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Location:
Brisbane
Registered:
January 2003
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1jz-gte Octane requirements.
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Sat, 25 January 2003 11:47
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I've heard some horror stories of nissan skyline engines that require the japanese 100RON and the detonation caused by running on lower octanes.
Does the 1JZ-GTE suffer from this too? Of course I'd only run it on 98 pump fuel, but is that enough? do I need to add octane booster each time I fill up?
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Location:
Southern Sydney
Registered:
August 2002
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Re: 1jz-gte Octane requirements.
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Sat, 25 January 2003 15:17
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The sticker on the engine bay of mine says minimum 92RON.
Performs signiciantly better with 98RON fuels though.
You definetly don't 'need' octane booster.
The dual knock sensor will retard timing if lower octane fuels are used. This should prevent pinging but you will loose power.
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Location:
Brisbane
Registered:
January 2003
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Re: 1jz-gte Octane requirements.
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Sun, 26 January 2003 00:53
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Ahh well thats okay then Thanks  I wouldn't run it on anything but 98.
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Location:
Wollongong
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Sun, 26 January 2003 00:59
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I run my 1JZ on 98 octane (Optimax) and it runs fine. Just make sure your spark plugs are in good shape, cos they tend to misfire a bit under boost (in my experience).
Yes, the knock sensor will retard the engine if lower octane fuel is used, but from memory, knock sensors are only active in closed loop ECU mode. If you are running WOT, I don't think they activate (although I could be wrong). Can anyone confirm ?
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I supported Toymods
Location:
Brisbane, QLD
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Sun, 26 January 2003 23:17
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From what I have seen with the older ECUs, that is correct. Knock sensor input is only used in closed loop. However, the 1JZ/2JZ ECUs might still use the knock sensor input in WOT because it makes good sense to do so.
Cheers
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Location:
Cabramatta, NSW
Registered:
May 2002
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 Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 01:06
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If the 1JZ is anything like the 1G, you don't want to be running SULP in it... It may not ping (thank you knock sensors), but it'll lugg like crazy and there's a HUGE flat spot in the middle of the rev range.
SULP = evil
PULP = less evil
I only ever run 98 octane, the engine is so much smoother.
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Location:
Southern Sydney
Registered:
August 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 01:24
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I ran Regular unleaded in my car on the weekend....
(Thankyou Woy Woy BP for hiding the Premium pump around the corner  )
And yes I can vouch that it ran pretty poor. Not that mine is running the best at the moment anyway.... still need to change the plugs and fix the mixtures up.
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 03:22
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I am sure my KNock sensors are active in WOT, whether that is because of my fconv or not I dont know.
When unsatisfactory fuel or high intake temps cuase detonation (not yet audible) the ignition is retarded.
That is what happened at the dyno day for me. I had discovered the ignition retard thing in the summer heat before christmas, and ever since have not run it at over 12 psi during the day since.
But on the dyno day I tried for a run at 16 psi and the ign retarded so far it nearly stopped as it climbed on boost.
stoopid me didnt turn the boost down and so got crap figures !!!
On a cold night I can run with Andy (212 rwkw) with very little difference.
DAMN !! I gotta get rid of this stock intercooler !
Matt
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Location:
Sydney
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 03:28
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hell I can feel the difference in performance on hot days to nice cool nights with my stock 1g, and running normal premium when on hols with octane booster felt a tiny bit flatter than optimax.
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 03:43
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I think the gist here is that even if you think your import motor (especially factory computers) is running happily on 92 or 95 RON fuel, IT WILL ALWAYS RUN BETTER ON GOOD 98 RON FUEL !!!
Even 98 RON fuel will not always completely fix this knock sensor intervention on a hot day with stock 'cooler and 1 barr boost. most commercial octane boosters will not stop this either. I have a cheap and accessable alternative that works, but if I told you what it was you'd laugh. So I wont. Try sniffing my fumes one day yuou should be able to guess !!
Perhapps Celicamad can shed some light here, he has been researching this topic and I beleive has found a solution.
Matt
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Location:
Ipswich
Registered:
July 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 05:36
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I heard a rumor that japan's PULP is 98 octane and their standard unleaded is 95. Most high performance import engines are designed to run on PULP japan pulp that is.
So if the rumor is true then only run optimax and ultimate.
better to be safe than stuck on side of road with a dead engine.
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Location:
Cabramatta, NSW
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 05:43
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Jap PULP is 100RON isn't it?
Lucky bastards.
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Location:
Brisbane
Registered:
January 2003
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 06:15
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Yes their premium is 100RON they even have a "high octane" at some pumps for 110 expensive as all hell though
Surprisingly in American they only get about 91 max, probably to help keep things cheap.
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Location:
Brisbane
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 06:23
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Americans use a different measuring system to us (and just about everyone else - bloody yanks, always have to be different). We use Research Octane Number (RON), while they use Anti-Knock Index (AKI) which is an average of RON and MON (Motor Octane Number). Confused? Good!
The point is, the 91 octane fuel the yanks have is roughly equivalent to our 98 octane fuel.
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Location:
Cabramatta, NSW
Registered:
May 2002
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Location:
Brisbane
Registered:
January 2003
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 06:30
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Ahh so thats what it is I did think it was a bit strange, bah why can't they just use the same system as everyone else 
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Location:
North Sydney
Registered:
May 2002
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Re: 1jz-gte Octane requirements.
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Tue, 28 January 2003 10:28
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I am sure my KNock sensors are active in WOT, whether that is because of my fconv or not I dont know.
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Yojimbo, i'm sure you'll find they arn't used in WOT whether you have a fcon or not.
When you were on the dyno and your ignition was retarded it was done purely because of the intake temps were high. Not because there was detonation occuring even if it was in-audible.
Preset ignition advance maps are used from the eeprom. The knock sensors are used below about 4000rpm on light throttle applications only.
Go with the premo, ultimate or optimax
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