Exhaust dilemma
Discussion
Hi all,
First post and nearly a Caterham owner:0
I've ordered a Supepsport and will be be collecting it in April but I have to finalise my spec now.
The exhaust is a 'pea shooter' type and pretty loud and i'm worried it'll fail the noise regs at track days', will I be best to spec the car with track day friendly exhaust from the off or keep the std one and have a sepaarte silencer?
There is the option of an 'Interim exhaust catalyst bypass pipe', is this a quieter or louder box do you think??
Any recomendations on quieter silencers for track days'?
Many thanks for any help and look fowrard to future chats
Cheers
Neil
First post and nearly a Caterham owner:0
I've ordered a Supepsport and will be be collecting it in April but I have to finalise my spec now.
The exhaust is a 'pea shooter' type and pretty loud and i'm worried it'll fail the noise regs at track days', will I be best to spec the car with track day friendly exhaust from the off or keep the std one and have a sepaarte silencer?
There is the option of an 'Interim exhaust catalyst bypass pipe', is this a quieter or louder box do you think??
Any recomendations on quieter silencers for track days'?
Many thanks for any help and look fowrard to future chats
Cheers
Neil
Welcome to the fold. It's also worth joining the lotus 7 Club as the forum 'blatchat.com' is generally more active than on here and you'll find a wealth of technical knowledge there too. There's quite a few of us that lurk on both.
Personally, if you're thinking of doing trackdays it would make sense to spec the car with a bigger silencer to help keep the noise down from the off.
The cat bypass pipe when fitted will mean a few extra horses being avaialble to play with, but you WILL need to refit the cat for MOT each year.
Personally, if you're thinking of doing trackdays it would make sense to spec the car with a bigger silencer to help keep the noise down from the off.
The cat bypass pipe when fitted will mean a few extra horses being avaialble to play with, but you WILL need to refit the cat for MOT each year.
Welcome to Caterham 7 ownership 
IMHO, if this is a new car you are buying then I would get it with the standard cat and exhaust. This will pass both the IVA and trackday limits. You don't say if you are buying a Sigma or Duratec engined Car, but it is only when you go throttle bodies on the Duratec that noise may become an issue (in my experience) with the standard exhaust. I've run with, and without, the cat by-pass pipe and it is hard to tell the difference - perhaps a little quieter with it.
David
Edit: read the spec now - Sigma engine, I don't think you'll have problems
IMHO, if this is a new car you are buying then I would get it with the standard cat and exhaust. This will pass both the IVA and trackday limits. You don't say if you are buying a Sigma or Duratec engined Car, but it is only when you go throttle bodies on the Duratec that noise may become an issue (in my experience) with the standard exhaust. I've run with, and without, the cat by-pass pipe and it is hard to tell the difference - perhaps a little quieter with it.
David
Edit: read the spec now - Sigma engine, I don't think you'll have problems
Edited by DCL on Friday 10th February 16:44
Edited by DCL on Friday 10th February 16:49
I had a cat bypass pipe put on my R300 from new, it was the same price as a new cat.
When I put the cat back on, I couldn't tell the differecnce. IMO the cat bypass pipe is a waste of money, and makes negligable difference.
Go for the quiet exhaust, and stick with the cat. Less hassle in the end.
When I put the cat back on, I couldn't tell the differecnce. IMO the cat bypass pipe is a waste of money, and makes negligable difference.
Go for the quiet exhaust, and stick with the cat. Less hassle in the end.
To the OP
I'm picking my SuperSport up 3rd March from Midlands. I'm going to call in at the BookaTrack day at Donnington on my way home with it and plan to have it noise tested as I have a Bookatrack day booked in June.
I have gone for the standard 'pea shooter' exhaust. I'll let you know the result, but don't know if you will need to finalise the spec before then.
IIRC Evo said its £250 for the larger exhaust if you want both, so it might be a case of having to get that for trackdays and keep the thinner exhaust for road use.
I'm picking my SuperSport up 3rd March from Midlands. I'm going to call in at the BookaTrack day at Donnington on my way home with it and plan to have it noise tested as I have a Bookatrack day booked in June.
I have gone for the standard 'pea shooter' exhaust. I'll let you know the result, but don't know if you will need to finalise the spec before then.
IIRC Evo said its £250 for the larger exhaust if you want both, so it might be a case of having to get that for trackdays and keep the thinner exhaust for road use.
I have a Sigma 125 with the cat and standard exhaust. It was 92db tested at Goodwood last year, so you wouldn't have to worry at trackdays even though the supersport rev limit is a little higher.
Removing the cat isn't as easy as it looks, as the springs are very tight and it's all too easy to scratch the paint doing the inner one.
I certainly wouldn't want to be doing that job every MOT.
By the way, I find the standard exhaust a good compromise, it doesn't cause offence around town, and doesn't boom on the motorway, but sounds quite rorty when pressing on
Removing the cat isn't as easy as it looks, as the springs are very tight and it's all too easy to scratch the paint doing the inner one.
I certainly wouldn't want to be doing that job every MOT.
By the way, I find the standard exhaust a good compromise, it doesn't cause offence around town, and doesn't boom on the motorway, but sounds quite rorty when pressing on
I'm unsure now ! ,please help and clear this up ,I have got an R300 on order April delivery and have added the interim exhaust catalyst bypass pipe to my order mainly because the demo R300 at c midlands has it and I think it looks better with out the cat !,when I added it to my order was told it would add a little more bhp and be a little louder not much thought,but nothing about having a cat on for mots ? Do they supply the cat then with the car if I have upgraded ? Do not want to keep changing it over ?
Strictly speaking you will be breaking the law if you run 2012 registered car without a catalytic converter on public roads. The bypass pipe is really just for track use. You need to make sure the by-pass pipe you have spec'd is in addition to, and not instead of, the standard cat.
Edited by DCL on Sunday 12th February 15:14
I asked Caterham about the track day exhaust when I ordered my Supersport (another April delivery). I was told it was worth about 4bhp, didn't sound as good and the standard exhaust would be quiet enough for track days (fingers crossed).
@Ady F - Let us know how you get on when you get it noise tested.
@Ady F - Let us know how you get on when you get it noise tested.
Thanks all for your posts, much appreciated.
Still not sure!
I think i'll stick with the standard exhaust as it's part of the Supersport's rowdy character and assess my options later on depending on whether it will actually fall foul of the noise regs. Not really worried about the cat bypass tbh.
Speaking with Anthony he seems to think it will be too noisy though and recommends the track day exhaust but most of my driving will be on the road so it would be a shame to miss out on the extra 'baaarghh' for just the occasional track event.
@Ady F- Your feedback on this would be a great help; my car doesn't go into build until early March so this may, just, be enouth time to change the spec. Thanks..
Still not sure!
I think i'll stick with the standard exhaust as it's part of the Supersport's rowdy character and assess my options later on depending on whether it will actually fall foul of the noise regs. Not really worried about the cat bypass tbh.
Speaking with Anthony he seems to think it will be too noisy though and recommends the track day exhaust but most of my driving will be on the road so it would be a shame to miss out on the extra 'baaarghh' for just the occasional track event.
@Ady F- Your feedback on this would be a great help; my car doesn't go into build until early March so this may, just, be enouth time to change the spec. Thanks..
Comadis said:
I would go home first before fitting one of those, Ive seen 2 bike engined cars both melt pistons and expire when they were fitted 
can only tell you what ive seen and both cars were perfect prior to fitting and trackday regulars , I can only imagine it will restrict the gasses flowing from the exhaust causing heat build up, possible might be ok on a car engine, but both owners of the becs blamed the bolt on silencer, as said I would go home first I personally wouldnt want to chance it.
A later than planned collection meant I didn't unfortunately have time to get the exhaust noise tested.
Spoke to Caterham when I picked the car up and they reckoned the Supersport with the 'pea-shooter' exhaust as I have is louder than even an R500. I suspect it would fail all but the noisiest track days.
But hells bells what a noise it makes, loud with a capital F!
I did close to 200 miles today and for me the noisy exhaust is a large part of the car's character.
Im going to have to rent the noise meter from BookaTrack which they post and you then return, I'll report back as soon as I've done it
Spoke to Caterham when I picked the car up and they reckoned the Supersport with the 'pea-shooter' exhaust as I have is louder than even an R500. I suspect it would fail all but the noisiest track days.
But hells bells what a noise it makes, loud with a capital F!
I did close to 200 miles today and for me the noisy exhaust is a large part of the car's character.
Im going to have to rent the noise meter from BookaTrack which they post and you then return, I'll report back as soon as I've done it
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