gareth

Martin - check the Scoobysport website for compatibility (or call them). I'm removing the kit before selling the car. Has been excellent fun for 12 months and without problems. My car had PPP already and this combination took it to 265 bhp/267 lbft.

Just noticed your location - you wouldn't be up for collecting the stuff then

[Edited by gareth - 11/5/2003 4:35:35 PM]

msonne

Hi there..

I want to go for a non restrictive exhaust on my WRX 03.

But I'm confused about the downpipe...

I read that the twindump minimizes the tubulence behind the turbo, but does anyone know how it compares to having just one big hole - can the differences even be messured?

And what about up-pipe - I remember someone saying that changing the turbo-back without changing up-pipe could dammage turbo?

Anyway - which downpipe is THE best - at any price
and - which one is the best value for money.

I would prefer the one with the best flow and not too loud inside the car.

(the BPM maybe - or what about the Helix??)

Thanks
Martin

nom

IMO, the best DP is the BPM. Quiet & very well designed twin-dump, but typically it's a good idea to steer clear of twin-dumps - they're not designed properly (join the flows together too early & at the wrong angle). I think the 'ScoobyMania' DP might be of the same style as the BPM though? The BPM does come as stainless or ceramic-coated mild steel - the mild steel is the quiet one, and will very quickly look as though it's falling apart, although it isn't! The ceramis just begins to look manky...
On an MY03, the up-pipe is a good idea as it removes the appauling cat-before-the-turbo. I'd go for the Lateral Performance slip-jointed one myself.
VFM I'm not so good at - sorry!

msonne

Thanks nom..

...Lateral Performance slip-jointed ...??!?

Does that men that it's fexible??

I believe I saw one on www.gruppe-s.com which has some kind of flexible thing on the middle minimizing the risk of cracks due to engine vibration...

Also - do you know about the MOT - is there a CAT on the centersection that I could put on when taking the car for check?
I had the MY99 before which had the centersection, but what about the MY03??

Martin

msonne

This one..

http://www.gruppe-s.com/Subaru/subex.htm
from Helix

nom

Well... the effect is that it can get longer/shorter - enough to allow for heat. The 'problem' with the flexi-joints is that they can wear over time & split - obviously not good! The slip-jointed are much tougher & have the same effect albeit by a marginally different method.
MOT shouldn't be affected for the up-pipe - the cat in the up-pipe AFAIK is for US laws, where the emissions need to be under control within 10 seconds or something - I don't think anywhere Europe, including Switzerland, has quite such ridiculous requirements, so it shouldn't need changing back, no! But a cat needs to be somewhere, yes... the centre cat can do the job, but it needs to be in perfect working order & very hot (the tricky bit) to do so. It's actually not that much hassle to change the DP back over, IMO, if there is a problem with emissions, the hard part about changing the DP is when bolts seize which choulsn't happen if the bolts are jiggled about from time to time!

msonne

So then, I could change the up-pipe and leave it there (which brand should I go for). And I would need the CEL-fix I understand.

Then what about from the turbo and back..

And then would you recommend the BPM DP?

Then there are the centersection and rearsilencer - or do they come in one piece?? And could I buy the DP from BPM, and then the rest from another manufacturer?

Sorry if I sound completely confused, but I'm not really clear about this.

I'm just looking for the best possilble system.
Only things I have in mind - should not be extremely loud (especially inside the car) and I noticed that some of the rear silencers are hanging extremely low (HKS, Blitz) - I could see this being a problem when I lower the car. One 3" roled-tip would be fine by me.

Thanks for helping me out here...

nom

Yes, I'd wholeheartedly recommend the BPM DP, but it might not be the best solution for you - it depends on what sort of power you're expecting/are after. The BPM is 3", and these are noisier than 2.5", and you won't really get any gain from them unless you are heading for 350bhp+.
For a 'full kit', I think the APS one is very good. The build quality is excellent, the flow is very good (I found additional fuel needed to be chucked in comparing it to 'similar' systems - this is a good thing!) & it can come with a high-flow cat which from what I have read is pretty good (mine had no cat). The system is (or was) a 'stand-alone', as in the DP/mid doesn't match with other combinations. I have never heard any bad press about it either. But it does depend what you are after! It absolutely doesn't drone either - a big bonus for 'after market' systems!
Sorry for complicating matters...

gareth

for sale: http://www.scoobynet.co.uk/bbs/threa...hreadID=264438 (not sure if compatible with MY03 tho).

G

MadMark

msonne - this is interesting becuase I am having the same dilema. Powerstation seem to do a rather nice Miltek Racing Cat downpipe / system and I have heard very good things about it. £7-800 for the whole lot including Cat ....

Going to talk to G-force in Aylesbury about APS stuff .......

msonne

>Gareth - sounds good.

If it fits the MY03 I'm ready - does someone know about this?
And if it would fit the standard center and rear.
Otherwise I'd have to buy something that would fit - from Scoobysport?!

...and is the DP......Lateral Performance slip-jointed ...??!?

Why are you changing it Gareth?

Feel free to email me about this stuff.

Martin

msonne

>nom

I'm not going for 350bhp.

My idea was to get an exhaust-system and the PPP, that should (i believe) give around 280bhp? (correct me if I'm wrong)

That way my garage will accept the car and I keep my warranty..

But thanks a lot for all you input.
...and what's droning??

Martin

nom

Droning - constant noise at motorway speeds - much more noticeable on the 'classics' than the new ones!
The APS system is still a valid one - the BPM would be OTT.

Bell-mouths & bell-mouths-with-splitter are the most predictably good & the 'safest' to stick with

msonne

Again thanks..

Gareth - I'll check with Scoobysport tomorrow and get back to you.
I might be getting some parts from Prodrive pretty soon (WRC spoiler and bonnetscoop from STi8)- are they far away from your place? It would be a pretty good idea to ship it all at once - since they want 220£ for shipping to Denmark!!!! Just an idea - otherwise we figure out something else.

nom - know whjere I can get info on the APS - never heard about it.

nom

These are they. Loads of stuff in there, including suppliers that may be more suitable than those in England! There's actually some figures in there too (back pressure @ various bhp & noise levels as well) which is interesting.

msonne

nom...thanks again...

Just looked through the pages - it looks like the stuff...
Will check the prices tomorrow.

Martin

hades

I have the APS system with cat, and IMHO it's very good. On my MY02 WRX, with up-pipe, ported headers and Ecutek, I got 284bhp/272lbft, with big spread of power (over 280bhp from 5800 to 6800rpm) and torque (over 260lbft from 2800 to 5300rpm). Quieter than most systems on cruise - there is a very small drone around 2600rpm, but easy to drown out with stereo, and I've not heard an exhaust that doesn't do this (most are much worse). The noise on full throttle is great IMHO, and several people with other exhausts have said they like the sound of mine. Their downpipe is a splittered bellmouth, by the way.

With the sports cat, and an up-pipe, you probably won't need a CEL fix, but if you do, there's an easy cheap fix (do a search or mail me).

I also think the matching APS up-pipe looks very nice - sleeved flex joint, so has the flexibility and the durability, and cast for better thermal properties.

No I'm not on commission from APS, I just like some of their kit. If you're over Bristol/Gloucester way at some time, you're welcome to see/hear it in action, but I realise it's a long way to travel!

currymonster

I've just bought an STI VI and as part of the purchase price a twin dump full decat system is being added. You mention safety above. In what way would a twin dump not be safe to fit to the car?

Cheers, cal

nom

Ah - by 'safe' in that context I just meant 'most reliable performer': bell-mouths & split bell-mouths will match most setups well, whereas a twin-dump can be much fussier. It may work very well indeed, it may be rather cack... from what I remember, it's also possible for an 'interestingly designed' twin-dump to cause boost creep - the wastegate can be fully open but the gases aren't able to rejoin the main flow from the dump pipe fast enough, giving the effect of a smaller wastegate.
But it doesn't happen very often! I presume the previous owner would have noticed as well