Contour Enthusiasts Group Archives Forums Modifications General Mods 1 gear or single speed automatic transmission

The risk with hydraulic system is: the great potential for leaks. We get that in our braking systems and ATs alone! Here's a radical idea for fuel economy when it applies to SUVs: don't build so many of them! There are more of these gluttonous peacockmobiles than real cars, haven't you noticed? I did a check at a Ford lot once, and they had more SUVs than any other vehicle type COMBINED!!! I can only hope that AWD sportwagon-type crossovers like the Matrix/Vibe bite REAL hard into SUV sales... oh, heck, I've REALLY gone off the subject here! Sorry. I tend to cimb on my SUV soapbox every chance I can get.

Back to the matter at hand: CVTs are great for gas/electric hybrids and tiny econoboxes like the old Subaru Justy. A hydraulic hybrid engine is asking for more trouble than it's worth. When they solve AT leaks, fluid breakdown, and burnouts, fine. But until then...

There is another type of single gear drive that uses a rotating pinion that can also move on the "y" axis to change it's position on the drive gear. Less moveing parts than belt drives and continuously variable hydro units... Can't find anything on the web about it right nnow though...

Anyone that says the variable ratio trans vehicles can't be modified hasn't ever ridden a snowmobile. Belt driven, 180+ HP, 10 second quarter mile, 0-60 about as fast as you can pull the trigger STOCK snowmobiles are quite common. Granted a snowmobile isn't a car, but the modifications would be similarly done.

"y" axis moves on a pinion? This I gotta see!Let me know when/where you find this info...

Yeah, but a snowmobile CVT isn't computer controlled to maximize efficiency/power depending on operating regime. Automotive CVT control is very complex and very specialized in that the engine and transmission must be designed from a systems approach. The transmission control and calibration is very complex compared to automatic transmissions.

CVT control is usually wheel-torque based, so the driver commands a wheel torque (like in any other car) and the powertrain decides how to best meet that torque with an eye on efficiency. Torque is not directly measured, but it's inferred from other parameters. While there would be some adaptation range for engine operation, I doubt it would be large enough to take advantage of extensive engine modifications.

Ah yes CSD's and hydraulic leaks Oops wrong world. CVT's, are they still playing with the segmented stainless steel drive belt?
Thanks Paul

Yeah maaan, I really haaate those SUV's!!!!
I feel you.
warmonger

Honda and Nissan do. The Audi CVT uses a chain link system, so instead of pushing the belt around like segmented belt system does, the chain links pull the belt around the pulleys. This gives them a much higher torque limit.

Normal sleds are controlled by spring seat pressure in the primary and secondary clutches (both opened and closed seat pressure), weight ramp angles and total weight down to fractions of a gram, clutch ramp angles, engine HP/TQ curves, gearing, snow conditions, and traction available. Running the wrong clutch settings in the wrong conditions can make your sled be off by several thousand RPM and as much as 30 MPH or more. May not be computer controlled (yet, several companies are working on it), but it is just as complicated as the system workings itself on any single gear drive unit. The engine and trans have to be a system in any type of single gear drive unit to get optimium performance and gas milage. Change one thing and you must change 10 others to compensate. I didn't say it would be easy, just that it is possible to mod single gear drive unit vehicles. Heck, computer controlled probably will be easier, mod the engine and a couple thousand lines of code to change operating RPM and you're on your way.

Yeah, no problem! LOL