performance gas... god i went through with this shit in the qr section with spec V's, some dumb ass is gonna have 100 people fuck up thier cars to save 30 cents at the pump...

in the end, if your car says 91, run 91, 87 will hurt it, 100 wont help it, use what is recomended...
We've already shown that 100 octane will help it.....
You'd lose power in a car running 87 octane that should be running 91 octane, knock sensor or no. Why? Because the knock is incomplete combustion..... The typical engine only uses 33% of the energy contained in a given amount of fuel. When improper octane levels cause knock, that means far less is used.
Knock is improper flamefront propegation in the combustion chamber. Typical knock can be best explained as too fast of such propegation, instead of uniting as a single "wave" and creating the powerful push on the piston, it splits up, "echoing" off the walls of the combustion chamber and charging the middle, where one or more meet and cause a reverberation effect. All of this is supersonic and takes place in milliseconds, your brain registers it as a high frequncy tapping sound.......
Anyway, what I'm trying to say , is that you would lose power whether the knock sensor heard that noise or not. Knock sensors are designed to hear that certain frequency of where 90% of all knock occurs. However, it can happen at a much lower or higher frequency, especially if the car has any modifications that affect airflow. Air density affects knock frequency. It's possible to have knock the the sensor will not even notice, especially in older vehicles.
 

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And I should perhaps point out that Irei is incorrect as to how the knock sensor hears the sound. It is not listening to the sound of the antifreeze. Not on gasoline cars anyway, that is reserved for the newer diesels. No, it is listening to the sound of the engine block itself. The metal is of a known composition and will conduct sound almost always in the same way. Composition of antifreeze can change, and could change how much or how little of that particular knocking sound is actually heard by the sensor. Go ahead, pull the knock sensor on any car, it is not in a water jacket...
 
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