The Generation 3 Revision D Legacy Detonation Problem

[twinturboboy]

anyone?

[Marky]

 twinturboboy said:

just to bring an old thread up again I have some Q\'s

1 - Why do we not hear of people melting pistons from det? - Becuase they nuke bottom end bearings first

2 - There are heaps of Rev Ds around and surely not all owners would get them reflashed? - A lot of drivers wouldn\'t know the sound of pinging or know it was something to worry about, also does not seem to affect all the cars as bad as the rest

3 - apart from lower octane fuel and the AFM what else can cause det? - Blocked cat converters, timing too advanced (which is the problem here), hot air pod filter won\'t help. Fuel octane plays a much bigger part than I think you realise to be fair.

4 - there are heaps of high performance cars in NZ why dont they seem to suffer from this? - or is it only a Subaru problem - Some do, listen to your average 20V blacktop pinging it\'s way down the road (think those little carib wagons, can hear them coming like a tin can full of rocks at times). I\'ve heard of stocker 25dets etc having issues with age, as fuel pumps start to be less than ideal, AFM\'s get grubby etc.

If you want some genuine helpful advice look into how they sort the AUDM libertys - the aussie tune on them was an abortion and they ping their heads off. I think even the jap tune is an improvement for them (havent read up on it for ages).

Physical fixes which work - front mount cooler, no more heat soak and no more pinging. Full exhaust - as in good downpipes as well - less post-cylinder backpressure, pinging drastically reduced. Reflash - best, simplest, most permanent fix. For best results, combine all three.

The problem is the cars get half their response from high comp ratio combined with quite advanced timing, means it drives very nicely, downside is it\'s on a fine line between ping and powah. From what I\'ve seen they just can\'t retard the timing enough to stop ping once you combine the lower octane fuel (it genuinely makes a huge difference), then throw in the subaru handicap of a heat soaked top mount, 10 years of use, and things are stacking up against the car.

The reflash I have heard of some dealers doing is simply resetting the ecu and trying their damndest to make it ping - loading it up on boost at low speed etc - to get it to retard everything to the fullest from day 1 (reverse to "training" an ecu on high octane for a day I guess?). Better fix would be to bust out the romraider/tactrix/whatever it is and give it a safe tune, treating it as a "blank slate" I suppose.

[Steveo]

This thread is quite interesting, I have a 2000 BH5 Subaru Legacy E-Tune, unsure if that makes it s Rev-D or earlier than that.

Running stock airbox, aftermarket exhaust, Walbro fuel pump (factory one crapped out), and not long replaced the AFM. Unfortunatly can only run on 95 down here as the closest 98 is a couple hours away and a no detonation issues.

[gazzy2000]

 Steveo said:

This thread is quite interesting, I have a 2000 BH5 Subaru Legacy E-Tune, unsure if that makes it s Rev-D or earlier than that.

Running stock airbox, aftermarket exhaust, Walbro fuel pump (factory one crapped out), and not long replaced the AFM. Unfortunatly can only run on 95 down here as the closest 98 is a couple hours away and a no detonation issues.

prolly a rev b, someone will correct me if i is wrong. they will always run beter on 98 oct being that most are JDM and tuned for 100 oct

[ODB]

Have also done some fairly extensive reading on the subject and Marky is bang on re: mods to fix the issue in Aus.

You forgot water spray though - one guy I read up on had set this up to activate whenever secondary came on with a manual override which appeared to have good results re: heat soak and reduced pinging.

/unserious hat on

Once again I think SOOPERCOOLER is the solution to the problem here really.

[twinturboboy]

 Steveo said:

This thread is quite interesting, I have a 2000 BH5 Subaru Legacy E-Tune, unsure if that makes it s Rev-D or earlier than that.

Running stock airbox, aftermarket exhaust, Walbro fuel pump (factory one crapped out), and not long replaced the AFM. Unfortunatly can only run on 95 down here as the closest 98 is a couple hours away and a no detonation issues.

yes yours is a REV-B - I also have a REV-D and a REV-B and only the D dets - thanks heaps for the help guys

[Divine]

I am a bit paranoid now, might need to invest in some down pipes.