Mito 443 Project
Discussion
Mornin'
Agreed. Yon mentioned the cub cylinders porting is pretty wild from standard, so i can imagine the low speed characteristics won't be overly grunty. If you oversize your carbs you'll end up with low venturi air speed which won't pull the fuel through meaning it'll bog terribly in the lower rpm. Then you'll be slipping the clutch to try and get her spinning up into the powerband to get her going. Especially if you're not running PV's to alter the port roof timing and fill out the bottom end.
Can't remember what Smads is running on his 485 but my reckoning is you'll be looking at 36, maybe even 34's. If you can get the carbs right, the bike will pick up much sweeter off the bottom end and whilst it may cost you a couple of ponies at the absolute top, it'd be a much quicker bike in the real world. But it's always going to be a compromise. If the bike is going to be used 90% road, i'd definately go for the smaller carbs to give it better pick up. Also look at things like V Force reed blocks etc.
But also have a word with Stan whle you're in there. He should be able to put you on the money given his experience.
Agreed. Yon mentioned the cub cylinders porting is pretty wild from standard, so i can imagine the low speed characteristics won't be overly grunty. If you oversize your carbs you'll end up with low venturi air speed which won't pull the fuel through meaning it'll bog terribly in the lower rpm. Then you'll be slipping the clutch to try and get her spinning up into the powerband to get her going. Especially if you're not running PV's to alter the port roof timing and fill out the bottom end.
Can't remember what Smads is running on his 485 but my reckoning is you'll be looking at 36, maybe even 34's. If you can get the carbs right, the bike will pick up much sweeter off the bottom end and whilst it may cost you a couple of ponies at the absolute top, it'd be a much quicker bike in the real world. But it's always going to be a compromise. If the bike is going to be used 90% road, i'd definately go for the smaller carbs to give it better pick up. Also look at things like V Force reed blocks etc.
But also have a word with Stan whle you're in there. He should be able to put you on the money given his experience.
I think smads is on 38s and his mate on 35s doesn't make much less power
Definitely going with vforce reeds, that's another thing, I'm not sure what reeds that other bloke was running or whether he had a stuffer in them or not which would make a big difference. He did say when he built it he had big figures in mind more than midrange, I'm pretty sure it's had further porting.
Definitely going with vforce reeds, that's another thing, I'm not sure what reeds that other bloke was running or whether he had a stuffer in them or not which would make a big difference. He did say when he built it he had big figures in mind more than midrange, I'm pretty sure it's had further porting.
If Smads is running 38's on a 485 then you'll be spot on with 36's on a 443. Also do your best to run either a boost bottle or pipes from the inlets to help the bottom end. The RS uses a 1 meter length of rubber pipe that loops off of the reed block to act as a resevoir for the low speed pulses. Even the old aircooled DT 125's we see here have a boost bottle fitted from factory!!
As for reeds i'd be careful using carbon reeds. Yes, they work for low rpm bikes like an MX machine, but they always seem to get frayed or chipped with higher revs. I tried them on my RS and the lasted no time before they'd broken. The standard Suzuki reeds actually proved to be the best.
As a point of reference, the KTM 200 to 300 models comes with a 36mm as standard. Going to a 38mm PWM on the 300 only gets it around 52bhp, up from a standard 45/47. So 38mm on a 293cc cylinder making peak power at 8500 should see you right at 36mm on a 220cc cylinder revving to 10500.
And what about filters?? I guess you're going to have to use pod type items? Only thing is, the RGV boys have found the K&N type pod filter actually robs power. So if you're going this far, maybe look at making a bespoke air box, with a ducted cool air inlet away from the heat off the engine and rad and as much volume as you can muster. Takes a bit of time, butmake it from cardboard templates then when 100% make the panels from a form of sheeting and fibreglass together.
As for reeds i'd be careful using carbon reeds. Yes, they work for low rpm bikes like an MX machine, but they always seem to get frayed or chipped with higher revs. I tried them on my RS and the lasted no time before they'd broken. The standard Suzuki reeds actually proved to be the best.
As a point of reference, the KTM 200 to 300 models comes with a 36mm as standard. Going to a 38mm PWM on the 300 only gets it around 52bhp, up from a standard 45/47. So 38mm on a 293cc cylinder making peak power at 8500 should see you right at 36mm on a 220cc cylinder revving to 10500.
And what about filters?? I guess you're going to have to use pod type items? Only thing is, the RGV boys have found the K&N type pod filter actually robs power. So if you're going this far, maybe look at making a bespoke air box, with a ducted cool air inlet away from the heat off the engine and rad and as much volume as you can muster. Takes a bit of time, butmake it from cardboard templates then when 100% make the panels from a form of sheeting and fibreglass together.
Good thinking about the airbox, I know a good ally fabricator to make one too. Boost bottle/link wise the billet carb manifold has an internal link between both inlets.
There's a lot to think about.. But good to get some ideas flowing before I start buying bits.
There's a lot to think about.. But good to get some ideas flowing before I start buying bits.
Edited by Yazza54 on Thursday 10th April 09:40
Can the internal link be rerouted to an external pipe or bottle arrangement? I've never liked the idea of cross linking the inlet manifolds, i think a small bottle on each inlet would be better.
So 36mm Keihin PWK's and a nicely size airbox could be perfect. Just make sure the airbox feed is from an area away from the engine heat. The Suzuki RGV race kit has an air duct that feeds the airbox from an inlet on the side fairing and a heat shield that sits over the engine to try to prevent the airbox getting heated up. Don't worry about trying to achieve a ram effect but cool air is king.
So 36mm Keihin PWK's and a nicely size airbox could be perfect. Just make sure the airbox feed is from an area away from the engine heat. The Suzuki RGV race kit has an air duct that feeds the airbox from an inlet on the side fairing and a heat shield that sits over the engine to try to prevent the airbox getting heated up. Don't worry about trying to achieve a ram effect but cool air is king.
Edited by bass gt3 on Thursday 10th April 09:57
kin about
bass gt3 said:
Can the internal link be rerouted to an external pipe or bottle arrangement? I've never liked the idea of cross linking the inlet manifolds, i think a small bottle on each inlet would be better.
So 36mm Keihin PWK's and a nicely size airbox could be perfect. Just make sure the airbox feed is from an area away from the engine heat. The Suzuki RGV race kit has an air duct that feeds the airbox from an inlet on the side fairing and a heat shield that sits over the engine to try to prevent the airbox getting heated up. Don't worry about trying to achieve a ram effect but cool air is king.
The link is internally machined in as it's a mono block, but you can get separate ones. Can't say I've ever messed with boost bottles, I'll have a read up on them as at the mo I'm not quite sure what the benefit is.So 36mm Keihin PWK's and a nicely size airbox could be perfect. Just make sure the airbox feed is from an area away from the engine heat. The Suzuki RGV race kit has an air duct that feeds the airbox from an inlet on the side fairing and a heat shield that sits over the engine to try to prevent the airbox getting heated up. Don't worry about trying to achieve a ram effect but cool air is king.
Edited by bass gt3 on Thursday 10th April 09:57
Yazza54 said:
The link is internally machined in as it's a mono block, but you can get separate ones. Can't say I've ever messed with boost bottles, I'll have a read up on them as at the mo I'm not quite sure what the benefit is.
Apparently they boost the low end torque by doingnweird pjlse magic in the intake. Can't believe Yamaha would fit them if they didn't do anythingYazza54 said:
The standard one is a link, did you say you didn't think linking was a great idea?
Don't know if its not a good idea, but most/maybe all later twins used separate tubes or such. If you look at the rgv arrangement, its a length of tube looped off the same inlet manifold. This length is the equivalent of a bottle or reservoir. Not sure if the volume is critical or not, but might be interesting to look into
Made new tie bars that bolt to the bottom of the motor and the mounts, the motor is totally solid now and fully rubber mounted.
Just tacked up here
Then made a little ally bracket which I'm going to rivnut to bolt the front of the tank up.
Did quite a lot of surgery on the subframe to make it mount on the inside of the frame to get the TZ tail to fit. As well as cutting off a load of unnecessary crap. Needs a mounts for the back of the tank and seat.
Threw it together as a bit of a mock up, the tank will be jacked up a bit at the back to close the gap at the front, it was just sat on the shock resi here. Also the seat is just sat on the tail unit, I'll cut the tail out so it fits around the seat which will be bolted to the subframe. Hence why the seat looks too high, but you get the idea
Just tacked up here
Then made a little ally bracket which I'm going to rivnut to bolt the front of the tank up.
Did quite a lot of surgery on the subframe to make it mount on the inside of the frame to get the TZ tail to fit. As well as cutting off a load of unnecessary crap. Needs a mounts for the back of the tank and seat.
Threw it together as a bit of a mock up, the tank will be jacked up a bit at the back to close the gap at the front, it was just sat on the shock resi here. Also the seat is just sat on the tail unit, I'll cut the tail out so it fits around the seat which will be bolted to the subframe. Hence why the seat looks too high, but you get the idea
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