Akrapovic Sp series Modification - more power less noise
 

My 2009 XTX with Akrapovic SP was too loud with the Baffles out and not running well enough with them in.

I had incresed CO2 by 6 and I have replaced the Air filter with a K&N stage one - I didnt want to do any further obvious things such as a power commander or drilling the air box as I was losing faith in the bikes ability to run well enough for my needs.
Having seen that Gianni had modified his Akrapovics I have been experimenting with mine and I am delighted by the results.

My bike has the O2 Sensor by the way and the AIS which have both been left alone and stock.

Hopefully people will find the details below and the pictures useful in deciding whether to attempt this mod - if it all goes wrong you can buy replacement Akrapovic Baffles for about �37 (GBP) each
http://i737.photobucket.com/albums/x...0/IMGP0034.jpg

So above is the bike - Nice eh?

http://i737.photobucket.com/albums/x...0/IMGP0038.jpg

Look into my eyes.... - the Baffles are the bits in the centre of each slencer, they are tubes with a mesh at each end that slows down the exhaust gases as they try to exit the exhaust.
By slowing the gasses down they create back pressure and smooth out the bangs and pops from the combustion process (make it quieter) but they also stop the engine breathing so well as the back pressure stops the gasses clearing the cylinder so quickly. Try breathing through a straw and you will get the idea!

We are going to modify the baffles to reduce the back pressure and help the engine breathe better whilst not making it too loud.

http://i737.photobucket.com/albums/x...0/IMGP0041.jpg

First remove the rubber bung from the bottom of the silencer, this allows you to get to the hex head screw that holds in the baffle

http://i737.photobucket.com/albums/x...0/IMGP0044.jpg

Put your 4mm allen key up inside and undo the screw, if you drop it inside the casing you will have to shake the bike about until it falls out - so do it slowly and dont let your hands shake!

http://i737.photobucket.com/albums/x...0/IMGP0045.jpg

Phew! - I got it out in one go - this is how you have to put it back in by the way - the screw is not Magnetic so if you have shakey hands you might want to use a bit of Blu-tac on the end of the Allen key to reduce the chance of dropping it.
http://i737.photobucket.com/albums/x...0/IMGP0047.jpg

Now you have to get hold of the end of the baffle and ja ja jiggle it until it comes loose and you can pull it out - mine came out easily but you might have to use grips to pull them if they are stuck in there a bit.

Once you have them both out, your off to the work bench to do some cutting!

http://i737.photobucket.com/albums/x...0/IMGP0056.jpg

I cut about 15mm off the end, I guess if you cut more off then the pipe will be louder, of you can also make it louder I think by drilling out the holes in the mesh as Gianni has done.

http://i737.photobucket.com/albums/x...0/IMGP0057.jpg

Heres one I cut earlier, I found Praying made a difference to the process - any denomination can do this and it seems to work.

http://i737.photobucket.com/albums/x...0/IMGP0059.jpg

Here is the bit I cut off each side - the holes in the mesh are what are slowing the gasses down too much - I now only have the mesh in the end of the baffle that shows - so I have halved the resistance and the exhaust still looks like it should to anyone inspecting the bike.

http://i737.photobucket.com/albums/x...0/IMGP0046.jpg

Now the baffle goes back in - I found a good way of lining up the screw hole with the hole in the silencer casing was to use an allen key and push it through them both and wiggle it to line them up.

http://i737.photobucket.com/albums/x...0/IMGP0045.jpg

The screw goes back in to hold the baffle in place - fiddly and nerve wracking in case you get it cross threaded - but eventually it goes in and your almost finished......

http://i737.photobucket.com/albums/x...0/IMGP0063.jpg

Put the rubber plug back in and in Homage to Kev make sure that the emblem of the hammer and sickle are both facing the right way and straight.

http://i737.photobucket.com/albums/x...h_IMGP0040.jpg

Now start it up!

I found that the surging has all but gone, the engine has more power and is so much smoother - its actually fun to ride again.
The noise is not too bad and all in all its well worth doing.

I have pasted a video below of the bike without any baffles that doesnt really sound as bad as the real thing - its unbearable in real life and is irresistable to the Police when commuting in London Traffic - but you might like it!

I have found no difference now in riding the bike with the modified baffles and no baffles at all - other than my neighbours are now talking to me again! I found that removing the Baffles increased performance which is why I started to experiment.

Enjoy

Robert

http://i737.photobucket.com/albums/x...h_IMGP0050.jpg

Good work !!!!!

Ciao.:thumbsup[1]::thumbsup[1]::thumbsup[1]:

Thanks Gianni - I wouldn't have done it without your original posting

Robert:YellowWink_VZHUX5:

Nice work mate, neat & easy job.

stupid question but some one have to ask it.
could it be done river sly ? what i mean, would it have same effect if we leave bottom end stock and somehow cut top part of db killer ? i don't have anything against its functionality but i do hate that net look...can this be done ?

Yes you could reverse the process and remove the mesh (net) from the end that you see - it is tack welded in so you could either drill it out or cut through the welds and remove it that way.

If you are going to do that though you might as well just take out the DB killer and have the bike look and sound evil!

Robert

Thats what I did with mine - I used a Dremel Multitool with a small cutting disc but you could use a drill or anything suitable to cut the welds. The noise is a *little* louder but very acceptable with the odd POP as you change down for traffic lights and none of the multiple shotgun blasts that it had without the baffles.

It looks much better by the way...

http://i41.photobucket.com/albums/e2...ikes/Akra1.jpg http://i41.photobucket.com/albums/e2...Dtaillight.jpg



'cptr

exelante :) now all i need is to find some decent second hand akrapovic's :Tosser:

http://i41.photobucket.com/albums/e2...es/th_AKRA.jpg

Video of modified dB killers in action...

SEXY! :eusa_dance:

Akrapovich Baffles
 

Hi Guys,
I have a set Akrapovich SP's on my 04 XTX. They came with the bike but without the baffles. It sounds the b*****ks but they dont help me when Im trying to sneak in home late past the wife !!! Does anyone know where I can get a set of baffles for the SP's?? I have checked fleabay but Im not 100% sure if they will fit them. Anybody have a contact for and Akra supplier ??
Tog go bog e

http://www.akrapovic.com/
i think they will give them to you for free if you have all original.

I did some research before I started cutting........

http://www.mandp.co.uk/productinfo/553299/Exhausts/Exhaust-Systems-and-Silencers/Akrapovic

I think this is the item but you would be best to ring M&P first - I thought they were about �17 each but this could be 2 for �39.00 I guess.

It does sound good with the baffles out...... but at 6.45 am when I leave for work I think my neighbours would soon get tired of the noise!

Good luck

Baffled!!
 

Thanks for the help Guys, I sent a nice mail to the Akra folks so lets see how they respond. Robbie its a pity that the M&P site dosent have any pics of the baffle up so I dont really know what Im buying. My cans have a flat end to them with a hole as opposed to a 'spout' so I need to research a bit more. Ill keep ye posted:dontknow::dontknow:

Nice Mod, gonna try this myself, have run mine since i got it without the baffles and i must admit its getting to the point where its getting a little annoying, have a brand new set of baffles sitting in the loft so will chop em tonight!

Hi Mate,

Did you manage to get the db iller for your Akros?
Where did you get them from?

Cheers.

Start with this lot,their the importers in the UK.

http://www.performanceparts-ltd.com/