mega_stream

I'm pondering on getting a throatier backbox for the car as the standard Sti backbox is almost silent.

Does my car only have a cat in the downpipe, I've no intention of decatting the car as i'm running a stock ECU. I've had a look but can't work out if its a centre cat or a resonator box...

The car is stock otherwise, and is staying that way

Would it be ok to go HKS Hiper and loose the mid cat if it has one without a remap??

Cheers

John

mega_stream

Thanks..

So fitting a HKS Hiper mid and backbox will have no effect on emmission's then?

I'm worried that it'll mess with fuelling..., also don't want any agro come MOT time.

ozzy

John,

All the later STI's have a de-cat centre with resonator. It's the same one that was fitted to the UK PPP cars.

Stefan

mega_stream

Thanks, so am I ok to run a Hiper mid/back with a stock ECU?

I might just stick with a Hayward and Scott 4.5" tailpipe and stick it on the back of the original mid.

ozzy

I would think so. Can't see how the backbox and mid would alter things so much that you would need to alter any of the ECU paramters.

If you were changing the downpipe, then you may need to start tweaking things.

The std STI would keep the noise from any of the loud bacboxes down. Going for a BB/mid combo may make things too noisy. That's one of the reasons I've left my STI backbox on my car (TSL de-cat centre and downpipe).

Just changing the BB would give you the extra noise and you wouldn't need to worry about how the ECU handles it. If it's not loud enough, then replace the centre.

The Ecutek guys would be better placed to advise you if these mods would affect any of the ECU maps.

Stefan


[Edited by ozzy - 1/4/2003 8:27:15 PM]

Tim W

iTrader: (1)

John, the centre section even with the resonator in place of a Cat is surprisingly restrictive!

Changing the downpipe to a Cat free one would make the biggest difference to flow, but will lean out the fueling a bit...

mega_stream

I had a full decat on my UK99 scoob, also had a Tek remap to compensate though.

From what I gather I'm ok with a my stock ECU and changing the mid and rear on my STi to a Hiper system.

I don't really drive the car hard anyway, no track days or sustained high speeds.

Dave R

The cat in the downpipe is the same as a UK car but where the UK car has a second cat in the centre, all Jap imports have just a resonator box in the centre pipe...

[Edited by Dave R - 1/4/2003 6:17:25 PM]