Turbo vs. nitrous vs. big bore.

[Donziweasel]

Went to the West Yellowstone Snomobile Expo this weekend in West Yellowstone, MT. It is the biggest Snomobile expo in the US and every after market and manufacturer are there to show their stuff. We went looking for more power for our sleds.

It seems the sled to beat right now is the Turbo Yamaha Apex. Although this sled weighs well north of 600 pounds, it also has over 300 horsepower. That is a much as a F-150 with the 5.4 V-8 option. They make a Turbo for my sled, the Arctic Cat M-1000 and Boo Boo's M-8. It costs over 6,000.00 and is good for 300 hp on mine and 270 on hers. My sled is around 194 hp and weighs around 490 pounds. Boo Boo is around 150 hp and weighs around 477. The other option is a big bore kit to bore mine to a 1200 and Boo Boo's to a 909. Hp ratings are 235 and 194 respectively. With a 25 horse wet nitrous system, you would be around 260 and 220 when you hit the shiney red button. The kit, with the NOS, is around 3000.00. What to do? Here are the pro's and con's of each-

Turbo- unmatched straight up power. Heavier than big bore (much heavier), been reports of heat issues. Will add around 50+ pounds to the sled with intercooler. Anything over 12 psi of boost requires a detonation sensor. Might have to run non-pump gas. Also heard they can be tempramental. No one will out climb you except possibly another turbo'd sled. Expensive.

Big Bore w/NOS- Weighs less, cost less, less tempramental. Probably won't out climb a Turbo. Doesn't sound near as good. The Turbo four stroke Yamaha's sound like a tricked out SB Chevy with a nice whine for the Turbo. Two strokes even sound deep and throaty with the Turbo. Turbo's are pretty much bolt on and can be removed if needed, big bore is forever.

Any ideas? I hate being outclimbed and have to do something. Two years ago you never even heard of a Turbo sled, now they are starting to show up everywhere and they are killing me in the backcountry. While my sled is still the baddest, meanest climbing and backcountry stock machine ever made, this is now a sport of aftermarket hp. People are buying sleds and before the even ride them out of the dealer, bolting and big boreing all kinds of performance crap. For example, mine came stock with 165 horse, and I have dynoed mine at over 195 with just some bolt on stuff. Oh well, decisions decisions.

We watched the snocross, drag racing and airiels. Ever seen someone do a back flip on a sled? Pretty crazy! Good weekend.

[Ed Donnelly]

No Brainer,

Big Bore...................................Then....... .......




Add the turbo..............................Ed

[Donziweasel]

Hmmm.... Big bore nitrous turbo= 370 hp. I like it!

[Carl C]

I can tell you a little bit about nitrous. I have it on my Banshee quad and my '82 Mustang GT and also had it on my 200 merc OB Hydrostream. IMO you need the turbo to compensate for the altitude you're at. Nitrous is only good for short bursts (probably no more than 15 seconds at a time) and is mainly for drag racing and hillclimbs. Nitrous is a hoot to have though and that extra 100 or so hp at a push of a button is undescribable. If used for longer periods the components will freeze up and the bottle will run out quickly. You will also need to mount the bottle where it will stay a little warm like against the exhaust. I would go for the turbo AND the nitrous for the occasional drag race.:smash: I just reread your post and the nitrous should be good for way more than 25 hp. The jets are tunable and you should easily be able to get 100 hp with the juice and not hurt anything. 25 hp is not worth the time and expense.

[Donziweasel]

Carl, I agree about the NOS. My last sled (Cat M-7) had it. Although you can get bigger (up to 80 hp and maybe even more) shots, I want a small shot. 25 horse on a 470 pound sled is a lot. I use a wet system. I don't want to big a shot as snowmobile engines are already on the ragged edge of performance. Whenever you big bore, turbo, or NOS you sled, you are really pushing it. See em' burn down the top ends all the time when you go over the edge. Sometimes less is better.

The shot is just enough to get you out of a sticky situation. You may be climbing up a chute with cliffs on both sides and although you thought you could make it, all the sudden, you might not. Hit the shiney red button and it might make the difference between trashing your sled over a cliff and making it. Just a little added insurance. I never count on it, but it is nice to have just in case. There were days I rode and never even turned it on, but other days, without it, I might have totalled my sled.

[BUIZILLA]

no screwrotor options??

[Carl C]

All my systems have been wet too because they are/were all with carbs. My Banshee is getting about 25 extra hp with only 350cc. I'm using the smallest jets since this is the same kit used on hogs. By the time I got it dialed in and was beating most of the quads and half the sleds I quit drag racing because it was too dangerous.

[Donziweasel]

Buiz, I have seen one supercharged sled, and it was impressive to say the least. Another Yamaha Apex. It seems that the four strokes have taken advantage of the turbo/super before the 2 strokes. I do know the kit for my 2 stroke comes with a Garrett turbo.

Carl, then you probably understand why a 25 shot on a four wheeler or sled is pretty good. Plus, your quad probably wieghs more than a sled. I know my Polaris does.

My sled is fuel injected and needs a plug in computer called a "boondocker" box the adjust the fuel for mods and NOS. It will only let the NOS flow under full throttle and fattens it up to compensate. The problem with all sleds is changes in altitude vs. fuel. Anytime you mod one, even with just a main pipe for exhaust, you have to fatten them up. Every mod leans them out and if you go over 1400 degrees on your EGT's, then BOOM! You always want to be on the ragged edge of lean for power, but go over, and your engine can be toast. That is why many of the mods you see can be temperamental, bad tuning. My Boondocker lets me adjust fuel at 6 different rpm settings, from 2000 to 7800. It is an art between EGT, plugs, and a feel for what the sled is doing. To be honest, many think it is a pain in the ass to tune for mods, but I love it. I get a lot of satisfaction of having a perfectly tuned sled at every altitude and rpm. Once it is set, I leave it alone for the season. Then you have clutching (primary and secondary, springs, weights, helix's, etc...). Clutching can have more of an affect on how your sled runs at different altitudes and snow conditions than mods. Personally, I am still learning clutching and leave much of it to those who know more about it than me (I only have 12 years experience, to truley understand it, 25 years experience helps). I'll get it one day. The adjustable weights are new and nice, makes tuning much easier than replacing them everytime. I currently run 2 68 gram wieghts and 2 70's (my clutch has 4 wieghts total), but still playing with them.

[Carl C]

My quad is under 400#, lighter than most sleds by quite a bit. One good thing about juice is that you can run it rich and still get the power and it actually cools your motor. I wouldn't know how to set it up with EFI though. Are the new sleds still using 2-strokes?

[Donziweasel]

I couldn't set it up without the Boondocker.

The only serious mountain four stroke sleds are the Yamaha's. Ski Doo, Arctic Cat and Polaris are still 2 strokes. The problem is that the 4 strokes are 100 pounds heavier with comperable hp to the 2 strokes.

At the Expo, Arctic Cat did say they are experimenting with a stock turbo version of thier mountain sleds. Stock turbo's are not new, but on mountain sleds they are. Arctic Cat has had a 660 touring sled that is turbo for a while. Starts at 50 hp and once spooled up, hits like 125-130 hp. Mountain sleds have to be very light for the hills and deep powder. Touring sleds come in at over 600 (and 700) pounds where suspension and comfort are key.

I spend a lot of time putting my sleds on a diet. Every pound counts. Mine came at 520 pounds, but I have shaved it to less than 480 with drilling the track, exhaust, running boards, etc.... If I had the option of losing 10 pounds or gianing 10 hp, I'd take the power though.

You have to think about trailering your quad out one summer. Great riding. We even have the St. Anthony sand dunes only an hour and a half from us.