the three fastest and quickest asphalt sleds in the world, running mid to low 7 second 1/4 mile times at 182-183.5 mph don't have these... how much do you think they will pick up with these gears?? were putting over 300 hp to the track in .7 seconds. while i agree it will be easier to grab a belt with these gears for the novice tuner, holding traction will become quite a factor with the torque increase you will see at the track, especially on asphalt. At the point we are at, i feel traction is the problem, not belt slippage or clutching efficiency, (providing your clutches are tuned properly). the big gains had this summer came from the new 2010 proline asphalt suspension, smith/mott and woodys could run effortless 1.15-1.20 60 ft times even in less than good conditions. as for clutch temperature, you can hold your hand on our clutches after every pass. while its a neat idea, i think the money would be better spent with a professional tuner. jeff
onestopjim
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Greg,
The biggest advantage to your gear reduction would be getting a hold of the belt at a high RPM on 2 step, on dirt or ICE. this is the hardest part of getting our sleds going, (trying to leave on 12 pounds of boost at 6000 RPM is near imposable to get a hold of the belt with our chassis any way)
BUT with STM's new wide pin clutch's we can do that. This is of the advantage's we have, there is no belt slip, the problem we have now is keeping the sled down because we bite the belt so hard I have to take power out to keep it from Wheeling...
I am a drag racer and on ICE we want more clutch speed we go faster so I don't see this helping me..
You might want to look at the NEW STM wide pin clutch..
GOOD LUCK , I hope to see you at the track...
The biggest advantage to your gear reduction would be getting a hold of the belt at a high RPM on 2 step, on dirt or ICE. this is the hardest part of getting our sleds going, (trying to leave on 12 pounds of boost at 6000 RPM is near imposable to get a hold of the belt with our chassis any way)
BUT with STM's new wide pin clutch's we can do that. This is of the advantage's we have, there is no belt slip, the problem we have now is keeping the sled down because we bite the belt so hard I have to take power out to keep it from Wheeling...
I am a drag racer and on ICE we want more clutch speed we go faster so I don't see this helping me..
You might want to look at the NEW STM wide pin clutch..
GOOD LUCK , I hope to see you at the track...
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Hey Jim,
Thanks for the kind words............I think there was a kind word there right?
Well, I would not say your wrong about that as I must give you credit, your Brent/OSP sled ran really well at Haydays. You can take pride, in the fact that's what pushed me to make gears. And it's what I said early on, Our best run was a 3.93 but as we turned up the power, we went slower. Last year That bucket of bolts RX1 I bought won the TOP FUEL class with a 4.16. Our new Fuel Injected Apex went 2 tenths faster but couldn't get close to your 3.76. You can't convince me we didn't have some efficiency issues, we have the power. Besides you can buy a number of gear sets for what those clutches cost.
I wish I could say the gear sets were all my idea, but lets be honest here, this is a proven commodity. I won't name names without permission, but there was a guy who won countless National Events with a V-Max-4. I believe it was due to at least 3 things I am a strong supporter of, 1) GEAR REDUCTION 2) EFFICIENCY and 3) DATA COLLECTION.
Well I'm glad to hear one thing you said," I DONT SEE THIS HELPING ME" Good, you don't need it, help that is. LOL
Hope to see you on the ice this season...
Thanks
Thanks for the kind words............I think there was a kind word there right?
Well, I would not say your wrong about that as I must give you credit, your Brent/OSP sled ran really well at Haydays. You can take pride, in the fact that's what pushed me to make gears. And it's what I said early on, Our best run was a 3.93 but as we turned up the power, we went slower. Last year That bucket of bolts RX1 I bought won the TOP FUEL class with a 4.16. Our new Fuel Injected Apex went 2 tenths faster but couldn't get close to your 3.76. You can't convince me we didn't have some efficiency issues, we have the power. Besides you can buy a number of gear sets for what those clutches cost.
I wish I could say the gear sets were all my idea, but lets be honest here, this is a proven commodity. I won't name names without permission, but there was a guy who won countless National Events with a V-Max-4. I believe it was due to at least 3 things I am a strong supporter of, 1) GEAR REDUCTION 2) EFFICIENCY and 3) DATA COLLECTION.
Well I'm glad to hear one thing you said," I DONT SEE THIS HELPING ME" Good, you don't need it, help that is. LOL
Hope to see you on the ice this season...
Thanks
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How did these work out last season? Track dyno information? Track information? Inquiring minds want to know! 
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Hi Allan,
They worked great!!!!! Was able to improve greatly how we grab the belt. Clutches and belt ran much cooler, belt life improved also. It did however cause a problem. With the added torque , we now are having a hard time controlling the power. The gear reduction multiplies torque as it slowes the clutch down. We even geared the sleds taller to offset the reduction in clutch speed but with 500 hp on our lake race sled to say nothing of the 550+ HP on the Promod sled we could not control the track. Need to pull some power away. We installed larger waste gates to hold the turbo back. With the quicker throttle responce, the engine revs quicker geared down, the turbo wants to spool too fast and the power instantly hits lake a freight train. At our first outing at Cable Wisconsin we were just Blazing the track. Never thought about the turbo issue, but learned quickly. Couldn't do anything about it there but we have the bigger gates on now. It's terrible to have all this power.
All in all couldn't be happier with the the gear reduction, hope no one else finds out about it, keep it a secret.
They worked great!!!!! Was able to improve greatly how we grab the belt. Clutches and belt ran much cooler, belt life improved also. It did however cause a problem. With the added torque , we now are having a hard time controlling the power. The gear reduction multiplies torque as it slowes the clutch down. We even geared the sleds taller to offset the reduction in clutch speed but with 500 hp on our lake race sled to say nothing of the 550+ HP on the Promod sled we could not control the track. Need to pull some power away. We installed larger waste gates to hold the turbo back. With the quicker throttle responce, the engine revs quicker geared down, the turbo wants to spool too fast and the power instantly hits lake a freight train. At our first outing at Cable Wisconsin we were just Blazing the track. Never thought about the turbo issue, but learned quickly. Couldn't do anything about it there but we have the bigger gates on now. It's terrible to have all this power.
All in all couldn't be happier with the the gear reduction, hope no one else finds out about it, keep it a secret.
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All of you are correct in what you are thinking, but if any of you also have experience in the automotive racing world, you'll hopefully agree that it's a matter of building a better "package".
One type of boosted motor will make power on a different curve than the next, so assuming there is an inherent power loss by over spinning a certain type of clutch, it'd make sense that the motor would be built to make it peak power higher than the clutches can allow? Just like a wheeled vehicle for instance, if you have a 9000 rpm race motor with the wrong transmission gears or axle ratios, you'll go slower.
One question I have after reading all this is:
Instead of changing output gears to reduce the clutch speed and rev the motor higher, would you be faster by building torque into the motor and reduce the rpm, and load the rest of the drivetrain to spin the track faster to use the torque? Or possibly even reduce the gearing and build a torque monster motor, assuming you can get the other parts to hold up?
If torque is what makes things turn, and obviously spinning everything at a lower speed, overall longevity would increase, as well as controllability and tunability? Maybe I'm wrong....
One type of boosted motor will make power on a different curve than the next, so assuming there is an inherent power loss by over spinning a certain type of clutch, it'd make sense that the motor would be built to make it peak power higher than the clutches can allow? Just like a wheeled vehicle for instance, if you have a 9000 rpm race motor with the wrong transmission gears or axle ratios, you'll go slower.
One question I have after reading all this is:
Instead of changing output gears to reduce the clutch speed and rev the motor higher, would you be faster by building torque into the motor and reduce the rpm, and load the rest of the drivetrain to spin the track faster to use the torque? Or possibly even reduce the gearing and build a torque monster motor, assuming you can get the other parts to hold up?
If torque is what makes things turn, and obviously spinning everything at a lower speed, overall longevity would increase, as well as controllability and tunability? Maybe I'm wrong....
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that is the purpose of reduction gears......
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Well Nate,
If I understand the point your trying to make; You most likely never built a Yamaha 500HP engine. I really hate to show my hand here but I will say RPM is your friend in this case. As I'm sure you know ( Torque x RPM / 5252 = HP ) To make torque, which ultimately makes HP, you must make cylinder pressure. We are at a point where the block just can't handle any more cylinder pressure without failling ie. cracking, therefore if we want to make more HP we must hold torque we can live with and spin the engine higher, thus making more HP. It's the only way to safely raise the bar. I have personally broke 2 blocks dyno testing and have given up trying to raise the torque. Raising RPM is the only direction we can go, and why not R1 motorcycles spin the same engine 13500 RPM stock. Why didn't Yamaha do the same you ask with snowmobiles? Clutch speed. Raising the torque at the PTO however, is OK as it does not effect cylinder pressure. That's what my gear reduction is doing, along with picking up clutch effiency, and I have real dyno numbers that show this to be true.
If I understand the point your trying to make; You most likely never built a Yamaha 500HP engine. I really hate to show my hand here but I will say RPM is your friend in this case. As I'm sure you know ( Torque x RPM / 5252 = HP ) To make torque, which ultimately makes HP, you must make cylinder pressure. We are at a point where the block just can't handle any more cylinder pressure without failling ie. cracking, therefore if we want to make more HP we must hold torque we can live with and spin the engine higher, thus making more HP. It's the only way to safely raise the bar. I have personally broke 2 blocks dyno testing and have given up trying to raise the torque. Raising RPM is the only direction we can go, and why not R1 motorcycles spin the same engine 13500 RPM stock. Why didn't Yamaha do the same you ask with snowmobiles? Clutch speed. Raising the torque at the PTO however, is OK as it does not effect cylinder pressure. That's what my gear reduction is doing, along with picking up clutch effiency, and I have real dyno numbers that show this to be true.
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No, I'm in the automotive aftermarket, so I can honestly say I haven't buillt any Apex motors with that output. My only comment/question had to do with the options in engine/drivetrain when pushing those numbers, and dealing with traction and speed issues.
I know full well that the bikes can handle that rpm, but unless it's a race application, I know they don't spin near redline as much as a sled does either. Granted, I understand you're building race motors and maybe not looking for the longevity or trailability if I'm speaking correctly?
I know full well that the bikes can handle that rpm, but unless it's a race application, I know they don't spin near redline as much as a sled does either. Granted, I understand you're building race motors and maybe not looking for the longevity or trailability if I'm speaking correctly?
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