secondary question

[srvfan]

I have lost MPG with latest flash and clutch kit that went in at same time. Seems to carry lots of RPM at 20-50 mph trail speeds. wrap is 6-3 . loosening that up a bit would let it open sooner and drop RPM correct ? thereby helping MPG but giving up a bit response wise ? there is way more tension on there than stock so I doubt it would slip.
thanx

 

[alexm2816]

More spring pretension will give you quicker backshift but it will create more friction within the driven clutch. You've got a ton of twist on so you might try toning that back and feeling the clutches to see how much friction they're getting.

 

[srvfan]

thanx that was my thought as well

 

[titanrcr]

Lowering the secondary spring twist won't get your MPG back. Carrying more RPM in your cruising range is likely responsible for the decreased MPG. Is your WOT RPM high as well ?

 

[srvfan]

WOT seems fine for short bursts at 8900-9050 I have not had a chance to run a long pull on a lake or RR grade . lakes way too bumpy to be safe, 8JP belt

 

[srvfan]

Lowering the secondary spring twist won't get your MPG back. Carrying more RPM in your cruising range is likely responsible for the decreased MPG. Is your WOT RPM high as well ?

by decreasing tension I was thinking it would open up a bit more at cruising speeds lowering the RPM and thereby gaining a bit of MPG

 

[titanrcr]

That sounds like a lot of twist and you may be able to lower it and drop a few RPM but I doubt you will see a measurable increase in MPG. When you say you have a new clutch kit, what was replaced and why? If you were happy with the previous clutching you could just put that back in. Just keep in mind that any change in clutching will usually have both a positive and negative effect in performance. You just need to decide if you gained enough or any performance for that matter to justify the new lower fuel mileage.

A few years ago I got lazy and bought a "Clutch Kit" for my Apex from a well known shop (should have clutched it myself). It had a bit more snap in the mid range and maintained the same top end. Mileage went from 15+ to 10 MPG. That "KIT" was in the sled for about 200 miles and has been sitting on the shelf ever since. 400 bucks down the drain.

So yes, try reducing the twist and see what happens, I just don't think it will be nearly enough to regain your lost fuel mileage.

 

[TPAY243]

Really lost MPG, you all buy these Sidewinders and soup them up to the nut bag and then worry about fuel mileage. If your worried about gas mileage you should look in to a Ski Doo 600 those things are supposed to get really good mpg well at least that's what everyone compares to. I do get pretty good mileage with my turbo Viper but if it did not i surely would not be complaining about it. It does have a lot on how you drive it.

 

[titanrcr]

Really lost MPG, you all buy these Sidewinders and soup them up to the nut bag and then worry about fuel mileage. If your worried about gas mileage you should look in to a Ski Doo 600 those things are supposed to get really good mpg well at least that's what everyone compares to. I do get pretty good mileage with my turbo Viper but if it did not i surely would not be complaining about it. It does have a lot on how you drive it.

I think the OP is just asking about a stock Viper with the latest ECU flash to improve starting and idle. Vipers get good mileage and shouldn't go to crap by putting someones clutch kit in it. I get around 14 MPG with my boosted Viper so no complaints here.

 

[srvfan]

I think the OP is just asking about a stock Viper with the latest ECU flash to improve starting and idle. Vipers get good mileage and shouldn't go to crap by putting someones clutch kit in it. I get around 14 MPG with my boosted Viper so no complaints here.

exactly correct, my MPG went from 15-16 down to 12 sled has a bit more snap pulls harder from 30 mph to 65-70. 30-40 mile less out of tank hurts range big time though for longer rides. Not really concerned with the few extra bucks $$ it cost to fill up.

 

[Allan]

When you say you lost MPG . you using you trip setting and on fill up working out MPG?
Why I ask this on my xtx I thought lost MPG after the new flash. But when I checked the miles on machine against my gps is was the same after a trip. But before the flash the sled would show 8% more miles than the gps.
So speed was out by 8% before the flash when check against gps and now it right on.

 

[srvfan]

When you say you lost MPG . you using you trip setting and on fill up working out MPG?
Why I ask this on my xtx I thought lost MPG after the new flash. But when I checked the miles on machine against my gps is was the same after a trip. But before the flash the sled would show 8% more miles than the gps.
So speed was out by 8% before the flash when check against gps and now it right on.

interesting I don't have GPS I'm checking trip meter and gallons on fill up

 

[Allan]

interesting I don't have GPS I'm checking trip meter and gallons on fill up

I do this all the time but I also run a gps.
Before the flash the miles on the trip meter were more than the gps when i check both.
But after the flash miles on trip meter and GPS were the same.
before the flash I thought sled was fast , after the flash it just normal lol

This could account for you thinking the sled is harder on fuel.

 

[TPAY243]

Ok my bad when you said flash i got cornfused I've never had mine flashed and it has it's moments replaced my starter and every thing else that goes to crap. If you want clutching that is spot on contact Ullmer Racing he will get ya pointed in the right direction.

 

[blueironranger]

Wrap of 6-3 would be very tight with stock springs, but might be correct if the kit came with and aftermarket spring. I’ve logged around 1,000 on the latest flash and haven’t noticed any drop in MPG, still using about 6 or 7 gallons on the usual 100-110 mile gas stop. I never ran the stock clutching so I don’t know if I get better or worse mpg with my Big Thunder kit.