Modified Akro Baffles · SuperDukeNet Archive

Post 1 by Gregz, 27 Dec 2006, 07:12

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.

Post 2 by KTMax, 27 Dec 2006, 08:39

#2

Post missing

This post could not be recovered from the original forum.

Post 3 by Gregz, 27 Dec 2006, 09:38

#3

Post missing

This post could not be recovered from the original forum.

Post 4 by Plipton, 27 Dec 2006, 11:18

#4

Post missing

This post could not be recovered from the original forum.

Post 5 by Dr F, 27 Dec 2006, 12:30

#5

Post missing

This post could not be recovered from the original forum.

Post 6 by Gregz, 27 Dec 2006, 14:49

#6

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

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

Post 7 by Plipton, 28 Dec 2006, 03:41

#7

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

Post 8 by DukeofCornwall, 28 Dec 2006, 20:02

#8

Post missing

This post could not be recovered from the original forum.

Post 9 by aP, 24 Jan 2007, 09:43

#9

Post missing

This post could not be recovered from the original forum.

Post 10 by Plipton, 24 Jan 2007, 11:37

#10

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

Post 11 by Gregz, 24 Jan 2007, 13:31

#11

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.

Post 12 by Gregz, 04 Feb 2007, 05:50

#12

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

Post 13 by Gregz, 04 Feb 2007, 11:19

#13

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

[/url]

Post 14 by Ya Mother, 10 Apr 2007, 19:03

#14

Post missing

This post could not be recovered from the original forum.

Post 15 by ktmguy, 11 Apr 2007, 00:24

#15

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:

Post 16 by Ya Mother, 11 Apr 2010, 22:32

#16

Post missing

This post could not be recovered from the original forum.

Post 17 by Jaxian, 12 Apr 2010, 09:43

#17

Post missing

This post could not be recovered from the original forum.

Post 18 by Ya Mother, 12 Apr 2010, 10:04

#18

Post missing

This post could not be recovered from the original forum.

Post 19 by Millar, 12 Apr 2010, 19:04

#19

Post missing

This post could not be recovered from the original forum.

Post 20 by tripoddave, 12 Apr 2010, 19:07

#20

Post missing

This post could not be recovered from the original forum.

Post 21 by BASH69, 12 Apr 2010, 22:44

#21

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.

Post 22 by Remy, 02 Jun 2010, 09:54

#22

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?