628cc Scrambler
#11
05-12-2002, 07:33 AM
ScramblerX,
Yeah, either the moderator or the kid decided to tke his message off the board. It's still sad to see they let children flame like that when people are in need of information.
Mickey,
First off, congratulations making the ONLY modifications that really make horsepower out of the 500cc four stroke. If I had a hankerin' to go wth the 500, I would see you first. Still, the fact that you are making more torque is the very reason why you need to make clutching changes. A properly tuned CVT machine should almost seem slower than one that is improperly clutched (until you get it to the races that is). Most often, wheelspin is corrected with a adjustment of the secondary clutch. You can do this with either a stronger spring, or by moving the position of stock spring in the secondary clutch. Heck why not just go with a roller clutch while you're at it? They make the machine backshift like it is completely gear driven. There is no hesitation on throttle response.
Or, you could make a simple change the gearing, like you said. I had a problem with wheelspin (due in part to a longer swingarm and too much HP/torque). I geared it down to 13/30 and the wheelspin is mostly gone, but the accelleration is way up. I've let a few of my "shifty" friends ride my machine, and while it really doesn't seem faster than their shifter machines, the drag race results bear this out every time.
Generally I would go with a lower engagement on the primary (softer spring, heavier weights) and a stiffer spring and a roller clutch on the secondary. This would probably tame the wheelspin problems and make it quicker off the line. There are also setups that you can make for specific tracks and conditions (muddy/slick or firm/hardpack) that would allow you to take advantage of the CVT design.
Yeah, either the moderator or the kid decided to tke his message off the board. It's still sad to see they let children flame like that when people are in need of information.
Mickey,
First off, congratulations making the ONLY modifications that really make horsepower out of the 500cc four stroke. If I had a hankerin' to go wth the 500, I would see you first. Still, the fact that you are making more torque is the very reason why you need to make clutching changes. A properly tuned CVT machine should almost seem slower than one that is improperly clutched (until you get it to the races that is). Most often, wheelspin is corrected with a adjustment of the secondary clutch. You can do this with either a stronger spring, or by moving the position of stock spring in the secondary clutch. Heck why not just go with a roller clutch while you're at it? They make the machine backshift like it is completely gear driven. There is no hesitation on throttle response.
Or, you could make a simple change the gearing, like you said. I had a problem with wheelspin (due in part to a longer swingarm and too much HP/torque). I geared it down to 13/30 and the wheelspin is mostly gone, but the accelleration is way up. I've let a few of my "shifty" friends ride my machine, and while it really doesn't seem faster than their shifter machines, the drag race results bear this out every time.
Generally I would go with a lower engagement on the primary (softer spring, heavier weights) and a stiffer spring and a roller clutch on the secondary. This would probably tame the wheelspin problems and make it quicker off the line. There are also setups that you can make for specific tracks and conditions (muddy/slick or firm/hardpack) that would allow you to take advantage of the CVT design.
#12
05-12-2002, 12:45 PM
Barely Legal, AAEN's clutching book is a must have. He also has an informative carb book, but nothing gets used more in the shop than his clutching manual.
Mickey, along with Mike I have to say I'm impressed with the power. Not to be mean, but I would put money on HPD,RCR,Hot Seat, or AAEN if they tuned your clutching. If nothing else, trying the roller secondary setup for the woods....REALLY improves performance. Hot Seat, along with AAEN and HPD all have roller secondaries available.
HPD is also coming out with a secondary slipper clutch. Lot's of avenues to dial your power to the ground.
One other note, HPD now has multiple finished cylinders on their workbench with the variable exhaust power valve. Don't think I'll be stepping up, but looks like a really nice unit. Darrel has tons of dyno time in R&D, should be a screamer. For those of you on the inner circle, this info was cleared for posting.
Ken
Mickey, along with Mike I have to say I'm impressed with the power. Not to be mean, but I would put money on HPD,RCR,Hot Seat, or AAEN if they tuned your clutching. If nothing else, trying the roller secondary setup for the woods....REALLY improves performance. Hot Seat, along with AAEN and HPD all have roller secondaries available.
HPD is also coming out with a secondary slipper clutch. Lot's of avenues to dial your power to the ground.
One other note, HPD now has multiple finished cylinders on their workbench with the variable exhaust power valve. Don't think I'll be stepping up, but looks like a really nice unit. Darrel has tons of dyno time in R&D, should be a screamer. For those of you on the inner circle, this info was cleared for posting.
Ken
#13
05-12-2002, 02:12 PM
Modquad, thanks. I'll go order the book right now.
What is the Variable exhaust power valve? Do they have finished cylinders or cylinder heads? If it a new cylinder, what's the displacement?
Mickey, Thanks for coming on and explaining some of your setup. Do you know about how much power it makes, and what the compression ratio is?
What is the Variable exhaust power valve? Do they have finished cylinders or cylinder heads? If it a new cylinder, what's the displacement?
Mickey, Thanks for coming on and explaining some of your setup. Do you know about how much power it makes, and what the compression ratio is?
#14
05-12-2002, 03:03 PM
The variable exhaust is the same as the snowmobiles are using. Darrell has his own very smooth operating valve designed. He gave me the O.K. to gab about it....although I'm not sure it's totally ready to be shipped. It's 416 cc. At one time I think he said it required a different pipe, reeds,etc, so like I said earlier, I probably won't be making that jump.
I'm patiently waiting for the Extreme experience. Although winter is over in northern Minnesota.......summer blizzards can happen!!!!
Cue up the Rage Against the Machine tunes, and hit the throttle! I think I might wire the helmet for surround sound....watch out bunnies!!
Ken
I'm patiently waiting for the Extreme experience. Although winter is over in northern Minnesota.......summer blizzards can happen!!!!
Cue up the Rage Against the Machine tunes, and hit the throttle! I think I might wire the helmet for surround sound....watch out bunnies!!
Ken
#15
05-12-2002, 05:32 PM
That good eh modquad? I like summer too. Summer is good. Maybe this one will be Extremely good.....
If we were to throw a few numbers out to not only determine how hot it might be this summer, but to also determine what levels of HP can be made from these temperatures, what do you think that number might be? Extremely close anyway, is what we're looking for.
If we were to throw a few numbers out to not only determine how hot it might be this summer, but to also determine what levels of HP can be made from these temperatures, what do you think that number might be? Extremely close anyway, is what we're looking for.
#17
05-12-2002, 08:15 PM
#18
05-13-2002, 04:54 PM
Mike,
I hear what you are saying about different clutching and to be honest with you, I haven't taken the time to do a whole lot because we are winning every race and we hole-shot the 2-strokes so there has been no need to make them better. However, Todd Ribblett is running a 600 for us this year (he won the overall last year) and he lives in Johnstown, PA which shouldn't be too far from you. If you want to work with him, I will coordinate a time and place where you guys can work on it. We have about 3 more weeks off before the next race. Both Jeremy Benson and Todd are running 600's this year instead of the 628's because it is easier to ride in the woods and it doesn't wear them out in a 2-1/2 hour race.
I hear what you are saying about different clutching and to be honest with you, I haven't taken the time to do a whole lot because we are winning every race and we hole-shot the 2-strokes so there has been no need to make them better. However, Todd Ribblett is running a 600 for us this year (he won the overall last year) and he lives in Johnstown, PA which shouldn't be too far from you. If you want to work with him, I will coordinate a time and place where you guys can work on it. We have about 3 more weeks off before the next race. Both Jeremy Benson and Todd are running 600's this year instead of the 628's because it is easier to ride in the woods and it doesn't wear them out in a 2-1/2 hour race.
#19
05-14-2002, 01:16 AM
I'm not a clutch pro by any stretch of the imagination, but I'm starting to figure it out. I DO think my stock secondary is taking way to long to upshift, especially with my new mods. It is pretty noticeable now. It just rips to 45 or so, then waits for the secondary to let go and swing the belt down in. The motor is just waiting there now. All revved up with nowhere to go.
Major changes are coming for it once I get that clutch book in the mail.
Mickey, what do you mean about the 628 wearing out? Do you mean the rider was getting punished from so much power, or the motor can only last about a race before teardown?
How much HP does the 600 motor put out with a good pipe? I'll be getting one once I start to hear more good stuff. Some say the crank can't live in there long at all, and anything over 7000 rpm will snap it right off. Others say the bottom end is built like Ft Knox.
Please explain your setup. Pricing, HP, CR, things like that.
Major changes are coming for it once I get that clutch book in the mail.
Mickey, what do you mean about the 628 wearing out? Do you mean the rider was getting punished from so much power, or the motor can only last about a race before teardown?
How much HP does the 600 motor put out with a good pipe? I'll be getting one once I start to hear more good stuff. Some say the crank can't live in there long at all, and anything over 7000 rpm will snap it right off. Others say the bottom end is built like Ft Knox.
Please explain your setup. Pricing, HP, CR, things like that.
#20
05-14-2002, 09:54 AM
Mickey,
I'd be more than happy to help anyway I can. I can understand where you're coming from, though. You have more than one machine to take care of (several different brands too, if I'm not mistaken), and why mess with success? I too know how it is to have many oars in the water and only one guy rowing. You can't physically take all the teams problems on yourself. Well, that's why guys like modquad and other guys like me are here for. The advise we give is cheap (read free) and we know what we are talking about through years of trial and error with Polaris machines. Have him give me an e-mail and I'll send him my phone #, then we'll talk.
You may not remember, but we met once at the CPATVA fall jamboree two years ago. Todd Knippenberg and another pro rider were there. That was when the Raptor's frame broke along the trail. Well, better to do it there, than in competition.
I'd be more than happy to help anyway I can. I can understand where you're coming from, though. You have more than one machine to take care of (several different brands too, if I'm not mistaken), and why mess with success? I too know how it is to have many oars in the water and only one guy rowing. You can't physically take all the teams problems on yourself. Well, that's why guys like modquad and other guys like me are here for. The advise we give is cheap (read free) and we know what we are talking about through years of trial and error with Polaris machines. Have him give me an e-mail and I'll send him my phone #, then we'll talk.
You may not remember, but we met once at the CPATVA fall jamboree two years ago. Todd Knippenberg and another pro rider were there. That was when the Raptor's frame broke along the trail. Well, better to do it there, than in competition.