Discrete/Quiet performance exhaust recommenations?

dave23572 · 18-07-14, 11:46 AM

I've decided to upgrade my exhaust system
Definitely decided on a Janspeed manifold and Sports cat.
I just need some advice on the cat-back system to suit my needs:-

Most importantly I don't want the exhaust to be loud.
I don't want to draw any unwanted attention. Loud exhausts just aren't my scene.
I will be looking for a dual silencer cat-back system that is no louder, or little louder than the standard exhaust. Does that exist? or are all performance exhausts quite a bit louder?

Would such a system have real performance gains over the standard system?

I'd also want the tailpipe to look as close to standard as possible.
Definitely not one of those "boy racer" huge tailpipes.

Any help in choosing a discrete performance exhaust most appreciated.

Dave

Fred68 · 18-07-14, 07:25 PM

The idea of a performance exhaust is to get the gasses out with minimal back pressure. This means using straight through silencers. These work by absorbing the sound into a glass or stainless steel wool pack. The more silencers you fit the quieter the exhaust becomes. These silencers take out high frequency noise quite well, low frequency noise often comes out unchecked.
Personally I'd try to avoid twin exit systems, if performance is what you are looking for.
A 2.5" pipe all the way from manifold to tail pipe is all you need with 2 or 3 quality silencers.

splinter · 18-07-14, 07:58 PM

I've got a twin box single exit cat back on my 120. Listened to some advice on here and opted for a cybox system. It's straight through but no louder than a standard system. Maybe a slightly different tone.
They will listen to your requirements 're tailpipe and are very approachable.

talkingcars · 18-07-14, 07:59 PM

I vert much doubt you will be able to make much difference to the sound of a janspeed system.

I went to my local bespoke exhaust builder (Powerflow in Redhill) and told them what I wanted - free flowing, quiet at tickover and at cruising RPM but a bit of sound under hard acceleration, a seperate decat and twin outlet, they were surprised by my choice descreet tail pipe. 3 hours later it was done and was even better than expected.

The term they use to describe the sound is mid sport.

R8NMG · 19-07-14, 11:33 AM

I have a Janspeed cat back system. The OE system is very quiet so any other performance exhausts will be louder than OE.

I actually find the Janspeed system to be not overly loud. Yes it is noticeably louder than OE but you get a good rasp from the exhaust. I certainly will not call it chavvy racket as I don't like that either but the Janspeed system on sound wise is very acceptable.

dave23572 · 19-07-14, 08:43 PM

Main reason I don't want it loud is because I use the ZS for house calls for my IT support business. Don't want to create a laddish impression as I turn up to fix someone's computer.

DuckFeet · 20-07-14, 12:15 AM

Janspeed manifold is not discreet. You'll have to put trumpet/baffles in the tailpipes I think, which slow the gases down enough that it's not worth having the freer flowing manifold. In my experience. Also dual exit made my old one louder.

stamford · 20-07-14, 08:09 AM

I would say you would be better off getting one made from Longlife or Powerflow to suit your requirements and make it a cat-back system and retain the OE manifolds and cat. Going down the Janspeed manifold and sports cat route will make it louder as already mentioned before you have even fitted a system. I have had a Janspeed dual exit cat-back fitted for around 8/9 years and a decat for about 6/7. I am running stock manifolds on mine. It is loud when pushed but a nice and healthy sound, not chavvy at all. My MOT tester and garage owner love my car and said it is one of the sweetest V6's they have heard. If going Janspeed cat-back stick with an OE cat to keep the levels as you desire. Plenty of options but Janspeed manis are not cheap and not particularly good quality from what I have read in recent times.

dave23572 · 20-07-14, 11:50 AM

I wanted the Janspeed manifolds for the performance increase.

What if I went with the JS manifolds only and retained the OE cat and cat-back system?

I guess it would be slightly louder because of the manifolds but would the OE cat and cat-back be costing a lot of torque/power?

I guess all I basically want is a good performance increase but not much more noise.

stamford · 20-07-14, 12:03 PM

Janspeed all the way through is alot of outlay for little gains. I haven't gone for Janspeed manis due to the cost and what gains there are, besides I'm happy with the car as it is. I found the remap better value for money over the manis. Each to their own. If I was in your shoes I would look at keeping the front end OE, get a custom made cat-back system, quality induction kit for optimum breathing then remap. That would be more economical in my eyes for decent gains and better all-round driving experience.