Removing the akrapovic DB-killer


Donut

New member
Please see attached picture of no damage to baffle.........excuse the slippers!

Years ago I had a VTR1000 Firestorm and on the list for that it was almost de-rigeur that any pic had to include slippers in it somewhere.

The bike has not yet been re-mapped or had a Power Commander fitted and the red line (on the dyno chart) was with the modified baffle which is an acceptable (to me) half-way house between needing ear plugs and thinking that I have a sewing machine with me.

I will get it re-mapped at some point but need to speak to Hilltop (Leicester) or Simon at S-Tec Newbury as I'd like to be able to switch between baffle in and out. Getting my 09 re-mapped at S-Tec in the morning (23rd April) so will speak to Simon then.

Also have a DNA filter and top to fit so will see how that goes when all fitted and mapped accordingly.
 

triple trouble

New member
Years ago I had a VTR1000 Firestorm and on the list for that it was almost de-rigeur that any pic had to include slippers in it somewhere.

The bike has not yet been re-mapped or had a Power Commander fitted and the red line (on the dyno chart) was with the modified baffle which is an acceptable (to me) half-way house between needing ear plugs and thinking that I have a sewing machine with me.

I will get it re-mapped at some point but need to speak to Hilltop (Leicester) or Simon at S-Tec Newbury as I'd like to be able to switch between baffle in and out. Getting my 09 re-mapped at S-Tec in the morning (23rd April) so will speak to Simon then.

Also have a DNA filter and top to fit so will see how that goes when all fitted and mapped accordingly.
It's a shame I'm not about tomorrow or I would have meet you
 

starvinmrvn

New member
Whew! I installed the Akrapovic last night. I severely underestimated how loud it was based on YT videos. Haha...this thing is L O U D. Love the sound though.
 

sash

New member
I run the carbon fiber akra system, to remove the baffle iI simply used a broomstick. Stick it in the engine side end of the exhaust and just gently hit it on the ground....baffle pops out. no damage no drama... As i do get a lot of popping when I go off the gas the bike obviously runs very lean without the baffle in so I contacted akrapovich to ask if it might be too lean and actually cause damage to the bike over long term.....They said it should be fine...I decided to get a powercommander regardless, should be here next week... haha.
 

addy

New member
I run the carbon fiber akra system, to remove the baffle iI simply used a broomstick. Stick it in the engine side end of the exhaust and just gently hit it on the ground....baffle pops out. no damage no drama... As i do get a lot of popping when I go off the gas the bike obviously runs very lean without the baffle in so I contacted akrapovich to ask if it might be too lean and actually cause damage to the bike over long term.....They said it should be fine...I decided to get a powercommander regardless, should be here next week... haha.
There's a guy on here that has been making a custom ecu flash for the bike, saying that with the standard ecu and carbon akra no baffle the bike loses quite a bit of power compared to baffle in.

http://www.motorcycle-talk.net/forum/mt-07-fz-07-modifications/1635-mt07-amp-amp-amp-bike.html
 

JHTPPX

New member
I am just about to pick up a 2017 model with a Acra euro 4 spot welded in baffle! Dose anybody know the exact location of this spot weld? Will be easy to drill with a spot weld drill once I find the spot and pull with a slide hammer internal bearing puller! Having used a EJK fuel controller on my crf250l with great success I intend to get one for the MT to sort any lean running problems! All help much appreciated!!!
 

JHTPPX

New member
Now I have the bike I can see the location of this spot weld In the Acrapovic exhaust can! With a bit of carful measurement it should be not too difficult to remove the little bugger!!!!!
 

Lemmy

New member
Bit late to this thread but ive just done the Akra mod and drilled 4 x 10mm holes into each of the inner baffle pipes just before the flange. The sound is definately louder/better than with the DB killer in but i still dont think its quite loud enough....? Can anyone tell me if theres a considerable difference between removing/cutting half the inner pipes out compared to the drilled holes method - i.e is it louder??
 

Affe

New member
Seeing that a pic is worth a thousand words and all that here is what I've done:

Started with removing about 2 inches of internal pipe, then removed another half inch or so (no real difference between the 2 to be honest) to leave about 1 inch of internal pipe. As you can see from the pic I've mashed one of the external pipes a bit with grips to remove the db killer. The hole you can see is one I've drilled to re-secure the thing to make life easier.

View attachment 2236

Here's the db killer in place with a new hole on the outside of the exhaust:

View attachment 2237

And here it is with a bolt to secure it in place:

View attachment 2238

I now use a spring puller (easily and cheaply available from Ebay) to remove the db killer when I want to:

View attachment 2239

Like this, in case you're in any doubt:

View attachment 2240

As mentioned before though, unless you re-map to run without the db killer the engine will run very lean. Here's my dyno chart to show both the power / torque gain without the baffle (2 bhp / 1.4 Ft/lb) - and the air / fuel mix. With baffle about a perfect 13 to 1 but without a very lean 17 to 1 with a risk of damaging the engine.

View attachment 2241

I guess the MT-07 has more of a torque plateau than a torque curve.
Hello! A bit late to the discussion here. Hope someones still active ;)
Iam trying to see if the DBkiller mod can be done without a tune, it seems so on your dynorun. But why are both curves showong extremely high a/f ratios before 4k rpm? Is it that its ok as long as its in low rpms?
 


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