Gear Vendors overdrive

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This is what I mean about getting answers that don't directly address my question.
Plus I love being taken out of context......

So, simplifying......
You drive at 70mph and your engine is running at 3000 rpm. Your converter stall (the theoretical point where pump and turbine speed are the same?) is 2500 rpm. Things are happy, right?

You add an overdrive that drops your rpm below the 2500 rpm, then isn't your converter "slipping" which in turn creates HEAT?

Isn't this why modern AODs have lock up converters?


yes and no -

Case in point - ME!

I have a 400 hp 360 3.23 gears and a 3800 stall dynamic 9.5" converter
I used to have a mopar 175k converter with the same setup and burned it up with the tranny - Why? It was slipping.

The 9.5" dynamic converter lowered my cruising RPM , raised my mileage and lowered my ET at the track.
It was more efficient and designed to handle the slip different then the old school mopar unit

The pitch of the fins, the stator angle and the case size determines flash stall.

I wrote a 2 part article on it a few years ago and went to dynamic converters and watched them assemble one and saw all the differences they had to choose from - neat **** right there!

Anyway - the car cruises 3200 @ 75 - so anything under that should be slipping and heating up but the pitch of the blades combined with the smaller case ( 9.5" diameter compared to the 11" stocker ) made the converter slip only when it was overpowered with torque ( when you nail it ) otherwise it acts like a stocker.
 
You add an overdrive that drops your rpm below the 2500 rpm, then isn't your converter "slipping" which in turn creates HEAT?

Isn't this why modern AODs have lock up converters?

thats why you need a converter built to that combo.. moden converters are a ,ot different the the ones a decade ago.. with OD it will have to be tighter then a non OD unit but it can still be a decent stall. they are using smaller dia. cases (9.5") to get a higher stall speed but using a positive pitch on the fins to make it lock up better for the street. it will still be a compromise though..
 
Thanks guys, that makes sense to me and I get the concept.

I have installed the GV units and agree that there is a place for them. Just not every place.
 
This is what I mean about getting answers that don't directly address my question.
Plus I love being taken out of context......

Get used to it with this guy. He loves to add crap in that you never stated as well. Mr arrogant looking down on the stupid peasants... LOL
 
being the original poster, after reading all of these post and reading "mopar to ya's" build thread i think i'll just put in a 5 speed lol.
 
being the original poster, after reading all of these post and reading "mopar to ya's" build thread i think i'll just put in a 5 speed lol.

You think the OD question gets busy here, wait for the ruckus with 5 speeds. :D (And they are pretty dang fun, rowing your own that is).
 
This is what I mean about getting answers that don't directly address my question.
Plus I love being taken out of context......

So, simplifying......
You drive at 70mph and your engine is running at 3000 rpm. Your converter stall (the theoretical point where pump and turbine speed are the same?) is 2500 rpm. Things are happy, right?

You add an overdrive that drops your rpm below the 2500 rpm, then isn't your converter "slipping" which in turn creates HEAT?

Isn't this why modern AODs have lock up converters?


Yes you will get that problem of heat build up with a TC that was built cheaply or like junk.
Again right back to only using specific TC builders as to not have that problem, i didn't answer you out of context i just didn't bother to explain in detail why a better TC does not kill your trans when operated below the lu area as DJVcuda did with detail.
More detail same answer, don't use a cheap or junk tc and you won't have anything to worry about, and you'll get better perf and mpg.

For 3K, I can add nitrous and go faster and still have plenty of gas money.

Well i didn't add the GV to go faster, i added it to knock down the gear after already owning one in my truck, then bought another added it to the car to knock down the 4.89, and then added another to the other car to knock down the 4.30
During a day at the track where there was no one around and making passes got boring i had played with the gv and split 2nd just for no reason it picked up 8hdt, so for $2400, not $3000 i knocked down my 4.89 on the street and at the track just for no reason split 2nd and p'u 8hdts doing nothing at all but pushing a button.
I can go to the track and for no reason most likely p/u another few splitting 1st, haven't tried it yet but i can.
I already have n2o in everything so all i had left was gear splitting, something that couldn't be done at all with od trans that never gives you the opportunity.


But doesn't the better first gear ratio of most AODs counter this "splitting"? I could see where first gear splitting might be good in my Jeep if I was pulling something out of the mud. Oh, I can't install a GV on my Jeep and use it in 4 wheel drive.......
Gear splitting in my experience has always helped, i have 3 of them behind 3 different trans and gear ratios.
I have a GV on my truck and have never had a reason to use it in 4x, however i have found going 1, 2, splitting 2nd, 3rd, splitting 3rd and 4th faster then just using 1,2,3,4 in the truck, towing and not towing.

Isn't the base GV unit the same and it just uses different adapters for different applications? Also, don't you have to also have to shorten your drive shaft because of the extra length? Doesn't it also alter your joint angles?
They are similar in outside appearance, there are different adapters and internal shafts and housings depending on use.
Shortening a shaft isn't a problem, fixing angles isn't a problem, and any vehicle for performance should have angles adjusted to 0 or accordingly either way.
 
Get used to it with this guy. He loves to add crap in that you never stated as well. Mr arrogant looking down on the stupid peasants... LOL

Yeah good thing for you than DJVCUDA was nice enough to go into detail so you can understand... LOL

Please excuse me for not being detailed and adding the crap that was missing eluding to why i used the terms junk and cheap tc... sorry i didn't go into detail about good tc builders and quality and why a cheaper tc is a killer of transmissions and a quality one isn't....
 
Yeah good thing for you than DJVCUDA was nice enough to go into detail so you can understand... LOL

Please excuse me for not being detailed and adding the crap that was missing eluding to why i used the terms junk and cheap tc... sorry i didn't go into detail about good tc builders and quality and why a cheaper tc is a killer of transmissions and a quality one isn't....

DJ and Joe gave me some base information to go by. Not huge algorithmic empirical data. Just some base info as to how and why. That's all I asked for.
Something a tad bit better than don't buy a "junk" tc. You're only defining measure was a $300.00 price point. So by the standard you set in type, under 3 C notes is BAD, over 3 is good. You seem to forget that not everyone that reads these posts is as well trained and precisely skilled as you appear to be. I try to keep in mind that someone just reading these posts may be very new to the hobby or may have never turned a wrench before.
 
After reading some of these od threads one has to wonder why the manufactures ever got rid of the old hydraulic 3 speeds? Hell, they could have just used a GV unit. Wonder if I can find a 3 speed trans that will fit behind my Duramax? Pull that piece of junk Allison/lock up t/c out of there and put a GV in its place....

I understand that today's t/c are more efficient. At the same time there are some serious hills in the Pacific North West, steep enough that my diesel builds 15+ pounds of boost climbing them empty. And needless to say these hills are long. Would not want to try to climb some of these hills in a car that makes a butt load of torque while lugging the motor in OD. Don't care what any one says the convertor will start to slip. And I am not talking .1 mile long grades, more like several mile long hills.

Not saying that the GV is not a great idea for SOME folks. But face the facts, modern day trans have come along way. 4r70w/aode hybrids with a lock up convertor, trans brakes and 4500 or so rpm convertors, ditto for the gm 4l60-80 etc. To a person that does not have a trans to begin with the GV probably will not save you any money. 3k on the GV plus the cost to build a good 727 will no doubt be more than most folks are going to spend on a modern day unit.

Like I said earlier, more than one way to skin a cat....
 
I was afraid for a long time to run a modern OD, spent lots of time and money avoiding them, until I came to the conclusion:

A transmission is a transmission, they all work the same way, and all can be modified the same way to get results that aid durability.

If your mindful of OD use, which should only be used cruising. Not in town, hills, towing loads, and big hammer RPM drops showing off for the ladies; treat them right, like any other tool they, they last just as well, if not longer because of better materials, computer control, engineering and efficiency.

I get tired of the armchair folks that copy and paste on and on about how it does not work, you should just take your ball give up and go home. Especially when it's some dry technical diatribe that is more about stroking the ego of the person posting it, than being helpful.

Well,

Once you realize all that talk should be labeled under 'troll: for entertainment purposes only' and not gospel, you realize it can all work out, and that you beat the matrix.

Congrats!
 
yes you do, unless depending on the tc some people have and didn't use a good one
or have it built right then its a different story......
HemiDenny doesn't use a TC......no stall speed issues here......all aluminum A833.

Different views of Gear Vendor Overdrive and minor tunnel modification.

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^probably could've dropped in a 6 speed for cheaper (maybe not the TR-6060 but the T-56 for sure).
 
This is what I mean about getting answers that don't directly address my question.
Plus I love being taken out of context......

So, simplifying......
You drive at 70mph and your engine is running at 3000 rpm. Your converter stall (the theoretical point where pump and turbine speed are the same?) is 2500 rpm. Things are happy, right?

You add an overdrive that drops your rpm below the 2500 rpm, then isn't your converter "slipping" which in turn creates HEAT?

Isn't this why modern AODs have lock up converters?

No, because when you drop the RPM you also drop torque so now your convertor doesn't stall at the same speed, plus most of us are cruising at light throttle with the OD on so you aren't seeing RPM flare. Last, you should have a quality converter built for your application. My 3500 converter bumps into gear and can only be foot braked to maybe 1300 without pushing and twisting the car. But matt it or do the flash stall test and it will whack 3500 on the nose everytime.

You can actually read about this on their website.
 
HemiDenny doesn't use a TC......no stall speed issues here......all aluminum A833.

Different views of Gear Vendor Overdrive and minor tunnel modification.

Old Man Mopar, I would like to see the pictures, I was thinking of GV on a 4 speed trans..... I have not seen a mounted set up. Can these pictures be clearer?
I belive a long tail shaft trans is whats required as an A body main shaft will not work? Any tips?
Thanks!!
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MillerHouse081.jpg

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MillerHouse012.jpg

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Splitting Mopar autos doesn't work all that well because the 2-3 ratio is not far enough apart
2.45-1.45-1.00. versus 2.45-1.91-1.45-1.13-1.00-.78od ; splits of .78-.76-.78-.88-.78
unless you gear the diff. to trap in second over.
Say your SBM traps at 106; and say you want the Rs to be 5600, with 27s. And say the slip is gonna be 6% That calls for 3.55s, and second-over. So you can see the problem there, right away, namely a soft 60ft.
Whereas trapping in third(Drive) would require 4.10s; now yer talking. But the GV is still good to split the 1-2 shift.
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For a streeter; splitting 1-2 would likely allow your streeter to run less stall.
You could run say 3.73s and hit 60@ 5600 in first-over.... and cruise at 65=2350(0-slip), like it would with 2.94s in the back. The starter gear is a very nice ratio, for an automatic, of 9.14
That 5600 trap at 60 would allow you to run say up to 224*@.050 cam and a 2400 stall, and pull up some great fuel mileage. And with that 224* cam in a hi-compression 360, it's gonna lay a lotta lotta rubber. Perfect for a streeter.

But I'll tell ya; shifting at 5600 the Rs will drop to ~4400 ........ just 1200 rpm. So that points to a new LSA.... in the 106 or maybe less zone. And that means;
More power with the same 224* cam.... or move up to a 230* cam without the penalty of a softer bottom end
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So, as others have said, the combo sorta has to be built around the GV.

In my combo,it works awesome with a Commando 4-speed and 3.55s.
 
Splitting is great.

2 example of when I do it are at the drags.

1/4 mile I go through the traps in 3rd gear at 6200. 1/8th mile I go through in 2nd gear + OD at 6200.

through town I'll drive through in 2nd OD instead of disengaging the OD. Perfect RPM maintained.
 
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