Quote Originally Posted by Dave Severson View Post
Well, it looks like Gear Vendors doesn't share your concern, less then 1hp per 400hp loss, and they come with a guarantee....

Quote from their site;

The GEAR VENDORS uses a common vertex (cone) Raybestos clutch system. This means there is no parasitic loss through dragging and unapplied clutch pack. For this reason the GEAR VENDORS is the most efficient transmission on the market using less than 1 horsepower per 400. Imagine - we race the Dakar, Quatar, Tunisian, 24hrs of France, and Master rallies (over 6,000 miles each race) with just 24 ounces of fluid in the unit and no cooler. And, we have won the Quatar, Tunisian and the Master. You cannot do that if you are converting hp to heat.

The GEAR VENDORS planetary carrier and power flow are ideal for motorsports. The planet carrier is all steel and carries a double row of narrow caged needles in each gear instead of a single wide set. It is the most sophisticated planetary we know of. The 18 element roller clutch and drop forged annulus can launch the current world record holder in Super Eliminator with 1850hp as well as the current record holder of HotRod Drag Week (these are 7 sec passes in a 3800lb car. Most racing products are no where near the level of engineering found in the Gear Vendors simply because of their low production volumes. Gear Vendors sells thousands of expensive overdrives to muscle cars, street rods, trucks, towing trailers, and Rv's every year for (27 years). It is this production volume that drives the engineering and that would be hard to justify if your product was only sold in small quantities. For this reason the UNDER/OVERDRIVE™ is a real bargain for racers in performance, and engineering per dollar.
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That seems to sum it up quite well......
Well, well, well!
Thank-you very much!
I had no idea that a unit like this was anywhere in existence...it seems it can be used all-the-same as a two-speed diff...is that assumption correct?
And from previous posts it appears to be a very robust unit; will handle virtually anything that's thrown at it.
Some of the horse-power/tourque figures quoted as being put through it are amazing!

I think I'm going to have to do a google and find out more...sounds like it will be just the bee's-knees to think about for the bus...which will finish up weighing about 3.5 or maybe 4 tons.

And considering our undulating terrain here in New Zealand; the more gears ya got the more better...

(Oh, by the way; I'm enjoying your thread...thanks! )

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