Could 2,5"/3" exhaust system be quiet?

[lynx]

Hi

I tested today car without exhaust system (only downpipe connected. I' m using k26/t04e hybid and rs2 em). There was a little different with 3 and up gear. Not too strong differend, but I could feel it.

Now I' m thinkig maybe to replace original exhaust system (cat' s are gone for a long time allready), but I' d like to have silent car. I have owned one car with "sport exhaust system" and . . I don' t want it again.

So, less word, more actions . . Could 2,5" or 3" exhaust system be quiet?

with best regards,

[rotoryboy]

I run a 3" system from the downpipe with 1 silencer. Dont get me wrong its not loud but you know its coming. You could have another silencer in the middle section to just take the edge off

[Greg_S]

Lynx.

I have a 3" turbo back system fitted with two silencers. on tickover and cruising around its fairly quiet. but gets louder when you are on boost.

only problem is if you are cruising at 70 its a bit boomy but get to 80 and it quietens down again

[WabTheKing]

if you have a single small diameter tail pipe it seems to make it quiet,

[S2 Ant]

I think Gregs sounds nice, has a good noise to it but isnt too intrusive, but then want i consider to be quiet and a smooth ride, others consider to be loud and harsh, so hard to answer really

[Sweeper]

I had 2(two) sport muflers in the row and it sounded like stock ! With all the 3" all the way.

Now i have none and it's sounds like a bike, gonna put atleast one mufler tomorrow.

[Ski]

I have a 2.5 powerflow with a special s2 box at end. its VERY quiet, just like stock

[Faheemo]

Cheapo move is to remove everything but the back box.
Replace all others with straight tru piping...

Cheapo but works gr8 .. Sounds gr8 too.
Not loud at all.

[HPmuirt]

What is the diameter of the standard system and what is the performance/noise difference between the 2.5" and 3" systems?

I plan to get a 280BHP homefry when my Porsche brakes are on and had assumed that my stock pipes would be OK for this. I was also assuming that moving up to 2.5 or 3 might give me a few (but just a few) more horses, particularly if I use an RS2 airbox?

Final question, If required, where can I get an RS2 airbox?

Cheers n

Si

[lynx]

thanks guys

Looks like the "noise level" is different for many people.
Anyway, I tooked my car to the service . . . the middle part of exhaust system is complicated (even when cats removed) and the last silencer.

I know, without exhaust system I have boost difference about 0,4bar. When I tried without exhaust system I was getting 0,4bar more overboost. Looks like exhaust system is handycap.

I told to the service that i want 3" exhaust system, the looked my car and sayd to me . . . impossibe . . . up to the back axle, ther' s no room for 3".

Anyway, at the monent I thinking if I let to do middle part new and last silencer (free flow), could I drive at the highway quietly. If that could be done . . . fine, I' ll do it, but unfortunately, nobody can' t tell my that before work has done. Danm, looks like I have to do it and find out that myself.

wth best regards,

[porkkis]

Material affects the noise also. Stainless tends to be more boomy than regular. Lasts longer of course but tends to be louder too.

[Greg_S]

a 3" system is possible, http://www.s2forum.com/forum/showthread.php?t=3051

Mine could have been fitted slightly better in places if the company had taken their time a little more. The section over rear axle needs moving back an inch and the downpipe needs a litle adjustment and the joint between front and rear section could have been placed about 1 inch further forward to give better clearance

[lynx]

I have done it . . .

I let the last silencer replaced, with stainless. One 2,5" inlet and 2x2,5" out.
First I was scared . . . maybe to load, but gues what. It' s more quiet even, that I was thought. Yes, it' s more noisy that original, but not so much . . . with 110km/h, very quiet (but not like original).

1000-1600/1700rpm, it' s more . . . noisy, but that' s ok, and I even like it.
Now, someday I will let replace the middle section.

but, hey . . . one picture can say more that 1000 words

[sailaz]

interesting old thread .... 3'' exhaust... I had straight one from downpipe with just one Magnaflow 12249 muffler at the end:

https://www.magnaflow.com/products?partNumber=12249

later I've decided it is 'a bit to loud' and somehow ( ) came to conclusion to go for a set up with 3'' Vibrant 1795 Resonator With Tube Ends & 3'' Vibrant 1149 Streetpower Black Flat Oval Muffler

http://vibrantperformance.com/catalog/product_info.php?products_id=293

http://vibrantperformance.com/catalog/product_info.php?cPath=1527_1032_1109&products_id=52

... and I ended up with even mo louder exhaust , actually it sounds more nicely but way too loud .

Any advices for 3'' quiet (straight without cats) exhaust setup would be appreciated

[Thuppu]

I just had my 80 exhaust loudness measured at MOT. 2.5" exhaust with a 200cell cat and one big muffler gave 96dB(@4krpm). Quite a suprise as my UrS4 gave 99dB at trackday noise measuring, and it sounds a LOT louder with 3.5" exhaust. I'll guess the 3dB will make a difference.