I'm getting my 08 R1 Indy ready for some trackdays. Now I need to get a trackday exhaust before I get it mapped.

I'd really like to be able to get it quiet enough for the quiet circuits like Combe and Bedford as well as the noisier tracks like Caldwell.

I've had a look around and the biggest straight through can I can find is CBS 7" x 26" long.

Do we think this would make it quiet enough?

Or would I be better of with a R1 bike can and hope it doesn't restrict the engine too much?

And and ice on this matter would be great.

Cheers

[Edited on 13/5/13 by -matt]

How much ££ do you want to spend?

Ive got a Raceco Titanium silencer fitted to mine. it is 7.25" dia, and 29.5" it is very quiet, and very light. It is a kilo lighter than my old 5" dia CBS stainless silencer. Not cheap though

http://www.raceco.com/silencers.html

The baffled bike can is a great way of cheaply reducing the exhaust noise down to 'acceptable levels', even for Combe. The static test isn't the issue here, it's the drive-by meter. Same at Goodwood, but even more difficult to comply with.

A sensible can (5-7" diameter) down the side of the car, check out the Westfield Megabusa can (the round catalyst can, not the oval race can) that size of anything similar will bring the noise down to a Combe level, and it won't affect the performance. At least it doesn't on mine.

Induction noise on the drive-by is where you need to worry. You'll need an airbox ideally. A foam sausage underneath an uninsulated GRP bonnet won't really do, it's marginal.

I went for a car engine on the track hack (finally), it all got too much, MX5's got too far cheap to ignore....

Thanks, unfortunately both the raceco and Westfield are out of my budget.

So I'm thinking of just going for the R1 can for now.

My only worry with it is that the extra restriction will overhead the engine? Cyl 2and3 being a weak point in this engine?
Although I have got an additional electric water pump to keep the coolant flowing nicely and hopefully stop it overheating here?

As for induction noise I've got This pipercross px600 air box, so induction noise is much quieter than a sausage filter.




[Edited on 13/5/13 by -matt]

Hi
We have a very low mileage 2001 carbed R1 on that we used the original airbox reversed
& the R1 can , about 97Db.
If it does not restrict the bike why should it restrict the car.
on the rolling road with standard jetting , tweaked by Austec Racing
we got 150 bhp, we were satisfied with that.

Hi, im not meaning to hijack this thread, but had anyone had any issues with backfires at trackdays.im pretty sure mine is quiet enough for the usual noise test, but with not running a dump valve it does tend to crack and bang similar a group of toffs at a pheasant shoot when on overrun,and wouldn't want a day called short if anywhere doesnt allow it?

Chris