4 Wheel Drive/SUVs/CVT/VVT Question

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Question
Good morning Carl.

I am hoping you can answer my question.  I've been taking my friend car shopping and he's looking at a Jeep Patriot Latitude.  There have been discussions about the CVT vs a VVT transmission.  I've googled quite a bit and from what I can discern, the CVT is a transmission and the VVT has to do with the valve control on the engine.  Is there such thing as a VVT transmission, or is that only an engine thing?  It's been insisted upon that they are both a transmission but I have yet to find anything definitive stating as such.  If you have knowledge on the subject it would be most helpful.  Thanks in advance.

Answer
Bob,

VVT stands for variable valve timing, Which is controlled by the PCM (powertrain control module) by way of electronic solenoids that control oil pressure to the camshaft phasers which controls the valve timing. Now CVT stands for continuously variable transmission which is nothing more than two pulleys that each change their diameter and provide a changeable effective gear ratio without the use of gearsets.

A couple of sites to check out are:
http://en.wikipedia.org/wiki/VVT-i
http://en.wikipedia.org/wiki/Continuously_variable_transmission

I hope this will answer your question.

Carl

4 Wheel Drive/SUVs

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Carl Brandt

Expertise

Will discuss suspensions, lifts, lockers along with tire suggestions. Trail ratings and possible requirements needed for specific type of trails. Safety equipment and what you should carry with you. Certified off-road instructor. I am not a mechanic, and 4-Wheeling is a hobby, so if I can't answer a technical question it is due to my mechanical knowledge being related to vehicles that I have owned, or have worked on. I do not have manuals on all vehicles, and I suggest that you obtain a repair manual for mechanical problems and do some research before asking your question. Most mechanical questions can't be answered completely without looking at, or listening to the vehicle in person.

Experience

40 plus years of 4 wheeling in a variety of vehicles. At the present time, my major off-road rig is a 94 Jeep Wrangler with a spring over and a 1 1/2" suspension lift. This gives me a total lift of 7" or so. I have lockers front and rear. I have removed the track bars, and sway bar for maximum articulation. I am running a stock 2.5 ltr 4 cylinder with a Jacobs ignition along with a cold air high flow filter. It has 4.56:1 gears with a Dodge NV4500 transmission along with a 3.8:1 Atlas II transfer case. This gives me a final ratio of 105:1 in low gear/low range. Other vehicles I own, are a 96 Ford F-250 with a 6" lift, posi rear end, 36" Hummer tires, 5 speed with a fuel injected 460 ci engine, an 87 Samurai with an 8" lift, Ford 9" rear end with a spool, Chevy Dana 44 front end with an electric locker, 5.88 gears, 16% reduction in high range and a 6.5:1 low range with 35" Baja Claws, and a stock 2003 Grand Cherokee Overland. Trails I have run are the Rubicon (10 times), Dusey Ershim, Fordyce Creek trail, McGrew trail, several trails in Moab, Utah along with local monthly runs.

Organizations
Lost Coast 4x4's Cal 4-Wheel Corva UFWDA Blue Ribbon Coalition

Education/Credentials
Certified off-road instructor - Certificates in engineering/electronics

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