Track friendly exhaust options

[tejr]

I know this is quite a hot topic, I've done a search but I know we all like a good discussion and it would be nice to get a more tailored answer.

Ideally I would love to keep my sports pipes as they sound perfect. They spit and pop on idle and are very bassy to the point where they will set off car alarms They are relatively loud but have a nice full sound, not like the tinny standard exhaust and even the guys at the TVR centre complimented them as sounding better than another Cerb they had in with a sports exhaust.

However, I would also like to do some track days this year and even with TVR Monster removable silencers I doubt they will be quiet enough (probably only 2-3db quieter with the silencers)

So, I'm looking for alternatives. I've emailed Tim at ACT and he reccomends the Big bore full system with the cherry bomb silencers will be best to keep the sound using 2" 1/4 pipe work, or 2" to reduce noise further though this sounds pretty restrictive to me?

As I understand the standard 4.2 system is 2.5" throughout? I may get a custom exhaust made up (£500) with 2.5" pipework and just add in some silencers each side?

In an ideal world I would like -

1) Keep the same note just quieten it down
2) Not loose power
3) Not bankrupt myself (<£700 ideally)
4) I will probably keep the cats in as well

[450Nick]

Give Tim a ring, he can do custom exhausts to suit your need if you're not happy with his off the shelf stuff - I'd ask him about how restrictive it is as well, he has done a fair bit of testing with his kit so it may not be as restrictive as you think.

I had a similar problem with my supercharged Chim and he made up some custom tail pipes with silencing in - I can swap them from straight through to silenced in 5 minutes and it reduces the exhaust noise by 10db with NO loss (measured on track with a DL1 datalogger).

[FUBAR]

Tim and Austec concocted my setup for me. Big Bore system but modified so the tails unclip and slip off and the ACT 3" TD silencers slip back on and clip up, and keep within the bodywork. So simple even I can do the job in 5 minutes





Call Tim again and mention my setup

[450Nick]

Looks like I have a similar setup to you FUBAR, though my ones use 40ish cm tails (so the whole last straight of the exhaust is lopped off. The silencers are much slimmer though (about 10cm diameter) with a slash cut at the end so you can't see the smaller bore inside. I'll try and stick a pic up later. They're so good that I often leave them on for a few weeks as it makes the car a lot more relaxing to drive.

[Onzlouk]

Powerflow exhaust and 3" trackday silencers, way under £700 and easy as pie

[Byker28i]

ACT 2 1/4" bore quiet system on mine. No Cats, just straight through pipes. Ran 362 bhp with cracked exhaust manifolds and iffy coils/leads. Now running 382bhp with act manifolds as well, so not restrictive.
106db at 4.5k revs, 96 db with track day cans added.

Cats add 8-10db noise restriction as well. I put the cats in as well last year and ran 88db at Thruxton

[FUBAR]

Byker28i said:

Cats add 8-10db noise restriction as well. I put the cats in as well last year and ran 88db at Thruxton

Blimey, I thought a Cerb at Thruxton was just a pipe dream

[tejr]

Byker28i said:

ACT 2 1/4" bore quiet system on mine. No Cats, just straight through pipes. Ran 362 bhp with cracked exhaust manifolds and iffy coils/leads. Now running 382bhp with act manifolds as well, so not restrictive.
106db at 4.5k revs, 96 db with track day cans added.

Cats add 8-10db noise restriction as well. I put the cats in as well last year and ran 88db at Thruxton

Great info thanks! Is that with the above add-on silencers? I'd rather not have to bother with them tbh. Especially as I have the TVR monster insert ones.

Edited by tejr on Tuesday 25th January 16:34

[markh1]

Byker28i said:

ACT 2 1/4" bore quiet system on mine. No Cats, just straight through pipes. Ran 362 bhp with cracked exhaust manifolds and iffy coils/leads. Now running 382bhp with act manifolds as well, so not restrictive.
106db at 4.5k revs, 96 db with track day cans added.

Cats add 8-10db noise restriction as well. I put the cats in as well last year and ran 88db at Thruxton

That's a good increase! I have the ACT manifolds but have not had the car remapped since they were installed. I would be interested to know how much of that power increase is due to the manifolds.

[Byker28i]

Joo said I was losing a bit due to cracked manifolds and the slight misfire from coils/leads, but it started at 346bhp before he worked his magic. Not bad for a 12/13 year old car.

88db was at Thruxton at 4K revs (it only revs to 6K - honest Guv, then praying - don't backfire, don't backfire) but it felt a little strangled, certainly strangely quiet. Cats plus quiet exhaust plus trackday cans.

Edited by Byker28i on Wednesday 26th January 17:10