Bombardier build has begun

[sho305]

It has IRS, that is great. Basically the CVT in a cart will run 13:1 stock gears, the CVT itself runs around 3:1 low gear to .9:1 high overdrive gear (so about 11:1 overall fully shifted top gear). If you run 22-23 tires that nets you around 25-27mph with a 3600-4Krpm engine and 38mph at around 5K rpm. If you put 8:1 gears in that cart it adds about 10mph to that. 18 changed to 22-23 tires adds about 8-10mph on a stock cart. So you have to figure out how fast you want it to go, fast is great for road running but more gear takes away your torque for acceleration and hills so mostly you gear for speed you need to get to and not more. Road running gear higher because they want higher cruise speed but not at max rpm, maybe they want 30-35mph but at 2500rpm max they would run 22s or more and 8:1 gears. Offroad like I run is max speed at max rpm, because I only hit it for short distances and need a lot of hill climb power. So I hit over 5K rpm at 38mph (22s, stock 13:1 gears, engine capable of over 5K rpm) but only go few hundred yards to next trail, and it has more power at lower speeds offroad. Running roads someone might go 8:1 gears even 6:1, maybe 24 tires, and get 35mph at lower rpm they can sustain without running the engine hard. Likely they may never try to find max speed or maybe not enough power to go 45+ mph the gears would allow, depending on what rpm their engine would turn. If you go 3600 stock engine you can get rev kits for some, some you can run up to 4K if you tweak them, then you want more gear than a modded engine with a cam that will run over 5K no problem. That said road running will still want lower rpm under 4K they can sustain over larger distance without the engine screaming all the time.

So if you have a 8:1 gear box you are at HS gears for a stock cart. With 22s you would run over 30 easily even with a stock 3600 engine. A stock old CC will run 28gps hitting the limiter on stock 18 tires with only 8:1 gears and no other mods other than the governor turned up. I would guess they have a 4K rpm limiter. A stock cart with 13:1 gears and 22-23 tires would run about identical speeds. This assumes you will run a CVT with slight overdrive as typical on carts. That means if you gear down your input from the CVT you will run less than a HS gear cart would. If you gear down 8 to 13 ratio (40%?) you would run speeds similar to a stock cart. It wont work well at all if you don't put a CVT of some kind on it.

I hope that does not sound confusing, I'm piecing together what I know from working carts. You should be able to figure out what your changes would do.

[Geno153]

Ok, that one I had to read twice. So, as I read it, as long as the TAV 2 is doing its job, the ratios will be constantly changing in relation to input from the engine. This cart has 22 1/2 total diameter wheels so the estimates you stated would work with this example. That helps me understand. Thanks for the reply as I was scratching my head on this and didn't want to order several sprockets and do a hit and miss.

[Gocarman]

How did it turn out? Have pics?