recommend me an exhaust

I think my car may have outgrown my SuperSprint exhaust.

Some poor dyno results suggest that it may be too restrictive for 400bhp, so I'm considering 3" (or more?) all the way.

However, as you all know, this car does LOTS of miles and needs to be fairly civilised at low boost. I need it NOT to be boomy at motorway speeds, although I don't mind a bit of noise - adds the the character. It can be as loud as it needs to be after 5,000rpm or above 1.4 bar.

So - any suggestions?

If anyone has a 3" pipe lying around that they would be prepared to lend me, I'd love to try it first to see if I can live with it. I love the sound of the SuperSprint - quiet and unobtrusive at idle, growly at modest revs, nice and loud at mid-range and totally beserk at high boost.

Nigel - you really dont want to go more than 3 inch with a few silencers for the miles you do in the car.

My 3 inch Longlife is boomy between 2-3k - particularly on a motorway, and would probably be more so on your car until it's on boost. Sounds nice at full chat though! If you go for anything smaller than 3 inches then IMO you are going to have the same issues that you have with the 2.25 supersprint mid and rear section.

You are welcome to go for a run in my car anytime to see if you can live with the noise.

Just posted in your other thread...

In my experiences of fiddling around with silencers and cat converters I found that boomy on the motorway and loud with the windows down are very different, and you can have one without the other and vice versa.

If I run with no cat and 2 silencers it's a bit boomy on the motorway, but not too loud out the back.

If I run with no cat and 1 silencer at the rear and a decat pipe it's quite loud out the back with the windows down (but a totally stunning soundtrack) and boomy on the motorway but ONLY between 2750-3250rpm. At any other revs it is not boomy at all. With the windows closed it's not too loud for me at all.

If I run with the cat on and 1 silencer there is no boomyness at all, really nice journey on the motorway, sounds nice out the back but it is fairly muted, no growl, no pops and bangs, just a nice tone.

My exhaust is 2.75" turbo back Blueflame one.

The silencers I was using were the standard blueflame one at the back and a big heavy one I borrowed off someone which just happened to fit in my decat section.

I have a removable silencer in the cat section which I think is the way to go so that you can have high performance when you want it. It is v-banded 3" so is removable with about 5-10 mins effort.

I actually have three silencers. 2x lightweight silencers that are fairly minimal silencers (i.e. barely any restriction) but are the type that can be repacked, and a normal silencer at the back.
All my power was actually made with all three silencers in place bizarrely. Never tried with my straight pipe or my cat

V-banded exhaust sections, I like that idea.

Make your own like me. Used and H&S 3" downpipe then made the rest up. I use a 600mm silencer in the middle of the car and one at the back. No cat mind but you could add one and reduce the middle silencer.

Marco

Nigel, what's the current diameter of your exhaust?

What kind of catalysator do you use? 100 cells?

No, a normal one.

I only use it once a year

Yeah I realised otherwise it was a pig to swap in the cat for MoT etc. Now easy peasy

I have BF 2.75". A lot of noise at 3000 rpm, I use one rear silencer and a 100 cells cat. I´m thinking of using the middle silencer next year and I was hoping it would not be so boomy with two silencer.

JohnS: tip of the day. I will use v-band next year

my current setup is 3" downpipe, running into a taper section for the decat - its then 2.5" all the way back.

I must admit, I have considered fitting a valve in the downpipe, with the gasses normally going through the SuperSprint, but at the flick of a switch, it turns into a VERY short side-exit pipe. Now THAT would be loud

Just one thing to potential consider
I think the point of having more than one silencer to capture the exhaust gas resonations at different frequencies and revs, so hopefully you are less likely to get booming at a particular rev range.
I also hear think stainless steel exhausts tend to be a bit louder than mild steel ones too...

mild steel gives a softer, more mellow sound. Stainless can tend to be a bit more harsh and tinny (although some stainless systems soften as they are heat cycled over a long period of time)

I thought Supersprint was 2.25 inch Nigel?

could well be - I really can't remember

That's why i asked you about your exhaust size

I've got a Supersprint decat and it's 2.25 inch. I imagine it is the same size for the cat-back.

yup s/sprint is 2.25,Barbz considered the Blueflame was well good for 400bhp,and was impressed by the build maybe better with a 3" downpipe going into the 2.75 blueflame sysytem

Mine is 3" all the way. Mandrel bends with two 3" silencers. It sounds just like a Subaru on the outside and not too noisy on the inside however Squid has the same setup but due the coupes poor sound proofing it sounds more droney inside.

http://www.torque-exhausts.com/

im having an exhaust system made and fitted to my 20VT by long life in the morning..was thinking of going for a 2.25 but i mite go for a 2.5 cat back with a de-cat pipe made up but not fitted..

I have 3" stainless steel exhaust pipe allway through with 2 silencer, no cat.
It is boomy in around 2000 - 2250 rpm, upwards very quiet. Especially above 4000 rpm it is nice to drive, you can hear wheel and wind noises better than exhaust noise.

My friend has 2 x 2" back pipes after 3" downpipe, which makes flow area app. 2.8" and it is good for 445 bhp/6700 rpm and the power curve was rising. So, his pipe was definetely not restrictive in that power level.


- Jari -

I have a stealth 3 inch system which has had the centre box (where the cat normally is) replaced with the largest box i could fit under there. 10" by 8" i think. This reduced the boomyness of the more than useless resonance only box. Ive also had the V band removed and a 5 stud flange welded in place as i'm now running the 28rs. Its still as most big systems are, boomy between 2 and 3 grand but not at all an issue like it used to be.

Been very pleased with my Longlife, would recommend.

If you can get yourself up here, you're welcome to borrow my 2.75" Blueflame system Nigel.

Depends which one as well I think - ask Kenno what he's heard about the one in around Clapham.

Yeah - I wouldn't use the one in Battersea/Clapham. The franchise owner of Longlife was doing burnouts on the forecourt in a customers Viper.

I also had a couple of things done to my exhaust by them and I could have welded it neater myself.

Barbz used to use the guys in Carshalton.

Think that's were I had mine done

mine was done at carshalton..he did my de-cat pipes on my Audi S4..
he told me he worked for torque italia for many years and knows the coupe inside and out..
very happy with my system..