My MTS 1200 LOST 40 HORSEPOWER!

[Aurelius]

Originally Posted by w0mb2t

ok , a picture tells a thousand words .. that is a HUGE restrictive plate.

And you wouldnt have necessarily felt it if you were just tootling around town but it would have killed the bike at higher rpm

So, does this apply to all decible reduction devices?

[moperfserv]

Think about it. The stock system is quiet and makes 135HP.
It has considerably more volume.
I haven't looked closely at the stock system but isn't there a large can in front of the rear wheel? Then two large (and heavy) mufflers. Plus a Cat.
Remove all of that and replace it with a short pipe and low volume muffler and then put a huge restrictor before the muffler, not at the end of the muffler.
Basically it was done all wrong. The system works well without the cork, but then they put a plug in it (in the wrong place) to cut the dB level.
With the limited volume, corking the end of the muffler wouldn't work much better.
Consider the volume of the Superbike exhaust systems.

Doug

[w0mb2t]

Originally Posted by Aurelius

So, does this apply to all decible reduction devices?

i dont know whether you could even call this a decible reduction device ... and i suppose from the result its more like a HP limiting plate similiar to what you would find in go carting . So it begs the question why did they bother manufacturing this plate for this bike which already has a 100hp map.

[moperfserv]

It's my understanding that they needed to decrease the dB level and added that plate. It does decrease the sound power level but it is functionaly, a HP limiter.
I looked at an MTS1200 fresh out of the crate today and there is a huge volume in front of the tire beneath the swingarm.
They make 135HP like that and meet the EEC and US noise levels. Volume!!!
And, to tnbob; I get down to Commonwealth a couple times a year, and they have a dyno.

Doug

[tnbob]

Doug, that's certainly doable. A Saturday would be even better as I have a hard time getting away from work for a few days. As an alternative I could bring it up the weekend before and leave it. Please let me know when you are going to Indy and I'll schedule accordingly. We are going to the MotoGP but that's not a time to be working .

[MultiFrank]

Doug,

Instead of saying:
"Once I pulled the cork out of the pipe, it felt like a Ducati instead of a Moto Guzzi. (ouch!!!!)"

You could have also said:
"Once I pulled the cork out of the pipe, it felt like a Multistrada instead of a R1200GS. (ouch!!!!)"

[Duc PP]

GOPR0077.mp4 video by MTNDUC - Photobucket

I have to tell you guys, it has made a huge difference on how much better it has run since having Doug redo the ECU air/fuel mapping. It has run perfectly with no need to add other gizmos to cure the lower rpm qwerkyness. If any of you guys out there want to switch over to a different exhaust, it is going to mess with the bikes ecu even more than stock, so I'd really recommend having Doug or someone that really know whats going on dyno your bike to get the most out of it.
I think the beak in the front of my bike smiles at me now....

[Turkishexpress]

Nice. What did he use to tune it?

[Nickpilot]

Doug (who I don't know, but he's famous), CJS (Chris) in the UK, (who did my ECU)...and someone in Scandanavia...and I believe a company in Aus...are some of the few people who seem to know what they are talking about...many others don't. The ideal has to be to get the bike to them...they get rid of the closed loop, and they tune the tables, on the dyno. The only real way to do it. If, (as I had to) you send your ECU away (to Doug or Chris), yes, they can reflash to get rid of the nasty closed loop....and put in tables 'nearest' to your configuration (in my case full termi)...but...as Chris pointed out...this is unlikely to be perfect. For whatever reason (and that's another story!)...there is a great variability between these engines, and unless you get the likes of Doug or Chris to get your bike on the dyno...you are not going to get the best. That leads on the the PCV...as the (very much) 'second best' soulution...AFTER you have had the Doug/Chris reflash...if you can't get it on their dyno. As Doug said...all you can do then is to 'modify' the tables for the front and back cylinder...on a local dyno. This IS worth doing, assuming you have a GOOD dyno man...and my bike is now a lot better...but you can't fine tune any of the 'trim' tables...so if you are after the 'ultimate' solution, this ain't it. But as most of us are not racing these machines...it's not really the 'ultimate' we seek...just the best we can get.
For those who can get to Doug or Chris...it has to be worth taking a hoilday and getting your bike over to them!!

[idleidolidyll]

Having bought and fitted the Leo Vince exhaust system (Cat eliminator and carbon muffler) i was interested in this thread. I had left the dB killer in the back of my muffler to keep it civilised but had not experienced significant power loss.
On further reading it seems I instinctively did the right thing when I was fitting the system. I saw that plate with the holes in it and thought to my self "that looks like a horsepower killer, I'll leave that out".
However, as has been noted here, this is only there for compliance purposes and you'd be nuts to fit that thing. The real dB killer is a screw in std style insert at the back of the muffler which I have left in to keep my bike civilised around town.
Now though, I'm wondering if there is a real benefit to removing the actual dB killer from the back of the muffler and whether the bike can be ridden without shattering eardrums in town and breaking windows on driveby's.

Having been in there since new; the dB killer is pretty much 'seized' in place and pulling it out is very likely to make a mess of the edges I'll have to grip with pliers.

Any comments from someone who HAS removed the dB killer?