3" exhaust question

[MarT2]

Hi!

I have a S2 coupe with RS2 setup, and some modifications (wagner inlet kit and exhaust manifold) and I want to do a handmade exhaust system.

My engineer says me that he will do a 3" downpipe, and 3" complete exhaust with only 1 silencer.

It will be very noisy? Or will be OK?

When you says that a good exhaust for RS2 setup is 3", what do you refer? 3" interior or exterior?

Sorry for my english!!!!

Cheers

[andyg plym]

ive had a 3" exhaust on my avant from turbo back with just a small back box,it was loud, but sounded more like a v8 on wot, it was faqirly boomy at 3000rpm.
good for flames though

[lind4hl]

76mm is 3" outer diameter, that is what i have, and 1mm thick so inner diameter is 74mm

i ran 3" full exhaust on my rs2 with 1 magnaflow silencer and it wasn´t too loud for me, i am an 17 year old kid that likes when things are loud though

[Cymru1]

agree with the above. Bit loud, but the boominess (?) at 60-70 can get a bit of a drag on a long trip. However idle in traffic is superb and when u floor it too overtake, wow! However, im fitting another box when funds allow, maybee two (old age!). If your having a custom pipe made, just have the one box, live with it for a bit and add another if needed.

[Bram]

I run full 3" with 3 silencers (yes three). First I had 2 Borla Silencers, but found the exhaust still quite loud when cruising or accelerating (normally that is). I added an extra silencer between the race cat and first (now middle) silencer. Still the car is very boomy between 2000-3000 RPM when the engine is hot. It did that from the beginning even with 2 silencers. The only solution on the highway is to drive 120 km/h in 5th or 130-140 km/h in sixth in order not to get annoyed on long trips. Above 3000 RPM the exhaust is not boomy anymore and sounds just fantastic.

[lind4hl]

the problem is often to get the exhaust tip(s) outside the bodywork, otherwise it will be loud at some points.

[Bram]

By the heat created by my heavy right food the exhaust extends by 2-3 cm in length, so that is something you have to keep in mind when designing the exhaust. It should have room to "grow" due to heat expansion

[popdemonic]

I just finished customed Exhaust & DP with 3" on dia. 2 stright muflflers on the system.The sound is nice.Definitely,not loud.it 's almost the same as stock.A bit louder the when REV ran over 4000 RPM.
I have GT2871 ,Wagner 'EM on my UrS6 though,

[popdemonic]

http://www.youtube.com/watch?v=J-_vJJB0jpA

[Bram]

What silencers do you have?

[dkw_dude]

The size of the silencers should be given some consideration. On my coupe I have a full 3" turbo-back from Ferrita, it has two silencers, one is bigger than the other. It works pretty well, quiet at normal driving, and a nice 5 cyl roar when flooring it .

I'm pretty sure the difference in silencer size is at least partly to avoid resonance/booming. If you have one, two or more silencers with the same size, they will all have the same resonance frequency, and chances are you will have annoying resonance/booming at the particular rpm which correspond to the resonance frequency. Hope this makes some sense

[Bram]

hmmmm, I have 3 different size silencers in my system and it's still very boomy, so I think it's more due to the 3" size of the pipes

[breitling]

Heres my first Rs2 with 3" dp, 2 silencers. No cat. Twin tip

http://www.youtube.com/watch?v=nAsR6Fg2t5k

[newsh]

Part of the "I5 sound" IMO comes from the across-the-car rear box and twin tailpipes, because the tailpipes have to go through 90degrees it means they are different lengths which means they are tuned to different frequencies. With a single outlet the boom is far worse. I've heard a coupe with 3" and large single rear box with twin exits and mine which has a single exit and 2 smaller boxes and I'd go for the twin exit next time, it sounds more like a quattro should and is actually less boomy. In fact I'd have had this system if Barclaycard hadn't messed up my online purchase at 034, meaning I ended up with the small box system

[Bram]

Heres my first Rs2 with 3" dp, 2 silencers. No cat. Twin tip

http://www.youtube.com/watch?v=nAsR6Fg2t5k

Nice!

Mine has the same sound, but a little less sound and the following spec:

full 3 " from turbo, with 034MS race cat, 3 silencers (of which the last 2 Borla silencers and the first one is home made), with at the end a big Borla silencer with 2 tips.

I have no video clip where you can hear the exhaust though