Stripping out silencing stuff

[trinitycall]

Hi all,

On the Surrey Run at the weekend I followed a green chimaera that sounded more like a formula one car than a chimaera. Very aggressive sounding with loads and loads of popping, and it really screamed like nothing on earth.

I was so exhausted at the end of the run that I forget to get the full details as to what had been done. As an outline i think the chimaera has had the silencing stuff taken out and the cat left in.

I'd really like to know a little more detail on what needs to be removed from the exhaust and any estimates as to possible cost.

Also is it stuff that can be put back in if required?

If anyone can help that would be great.


Thanx

N

[Jem]

My understanding is that this is the sports exhaust modification, stripping out the wadding and welding back up the silencer.

The other threads on sports exhausts, on this page and in a search, will give you further info.

J

[Big Al.]

Jem said:

My understanding is that this is the sports exhaust modification, stripping out the wadding "Insert" and welding back up the silencer. The other threads on sports exhausts, on this page and in a search, will give you further info. J

"Insert" "Welding in straight thro pipes and" IIRC the stripping out of the wadding is immaterial with straight thro pipes.

[billynomates]

trinitycall said:

Hi all, On the Surrey Run at the weekend I followed a green chimaera that sounded more like a formula one car than a chimaera. Very aggressive sounding with loads and loads of popping, and it really screamed like nothing on earth. I was so exhausted at the end of the run that I forget to get the full details as to what had been done. As an outline i think the chimaera has had the silencing stuff taken out and the cat left in. I'd really like to know a little more detail on what needs to be removed from the exhaust and any estimates as to possible cost. Also is it stuff that can be put back in if required? If anyone can help that would be great. Thanx N

You know Dave Batty--and I know you take your Chim there

Dave charges about £160:00 IIRC

Phil

[chimhunter]

Ahh, it's nice to be famous. You were indeed following Smaug. Vid here from when I got it done:

www.robcole.gb.com/video.html

Done at Austec. Opend exhause silencer, removed fibre glass, welded in solid pipes (i.e. not perforated), welded exhaust back up. Nice. Took about 2 hours.

Rob

[trinitycall]

Has to be done. Simple as that. Will call Garage tomorrow.

Thanx for the info.

[redleicester]

I had this done to my Chim400 at Horizon Motorsport in Birmingham, for the princely sum of £72.

AWESOME noise. It now rattle the kitchen windows when it's sitting idling on the drive. Well worth it, and if God forbid you change your mind, it's reversible... So you won't have lost half as much money as if you'd shelled out for a "proper" sports exhaust.

Pops and crackles on the over-run, well they all do that sir, but no one warned me about the flames!

[Podie]

Andy at APM did mine... but I know that Offords and Joolz do it as well.

Leave the wadding in... makes a deeper sound!

[my 350i]

I`m thinking of having my 500 done the same. What does it measure on db when its done though ?
I know that every car will be different on different days but is it likely to pass noise tests for track days at 98db when fitted with ACT`s finest track silencers ?

[redleicester]

Mine passed with no silencers fitted (sitting in the boot incase I needed them!) at the TVRCC trackday at Oulton Park earlier this year.

Having said that, a pals standard 450 was failed... so I'm not convinced about the accuracy of their tests! With the silencers you should be okay for most tests.

[Big Al.]

One metre behind the each pipe held at 45 degs IIRC.

[shpub]

0.5 metre at 2/3 or 3/4 revs is the norm.

[Big Al.]

shpub said:

0.5 metre at 2/3 or 3/4 revs is the norm.

You sure Steve?

[chimburt]

i've said it before and i'll say it again - if you're considering going on track be very cautious about doing this mod.
my 400 has been measured at various noise levels, varying by something like 4-5dB ( actually 2- 2.5 times diffence in volume! ), all at the same track!
i'd be gutted rolling up to a trackday and having to go home again, tail between legs and a couple of hundred quid lighter without going on the circuit.