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Ea82t


TheBush
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I run my EA Turbo off of regular (which is 85 octane at this elevation). No problems at all. Try regular, if it pings, then run premium.

+1.

 

the most succint piece of advice on "what octane should I run?" is this: Any internal combustion engine should run on the lowest octane fuel it can without detonating. Not that anyone would blame you for running high test when you didnt really NEED to.. but if others run on low test fine, then you should be able to as well.

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I ran 91 in my EA82T at all times. Anything less and it ran like crap.

 

I didnt read a book or look for decals. I just used common knowledge. Turbo's require higher octane to prevent predetonation. If you don't have an intercooler I wouldnt recommend 85 or 87. Even if you do have an intercooler, spend the extra $0.10 a gal and get 91.

 

-Brian

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If you get anything from this thread, try what works best for you.

 

My EA81T (granted, not an EA82T, but still has same compression, same turbo...) gets the same power and same mileage on 85 oct or 91 oct. It could very well have to do with the fact I live at 6500ft, and almost never go below 5000ft in elevation.

 

My suggestion, try a couple tanks of premium. Calculate the gas mileage.

Try a couple tanks of regular, listen carefully for detonation, and calculate the gas mileage.

 

You can figure the rest out. FYI: The manual says 87 octane.

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I ran nothing but 93 in my GL-10 and I have an intercooler, fenderwell intake, and adjustable FPR. I completely agree with Caleb and Brian. It is always a good rule of thumb to run premium or the highest octane available(I'm not talking about 110 octane race gas, for those of you who have it readily available;) ) in you area. It prevents pre-detonation(aka "ping"), which is a killer of turbocharged engines, especially modified ones.

 

Patrick

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  • 2 weeks later...

i have been running 91 in my 88 turbo wagon with a wrx top mount, but i have detonation problems once i get into higher revs in 3rd-5th gear.....its not just knocks its full on to where my car just nose dives for a sec and then starts to drive normal again.....for some reason my manual says 90 octane or higher but iono....i think that my detonation problem could be in part to the fact i redid my head set but had the typical cracks across the valves on both of my heads, i think that this is my hot spot and is the main cause for the detonation problems......

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Sub Speed 559, it sounds like your timing may be way too far advanced. Let me ask this before I jump to conclusions about what is wrong with your car, how much boost are you running? Also, what rpm are you wringing it out to before you shift? Some of the old school sube's won't take more than between 10-12 psi before they start hitting fuel cut. Others(the lucky one's) can go well over 12psi with no inherent fuel cut problems. If you have your boost turned up too high, this could be the problem.

 

Patrick

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Sorry I am so fussy, but let's get the terms right:

 

THERE IS NO PREDETONATION!

 

There is preignition, when the charge goes off before the spark hits.

 

There is detonation, when the charge burns faster than it should, after the spark. This is also called "knock."

 

Low octane ping is a sign of detonation.

 

http://en.wikipedia.org/wiki/Engine_knocking#Pre-ignition

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Use what the owners manual says to use. If it pings, use the next higher octane.

 

I used 93 octane because I was wuss and didn't want to try and wait to hear ping, detontation, etc on a lower grade octane. Also, I remember that thread that was posted with the inlet temperature of a non-intercooled EA82T. I loved that thread and the numbers. Hot air is not good. I thought of cylinders #1 and #3 overheating and the cooling system problems people have had over the years. I thought of headgaskets going bad and leaking. Using 93 octane gave me a warm, fuzzy feeling inside, even when it was intercooled. Car ran great even though the body went all to hell. Hrrm...I think that is all. :cool:

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i use 91 octane also. anything else runs like crap, pings. but then, i have the high compression bottom end with no intercooler... maybe i should get one....

 

Not to go to far off topic but maybe this link will convince you to get an intercooler installed (Especially being higher compressioned and all).

http://www.ultimatesubaru.org/forum/showthread.php?t=15554&highlight=inlet+temp

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Definatly if you are running a high comp block, get an intercooler!

 

The Saab 900 IC is almost a direct bolt in:

DSC00459.sized.jpg

 

The inlet and outlet are both 2 3/8" outside diameter, which is the same size as the intake manifolds outside diameter.

 

DSC00433.sized.jpg

 

The difference with and without are night and day.

 

-Brian

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Definatly if you are running a high comp block, get an intercooler!

 

The Saab 900 IC is almost a direct bolt in:The difference with and without are night and day.

 

-Brian

 

Brian,

 

That is a beautiful setup. Seems like the car should have came like that from the factory. Would be nice to see someone sell that as a kit. :slobber::lol: The brackets that stand the intercooler up is sweet.

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Yeah it worked out quite well. Turbohoses.com sells the silicone couplers, and I bought two 180 degree mandrel bent U bends in 2 3/8" inside diameter, then cut them both in half to give me four 90 degree bends.

 

The brackets were just angle and strap I got from Home Depot.

 

The hardest part was adapting the turbo outlet which is 1 3/4" outside diameter i believe.

 

Sure wish the intercooler install on my Legacy was that neat and easy :)

 

-Brian

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Sorry I am so fussy, but let's get the terms right:

 

THERE IS NO PREDETONATION!

 

There is preignition, when the charge goes off before the spark hits.

 

There is detonation, when the charge burns faster than it should, after the spark. This is also called "knock."

 

Low octane ping is a sign of detonation.

 

http://en.wikipedia.org/wiki/Engine_knocking#Pre-ignition

 

Wooo! My bad man! You don't have to be so grouchy about it. I was thinking the words pre-ignition and the other word for it detonation, then wound up typing pre-detonation. No need to blow a gasket over it. Besides, unless you are contributing something to the topic at hand, you might think twice about posting, or at least just say nicely,"Hey, you may have misspelled something. It is pre-ignition, not pre-detonation." Geez.............

 

Anyway, an intercooler on these engines is the way to go. You increase the engine reliability greatly with one. Your engine will Thank You for it!

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