viper fuel economy

D

duck57

New member
Joined
Jun 6, 2003
Messages
24
Age
67
Location
fond du lac wi
I have an 02 Viper with cpr tripple pipes, my fuel economy sucks. maybe 6 mpg. whats everybody else getting? I've been through suspension , cluthing new pistons . i,m stumped.
 
what jetting specs are you running and whats your clutching???, fuel economy and clutching are hand in hand, alot of cpr specs are way,way rich to insure no claims of burn downs. The best I could ever get when I had those pipes was with h/c clutching and could do 9 mpg, 10mpg on groomed trails up in the u.p.
 
best advice i ever had was once u got up to speed keep it at 1/2 throttle cuae ur not gonna go any faster then that in the trails. also if theyre twisties try to to hit ur break as much try engin breaking it will make u overall faster in the woods too. plus are u studed? if not on a 200 mile ride ur track can sping an adtional 100 miles then a sled that is studed.
 
MAINS ARE 160,160,&162.5 . PILOTS 47.5,47.5 &50. hEAVY HITTERS 40/20. SUPER TORQUER SECONDARY. PULLS TO 8800 THEN UP TO 9100.
 
tempaflow or variflow will help - put one on my son's sled this year and mileage went from 8.5 to 12.
 
took sled out this weekend again still only 6mph a little burrble coming off mid range. seems crisp at full throttle. help
 
well thats the same jetting I ran in mine, I could do 9-10mpg pretty consistant, I used heel clickers and a aftermarket helix. I dont see you ever doing any better without being safe with a cpr piped viper, 9-10mpg is as good as it gets and not have to check your plugs all the time. I would work on the clutching. Clutching and fuel economy go hand in hand. If you for instance raise the engagement speed to 4500 from 4000, that can make a dramatic differance in fuel economy, because you actually move the entire curve upwards in effect. A low engagement will hang onto the belt better in trail riding. Your not revving the engine up as high rpm to get the same clamping force with a lower engagement speed, and this holds true thru the curve, the sled may travel at 45mph at 1/4 throttle on a smooth straight away where as if it were clutched a little stiffer would need to be 3/8 or better throttle to provide the same clamp on the belt to maintain the same 45mph speed.

BTW- where are your needles set at? this is usually where the burbling comes from.
 
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needles at #4 2 up,2up, 2dn.i,m engaging at 5400 ringht now i,m going to change to a little lighter primary spring should drop engagement about 500 rpm. not much snow here so testing sucks
 
its definitely your clutching!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


you need 4000-4200rpm for trail riding, your way, way,way to high, thats your problem and I will bet the farm on it!
 
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