Hi All,

As you may or may not know my vRS has been down at Hayward & Scott for the last week under the watchful eye of Mr Disco (John) having a new full system developed exclusively for Imprezive Motorsport.

The system is complete replacement and runs from downpipe to tailpipe.

Downpipe:

2.5" Drops straight down and makes its way under car replacing cats. 2 existing sensors are tapped back into pipe.

Mid Section:

2.5" gentle flowing bends into

End Bit: (technical aren't i :p )

2.5" into handmade backbox which then splits depending on choice of finish (double welded) - I went for twin 3" as that's what I like, other options include the same twin 3s but slash cut or you could have an oval.

When looking at the original system (see photos in following posts) it is incredibly overcomplicated and has uneccesary bends+rightangles all over the place. This new system as you can see is far superior with minimal bends with minimal angles.

Sound:

It's a lovely deep burble It seems to have 3 styles:

1) Feathering throttle/pootling around

Surprisingly refined actually - you can tell it's there but its not intrusive.

2) Pressing on

Now it gets interesting! All of a suddenly you hear the mechanical whir of the turbo spinning up followed by what can only be described as (and i've been trying to think all weekend of something similar) a fantastic Cosworth type sound on acceleration. Back off and you get pops and bangs from the backbox

3) Absolutely flat out

Well now it just gets silly! If you really punch it you are rewarded with a serious roar! It's quite addictive really

Performance:

Obviously i'm still overly excited but I reckon this is the type of exhaust they should put on all performance cars. All the popping and turbo type noises you can now hear and feel make you much closer to the car and what it is doing.

Where-as before if you wanted to explore the upper end of the speedo you would need quite a reasonable stretch of road, you now don't! You can go from a standing start and just hammer straight through all the gears: 1st, redline into 2nd, redline into 3rd, redline into 4th and redline into 5th. It pulls like a train with no effort - I went past 140 before an inconsiderate corner required me to back off, i've never hit those speeds before on that stretch of (private ) road.

Mid range and in gear response times are improved as well with quicker spool up. The car now feels like it has been woken up.

Oh - and no CEL either - and that's without the ECU fix which is just around the corner!

So, all in all? Very Imprezive

This is the new downpipe fitted:

oops

This is the mid section:

Backbox:

This is the OEM downpipe - note the uneccesary bends and changes in bore all over the place - what were the vw/audi boys thinking when they created this?

Sounds and looks like another satisified H&S customer!! I am still very happy with the rear box that H&S fitted to my RS. I would recommend them to anyone who is looking at replacing the standard RS exshaust system.

Lloyd

Hopefully mine will be done this Saturday

I'm going for the oval as its more like standard but I may keep the hi-flow cat in mine.

Glad you like it Dave, all you need now is a front mount, a remap, a brake upgrade and some decent suspension

Originally posted by TaviaRS in this post

Glad you like it Dave, all you need now is a front mount, a remap, a brake upgrade and some decent suspension

it's a slippery slope which i'm well on the way to going down

Dave, really nice job. Looks good.

Jon, fancy selling me your old miltek.

Looks v. cool. Ahh, us TDi owners can only dream of such things. :(

Could poor downpipe design be VAG's equivalent of Microsoft - got to leave room for after market guys to do a better job??

For the abbreviationally-challenged, what's a CEL???

Howard

Check Engine Light

Manny, full system or just cat back? If its cat back, PM me.

Jon

Dave,

you have PM.

Cheers.

Adrian.

Will this custom exhaust (not too familiar with all the terms) fail the emissions test? Or did I misread it and it does still have the cat fitted?

Q.

Oh, and whats the price like? Comparable to the Militek? Or better?

It will fail an emissions test. You need at least a 200CPI (cells per inch) CAT to pass IIRC, hence me probably keeping the free flow cat I have in place.

Jon

Cheaper than Milltek, mainly because it has no CAT. With cat I think its a comparable price but I'm prepared to be corrected by Disco (John).

whats the performance like in comparison to the milltek?

as you know ive just had mine on with hi flow cats and big bore down pipe...

i didnt feel the difference as much as i thought I would - having said that I absolutely destroyed a tt 225 on my private drag strip.

...

The system is complete replacement and runs from downpipe to tailpipe.

Downpipe:

2.5" Drops straight down and makes its way under car replacing cats. 2 existing sensors are tapped back into pipe.

Mid Section:

2.5" gentle flowing bends into

End Bit: (technical aren't i :p )

2.5" into handmade backbox which then splits depending on choice of finish (double welded) - I went for twin 3" as that's what I like, other options include the same twin 3s but slash cut or you could have an oval.

When looking at the original system (see photos in following posts) it is incredibly overcomplicated and has uneccesary bends+rightangles all over the place. This new system as you can see is far superior with minimal bends with minimal angles.

DaveU,

Do you have any dyno tests from other people to see exactly what the gains are? Is your RS a chipped one or stock?

I would rather say that with a cat-back system you have some power gains at about 4-5%, but if you add a larger down-pipe+race cat you cause much more turbo boost raising (by significantly reducing back-pressure), and the ECU is always there to drop turbo pressure at the spefified levels. In other words in order to get any gains from a down-pipe + race cat you need to do that with re-programming/re-mapping the ECU... Is that right or I am wrong?

Phew, I have been looking forward to this post Dave, albeit with 'nervous' anticipation;)

I take it as read, that you consumed rather a lot of petrol enjoying and testing the system this weekend?

With regard to theoretical performance with/without a remap:

Without: All turbos require a degree of backpressure to assist in spool up. But none except dustbin sized ones require it to be as sufficient as the back pressure generated by standard exhausts on almost every performance car. The now considerably freer flowing exhaust aids/increases turbo spool up by allowing the combustion to flow quicker and therefore quicker thru the turbo itself. This means that low down spool up is quicker, and also mid-range turbo is vastly improved as the engine can reintroduce the turbo quicker. The ECU will obviously control boost limits etc to that of standard, however low down the car will be able to hit its boost targets earlier which is where the power gains come from. Power is not dictated by boost alone.

With: With relation to exhaust alone, the main benefits of adding a remap to the system is that you can a ) Improve the power gains by adjusting other parameters to deal more effectively with the altered flow characteristics and if you want you can increase the boost/turbo pressure and deal with the extra combustion more efficiently.

Interms of cost, it will work out cheaper (slightly) than a full Milltek, however I'm trying to work out some prices now. The production cost is/was fairly high but I dont want to pass too much on and make it unsellable.

9 times out of 10 it will probably fail emissions test on an MOT, so you'll need to find a friendly MOT station;) , but if you consider how many Cosworths and Subarus etc out there mostly running decats, you'll realise there are plenty about.

Officially this is sold for off road use ;)

Anyway glad you like it Dave, sounds like its pretty much everything you were after?

Q,

it will fail the MOT.....

Doh! Didn't go tot the next page.

So, what you're saying is that it will fail its MOT yeah? :p

Guess it's only for the die-hards then, as I'm sure 'friendly' MOT stations are becoming thin on the ground...

Must admit the MOT is the thing that puts me off; I don't want to have to look around for a friendly tester or have to put a CAT back on for MOT.

That said MOT is another 2 years to go: hmmmmm.........

Have just mailed Jabba about sports CAT so I'll mail out my findings.

Cheers.

Adrian.

I've not got any dyno figures and i've not driven a car with a Milltek full system to compare it against (anyone near Bucks with a std car barring full Milltek that wants to compare?). Hopefully i'll have some soon.

My car is currently std but soon to be Jabba chipped along with induction kit + new DV. Can't wait

(oh and new brakes + fmic + bodykit + suspension thanks to certain people on here - you know who you are )