02 viper top speed mods


I would start with clutching. Many people think vipers are slow but the truth is it just has a hard time getting to top speed because of bad weight transfer and lots of track spin. Clutching it may make your sled loose 3 mph but from start to midrange will be a little stronger and make it get to top speed a little quicker. Gearing it may make a difference on top but you might loose a little in the middle.
My viper was fastest in stock form, saw 118mph to 121mph at 8900 to 9000 rpm's on very long runs on the lake. For trail riding and great mid range clutching did wonders. I guess you gain a little and loose a little with gearing /clutching ect.
If you clutch it and find top end important try keeping top rpm's above 8600, the viper peaks (hp curve ) at 8600 to 8800 rpm's. Many find low and mid range important and clutch at 8300 to 8400 but you loose 8 to 10 mph, 8400 to 8500 rpm's is more a set top rpm for The srx not the viper.
 
no need for me to comment on clutching as its already been said, but I would also look into reducing parasetic drag in the driveline, its makes a large differance in speed.

Oversize wheels in skidframe, all 6 small ones changed to 5.350" wheels and then change the rear wheels to 7.5" diameter ones from a 79 srx440, you will need to slightly grind off about a 1/8th" off the axle spacers as the new yamaha wheels are a tad thinner bearing then the older 79 srx ones. Add a marginal wheel kit to the curve of the rails.

clutch alignment/offset should be spot on perfect to srx specs, and a engine tensioner off a srx should be added.

chain tension should be checked and add some ATF for chaincase lube while you are in there. Adjust the chain tension to have about 1" total movement on the backside of the chain, meaning you can move it with your finger 1 way 1/2" and then the other 1/2". Another thing is if your wanting more top speed would be to gear up to a 23 top gear same as a srx.

next thing is to set up your suspension sag, meaning you want the sled to set in a little bit, this will lower the sled some and reduce drag. You can set it up softly and as long as you dont want to go snocrossing it will be fine if your a big jumping kind a person dont do this.
 
How tight do you suggest we set the track? I've ran on the loose side of factory specs. Now that I have anti ratchet drivers, how loose should I go? how loose is too loose?
 
its too loose if its racheting or hitting the tunnel or heat exchanger at top speed from the ballooning effect.
 
Obviously weigtht reductions and performance upgrades I"m sure can help allot...
but Curious...
I remember reading as a kid in a magazine that they used to drill 1/2 inch
holes in the hyfax from front to back to allow less friction...buuut...when
snow gets in there...it can tend to freeze and allow for a slippier surface...
curious if this still works...or is unexceptable with todays machines
 
yes some people do this, but most racing organizations do not allow you to do this. I drill holes in my slides (not 1/2", more like 1/4") for the same purpose, and also so i can check exactly how much slide material is left at any given point on the slide rail so i know when to change them. And let me tell you, that last 1/4" of material takes YEARS and THOUSANDS of miles to wear off if you ride in good conditions.
 
you can also shave your primary 30 thousandths on the inside and get a little over drive out of it. do this and gear down and you dont loose topend but are quicker
 
a looser track is a faster track TILL it rubs the tunnel strips or protectors, so you have to play with the tension till it just doesnt rub.Ya cant really give a spec for it because everyone has a differnt track and differnt amount of studs and the heavier the track the more it will balloon up at speed, so play with the tension until it just doesnt rub, thats the sweet spot.
 
hmmmm...I've always tried to use factory specs on my track tightness...never
really tried to loosen it up...but the guys I ride with sometimes talk about sitting
on the border of "Ratcheting"...so I guess if I loosen it off a bit..it won't hurt eh?...
 
mrviper700 said:
a looser track is a faster track TILL it rubs the tunnel strips or protectors, so you have to play with the tension till it just doesnt rub.Ya cant really give a spec for it because everyone has a differnt track and differnt amount of studs and the heavier the track the more it will balloon up at speed, so play with the tension until it just doesnt rub, thats the sweet spot.
Click to expand...


cool, right now i lossened it off till i could just barely get 3fingers under the center of the slide and the track, if i pull down about 25lbs.

What about studs, will more studs slow me down because of the wheight, right now i have 120 1.075 studs down the middle, and the stock .92 track.
 
All depends what conditions your riding in. Take me for example I bought a 1.25 Predator track this year and running no studs. Reason why 90% of my riding is done off trail and trail riding, other 10% is out on the lake. Studs do nothing when off trail riding, they do come into affect pending your reg. trail riding snow conditions. But running the stock .92 I'd run studs no matter what cause that track doesnt hook for sh**, just spins and spins. Thats why my stocker has 144 1 inchers.
 
thanks i was thinking of adding another 96 on the sides, would that be over the top, i do alot of tral riding and some lakes, but the trail around my house get very icey.
 
if a guy is worred about max top speed then yes, a heavier track is harder to run fast with the same amount of hp available, so its kinda like taking a rope about 5 ft long and tie a brick to the end of it and swinging it around your head, its not too bad, now... tie on a cement block instead and try to swing it the same way, not so easy....... so to answer your question, you need enuff studs to satisfy YOUR own needs as far as traction ges, the more studs the heavier the track is, the harder it is to go fast with the same amount of hp available!
 
yeah thats what i thought i went from a .750" track with 96 studs to a 1.188 preditor with 192 studs, it hooked up like crazzy but i lost like 20kmh off the top or I should say 12mph, now that explains it.
 
You must log in or register to reply here.


Back
Top