Dilema: Switch to 95 Octane and retune, or detune" it for regular petrol?
- 2nd Hand Yank
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Dilema: Switch to 95 Octane and retune, or detune" it for regular petrol?
So it sounds from forum members that my engine is probably getting detonation at low rpm sometimes.
I'm using regular petrol, but I could switch to 95 octane. (or higher if need be)
I haven't done a full tune-up yet with my EA82 though,
I've only owned this '93 L Series for 2 months.
Today I bought what could be my last full tank of regular petrol,
in case tuning it for regular petrol is the best idea.
*Question* - Can my old EA82 actually see performance or economy gains by tuning it for higher octane petrol?
It would be a waste to end up with the same amount of power and economy and be paying more per-Litre.
Thoughts?
I'm using regular petrol, but I could switch to 95 octane. (or higher if need be)
I haven't done a full tune-up yet with my EA82 though,
I've only owned this '93 L Series for 2 months.
Today I bought what could be my last full tank of regular petrol,
in case tuning it for regular petrol is the best idea.
*Question* - Can my old EA82 actually see performance or economy gains by tuning it for higher octane petrol?
It would be a waste to end up with the same amount of power and economy and be paying more per-Litre.
Thoughts?
It will be more fuel efficient and will have a bit more power if it is properly set up for a higher octane fuel. However i think its pretty well established that it is not more economical finacially, but if you see value in the performance benefits then that would change the equation. There are probably other things you can do to compliment the higher octane fuel too, like a more powerfull ignition system.
I reckon try it for a tank and see if it cures that particular problem you have, thats a pretty simple and quick way to see if it is a pinging problem. Plus you get to try a higher octane fuel, although your car might not be getting the most out of it.
I reckon try it for a tank and see if it cures that particular problem you have, thats a pretty simple and quick way to see if it is a pinging problem. Plus you get to try a higher octane fuel, although your car might not be getting the most out of it.
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- Gannon
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You will only see a difference if you adjust your ignition timing to suit the higher resistance to knocking. You could also raise your compression ratio, but it isnt really worth the effort.
Current rides: 2016 Mitsubishi Triton GLS & 2004 Forester X
Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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apparently 91 is or will be phased out over the next few years to make way for a ethanol based replacement as the new cars on the market are not rated for such a low octane fuel . . . just what i was told not 100% sure on its validity and on personal experience the extra fuel economy almost accounts for extra cents and the boxers seem to like 98 better.
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to do list:
-3" strut, 2" body lift uni mid-year break
- discopotato03
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- sven '2'
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PULP = Slightly better response. Slightly smoother. Better economy makes it worthwhile to run on PULP. Much better behaved in summer.2nd Hand Yank wrote:So it sounds from forum members that my engine is probably getting detonation at low rpm sometimes.
I'm using regular petrol, but I could switch to 95 octane. (or higher if need be)
I haven't done a full tune-up yet with my EA82 though,
I've only owned this '93 L Series for 2 months.
Today I bought what could be my last full tank of regular petrol,
in case tuning it for regular petrol is the best idea.
*Question* - Can my old EA82 actually see performance or economy gains by tuning it for higher octane petrol?
It would be a waste to end up with the same amount of power and economy and be paying more per-Litre.
Thoughts?
Re-tuning to a better grade fuel is a waste of time in NA L-Series though. Just switch and enjoy.
Sven
73 Yamaha DT3 250
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
- d_generate
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No EJ should be running on 91 period, if it was mine it would be on 95 minimum. I have to run both my Lib & WRX on 98 as they have JDM computers and should be on 100 but I wouldn't use anything else unless I was driving a HQ Belmont.
98 Libbo with V3 STI running gear. 13.0 @ 105mph with CAI & 3" Zorst:mrgreen:
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- 2nd Hand Yank
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^^ The only reason I'm running 91 is thats what the motor was designed for.
If my noises are detonation,
then my right foot really can't ask it too much without yelping.
I'm not expecting it to be immediately more economical,
but if it's 10 cents more a Litre (7-8% more expensive) and it goes 2-3% further,
that means I don't have to fill up quite as often
or can get a little further on a full tank.
A marginal increase in power would also be VERY welcome.
I'd just hate to switch if the noises aren't causing long-term damage,
I won't get better economy and my power won't change.
It'd be silly to switch for that.
If my noises are detonation,
then my right foot really can't ask it too much without yelping.
I'm not expecting it to be immediately more economical,
but if it's 10 cents more a Litre (7-8% more expensive) and it goes 2-3% further,
that means I don't have to fill up quite as often
or can get a little further on a full tank.
A marginal increase in power would also be VERY welcome.
I'd just hate to switch if the noises aren't causing long-term damage,
I won't get better economy and my power won't change.
It'd be silly to switch for that.
- 2nd Hand Yank
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- littlewhiteute
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Detonation is causing long term damage, even imediate for that matter in the form of very small/tiny holes in the piston and combustion crown. It is causing extra load on the big end bearings although they hardly ever give out, eventualy the piston will break around the ring land.2nd Hand Yank wrote:^^ The only reason I'm running 91 is thats what the motor was designed for.
If my noises are detonation,
then my right foot really can't ask it too much without yelping.
I'm not expecting it to be immediately more economical,
but if it's 10 cents more a Litre (7-8% more expensive) and it goes 2-3% further,
that means I don't have to fill up quite as often
or can get a little further on a full tank.
A marginal increase in power would also be VERY welcome.
I'd just hate to switch if the noises aren't causing long-term damage,
I won't get better economy and my power won't change.
It'd be silly to switch for that.
Also detonation/pre ignition is robing your engine of power and economy. The way I see it 91 octane is false economy.
Put a full tank of 98 in it and you will understand.
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Current
00 Outback with class, SOHC EJ25 auto 240,068ks
"B1" 90 Brumby with character 271,800K EA81 (But soon 5speed,103,000k EJ202)
"B2" wrecked and crushed
"B3" 89 Bush Bashing Brumby (BeeRumBee) Kept a Bucca
"B4" 89 Black Brumby (wam balam ) Kept at Kempsey
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Brumby Trailer (Sulky)
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Current
00 Outback with class, SOHC EJ25 auto 240,068ks
"B1" 90 Brumby with character 271,800K EA81 (But soon 5speed,103,000k EJ202)
"B2" wrecked and crushed
"B3" 89 Bush Bashing Brumby (BeeRumBee) Kept a Bucca
"B4" 89 Black Brumby (wam balam ) Kept at Kempsey
"B5" 92 Brumby (sold it)
"B6" 88 Beige Brumby
"W1" 83 wagon 308,000 AC and alot of rust repairs. (Wanda)
Brumby Trailer (Sulky)
LUV THAT BRUM !
RevMax Hobbies
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- sven '2'
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No it wasn't.2nd Hand Yank wrote:^^ The only reason I'm running 91 is thats what the motor was designed for.
Was designed for JDM and OS fuel markets, generally much higher quality fuel than the AUDM.
The AUDM Subarus were detuned for for our market - as all (or most) JDM cars are.
You are running technology circa 1915 - ie a carby - therefore the best thing you can do is put the best fuel in.
73 Yamaha DT3 250
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
- steptoe
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Starting to look at fuel numbers again myself (been used to no-choice-but- high- octane LPG) and noticed woolies and caltex offer a product called Vortex in 95,98 and Diesel. Not sure if it was timing or location but ended up paying 3 cpl more for 98 than 95. Think i will stick to the 98 - gave me 10 litres per 100km of varied driving in the EA82TS Vortex
While the knock sensor works on efi they "self adjust according to fuel grade" (Lexus sales pitch )
On my old EA81 in my Brumby I found to shove ten bucks of 98 on an empty tank it ran better by allowing me to stomp on the loud pedal get more torque down lower, so not needing to rev higher it should give better mileage, yet I never allowed self to fill up on it so cannot tell you to budget for a few tanks of 98 and just try it can I?
Maybe try gearshifts 500rpm lower... actually, what are you hoping to achieve ? performance, economy or a balance?
Wait for the fit a new big zap coil people to come on in
While the knock sensor works on efi they "self adjust according to fuel grade" (Lexus sales pitch )
On my old EA81 in my Brumby I found to shove ten bucks of 98 on an empty tank it ran better by allowing me to stomp on the loud pedal get more torque down lower, so not needing to rev higher it should give better mileage, yet I never allowed self to fill up on it so cannot tell you to budget for a few tanks of 98 and just try it can I?
Maybe try gearshifts 500rpm lower... actually, what are you hoping to achieve ? performance, economy or a balance?
Wait for the fit a new big zap coil people to come on in
just try the 98. its what everyone else on here had to do to see if it made a difference.2nd Hand Yank wrote: I'm not expecting it to be immediately more economical,
but if it's 10 cents more a Litre (7-8% more expensive) and it goes 2-3% further,
that means I don't have to fill up quite as often
or can get a little further on a full tank.
A marginal increase in power would also be VERY welcome.
I'd just hate to switch if the noises aren't causing long-term damage,
I won't get better economy and my power won't change.
It'd be silly to switch for that.
run your tank to nothing and fill it up with premium. you will be the only one who knows if it makes a difference to your car. then you can decide if its worth it or not. it will cost you all of 5 bucks, just take an extra bottle of water to work and dont buy a drink or whatever and you will be even anyway.
even better, run it for a couple of tanks and do a L/kms test on it and see if it is more efficient then go back down to 91 (i am almost certain you will feel the drop in power, even if you dont notice the increase as much when you initially filled).
sometimes you have to stop thinking and working out little percentages and just give it a go. in the end it comes down to whether you notice the difference in fuels (i know i do!)
im going to be different to the crowd
i wouldnt bother. Spending anything but the minimum on an ea82 is still too much.
ive been there done that, tried to get more performance from my old ea82 carby, just a waste of time and dollars.
id just run normal fuel, ea82s are moderately bullet proof, when it dies put a ej motor in there.
itll probably last another hundred tanks if its even pinging, then with the money youve saved on 98octane fuel about 15c per litre extra than 91 youll be 3/4 of the way there for a ej motor.
put simply i wouldnt spend any money an ea82 if it isnt 100% needed.
alex
i wouldnt bother. Spending anything but the minimum on an ea82 is still too much.
ive been there done that, tried to get more performance from my old ea82 carby, just a waste of time and dollars.
id just run normal fuel, ea82s are moderately bullet proof, when it dies put a ej motor in there.
itll probably last another hundred tanks if its even pinging, then with the money youve saved on 98octane fuel about 15c per litre extra than 91 youll be 3/4 of the way there for a ej motor.
put simply i wouldnt spend any money an ea82 if it isnt 100% needed.
alex
my07 Outback
my13 Hyundai i45(shhhh)
my02 Gen3 Liberty limited ed.
previously
L-series wagon, LSD, EJ20turbo, 29in tyres, 'wanky wagon'
2000 gen3 outback, lifted, otherwise stock.
my13 Hyundai i45(shhhh)
my02 Gen3 Liberty limited ed.
previously
L-series wagon, LSD, EJ20turbo, 29in tyres, 'wanky wagon'
2000 gen3 outback, lifted, otherwise stock.
- sven '2'
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Differing compression ratios, emission controls, jets etc.steptoe wrote:Detuned for AUSDM - how so?
Am sure I read that the JDM service manual specifies a different coil, spark plug gags and timing - maybe that was on USMB, back when I suffered carby syndrome*
In my experience, this is partly why when you buy an import engine, the manifolds etc are changes from your dud motor to the 'new' one.
More modern cars sport a different ECU map
* carby syndrome (noun def) - thinking one can increase the power of a EA82 by tinkering with the carby - most often a delusional state, fixed only by 2,000ml of EJness, and in rare cases, 1,800ml of EA82Tness
73 Yamaha DT3 250
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
08 Ford BF wagon - LPG FTMFW
14 Toyota Kluger - goodness!
BAHAHA!sven '2' wrote:
* carby syndrome (noun def) - thinking one can increase the power of a EA82 by tinkering with the carby - most often a delusional state, fixed only by 2,000ml of EJness, and in rare cases, 1,800ml of EA82Tness
very rare EA82Tness
my07 Outback
my13 Hyundai i45(shhhh)
my02 Gen3 Liberty limited ed.
previously
L-series wagon, LSD, EJ20turbo, 29in tyres, 'wanky wagon'
2000 gen3 outback, lifted, otherwise stock.
my13 Hyundai i45(shhhh)
my02 Gen3 Liberty limited ed.
previously
L-series wagon, LSD, EJ20turbo, 29in tyres, 'wanky wagon'
2000 gen3 outback, lifted, otherwise stock.