IVA Friendly silencer

[dogwood]

Hi Ronnie.

The Robinhood one won't pass IVA
I've got the same silencer, and it only just passed the SVA test.
I know the IVA is a lot lower. As Ash found out.
I fitted the Sierra cigar shaped first box, after the test.
See my pic on FS post
Defo made it quieter, Still not sure it's IVA friendly though

[HandyAndy]

Originally Posted by dogwood

The Robinhood one won't pass IVA
I've got the same silencer, and it only just passed the SVA test.

Oops oh well never mind ....£7.50 down the drain

cheers
andy

[Bonzo]

Cheers for your thoughts chaps

To be honest, I hadn't given a bike can a great deal of thought .... I am sure if one is able to deal with a 10,000 rpm / 150 bhp fire breathing monster, it'll be well capable of dealing withe the exhaust flow of my litte Zetec engine

Andy

All is not lost, why not open up the RH one & repack it

[davidimurray]

Ronnie - if you need any info or dimensions of my can let me know. I was quite surprised how light the bike can is as it is all aluminium and titanium I think a couple of other guys on here have used bike cans.

Cheers

Dave

[spud69]

Originally Posted by davidimurray

Ronnie - if you need any info or dimensions of my can let me know. I was quite surprised how light the bike can is as it is all aluminium and titanium I think a couple of other guys on here have used bike cans.

Cheers

Dave

Bike Can for me and easily passed SVA, ebay special with the flared end. Tis really quiet until you boot it then it gives of a nice meaty tone. If you can get a repackable one just to be sure for the tighter IVA test.

AndyH

[Bonzo]

Thank's Dave

Just out of interest, what are the basic dimensions of the GSXR can ?
Oh & what size pipe enters the can ?

It'll not be too long before I make my exhaust manifold up & still havn't decided on: 4 - 2 - 1 or just 4 into 1 I guess knowing the manifold to silencer pipe size will de the decider

Andy

Thank's mate

May I enquire as to the origin of your bike can ?

Lost track of bikes a long time ago !!?? .... In fact the last bike I rode was very early Yamaha RD 125 twin .... Was race tuned though & was s**t your pants scary at the time

[davidimurray]

Ronnie

I will check out the dimensions next time I'm down the garage - from meory the inlet pipe is 2 5/8" OD and connected by a 4 bolt flange. There are some more pics here - http://www.haynes.co.uk/forums/showthread.php?t=4119 The can itself came from good old Ebay.

With regard to exhaust configuration it really depends on what you want. The different arrangements do not give you any more power - they just move the power and torque up and down the curves. Generally the longer the pipes, the lower down the curve the peaks will be. If your not familiar with the theory, it is basically that wherever you have a change in volume you will get a wave reflected. If you time this wave to be in sync with the exhaust port open you will create a negative pressure and actually suck exhaust gas out of the cylinder (giving you more space for fresh charge on the next intake cycle). If you look up helmholtz or organ pipe theory, you should be able to calculate for your engine for a certain RPM how long your exhaust runners should be. If you need any help let me know and I could probably dig the calcs out - good excuse for a spreadsheet!

For my own car, which will be mainly for the road, I plan to use a 4-1 and the longest primary runners I can package tidily as I would prefer a good low/mid range power than the max HP somewhere up the top of the rev range.

Out of interest Ronnie are you planning to weld up your own exhaust? I'm going to have a go at doing my own from scratch in stainless. Seems like a good challenge and one of those jobs that will probably be a complete pain in the a** but a satisfying one. Most bits seems reasonably easy to get hold of - the only thing that amazes me is the price of weld on merge collectors - yet to find any below about £55