Gear Vendors Overdrive

grover said:

In reply to A 401 CJ :

Some things need more value add mathing than just the mpg imo. It's stressful to hear a motor humming at high rpm's that isn't a vtec or other normally high strung model. How much value does the lower rpm and related stress/wear and tear add up to? 

For me, yes, I see your point.  For the cold, hard calculations of SWMBO, it adds up to nothing.

Curtis73 (Forum Supporter) said:

grover said:

In reply to A 401 CJ :

Some things need more value add mathing than just the mpg imo. It's stressful to hear a motor humming at high rpm's that isn't a vtec or other normally high strung model. How much value does the lower rpm and related stress/wear and tear add up to? 

That would be an interesting metric to know.  Like... if you have a the same engine in a 2wd chevy pickup with 3.27 gears, does it last any longer than a 4x4 with 3.73s?

How would that work in a truck with say a granny low?  It wouldn't take much of an engine before you were seeing well in excess of 2000 #ft at the input of the overdrive unit.

In reply to A 401 CJ :

Disengaged, there is just a 1:1 shaft.  Engaged in granny involves the planet set, but this is from GVOD website:

GEAR VENDORS provides overdrive product to racing cars and trucks up to 2000hp and trucks towing heavy RV’s up to 25,000lbs gcvw. 

They're also marketed for off-road racing and 4x4s, so they can take the torque of a granny low plus a low range transfer case.  Somewhere else they said they tested it up to 2000 lbft, but it likely will take a crapload more.

Curtis73 (Forum Supporter) said:

grover said:

In reply to A 401 CJ :

Some things need more value add mathing than just the mpg imo. It's stressful to hear a motor humming at high rpm's that isn't a vtec or other normally high strung model. How much value does the lower rpm and related stress/wear and tear add up to? 

That would be an interesting metric to know.  Like... if you have a the same engine in a 2wd chevy pickup with 3.27 gears, does it last any longer than a 4x4 with 3.73s?

There also a sweet spot in gearing for in town economy vs highway. Going from 2.73s to 3.40ish in a square body 6cyl, 2wd pickup improved mileage around town, and made it more enjoyable to drive around town, but less pleasant on the highway with no OD.

As for the quoted question, while lower rpm's are easier on the ears, you still doing the same amount of work so lower rpm requires higher torque output from the engine resulting in higher stresses on components. 

I think the results might be counter intuitive for longevity vs rpm unless working at extremes. I would expect 1500 rpm vs 3000 rpm vs 4500 rpm when pulling the same load might show higher wear at the 1500 and 4500rpm, but albeit different wear patterns due to the unique stresses from each case. 

If you've got a 2wd vehicle with gears like 3.08 or 2.72, you should look at a Doug Nash 4+1.

They were built for the miserable late 70s and 80s pony and muscle cars with wheezing engines and numerically low (fuel economy) rear gears.

1st is usually 3.27 or lower and 5th is direct, not overdrive.

You put it in something like a T/A or Camaro with 3.08 gears and it will launch like it has 4:10 gears but still has great highway gearing in 5th.

Richmond eventually bought them out and made them into conventional 5-speeds but you can still order the old-school ratios in them.

Appleseed said:

Those free RVs might be worth investigating .

The "free" motor homes on F B M around here, it be cheaper to spend the $4 grand on a new one! 
That being said, I've seen complete running trucks with one installed, for half the cost of a new unit!

Still outa my play budget, but always had me thinkin' 

03Panther said:

Appleseed said:

Those free RVs might be worth investigating .

The "free" motor homes on F B M around here, it be cheaper to spend the $4 grand on a new one! 
That being said, I've seen complete running trucks with one installed, for half the cost of a new unit!

Still outa my play budget, but always had me thinkin' 

Best way to get the "good stuff" out of a free motor home is an excavator with a thumb and a dumpster.  You just rip the trash off until you get to the engine, trans, and hopefully OD unit.  Then you just torch that out at the mounts.  Load what's left into the dumpster.  It's crude, violent, effective, and fun.

In reply to A 401 CJ :

No one let's ya do that on their property, though 

Tons of fun, but definitely not your average citizen!

a friend just bought a 99 v10 motorhome with 8200 miles on it. Window and roof leaks have utterly destroyed it! Esensually brand new, and none of the coach is save able. It's so saddening, this one won't be fun ripping the coach off. I'm hoping to recover enough to buy the chassis, and roll my one

OK, sorry... back on topic...

In reply to 03Panther :

It's good being out in the country.  I have a backhoe, a dumpster and my closest neighbor is 5 miles away. 

In reply to ShawnG :

 Amen to that!