Sports exhausts

[nickrudd]

To all you Chim experts out there!

The sports exhaust exhaust I believe, was an option from the factory. How can they be identified? ( I may well be on the lookout for a Chimaera soon. Is there a difference in power output or is it just noise?

Importantly, would the sports system still pass 100dB trackday noise test??

Any help most gratefully received.

Cheers,

Nick

[that daddy]

Im not a chim expert but i cant see any sports exhaust making any worthwhile performance increase,unless you change that manifold/tubular set/up 1st,its not very good,all you will increase is noise.

[bigdods]

that daddy said:

all you will increase is noise.

Cant think of a better reason for doing it. Go for the cherry bomb conversion

[e2djh]

bigdods said:

Cant think of a better reason for doing it. Go for the cherry bomb conversion

wot he said

[john p]

My standard exhaust was modified by Team Proactive in 2003.The silencer has been cut open,the baffles removed and welded back up.This was done by a previous owner,so I can't comment on any power increase.It cost £60 labour,and sounds awesome.I think TVR Power do this mod aswell.

[Wildfire]

Any conversion, cutting open, straight through pipes, cherry bombs etc. are very unlikely to pass the 100db noise limit.

[The Surveyor]

My car was recorded at 103dB's (Using normal track-day static testing) at the BNG and would not pass the noise limits for some tracks (Croft is 105!), then went up to a rip-snorting 124dB's at full chat.....

Thats with the pre-cats out and the rear box fully sleeved. No increase in power at all from a standard, but does sound faster......

[petea]

[quote=The Surveyor]My car was recorded at 103dB's (Using normal track-day static testing) at the BNG and would not pass the noise limits for some tracks (Croft is 105!), then went up to a rip-snorting 124dB's at full chat.....

No consideration for others eh paul...(only jealous!)

[the dodger]

Nick, to answer your Q - I don't think an alternative was offered by the "factory" - lots have been modified (by dealers) since. As previous posts: No actual power gain but sounds it!

[nickrudd]

Thank you all for your replies. I don't know if I've actually HEARD one, but I like the idea of it. I would like to be to do the odd track day (well, I've managed one in four years!). Castle combe is my nearest and they have a stingy 100dB limit!

[dumbfunk]

I seem to remember hearing that every Chim/Griff was originally produced with a standard exhaust (thereby meeting noise regulations) and then every UK car was immediately fitted with the sports option. So its a bit of a red herring - they all have sports exhausts.

What most people mean by the term however is the cutting open of the silencer and replacing the perferated tubes with solid. On an otherwise standard car you'll see no performance change.

Dumbfunk

[edward1]

Mine has a factory fit sports exhaust (I have the original invoice that shows it as a cost option). The difference between this and the standard is only the pipe diameter over the last couple of feet. It is probably a good 1/2 - 3/4" larger bore than the standard. It won't give any better performance but a deeper sound than the std fit system. I don't know who the sound track compares to the after market mods though.

I have done a couple of track days with it and not failed a noise test yet although it always worries me.

[the dodger]

dumbfunk said:

I seem to remember hearing that every Chim/Griff was originally produced with a standard exhaust (thereby meeting noise regulations) and then every UK car was immediately fitted with the sports option. So its a bit of a red herring - they all have sports exhausts.

I certainly do not think this is true - not the case with mine or most that I know.

dumbfunk said:

What most people mean by the term however is the cutting open of the silencer and replacing the perferated tubes with solid.
Dumbfunk

- I guess you mean plain tube rather than solid?

[hugerr]

The typical after-fit (or after-modded) 'sports' exhaust on a Chim will put out something like 110dB SPL in a 3/4 max rev static test.

But it is a simple matter to bolt on a pair of additional external silencers for track day use to bring it back below the 100dB limits of most circuits.

...and then you can take them off after the event and drive around the local country lanes for a while to find your way home...

hugh

[dumbfunk]

the dodger said:

- I guess you mean plain tube rather than solid?

Solid as in not perforated.
(Unless shoving potatoes up the exhaust pipes is a performance mod I'm not familiar with?)


Dumbfunk

[gf350]

I thought sleaving the exhaust, would if anything, produce a slight power drop as the rover v8 likes a bit of back pressure?
But it is worth it for the noise.