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?
Very good post. You put it in words better then I did.
I didn't point out the knock sensor Zen good point, the EJ25 has more problems then the knock sensor, the ecu is just a pain and it is hard to keep the pre 05 STis away from knock. In 05 they redid the ecu so now that is no longer a problem.
Most cars have multiple spark and fuel maps stored in the ECU. Most cars run fairly conservative timing advance and injector pulse width depending on what the knock sensor and 02 sensor sees. Most cars also run a touch rich from the factory, turbo cars definitely do. This is to protect engine warranties, for no other reason. What happens when the knock sensor hears less knock, is that it lets the ECU advance timing until it once again hears threshold knock, within the fuel maps capabilities to do so..... If timing can not be retarded enough to combat knock, a lower value fuel/spark map is switched to. When less knock is heard, the ECU advances the timing til it gets threshold knock, or if it comes up on the out of range of a low end map, switches to a more aggressive one. This is why putting higher octane gas in a modern vehicle can have big results. Older vehicles with less advanced ECUs, or even no ECUs at all, don't really benefit from using higher octane gas, except to combat piston deposits, as was mentioned before.
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1992 Yamaha FZR 1000. 145 Hp, all stock..
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...
At first, I was wondering why you were talking to me but then I realized I responded to you thinking you were IreiMember. So please disregard my comment to you?
On a side note, please be mature enough to respond like an adult? You can disagree so long as we agree to be civil, ok?
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