Sad Story On a Gear Vendors OD

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Any overdrive is better than none,
and If your engine is shy on bottom-end torque that you gotta run the higher number gears, then this becomes ever more important, for those who actually want to cruise their streeters. But if I had a stroker, or a BB, and could run 3.23s and tall tires, I'd pass on the OD.
 
AJ/FormS said:
Any overdrive is better than none,
and If your engine is shy on bottom-end torque that you gotta run the higher number gears, then this becomes ever more important, for those who actually want to cruise their streeters. But if I had a stroker, or a BB, and could run 3.23s and tall tires, I'd pass on the OD.
Click to expand...

You could run 4.30’s or 4.56’s and be in the 3.23 final drive ball park.

4.30 X .73 = 3.13
4.56 X .73 = 3.32
 
pishta said:
so a blanket ".xx is no good" is purely an application specific opinion, could be great for certain combo.
Click to expand...

I agree with this completely.
For example, in my case as things are right now I have 2.73 rear gears and the OD in my 42RH is .67:1 and my converter has a stall of 1,800 RPM's.
This puts me at about 2,000 RPM's at 70 MPH, which is just barely over the converter stall speed.
To put that another way I almost still have converter slip at 70 in OD, which is kinda dumb.
If my OD ratio was any higher I would have converter slip at the freeway speed limits.

Things are in the works right now to swap out my rear end for a 3:55 Sure Grip.
Once that is done my OD RPM's will be in a more reasonable range for the 75 MPH speed limits.
I normally drive about 85-90 when out on the interstates, and only then use converter lockup giving a cruise RPM of around 2,200-2,300.
Lugging an engine is as bad as revving as far as efficiency, so I try to keep the engagements of OD and lockup above the 2k RPM range at the lowest.
 
I am still looking into Passon A855 trans option? Problem with a beefy glide with a GVOD is not performance. Can easily handle 1000+ horse. Its that these glides really heat up under stall conditions which is very prevalent in any street duty. They are designed for race application. It's the classic question. How can I make a race setup streetable? Heat is the enemy. so yes, I want my cake and eat it too damn it!

There is always a Lenco option?
 
cojohnso said:
I am still looking into Passon A855 trans option? Problem with a beefy glide with a GVOD is not performance. Can easily handle 1000+ horse. Its that these glides really heat up under stall conditions which is very prevalent in any street duty. They are designed for race application. It's the classic question. How can I make a race setup streetable? Heat is the enemy. so yes, I want my cake and eat it too damn it!

There is always a Lenco option?
Click to expand...

I had a friend that ran a glide in his highly built 351 Cleveland in his 66 Ford Falcon Futura that had the heat problems unless he put it in neutral at stoplights.
The main problem he had was when he put it back in gear again it would bark the big slicks and the cops would write him up for exhibition of speed.
They didn't care one bit that all it did was bark the tires without even moving yet.
 
Big Double trans coolers with fans on the coolers.
Deep pan.

What trans again? A glide?
 
AJ/FormS said:
Winter's 2-speed QC rearend. almost bought one of those instead of the GVOD.
Click to expand...
will QC gears handle the shock loads of drag racing?? i got a hand full of standerd QC rears id use but always herd thay wont hold up doing burn outs and hole shots with good traction!!
 
dirty white boy said:
will QC gears handle the shock loads of drag racing?? i got a hand full of standerd QC rears id use but always herd thay wont hold up doing burn outs and hole shots with good traction!!
Click to expand...
I'm a streeter, so cannot answer that, but have heard similar things.
But I decided, an electric splitter was more handy than crawling underneath to swap the Quick-Change gears every Friday evening.
Plus the winter's was a G more.
 
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TrailBeast said:
I agree with this completely.
For example, in my case as things are right now I have 2.73 rear gears and the OD in my 42RH is .67:1 and my converter has a stall of 1,800 RPM's.
This puts me at about 2,000 RPM's at 70 MPH, which is just barely over the converter stall speed.
To put that another way I almost still have converter slip at 70 in OD, which is kinda dumb.
If my OD ratio was any higher I would have converter slip at the freeway speed limits.

Things are in the works right now to swap out my rear end for a 3:55 Sure Grip.
Once that is done my OD RPM's will be in a more reasonable range for the 75 MPH speed limits.
I normally drive about 85-90 when out on the interstates, and only then use converter lockup giving a cruise RPM of around 2,200-2,300.
Lugging an engine is as bad as revving as far as efficiency, so I try to keep the engagements of OD and lockup above the 2k RPM range at the lowest.
Click to expand...


Actrually you may not, especially if you have a very efficient convertor. I cruise at 2500 and stall at 3500. There is no slip. Why? stall is based on power output. You aren't making the same tq at 2g you are at X RPM. As you are aware, convertors don't flash to a given RPM behind any given combo. That's how it works. (which you can read more about on GVOD site)

Look at the combos they are running in drag week. Way more extreme than most of ours and all of the run OD units.
 
roccodart440 said:
Actrually you may not, especially if you have a very efficient convertor. I cruise at 2500 and stall at 3500. There is no slip. Why? stall is based on power output. You aren't making the same tq at 2g you are at X RPM. As you are aware, convertors don't flash to a given RPM behind any given combo. That's how it works. (which you can read more about on GVOD site)

Look at the combos they are running in drag week. Way more extreme than most of ours and all of the run OD units.
Click to expand...

That's where I would look for answers, Hot Rod Drag Week for sure. All those guys trying (and many succeeding) at doing the insane race-car-on-the-street deal.

My AX-15 5-speed in my Jeep has a .79 overdrive, I do wish it was a bit taller but it still makes a difference. With 3.55 gears and 29" tires I'll go from about 3200 RPM in 4th at 75 MPH down to about 2400-2500 RPM in 5th. 1st gear is pretty deep though I think 3.83:1? It's really intended to be used with taller final drive gearing, my Jeep loves the 3.55s though it gets great mileage around town and it's pointless trying to go over 85 MPH in that thing, that's what the Duster is for.
 
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TrailBeast said:
I agree with this completely.
For example, in my case as things are right now I have 2.73 rear gears and the OD in my 42RH is .67:1 and my converter has a stall of 1,800 RPM's.
This puts me at about 2,000 RPM's at 70 MPH, which is just barely over the converter stall speed.
To put that another way I almost still have converter slip at 70 in OD, which is kinda dumb.
If my OD ratio was any higher I would have converter slip at the freeway speed limits.

Things are in the works right now to swap out my rear end for a 3:55 Sure Grip.
Once that is done my OD RPM's will be in a more reasonable range for the 75 MPH speed limits.
I normally drive about 85-90 when out on the interstates, and only then use converter lockup giving a cruise RPM of around 2,200-2,300.
Lugging an engine is as bad as revving as far as efficiency, so I try to keep the engagements of OD and lockup above the 2k RPM range at the lowest.
Click to expand...

I'd be interested to hear what your rpm's are like after the swap to 3:55's
 
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