Come on then lets settle this once and for all(yeah right!).
Which of the exhaust options do you the impreza driving public think is the best?
With the likes of scoobysport,Trust,Hks,blitz
etc all offering systems,b.boxes,front pipes and all that i am totaly confused!
Also has anybody had any experienc of the blow off valve,would they make much difference to an sti2??
Cheers.

You are very unlikely to get a satisfactory answer on the exhaust front http://bbs.sidc.co.uk/wink.gif So many people have different systems and all appear to be happy with them, it would be difficult to say one is better than the other. They seem to provide similar performance increases, slightly different sounds and costs. The only thing i can say, is turn up at a meeting or track day and sample the sounds etc of as many as you can, and make a decision based on that. The one thing to remember is if you want to remove the cats, keep em, or fit sport cats. Not sure if your sti 2 needs cats or not, probably does ????

I havent touched modified blow off valves, but there are bound to be people on the list that have.

Ive tried Blitz and Scoobysports. Ive also seen results on most of the others (HKS, Trust etc and listened to them). Ive not as has anyone else seen the 40bhp monster muted on the bbs.

Ian is right. Most owners are very happy with what they have. Its down to styling and noise.

I liked both the Blitz and SS on my STI. One looks like a drainpipe and the other subtle. One has a deep throb and the other a harder note. The option is down to you. Look at all sytems and listen to them (on the road & through the rev range)

The Blitz for me suited the STI (bit more wild). I had a SS on my UK car then my STI (followed be a Blitz). The RB5 will have a SS. The HKS and Trust are very similar to the Blitz. The Miltek is more like a SS (sorry TIM but the SS has it for me).

Jonathan

Each owner has different requirements from an aftermarket exhaust, so you are unlikely to get one that is the "best" for everyone.

Some are complete systems from the turbo back, some are just from the Cat back, some are just back boxes. Prices vary from under £200 to about £1,000, and differ in materials and build quality.

Some are just as quiet as the standard system, and some are *LOUD*. Some sound nice and sporty, some can be irritating on long journeys.

Some look unobtrusive, whilst others are so big, they could accomodate your whole leg up to the thigh!!

Some will make your car "illegal" by removing the Cat, and most will invalidate your warranty.

Obviously the "full" systems have greater potential for increasing power, but are generally more expensive, take longer to fit and produce more noise. However, the back box replacements give a modest increase in power, for a modest outlay, and are simple to fit.

With all these variables, there is no "best" system, and it's down to each individual to look at, listen to, and review results for each possible system, deciding how much they want to spend and then choosing the system best suited for their own needs.

Yeah,
there's loads of exhaust related threads and none of them are conclusive by any means apart from the general consensus that Scoobysport are the most popular amongst the SIDC fraternity and everyone seems happy with them, but then most people seem happy with whatever aftermarket exhaust they've plumped for.

While pure gains of over 20 BHP have been achieved with some catless/highflow downpipe systems, I'd be very surprised to see 40BHP+ gains- unless of course a drinking-straw had been used as the original system,ho,ho,ho.

Also as other threads have pointed out,it's a bit of a balancing act between pure free-flow exhausts producing max.bhp figures at the top-end, and systems that utilise a degree of back-pressure to enhance torque(particularly low-down) that may prove more useful and driveable on the road.

Quite a few threads on blow-off valves also.

Since I do not (yet) have an aftermarket exhaust I thought I'd share my views, and why I've come to choose one product over another.

Firstly, the manufacturers come down to Scoobysport or Japanese Imports (Trust, Blitz, HKS). Why ? Cos
a) This is what decent tuning companies are offering (and they've done the investigations)
b) The majority of you guys are running with them ! The likes of Magnex, Scorpion etc are in the minority.

Full system or backbox ?
well it would seem that a full system is
a) costly
b) possibly "illegal" due to emissions
c) loud(er)
d) more complex to fit/swap
e) more concerns about warranties.

Plus it would seem (from some comments) that full systems may give better increases top-end but remove driveability (less mid torque).

The backbox however seems to win for me. The only con is that it doesn't give the absolute tops in the power stakes.

If I was going to have built a mega engine i.e. more boost, ECU, water injection etc etc then I would go for the Trust system.

However since I'm not (and I want my warranty intact) I'm going for the backbox option of which there "can be only one"..

so yep I'll be after the scoobysport/filter package soon.

Also, has anyone noticed differences in lifetimes ? I.e. mild steel systems lasting 2 years vs the stainless jobbies ?

hope you found the viewpoint from a newbie interesting to you converts.

My understanding is the Scoobysport may well outlive the car (or certainly my tenure of it anyway!). It feels like its hewn out of a solid block of stainless steel...

and it does turn a fetching gold colour after a couple of track days http://bbs.sidc.co.uk/smile.gif

Also useful for scaring old ladies http://bbs.sidc.co.uk/smile.gif http://bbs.sidc.co.uk/smile.gif

[This message has been edited by Andy Holden (edited 17-06-99).]

After Lee's comments I just felt it necessary to speak up for us 'minorities' out there with euro-exhausts other than S/sport as I feel stigmatised now.

Scorpion,Magnex,Janspeed,Devil,Supersprint and,ahem,..Mongoose are all hugely reputable exhaust manufacturers whose Impreza systems are unlikely to disappoint anyone who opts for them and I'm not even sure that owners of such systems necessarily are in the minority in relation to owners of Japanese aftermarket systems.

As regards reputable tuners not using such systems well... GGR market Magnex,Paul Bailey uses Scorpion,Janspeed have a phenomenal tuning and competition pedigree in their own right,Collins Performance Engineering developed Mongoose exhausts- all the above have enviable competition tuning records and Devil and Supersprint are legendary in tuning and Motorsport circles in France and Italy respectively.

Let me stress that I'm not knocking either Scoobysport or any of the Jap. systems(I wouldn't say no to either the HKS or Blitz systems) but I wouldn't dare to suggest they were particularly superior nor inferior to any of these other systems and it's a little unfair to simply dismiss the others so off-handedly.

As said before, it's horses for courses and personal choice but I feel Lee's being a little blinkered to completely dismiss the other systems available so readily.

Or am I being over-sensitive? http://bbs.sidc.co.uk/wink.gif

I have a Janspeed rear box and K&N panel filter - I am very happy with them - power 246bhp and 230 torque. The sound and looks suit me well as they are not intrusive but still loud enough to excite the right foot!! I am considering a blitz induction system and a bailey dump valve - any experiences with these good or bad?

Where is Top Gear?

Thanks chaps
Paul

I feel I must retort http://bbs.sidc.co.uk/smile.gif

Rob, I'm very possibly blinkered, and didn't mean to incur inferiority complexes on euro-exhausts !

As I said I am a newbie. Thus I go solely on recommendations/comments/reviews I read.

I have had 2 companies recommended time and time again for serious subaru tuning and they both promote imported jap exhausts. GGR was not one of them and I don't doubt they are "serious" tuners..BUT they just weren't recommended to me !

Reviews/comments I have read state that the jap exhausts are best for full power and the build quality is second to none. BUT they do cost and some may not have an impressive lifespan. They seem to sacrifice cost/lifetime for all else.

I'm not knocking the other exhausts, but nothing I've read (apart from a v.f.m factor) puts these ahead.

Remember this was my personal viewpoint. I guess I'm one of the lucky ones cos cost isn't a factor. If it was then I daresay I would look closer at the euros.

So yes I dismissed them a bit quick but my arguments won't be the same as the next guys.

Over-sensitive. yes http://bbs.sidc.co.uk/smile.gif

Fair enough Lee,
BUT(cos,I'm an argumentative git) I would just say this;

Admittedly I did get my exhaust,(Mongoose £480inc-inc.high-flow downpipe+does away with both cats), a few years ago, and there have been quite a few additions to the market since then,but the main reason I went for it was the rolling-road bhp figures I had seen quoted for it (in excess of 20bhp).

The HKS super-drager system[replaces 1st cat.](which at just over £660inc.was and is possibly one of the most expensive Jap. systems you can buy) was quoted at 8bhp. Admittedly the highflow downpipe option(£150)[replaces 2nd cat] might add a bit more to this figure but I'd be surprised if it bettered 20bhp.

Now, if this sounds as though I'm trying to claim the Mongoose as the best of all systems then I'm not. The Mongoose has a number of downsides, not least being the necessity of swapping the whole bloody thing over for the old one come MOT time. It hangs too low and is very easy ground if you're not careful,it's short of a hanger on the rear silencer and quite a few people that have tried it have complained it's too noisy-both outside and in.
I like it primarily for the (very noticable) extra-power,the lifetime guarantee(you get that with most s/steel exhausts- though I'm not sure about the Jap. ones), and for the fact that it has a tail-pipe that is subtle and doesn't draw attention to itself(if you prefer the HKS tailpipes that can comfortably accomodate a small family then that's fine.). Yeah, it is quite noisy- though not unduly so- but then I quite like that.

I'd totally agree with you about the undoubted high quality of the Japanese systems,(though again I wouldn't say the quality of any of the others is particularly lacking) and as I said before I wouldn't object to such a system on my own car,but I chose the Mongoose over the HKS for power alone.
I can't remember the point I was originally trying to make now.
Anyway, there you have a microcosm of the mass of subjective arguments that go into determining exhaust preferences.

My head feels funny.

I have to admit that I'm also a newbie here and I feel like a kid in a toy store. My head doesn't feel funny...its spinning!! Someone mentioned about some systems that remove the catalyst. Can you use leaded fuel after that??what happens with the lead sensing sensors?? does anyone know of a company that ships s/sport systems overseas?
Aaaaaaagh!!!!!

The fact you can't use leaded fuel has nowt to do with the exhaust.

The cylinder head is designed for unleaded (otherwise the valve seats would be softer) and leaded fuel would knacker the various sensors (lambda mostly).

Rob, I'll be quiet now mr argumentative http://bbs.sidc.co.uk/wink.gif

Cheers guys.
so if i wanted either a system or back that is legal,that wouldn't be too loud inside the car and would give maximum power gains(prefferably lower down the revs)and am not to fusted about the size or price,what would you recomend.

P.S. Am also a "newie"!
P.P.S. Head is also spinning!!!!
P.P.P.S. How do you lot do those cool smiley face things??

Mike,

what I said was correct though my use of english was poor !

>The cylinder head is designed for unleaded otherwise the valve seats would be softer)

in other words an unleaded head has harder seats since it does not have the benefit of leaded lubrication.

you can't use unleaded in a leaded head unless it is modified.

you could use leaded in an unleaded head (leaded is 97RON I think??) provided the ignition is altered, but it is the sensors that stop you like we've said.

Mike - your message is clearer than Lees. The important points are:
1) Soft valve seats from early vehicles need leaded fuel to prevent wear.
2) Systems with catalysts in MUST not be run with leaded fuel since the lead coats the precious metals on the surface and prevents them operating to convert the remaing uncombusted or poorly combusted exhaust gasses to H20 and CO2.
3) Also VERY important to note is that it is very unwise to attempt to 'bump start' a vehicle with 'cat' since unburnt fuel will pass through the engine and into the 'cat'the neat fuel will be 'burnt' in the catalyst and may cause the brick to melt requiring the part to be replaced.

Mick

Lee.

I may be wrong but I think you've got that unleaded thing backwards??

I thought the rule was that you can't use unleaded fuel in a car that was designed solely to run on leaded?

The reason being that the valve seats are softer.

Also you cannot run a car on leaded fuel which is designed to run on unleaded, the resultant lead emmissions would coat the surfaces of the cat, knackering it up in the process. (Technical Jargon) http://bbs.sidc.co.uk/smile.gif

Don't know if you can use leaded (for the next year or less) after removing the cat's. What RON is leaded fuel?

Mike.

Can anyone recommend a good english tutor http://bbs.sidc.co.uk/frown.gif

some urls to help you decide + some sound clips from loonie japs -

http://www.geocities.co.jp/MotorCity/1692/GC8_muffler.html

and... (shotgun has to be the loudest surely)

http://www.hh.iij4u.or.jp/%7Ekou-chan/MyImpreza/index-j.html

and...

http://www.glink.net.hk/~markpatt/sti.html

have suggested before that iwoc or sidc file upload areas should be used for uploading pics + sound clips of all the offerings so the troops can try before they buy - will upload a sound clip of my sti 5 with s.sport backbox sometime to start the ball rolling on this one.

cheers,

Paul W

Nobody has mentioned the Devil system PTS sell. No, this isn't meant to be a plug for them - I am asking to see if anybody has ever experienced this system?

The reason I ask is that a few years ago I heard a well fettled Renault 5 GT Turbo with one of these beasties on it (Turbo's really make Devil systems apparently). It turned my head when I first heard it over 100 meters away. Not so special you might say - until I mention that it was just idling at traffic lights at the time!

It drove into the Kwik Fit I happened to be in at the time and sounded absolutely stunning. So rich, burbly, smooth and loud. All from a 1.4 liter engine! I was smitten immediately but I've never heard another since http://bbs.sidc.co.uk/frown.gif

When I get my Imp eventually I'm going to get the system just to see... At worst, I discard it in favour of the original replaced with a SS back-box...

For the record; the SS backbox sounds like a *much* quieter version of that Renault (hard to believe, I know). I just want to know if that 5-GT was unique, or if I can replicate the same aura on a Scooby...

Anyone?

Ross.

Nobody has mentioned the Milltek system either.

I have their Backbox on my UK 98 Scoob, and OK the tail pipe is 4 inch diameter, but it is rolled into a silenced 2 1/2 inch centre.

Noise isn't too intrusive on a 4 door, but it does growl like a TVR at idle, and maintains a deep rumble even at high revs.

Build quality is good, price is cheap (I got a backbox, ITG filter and tank of SUL for the price of the SS box) but downside is the tail pipe does hang a bit low, and look a bit big!

[This message has been edited by Tim W (edited 21-06-99).]

There will be an exhaust dyno shootout organised so we can all settle the matter once and for all. Lets have an informed market. What I propose is let all the dealers
put a stock Sti or WRX with a full exhaust
ie from turbo back utilising a cat.
The car will be checked and the dyno tests will be performed under strict conditions by an independant source, ie EVO Magazine etc.
We can then accurately guage this wild claims!
I step to plate , batter up!


Greg Nikolettos
BPM/AVO
UK/USA Marketing Manager


[This message has been edited by BPM (edited 28-06-99).]

Should we discuss this in the event forum?

Greg Nikolettos
BPM/AVO
UK/USA Marketing Manager

[This message has been edited by BPM (edited 28-06-99).]

BPM..... Please do. This would be good for all member. Please let me know the results.

When you mention AVO .... would that be Terry Wilson A.V.O ??? ... from Australia???

Trust & HKS are better one to go with.. when comes to exhaust system.

I used mongoose back box .... not that loud and sound good too.

As for the front pipe and centre pipe ... custom made.

AVO is a large part of BPM but there are other developers and specialists that make BPM. We are serious about the UK and this is the first step.

Regards


Greg Nikolettos
BPM/AVO
UK/USA Marketing Manager

I had a SS back box on my UK turbo, now STi -all I can say is that at track days I always had people coming up to me asking what it was, saying it sounder the best etc

"BPM..... Please do. This would be good for all member. Please let me know the results. When you mention AVO .... would that be Terry Wilson A.V.O ??? ... from Australia???"

Yes Terry wilson, his sons lee and Ross who just came back after working with Subaru on the MY2000.

"Trust & HKS are better one to go with.. when comes to exhaust system."

Although we do sell Trust as the EVO Launch we show the results are not what People perceive them to be. Let's do the dyno and prove it to the world.


Greg Nikolettos
BPM (Boost Performance Motorsport)
UK/USA Marketing Manager

Just thought i would tell you seeing as the topic is still on the board that i have finally gone with a scoobysport backbox and am well pleased http://bbs.sidc.co.uk/smile.gif !! Although i havent noticed any difference in speed or power(only done about four miles though)the sound alone has made it all worth while.