Before I go off and get a noise test done at a track…what’s the chance of my K-series VHPD getting through the noise tests with a steel Janspeed exhaust (the one with the oval exit pipe)?
It makes a mighty noise at the moment so I expect it has two chances of passing; slim and none.
Anyone got a quiet exhaust for sale?
Have you got a cat replacement pipe on ?
A silence CRP will help a bit.
May I recommend the Larini for the S1. Not the cheapest but sounds great and I’ve never had a noise issue.
Ian 
Ps. From years gone passed (try a search waaaaaay back), I agree, not much hope with that set-up. 
It has a cat fitted at the moment. However, when it had it’s MOT I could hear it howling from he test station when I was in the village centre (200 metres away). It is nosey; but sounds good!
My Janspeed supersport was measured at 107dB static which was pretty loud …
Changed it for a 2Bular 8x24 last year (the biggest can that will fit in the rear clam) which, even with an unsilenced CRP, is always less than 105dB. Still have to steer clear of 100dB limits and 98dB drive-bys though!
I think the overall answer is a big 2Bular or Larini with a sports cat and then you should be OK just about everywhere.
My Larini (with SCRP) on a NA Honda (@ about 5500rpm) was something like 95dB! Never been caught out by 100dB.
[quote=Rotorhead]My Janspeed supersport was measured at 107dB static which was pretty loud …
[/quote]
likewise with the CRP but with the silenced pipe it was something like 102-103 db I think
I have the Janspeed exhaust and bought a silenced CRP to go with it - result, low 90’s Db.
However, as both of these itmes have got older, I am now getting 104 - 105 Db, so I’ll be too noisey very soon.
If you are going to keep the exhaust, get a silenced CRP. Don’t do what I did, and get one for ‘up to 200bhp’ from Deamon Tweaks - go for the ‘over 200bhp’ one to make it quieter for longer. Be prepared that one day you may have to additionally buy and fit a super trap on track days (as I am going to have to).
However, if the alternative exhaust option ends up being cheaper by being quieter for longer, then go with the systems that the other chaps here recommend.
However, I must say that the Janspeed sounds bloomin’ marvelous!
Cheers,
Clive.
Book a track kindly let me take my suspectedly too noisy S1 out for a few laps at Donington (as I have done a few sessions in my Elise with them). It passed the noise test with ease (89db drive by) with 190-VHPD, CAT and Janspeed - rusty steel job. So how does it compare with a S1 140bhp Elise running on Bilsteins and Neovas?
Acceleration - did not really feel any faster than the Elise.
Brakes - not as good as the Elise, but I had a large(ish) person riding shotgun and it only has road pads compared with Pagids in the Elise.
Grip, turn-in, stability - wow. I got it nowhere near its limits but after only 6 laps I was as fast as the Elise. AO48s are now on the shopping list for the Elise.
Downside as that after 6 laps it also managed to rub holes in the new wheel arch liners. I think I need some Nitrons and stiffer springs! At least it did pass the noise tests!