Modified Akro Baffles

From experience I have modified the std akro baffles. So far I can say they sound awsome awsome - like a low flying helicopter. You can actaully hear your own SD without leaning back! Well worth the trouble.

For the intake and exit ends design see this link:


Chambered muffler design for reference:


These are the basic concepts for the modifications... my bike will be going on the dyno with these, but as I have made intake and throttle mods... I will not be able to provide evidence on their specific performance.

BWWWWWWOOOOOOOAAAAAARRRRRRRR!!!!!!....phut...phut...POP!............BANG!!!!!......BWWWWOOOOOOOAAAAAARRRRRRR!!!!!!!!!!!....Luvly.





......pass the tablets will you dear!

Will try plipton... not sure how to post it yet or record it?? maybe my mobile.

Dr F... I am sure that was a positive BWOAR

Oh BTW I used a very delicate form of cutting using a specialised tool to create these precise specific modifications. These tools are:
1) angle grinder
2) cold chisel
3) 2lb hammer

I have shorten both tubes by 25mm and replaced the soft bolts with allen head High tensile. The difference in noise level was very small and no difference to the tune / performance.
Considering some small holes in the disc section but I am trying to get a spare set just in case. I have heard several time of the DB killers just being discarded, bit of a waste IMO. more testing is required here i think.

aP

Silly question (yes, I know I'm known for them )...

Have you tried riding with 1 dB killer in and 1 out? That would give some attenuation but should be loud enough to get the hairs standing up on the back of your neck. Not tried this so possibly might not work that well.

BTW - here is a cool link for you guys wanting some good sounding exhaust tambre:

this is a new idea that I have just found... very cool! Similar to my baffle mod - but much more sophisicated

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Have a look in the gallery - the pics are all there of what to do.

You want the airflow to ripple and combine one flow with another to create sound. Drilling holes or cutting has no effect on noise.

To improve sound quality you need air turbulance... the trick is to make cambers. See the gallery for my way of making the flow ripple:




I have also created a technical document about this topic that you may be interested in reading:

I did the Gregz mod to my baffles, it brings up the volume and does produce a nicer sound. Somewhat deeper and more aggressive than with plain baffles.
I actually need to find a way of 'undoing' the mod by having another tube to fit inside the baffle as it's made it a bit too loud for certain tracks.

Got to say I'm 'baffled' by all this.
Surely the only time you put the db killers in is when you're at a 98dba trackday or when the bike's in for it's MOT?

Far as I'm concerned the SD sounds just fine with the Akra slip ons and the db killers out. My neighbours are all octogenarians and they tell me they like the sound of the SD on full noise. I've done about 30,000 road miles and never been pulled for the noise (plenty of other stuff, mind) even if a cop did pull you up for a loud pipe all you've got to do is pop the db killers in and go round to your local MOT centre and have them stamp the chit and you're done. No fines, no pain.

Am I out of step here?

That would be great !
Thanks

UP
Nobody with pics or explanations of the mod ? I can't wait to test it

We've got our pictures back