Exhaust restriction
Exhaust restriction
Just reading on the oz firestorm site about filing out a restrictive bit as the pipe enters the right side can.
Is this the same on uk bikes? and if it is has everyone already done it?
Is this the same on uk bikes? and if it is has everyone already done it?
it most likley will be dookie m8 . i got link pipes when i fitted my end cans.
and im not sure i saw the[ FLANGE] when i fitted them, and yes i think it would be beneficial to remove ,increasing flow of exhaust gasses ..IMHO of course
and im not sure i saw the[ FLANGE] when i fitted them, and yes i think it would be beneficial to remove ,increasing flow of exhaust gasses ..IMHO of course
I AM THE STRANGE MAN YOUR MOTHER WARNED YOU ABOUT......
Have a sweetie and stop crying........
[Werthers Original...they never get rid of the taste]
Have a sweetie and stop crying........
[Werthers Original...they never get rid of the taste]
Yup, i know mine are like that, never really thought about removing it though.
but i'm going to get my pipes ceramic coated to bring back the shine, as they have discoloured badly, poor quality material, might remove it before i send them off to get treated.
anybody know if these guys are still going, the website prices are from 2002.
http://www.camcoat.u-net.com/Exhausts.htm
i'll prolly phone them soon anyway but just wondering.
but i'm going to get my pipes ceramic coated to bring back the shine, as they have discoloured badly, poor quality material, might remove it before i send them off to get treated.
anybody know if these guys are still going, the website prices are from 2002.
http://www.camcoat.u-net.com/Exhausts.htm
i'll prolly phone them soon anyway but just wondering.
cheerz
kev
kev
- Stormin Ben
- Posts: 1234
- Joined: Sun Dec 01, 2002 12:23 am
- Location: Birmingham
DON'T DO It
Quote from Roger Ditchfield at Revolution racing (VTR GOD!!!)
My thought on it would be that at high revs removing itt allows more gas to escape therefore more power
However, at lower revs its gas SPEED you're interested in to provide response (how quickly the engine picks up) and a large hole is gonna make the gas speed SLOWER (think of putting your finger over the end of a hosepipe)
Ben
Quote from Roger Ditchfield at Revolution racing (VTR GOD!!!)
> > ----- Original Message -----
> > From: "revolution racing" <roger@...>
> > To: <VTR_List@yahoogroups.com>
> > Sent: Thursday, October 06, 2005 9:32 AM
> > Subject: Re: [VTR_List] Stock header clean up
> >
> >
> > The restrictor in the standard headers is there to
> > assist the pulsing which
> > helps to scoure the front cylinder and to create a
> > turbulence vacumn thus
> > accelerating the gas speed at that point above certain
> > revs. If this is
> > removed the left hand exhaust can will discharge a
> > greater proportion of the
> > gas emmisions.as did the first Akropovic and Two
> > Brothers full exhausts did,
> > until they were modified, to the detriment of the
> > engine performance. Later
> > full systems were designed to overcome this effect by
> > changes in their
> > length, merge angles, tapers and taper length.
> > Honda, Moriwaki, Akropovic and others could have
> > saved themselves
> > millions in R&D if they had only listened to some AU
> > guy and cut away the
> > "excess" to improve power output !!!!
> >
> > Regards
> > Roger
My thought on it would be that at high revs removing itt allows more gas to escape therefore more power
However, at lower revs its gas SPEED you're interested in to provide response (how quickly the engine picks up) and a large hole is gonna make the gas speed SLOWER (think of putting your finger over the end of a hosepipe)
Ben
Nice 1 guys , being a 2 stroke nut i understand about exhausts and understand what rodger is on about.
And im also clever enough to not question someone with a million times more experiance with exhausts than myself.
Thanks Stormin Ben i was thinking of getting the dremmal out this afternoon , PHEW
Seems that most of the oz site have buggered ther exhausts up then.
And im also clever enough to not question someone with a million times more experiance with exhausts than myself.
Thanks Stormin Ben i was thinking of getting the dremmal out this afternoon , PHEW
Seems that most of the oz site have buggered ther exhausts up then.
-
- Posts: 151
- Joined: Tue Jan 10, 2006 4:53 pm
- Location: Glasgow
There is another reason why it may be there...which nobody has mentioned in the UK.
Honda made several mods to get sound down, I have been told by a friend who worked for honda and had a vtr as company bike. These may have included the 16t sprocket, lip on the airfilter and the flange in the pipe. All these mods reduce the sound at 4500rpm, doesnt the vtr have a flat spot on a dyno here? The two noise tests he mentioned were the 60kmph ride by in top gear and the rpm at half peak power noice test. anyway food for thought, I have removed all these base on that understanding, storms going better than ever!
Honda made several mods to get sound down, I have been told by a friend who worked for honda and had a vtr as company bike. These may have included the 16t sprocket, lip on the airfilter and the flange in the pipe. All these mods reduce the sound at 4500rpm, doesnt the vtr have a flat spot on a dyno here? The two noise tests he mentioned were the 60kmph ride by in top gear and the rpm at half peak power noice test. anyway food for thought, I have removed all these base on that understanding, storms going better than ever!
- LotusSevenMan
- Posts: 1915
- Joined: Wed Sep 06, 2006 8:32 pm
- Location: Liss, Hampshire. UK
Well I did the mod today so here is my two penth for what its worth....
1) Smoother reving
Have to agree with the OZ dudes as the bike is noticeably 'smoother' from idle 1200rpm to 4000rpm. I can't really say if its 'smoother' above 4000rpm as it was always pretty smooth reving from that point to the red line anyways.
2) Less raspy exhaust note (suits my preference)
At idle both Scorpion race cans are pumping out an equal amount of gas with the 'two hand test'. Before the mod I could only ride for 2/3mins with out earplugs (as soon as the pipes were at full operating temp they would get much noiser than from cold) today I road for a full hour with no complaints. Granted the "thump" isn't as strong as before as two cans are absorbing the noise where as before it was 80% RHS and 20% LHS (my guess) Defo better in my opinion.
3) Reduced engine braking
I don't really miss this but the bike has lost a little "character" it still has better engine braking than a CBR600 but i'd say its 1/2 as strong as it used to be.
4) Less backfiring on overun
I'd guess this follows from 3) defo suits my preference as this used too wind me up.
5) Less torque in 4000-5000 ish range
I have a 15t sproket, in 2nd gear at 4000rpm if I give her full throttle to the red line it is definately less agressive. It reminds me of a VFR800 or CBR600 you get a change of engine note when you give it full gas and the pickup comes later. Previously there was no delay, not a sniff
Some dyno time may get back some of the lost torque . I feel pretty sure the restriction was there to boost torque. There are guys in this forum who have gone from two exhausts to one and all state that "torque goes up but you loose top end". Seems to me that with my 80% - 20% anology Honda were balancing the exhaust so that a large porportion is just going through the RH pipe i.e just one exhaust for torque.
All in all I'm happier with the bike now than I was before, it sounds better is easier around town as the engine braking is less severe and I can enjoy the sound with out earplugs!. If you don't mind loosing some power and engine braking then the mod is a no brainer.
1) Smoother reving
Have to agree with the OZ dudes as the bike is noticeably 'smoother' from idle 1200rpm to 4000rpm. I can't really say if its 'smoother' above 4000rpm as it was always pretty smooth reving from that point to the red line anyways.
2) Less raspy exhaust note (suits my preference)
At idle both Scorpion race cans are pumping out an equal amount of gas with the 'two hand test'. Before the mod I could only ride for 2/3mins with out earplugs (as soon as the pipes were at full operating temp they would get much noiser than from cold) today I road for a full hour with no complaints. Granted the "thump" isn't as strong as before as two cans are absorbing the noise where as before it was 80% RHS and 20% LHS (my guess) Defo better in my opinion.
3) Reduced engine braking
I don't really miss this but the bike has lost a little "character" it still has better engine braking than a CBR600 but i'd say its 1/2 as strong as it used to be.
4) Less backfiring on overun
I'd guess this follows from 3) defo suits my preference as this used too wind me up.
5) Less torque in 4000-5000 ish range
I have a 15t sproket, in 2nd gear at 4000rpm if I give her full throttle to the red line it is definately less agressive. It reminds me of a VFR800 or CBR600 you get a change of engine note when you give it full gas and the pickup comes later. Previously there was no delay, not a sniff
Some dyno time may get back some of the lost torque . I feel pretty sure the restriction was there to boost torque. There are guys in this forum who have gone from two exhausts to one and all state that "torque goes up but you loose top end". Seems to me that with my 80% - 20% anology Honda were balancing the exhaust so that a large porportion is just going through the RH pipe i.e just one exhaust for torque.
All in all I'm happier with the bike now than I was before, it sounds better is easier around town as the engine braking is less severe and I can enjoy the sound with out earplugs!. If you don't mind loosing some power and engine braking then the mod is a no brainer.