Passon 4 speed OD vs. 5 speed OD or any other for that matter

[696pack]

EDIT:
Sorry, the sites posting format pushed the chart for the gear ratios togather so they are not directly under the headings and it is harder to read.

I don’t understand why everybody is so excited about the 5 speed transmission regardless of what brand? If you want to have a car that does 150 mph or faster, these old cars are NOT the thing to do it in. They were not designed for that kind of top speed like the newer cars are with front spoilers and more aerodynamic bodies that keep the air from pushing up against the underside of the hood and lifting the front tires off the ground.
If it is a gas mileage thing then people better be doing the math for the cost difference for ANY conversion to see how much they will save verses the cost.

I recently purchased/installed the Passon 4 speed OD in my 1966 Charger. I did so because I want to be able to drive at freeway speeds (85) without wearing out my 523 stroker, for a little better fuel economy and to still be able to race my car in the 1/4 mile with a strong enough trans to hold up to the engine. I can run the 1/4 mile in the first three gears just like a Torqueflite. With my 3.54:1 Dana rear ratio the OD trans makes for an adjusted rear ratio of 2.83:1 in 4th gear.

I paid around $2500. for the trans gear set and install. If I increase my mileage by 5 mpg with gas @ $4.00 per gallon, I will have to drive around 70,000 miles to break even on the cost of the conversion. If you are doing it for gas mileage it is not very cost effective. If you want to go fast on top end you may want to reconsider you vehicle choices and go with a newer car that is safer to do it in and more aerodynamic that already has a 5 or 6 speed trans. If you are like me and want an old car with my above listed advantages and are willing to pay the price then go for it. Do the math on this for a Passon 5speed OD and it will take you over 150,000 miles to break even on the conversion and many more miles for any other 5 speed OD conversion. Is it worth it for the extra gear with a small difference in the final drive ratio over the Passon 4 speed OD? I think not.

Below are the differences in the trans gear ratios from stock to 4 & 5 speed. I have also listed the Torquflite gear ratios for your comparision.

stock Passon 4 speed OD Passon 5 speed OD Torquflite
1st--2.65: 2.66:1 2.64:1 2.45:1
2nd--1.93:1 1.59:1 1.92:1 1.45:1
3rd--1.39:1 1.00:1 1.40:1 1.00:1
4th--1.00:1 0.80:1 1.00:1
5th-- 0.70:1

You can buy the Passon 4 speed OD gear set to install in your existing 4 speed case for $1845. and use your existing shifter, just change your clutch disc to the 18 spline. This is what I did for a cost of aproximately $2500.

 

[Dennis H]

I'd rather cruise at 70 mph @ 2150 rpms than 70 @ 3 grand. Keisler/Tremec 5, 3:54 Dana. Like having the old A833 with an extra gear on top. Tired of waiting for the Passon new no-cutting 5 speed and the Keisler SS700. Both promised, neither one to market yet. If you want to really drive your car, gotta have overdrive. I don't want to show up at MATS in Vegas with my 09 Challenger.

 

[696pack]

I'd rather cruise at 70 mph @ 2150 rpms than 70 @ 3 grand. Keisler/Tremec 5, 3:54 Dana. Like having the old A833 with an extra gear on top. Tired of waiting for the Passon new no-cutting 5 speed and the Keisler SS700. Both promised, neither one to market yet. If you want to really drive your car, gotta have overdrive. I don't want to show up at MATS in Vegas with my 09 Challenger.

I am not disagreeing with the idea of overdrive. In fact, if you read my entire post you will see that I have a Passon 4 speed overdrive. Have you considered the 4 speed overdrive unit?

 

[Dennis H]

OK. I don't have to go 150 to enjoy the Coronet. Triple digits are fun though in the right place and time. i don't care about the mileage or cost. I want to loaf along at 70 plus in my 44 year old car.
Tired of waiting for Passon's 5 speed. Or keislers ss700. Modern cars just don't have the panache. Even Mopar Modern Muscle and I have two of those. Guess I don't get the point.

 

[RustyRatRod]

I see absolutely zero wrong with the Mopar A833 OD unit. If you can find the cast iron case transmission, they are plenty strong enough for a moderate big block. I like them because their first gear is 3.09:1. lol

 

[696pack]

OK. I don't have to go 150 to enjoy the Coronet. Triple digits are fun though in the right place and time. i don't care about the mileage or cost. I want to loaf along at 70 plus in my 44 year old car.
Tired of waiting for Passon's 5 speed. Or keislers ss700. Modern cars just don't have the panache. Even Mopar Modern Muscle and I have two of those. Guess I don't get the point.

I guess not. Did you read the specs I posted for the Passon 4 peed OD? Pleas go back and read my entire post

With the Passon 4 speed OD and a 4.10:1 rear end with 28" tires @ 65 mph your RPMs are 2580.

With my 3.54:1 which brings the rear gear ratio to an adjusted ratio of 2.83:1 and around 2000 RPMs at 65 mph.

Have you done the math on what ever you cars gears are with the 4 speed OD?

The point is everyone is so excited about the 5 speed when we already have a very good choice with his 4 speed for much less money.

To the other poster, you can't begin to compare the old factory 833 OD with the Passon unit which is stronger than the original Hemi 18 splines. It is ok if you never get on your hipo car but who buys them to baby them? The gear spread is terrible for racing and they will not hold up to the h.p. of the hipo cars we build.

 

[Meep-Meep]

I will agree with 696Pack about the OD tranny benefits. I am looking at the OD gear set conversion to provide a more enjoyable cruise on long trips. The gas mileage benefit may be small, and I'm happy to have it, but the noise level reduction will be huge! I had a Porsche 911 T and resorted to putting ear plugs in for a five hour trip. The 911 engine is a work of art and loves to run at 4000 RPM down the highway, but after 5 hrs my head was pounding.