I'm looking at getting an Sti, but I want to know the whole deal with det, or detonation. I've seen several posts talking about it, but I can't find anywhere that explains exactly what it is. Could I get some help? Thanks.

 

when the gas ingnites before the cylinder is at top dead center. this causes the downward force to oppose the rising piston and rotating mass. Detonation can lead to engine failure.

San

 

That's a decent working idea of it, however if one wants to get a little more technical (without being Bill Nye the Science Guy) the air/fuel mixture is almost always going to start ignition before the piston is at TDC (that's why it's called ignition ADVANCE and it's measured in degrees BTDC [before top dead center]).

Here's something a bit more specific:
As it applies to the STi: It appears that the STi has a relatively agressive timing map that causes the car to ping under heavy loads/high boost on pump gas.

Looks like the factory was a little overzealous in getting every last pony out of the EJ257.

Hawaii-specific, it seems like the 92 octane we have is slightly less prone to ping that the 91 swill they get in Cali - but there's still evidence of detonation. Subaru USA has released a fix and has it available at their dealers and most people seem to feel that the ECU reflash helps. It apparently is not available to do in-house here in Hawaii yet.

Detonation is NEVER good and will eventually cause damage if left unchecked.
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info on the sti problem.

http://forums.nasioc.com/forums/show...hreadid=415592

 

Plus they wanted to give us something to listen to, since we didn't get a stereo!

 

Hmm, that doesn't sound good, so would you recommend waiting until this problem is taken car of to buy and STi? I've also read several things some saying that you loose power, some saying you don't. They were all on nasioc. What is the verdict? Do you loose power, and can they ship the ECU's back to get them reflashed?

 

I don't think anyone locally has had theirs reflashed, but the newer STi's may already be reflashed.

With Hawaii's 92 octane gas you really have to push your car hard and the right way to get detonation.
Once they can do a reflash locally I'll probably go for it. I'll take a little power loss if it prevents damage to the engine.
You can always get an engine management solution (ECUTEK, Xede, etc...) with maps from a professional tuner that will give back any power loss and then some.

The problem has been acknowledged and remedied by Subaru which is the key thing.

 

I only experienced it once hard on the throttle going up a hill I too am waiteing until they can do it locally also because of it taking up to 10 days.

 

Well I got my STi, and it is so awsome I want to start humping it.

 

CONGRATS u bastiige !!!

And about u humping ur car.... i don't think any of us will wanna ride it in if we know u spooged on it somewhere !! hahaha

J/K !!!