4 speed or 4 speed OD?

[Rockerdude]

Help me understand what two worlds that is. Since the Mopar OD unit has a 3.09 1st and a .69 OD, it already would seem you have the best of both worlds. Who needs to spend 3K bucks for one more gear?

Nice close ratio gears and overdrive.

 

[RustyRatRod]

Nice close ratio gears and overdrive.

And that matters on a DD why? I'm not trying to be an ***. Help me out here. I mean, unless I am racing autocross or some such, I couldn't care less about close ratios. In fact, most street stuff is wide ratio, because that's the best compromise for a daily driven street car. That is, unless you've discovered something that I and thousands of automotive engineers don't know. We're not talkin about BS magazine articles and rumors here either, but real world facts.

 

[d55dave]

And that matters on a DD why? I'm not trying to be an ***. Help me out here. I mean, unless I am racing autocross or some such, I couldn't care less about close ratios. In fact, most street stuff is wide ratio, because that's the best compromise for a daily driven street car. That is, unless you've discovered something that I and thousands of automotive engineers don't know. We're not talkin about BS magazine articles and rumors here either, but real world facts.

I have to say I agree, I kind of like a well built engine with a wide power band winding out in each gear, not changing gears every 500 rpm. I have never figured what all the close ratio hype is, these aren't formula 1 cars...

Just my opinion

 

[slickchick]

. . .

 

[YY1]

So, the O/D second is close to the T/A and "Race Red Stripe" second.


Interesting.

 

[RustyRatRod]

I have to say I agree, I kind of like a well built engine with a wide power band winding out in each gear, not changing gears every 500 rpm. I have never figured what all the close ratio hype is, these aren't formula 1 cars...

Just my opinion

Yes, if you notice, close ratio transmissions came mostly in very hot street cars. Chevy is a good example.....I know Chevy. lol But TONS of their cars got the M20 and M21 wide ratio transmissions. Much fewer cars got the M22 close ratio "rock crusher" transmission. The ratios are closer to keep the engine RPM up in its power band for performance reasons that are not really necessary on a daily driven street car......or necessarily desirable. Most mild street builds don't need all the RPM from the close ratios and it burns extra gas, too.

 

[Walker434]

FABO member Badlilred79 has a 4 speed OD in his yellow 70 duster with a blown 340 in it. It has stood up to a lot of abuse for years.

I can't say if it has been beefed up internally but I know I have taken a wild ride in that car and the transmission has held up.

I also know he doesn't power shift into 4th. Hard throttle is 1-3 and 4th gear is just for cruising.

 

[teringer]

I also used one od from a 78 aspen in a 450 hp stockcar 30 laps 2 times a week /1/2 mile oval ,strength was not a issue ,and the 8 1/4 rear built proof ,lost 10 t0 20 tires wheels from a little rubbing and never had axle issues with stock parts while the others brand wood snap a axle just hitting a bump. my only problem with them is you just cant shift them as quickly with the wide gear ratio ,but I will trade that for 28 miles to the gallon with a nice build 318 any day.

 

[YY1]

My O/D is living just fine behind a mildly build 440 in a full size truck.

It's super fun to drive, despite the 3.09 first being a bit short, and need to watch shifting to 3rd too soon.

(lots of time spent in that second)

Serious power shifting into ANY overdrive gear is probably not a great idea anyway.

At that point you're likely up pretty good in RPM.

 

[racerx23]

The demon had 456 gears and 31.5 Mickey Thompson pro sportsmans

 

[Idaho]

Summarizing feedback from those who have done it.

I ran a OD behind a stroked 340 with 410 gears. It was great for gas millage and burn outs. Just don't make the mistake of shifting under power, they wont take it. I broke two of them going from 3rd to 4th. Got great gas millage ,Drove from LR Ark to the nats with 340 6pk,4spOD, 410 gears and got decent gas millage. I would vote go for it.

racerx23 My 2 cents. I have a demon with a 426 wedge that was backed by the od trans.the car ran mid 12's with no trans problem, I personally like the trans and have no issues. As a matter of fact I just put one behind my stock demon and almost doubled the mileage.

marksmopar1 I had a regular 4 speed behind a hot 360 in a 73 Dart Sport...I changed to a OD 4 speed and loved it! Great street power between lights, and highway cruise RPM was noticable.
As for strength, work fine no issues! Drag out the 1 st gear and I would skip 2nd straight to 3rd...lol 2 speed with OD on the Highway! I would do it again...was 3:23 sure grip by the way

Walker434 FABO member Badlilred79 has a 4 speed OD in his yellow 70 duster with a blown 340 in it. It has stood up to a lot of abuse for years.

I can't say if it has been beefed up internally but I know I have taken a wild ride in that car and the transmission has held up.

I also know he doesn't power shift into 4th. Hard throttle is 1-3 and 4th gear is just for cruising.

teringer I also used one od from a 78 aspen in a 450 hp stockcar 30 laps 2 times a week /1/2 mile oval ,strength was not a issue ,and the 8 1/4 rear built proof ,lost 10 t0 20 tires wheels from a little rubbing and never had axle issues with stock parts while the others brand wood snap a axle just hitting a bump. my only problem with them is you just cant shift them as quickly with the wide gear ratio ,but I will trade that for 28 miles to the gallon with a nice build 318 any day.

YY1 My O/D is living just fine behind a mildly build 440 in a full size truck.

It's super fun to drive, despite the 3.09 first being a bit short, and need to watch shifting to 3rd too soon.

(lots of time spent in that second)

Serious power shifting into ANY overdrive gear is probably not a great idea anyway.

At that point you're likely up pretty good in RPM.

100% positive.

 

[sireland67]

Ran one for years in my first duster, hot small block, 3.23 gears.
Trans never gave me an issue, gear ratios were not the best.
It would have worked much better with about a 3.91 gear, but the speed limit was only 55 on the interstate back then.

 

[Princess Valiant]

Summarizing feedback from those who have done it.

I have too but I am the party pooper here to give it negative feedback.

If you live in a mountainous place forget it. Going up the mountain OD is useless and you cant stay in second the whole way and 3rd gear (1 to 1) will bog out especially when you get behind some dork in a prius who cant keep up. so you end up going from 2 to third constantly and every time you downshift....there goes your mileage.

Coming off the mountain, OD is useless and you cant stay in 3rd the whole way to keep your speed in check so you end up in a constant shift battle again between 2 and 3.

Same situation with a one to one ......keep in one gear down from normal and ride it the whole way through.......wont bog and wont rev you up to much because they are closer ratio wise anyways.

All depends on where you live and what you are going to with it. As a commuter for me, it didn't work because living in Colorado, gives new meaning to the long and winding road through a mountain pass.

 

[Idaho]

You just had to rain on my parade.
Rani... Change the letters you get rain.
You're right of course I forgot to include you.
My bad.

 

[66fs]

I have too but I am the party pooper here to give it negative feedback.

If you live in a mountainous place forget it. Going up the mountain OD is useless and you cant stay in second the whole way and 3rd gear (1 to 1) will bog out especially when you get behind some dork in a prius who cant keep up. so you end up going from 2 to third constantly and every time you downshift....there goes your mileage.

Coming off the mountain, OD is useless and you cant stay in 3rd the whole way to keep your speed in check so you end up in a constant shift battle again between 2 and 3.

Same situation with a one to one ......keep in one gear down from normal and ride it the whole way through.......wont bog and wont rev you up to much because they are closer ratio wise anyways.

All depends on where you live and what you are going to with it. As a commuter for me, it didn't work because living in Colorado, gives new meaning to the long and winding road through a mountain pass.

Rani, What engine? What car? What rear gears, please?