This video of a supercharged snowmobile engine powered roadster, has been posted before I think but not much follow up. Seems like the cvt could be fun. So other than the need for a drive shaft and clutch cover (see video for jankyness) , why don't we see more of this?
I clicked expecting to write "ask the guys from Grind Hard Plumbing"!
Why is he wearing ear protection? Do snowmobiles have reverse? How much torque at what RPM? Looks like it has a torque band about as wide as a pencil (not uncommon for 2 strokes). That Triumph is likely 3 or 4 times the weight of a snowmobile.
It might be more fun to goof around in then to drive, e.g. a full on race car would be a nightmare on the street. Depends on what you want to use it for. This one seems to have very limited use.
In reply to aircooled :
The snowmobile motor has 200+ hp too.
Great. If it makes 20 hp at 5000 rpm, not so great.
In reply to aircooled :
The have a really cool plot of land and a dirt track they do laps on. Probably bouncing of the rev limiter most of the time.
Because it's easy to get 200hp out of a lightweight 4-cylinder car engine these days, with torque in a much wider range.
Because that only remotely looks drivable on dirt, and would probably be awful if the tires actually had traction
Because it's annoyingly loud
Because he already used basically one of the lightest cars that exists in the world and it still didn't look fast or fun
I know recently a new member on here was talking about putting a snowmobile engine in a rallycross car and nobody could seem to think of a reason that would be a good idea unless the goal is simply to say you have a snowmobile engine.
In reply to aircooled :
CVT.
Tuned right, they are way better than a manual trans, which generally is always in the wrong gear.
In reply to irish44j :
Well, the Barbie cars they build and some of the other things they create are plenty over-powered and look like lots of fun. They're having a blast doing what they love I'm sure.
A 2JZ riding lawnmower for instance.
I was just going to link to stuff about Balto the snowmobile powered Miata but you beat me to it. I don't think it's a terrible idea at all given the right application!
ebonyandivory said:In reply to irish44j :
Well, the Barbie cars they build and some of the other things they create are plenty over-powered and look like lots of fun. They're having a blast doing what they love I'm sure.
A 2JZ riding lawnmower for instance.
oh, no doubt about it.
I was just answering the thread title question.
There are lots of fun things out there that are bad ideas ;)
In reply to irish44j :
Just because it is a bad idea doesn't mean it won't be a good time 
Knurled. said:In reply to irish44j :
Just because it is a bad idea doesn't mean it won't be a good time
most good times are bad ideas!
arnt there a number of snowmobiles powered by suzuki f6a's? like those that come in the cappuccino and the jimny's?
The miata had a 2 stroke, the spitfire has a 4 stroke motor, so different animal, but both used a cvt belt drive which is a bad idea for a car, they got hot and fail.
I just came in to say, go spend time near an F mod in grid at an SCCA event.
Loud, like in numbers dear god it gets old FAST.
Novel idea, Blato is friggin cool. but it's not what one might call streetable in any form..
Knurled. said:In reply to aircooled :
CVT.
Tuned right, they are way better than a manual trans, which generally is always in the wrong gear.
Sounds reasonable, but also seems to indicate they are using a transmission designed for a vehicle a quarter the weight of the Triumph.
I run a Formula 500 in F-mod and the whole point of the CVT drive train is it keeps the motor in the powerband all the time. So even if the motor only has a 1500 rpm wide powerband the CVT can be tuned to compensate. The CVT is essentially a 45 speed close ratio gearbox.
While they can be very complicated to maximize the last 1% of performance, the actual changes are extremely simple. Nothing more than springs and flyweights to change.
Two strokes snowmobile engines are light 90-100lbs and the 500cc engines in F-mod/F500 are making 100hp.
In a lightweight car such as a Sprite/Spitfire it would be a potent combination.
I've talked with John Pagel(Balto) about driving the 2stroke CVT. He said it only makes about 90hp, but because CVT it's ALWAYS making 90hp. You just drive it flat out and left foot brake. Sounds like they got the CVT belt figured out too. Still holds a Lemons track record I believe.
Besides F-Mod, I've also seen A-Mods and hillclimb cars with big snowmobile engines. They're equally loud, but very fast.
Wouldn't you want to add the minimum needed to adapt the snowmobile to street use?
From a driving standpoint there is indeed a bit of a different style; the first few events in the F500 I'd roll of the throttle in an effort to get the car to rotate back into 2nd apex in double apex corners and nothing would happen. The CVT pretty much negates what little compression braking the two stoke motor has, so you just need to revert to trailing the brakes and preloading the throttle slightly to keep the car rotating once you come of the brakes.
In general you end up with a bit of overlap on the throttle and brakes.
The downshift knonw as back shift is controlled by the weights and springs in the clutch.
A couple things about snowmobile engines and CVTs:
- noise can be controlled with a proper muffler. Snowmobiles have noise requirements they need to meet, and just like modern cats, the manufacturers have managed to keep noise levels in spec without hurting power output.
- Reverse have been accomplished a couple ways. Two and four stroke engines can use a "reverse gear" in the chain case. Many modern 2stroke engines use a special secondary (driven) clutch and Reverse Engine Rotation "RER".
- Many sleds are in the 400-600 lb and 121"x16" up to 154"x16" track with up to 3" tall paddles. While the weight isn't car level, the rotating mass of the track probably takes much more power to move the sled than the weight would imply.
-power levels range from 60hp for a 440cc air cooled engine to 180+ hp for 1000cc liquid cooled.
-engine braking is there, but required a modified driving technique to use is. Traditional car engine required just letting the throttle close to have engine braking happen, and selecting a lower gear can increase that effect.
On a CVT snowmobile engine the rider can't just close the throttle because the rpms will drop too low to engage the primary clutch, so the belt freewheels and no engine braking. If the rider brings the throttle up enough to engage the primary clutch then the belt tries to drive the engine and there is engine braking.
edited to fix autocorrect so it says "noise" and not "loose"
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