ASJ

Does anyone have an opinion on replacing a standard UK twin tailpipe backbox with an STi single tailpipe one?

Is it any louder, does it flow better, or is it just cosmetic?

Not sure what STi it is off, but has STi pressed into the side of the polished tailpipe with approx 3.5" diameter exit.

Craig H

The Sti box is slightly more bassy and looks miles better. I doubt whether you'd notice a performance increase though.
Most Sti owners change to the SS box for the sound.
If anyones interested I have 2 Sti boxes for sale.
One with 120 miles on it, so is mint. Fairly cheap as well.

Timothy Leuers

Craig,
If STi people are changing to Scoobysport for the sound (by implication the performance is not significantly different)and STi boxes won't produce a noticable improvement over non STi, then are you saying that exhausts in general do not produce noticable improvements? I do not want sound. I wouldn't mind closer to STi level hp, however.

BTW The local HKS tuning shop says that while the exhaust on its own will not have much effect, you need to improve the exhaust before changing, or piggy-backing, the ECU. With higher boost the exhaust back pressure starts to become a problem.

alistair

The STi backbox is basically the same as the UK backbox but with a different tail pipe. If you look at one properly you will see that whilst the pipe looks about 3", it is only about 2" when ot comes out of the box and is sort of cone shaped.

The Scoobysport box does give a performance increase, see -

Timothy Leuers

The STi is not too noisy, pretty quiet compared to some, but more bassy than the twin pipe on my Japanese WRX. All the same I am thinking of fitting a STi backbox because I can get one cheap, I can't use a noisy exhaust due to my work and I presumed that they are better, performance wise, than the standard. What is the truth?

BTW I also hear that the STi Backbox is made by Fujitsubo who make performance exhausts. I wonder how it compares with others made by the same company.

I guess that STi owners in the UK are changing their backboxes for those made by Scoobysport so there must be room for improvement.

Craig H

Timothy,
I'm saying I doubt you'd notice performance difference over STi and std backboxes.
And I'm also saying most STi owners probably buy the SS backbox for sound - it does make a slight difference on it's own. A back box, downpipe and airfilter can give anywhere between 10 and 25 bhp depending on the car. If you don't want noise, you're unlikely to get extra power.

GavinP

If you want a quiet exhaust...look at a Remus.

I have one and it definitely helps breathing at the top end of the rev range.

The sound is quieter or at an absolute maximum, level in noise with the OE exhaust.

I haven't put it on the dyno since fitting it so no power figures so far.

Thanks

Gavin

steve McCulloch

Craig is right

most sti owners junk the sti back box and go for an SS system, or better still fit a full mongoose system - noise levels not too bad overall - well, was ok at 150 mph (private stretch of road of course officer)

If I were a UK ownerand wanted cosmetic appeal I'd go for STI back box - of I wanted noise and performance but on the cheap - then SS backbox is the way to go.

alistair

Also the STi box is mild steel not stainless. Mine is sitting in my garage rusting nicely !

Timothy Leuers

The Dyno improvements were impressive, thanks alistair.

Craig -- So...no pain no gain, (no din no spin?) That is a shame. I work at a university in Japan and it would not do to park in the profs car park with a car that makes a loud phut phut phut noise.

But how loud is "loud"? I would not want the kind of exhaust that would wake people up at night either.

Gavin I will look into Remus but I will not be buying a non Japanese make. Where is Remus from?

Anyone know a Japanese exhaust with a good power to noise ratio? I heard that Fujitsubo used to be quiet but that they then produced a new louder version to meet demand. Most people want noisy exhausts it seems.


[This message has been edited by Timothy Leuers (edited 25-11-1999).]

Craig H

Timothy,
If it's Jap only then I think you're stuck - they're the noisiest of all.
Sti box may be the only option.

Pete Croney

Timothy

Why would you not consider an exhaust made outside Japan?

When you consider that all year 2000 Japanese WRC teams will be run by UK companies, as are the majority of F1 teams and most non Japanese WRC and rally F2 teams, why are Japanese people so reluctant to buy products made outside their country?

Most Japanese aftermarket exhausts are very big and very loud. European ones are much quieter.

Remus exhausts are German and Scoobysport are made in the UK.

BPM

In regards to the performance side the std backbox is more restictive than the Sti one. The Sti one still suffers in the high rev range ie 6000 and up , due to EPA and meeting the 206KW maximum the Japanese have.
You have to admit though the Sti logo makes it "feel" faster....


Greg Nikolettos
BPM Marketing Division
P:617 3272 8885
F:617 3218 8880
bpm@bpmpsports.com

Craig H

Also, the Jap exhausts IMO look very Max Powerish. Nothing suits the Impreza as well as the SS one.
And after you've thrashed it on the track, it goes a loverly colour!
And it sounds the best.

Timothy Leuers

Pete - I can get a Japanese exhaust discounted. If I bought Remus or SS then I would probably be paying RRP and shipping. But I will look into it. The Aussie firm MR-something(?) also makes a backbox which it claims is quiet and well tuned. These things are quite heavy though so... I wonder how much shipping will be. As to why people in general don't buy things made outside of Japan -- I guess that they general feeling is that Japanese things are well made (take the Impreza for instance). But I take your point that when it comes to Rallying and F1, the the Brits, seem to lead the way. Thanks for telling me where Remus is made.

Greg - Thanks for telling me that the STi box gives some improvement. I think that I rarely get above 6000 revs. But the dyno chart that Alistair posted shows that the STi box is inferior to the SS and Blitz (where is that made?) even at lower revs.

It also seems that (from the page here)

MorayMackenzie

Timothy,

Dont read much into a dyno comparison chart unless both runs were conducted on the same car on the same day! The chart you link to was made of two runs three months apart.

The engine will have loosened up more (up to about 10,000 miles), fuel quality may differ and, much more importantly, the dyno at PE is not generally run using their climate control cell, so the prevailing atmospheric conditions will greatly affect the results.
February would probably have been the more advantageous conditions for power runs, the STI box would have had an unfair advantage if this was the case.

Moray

[This message has been edited by MorayMackenzie (edited 26-11-1999).]

Sam Elassar

Hi Timothy
I think you are doing the right thing for £50 pounds you can't beat it at this price. the STI box is better than the standard one i thought that was the whole purpose of the STI division. as for "Japanese people can't tune their own cars and we can better" I can only find this quite comical really. they have the best after-market mods for the scoobies whether it is exhaust systems or ECU ( that don't blow up)or air filters that don't leave oil residues !!.
ok may be they are a little bit into their little gadgets !!

have you tried Trust exhausts they are suppose to be one on the quietest Japanese ones.

looks is only a matter of taste most people like the ss backbox (on this BBS) some people don't. I for my self have a blitz on and I think it looks great..

Timothy Leuers

Moray - So you think that the climatic conditions may be responsible for the lack of an improvement. Hmm... possible...that might explain why the results Alistair posted show a greater difference. I have not lived in the UK for a long time. Is the weather very different between late Feb and late May?

Sam - thanks for the encouragement and recommendation of Trust exhausts. I may try one if I don't like the STi. BTW Can you recommend any good Japanese ECUs and filters?

Timothy Leuers

Malique - Thanks very much. The Trust sound nice: what I might choose if I had free choice. But the 4" pipe... You see, I park in a car park next to profs who will look me up and down and say, with their eyes, "You are a yob". Or so I imagine. How things look is rather important too.

I think that the list price is around 400 quid here. I shall have to think about that.

And thanks for the ECU recommendations. The tunining shop is recommending HKS, possibily a piggy-backed afair but I would rather go for a full ECU after reading about the dangers.

4G63/93?? My car is two years old but I am not sure of its number.

I'll get back to you if I can't find these people on the Net.

BTW upgraded 15" to 16" wheels on Saturday. Feels like a big improvement.But there is "tramlining": bumbs in the road did not used to move the steering wheel before. Now it seems I can really feel what is going on below.

malique

Hi Tim.

I was about to suggest the Trust but since Sam has I'll just add to it. I think the Trust performs well and sounds great. Its got more beat and doesnt "howl and wail" on the run. It is one of the "quieter" exhausts. If not for the 4" exit.....let us know how much it is in Japan. Here in Malaysia it is around ~300quid.

The STI box on my car is made by Fujitsubo.

malique

Oh and ECU, try Prova, I think they've done good work for the GC8. I think its better than Mines. Mines have good ECU for the 4G63/93.

Mail me if you need contacts.

MorayMackenzie

Timothy,

Yes, the weather is quite different, although it was probably raining on both occasions . I would imagine that the february run was in colder and denser air.

Moray