VIPER-D
New member
I have a friend that has a viper w/cpr pipes and he whats to know gear to run for top end.Thanks
23/38 will be plenty of gear for topend.
VIPER-D
New member
what is stock.
22/38 viper
I believe 22-38 is stock but when you put pipes on you run higher rom's so there for it acts like taller gearing.I don't know how to explain it very well.
Running at stock rpm with stock 22-38 gearing
8500@105.69
with 5% O/D 110.98
@9100rpm's same gearing 113.15
5%O/D 118.81
Running at stock rpm with stock 22-38 gearing
8500@105.69
with 5% O/D 110.98
@9100rpm's same gearing 113.15
5%O/D 118.81
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Thats EXACTLY right Pro116, great point!!!!
Any time your raise the rpm of the engine it changes the gearing, spinning the same gearing at a faster engine speed results in the gearing being at a higher percentile then before .
A stock sled will be geared for a good 10mph or so higher then the sled is capable of doing stock. The reason they do this is to keep the belt from spending too much time at high belt speeds which lowers the efficency of the system and builds heat from slippage, which shortens belt life.
In a nutshell say your engine was running at 8000rpm, if you mod it and then run it at 9000rpm it will be geared 11% higher then it was at 8000rpm!
This subject has alot of formulas you can use to figure out where you nned to gear to obtain the speed your looking for at the shift ratio your looking for.
best bet is to buy Aaens clutch tuning book, they are all listed intheir and he does a excellant job explaining it all.
Any time your raise the rpm of the engine it changes the gearing, spinning the same gearing at a faster engine speed results in the gearing being at a higher percentile then before .
A stock sled will be geared for a good 10mph or so higher then the sled is capable of doing stock. The reason they do this is to keep the belt from spending too much time at high belt speeds which lowers the efficency of the system and builds heat from slippage, which shortens belt life.
In a nutshell say your engine was running at 8000rpm, if you mod it and then run it at 9000rpm it will be geared 11% higher then it was at 8000rpm!
This subject has alot of formulas you can use to figure out where you nned to gear to obtain the speed your looking for at the shift ratio your looking for.
best bet is to buy Aaens clutch tuning book, they are all listed intheir and he does a excellant job explaining it all.
VIPER-D
New member
How much more speed will be gained with this setup.
So you think a 25 top is too tall. LOL Maxdlx
Do you mean how much speed will be gained with gearing up to a 23 or with the pipes?
The 23-38@9100 will run 118.29
5% o/d 124.21
Again this has to be ideal conditions.If your running on snow that's not packed down you may run higher mph with the stock gearing because the low gearing will pull harder.
The 23-38@9100 will run 118.29
5% o/d 124.21
Again this has to be ideal conditions.If your running on snow that's not packed down you may run higher mph with the stock gearing because the low gearing will pull harder.
tagoes10s
New member
What formula are you using to calculate speed? Since I have 8 tooth drivers, what would be the mph with 24/35 gears at 9100?
go to the 4 stroke side and look up srxspec post. There is a gearing calculator there. 24/35 with 8 tooth is 119 mph. Maxdlx
engine speed(rpm) X sprocket pitch diameter = ? /divided by shift ratio X gearing X 336= MPH
There is also a formula to figure it out as: RPM/GRxSC/12x60/5280=mph@1:1 clutch ratio
8 tooth sprocket circumference is 20.16
9 tooth is 22.68
to convert sprocket circumference to diameter you just divide by pie, 3.1416
Gr=gear ratio, bottom sprocket divided by top
SC= sprocket circumference
I like the first fomula better that way you can put in what ratio you want to be in the clutch and see how it affects your speed, but keep in mind that 1:1 is the most efficient ratio, the ebnd is the same on the belt in both clutch's, and a efficient clutch is a cool one and not slipping the belt!
There is also a formula to figure it out as: RPM/GRxSC/12x60/5280=mph@1:1 clutch ratio
8 tooth sprocket circumference is 20.16
9 tooth is 22.68
to convert sprocket circumference to diameter you just divide by pie, 3.1416
Gr=gear ratio, bottom sprocket divided by top
SC= sprocket circumference
I like the first fomula better that way you can put in what ratio you want to be in the clutch and see how it affects your speed, but keep in mind that 1:1 is the most efficient ratio, the ebnd is the same on the belt in both clutch's, and a efficient clutch is a cool one and not slipping the belt!
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tagoes.I'm using a chart on the 4 stroke side.
9100,8t drivers 24-35 gearing
1.1ratio 119.13
5%O/D 125.08
9100,8t drivers 24-35 gearing
1.1ratio 119.13
5%O/D 125.08
juniormax
New member
oh kay you guys soound really high up with this gearing stuff so I have a question on a stock 98 srx with pipes and 151 if I run 20 40 gears what chain should I run Ive been told that the less gear to chain contact the better? and maybe clutching aspecs for the mountains.
do you alredy have the gears if you don't I would run 21-42.I take it your running 8t drivers or do you have a rolled chaincase with 9t?
tagoes10s
New member
I assume the mph is on Radar. I guess the question is anyone calculate what there top MPH should be and go out and have it tested on radar? is it close?
Who posted? "In Theory, reality and theory are the same, In Reality they are not always the same"
Dan
Who posted? "In Theory, reality and theory are the same, In Reality they are not always the same"
Dan
I have ran the gearing on radar and it comes out exact if your in the right condition and able to reach full shift out on the clutches.
vipertripplexxx
New member
Viper D, run the 23-38's on a piped viper. On sheet ice with 192 picks and the stock track, you should see 122-124 mph. If tuned and clutched right. I ran 23-37's and gained nothing, then tried 23-39's and lost a tad.