OD trans options

[Mesozoic]

Alright, so I've made my decision. I'm going with a 4R70W. I already have a manual transmission Mustang that's TKO equipped, so I don't need another. Besides, these modern autos can be manually shifted and lockup in any gear so I don't think the efficiency that manuals used to have over autos is really that much different anymore.

If I have custom headers built to accomodate the C6 in the car presently is it a safe bet to assume that the 4R70W will fit them as well?

 

[Jeff73Mach1]

Positives: Autos are easier to install. They launch better. They perform better. They are effortless to drive, anyone will be able to operate the vehicle and no need to fight a big old fashioned mechanical clutch

Cons: They tend to be heavier and physically larger. They must be cooled in order to last. Some require electronics while others require vacuum and others require mechanical linkages to work properly.

An automatic transmission in this day and age is superior to a manual in most ways. But, manually shifting an automatic is not like shifting a manual in any sense of the word. There is one thing that the automatic cannot do better than a manual transmission and that is to be a manual transmission!

 

[Mesozoic]

LOL yes. But I have a 700 hp supercharged Mustang with a 5-speed behind it already. Besides, they make paddle shifter kits for the new autos now.

 

[droptop73]

A manual transmission is also a great theft deterrent!

 

[matrixx]

To each their own. Mine is just a toy and I like to drive my car, not ride in it.

Medical issues (ie.arthritis)and general old age can make driving an old manual car a workout.

I never had wonderful luck with my old automatics. I also think diagnosing mechanical issues is easier with a manual. Plus, one of the first things people look at on my car is that handshaker in the middle of the floor and just smile.

Sent from my SCH-S960L using Tapatalk

 

[Mesozoic]

To each their own. Mine is just a toy and I like to drive my car, not ride in it.

Medical issues (ie.arthritis)and general old age can make driving an old manual car a workout.

I never had wonderful luck with my old automatics. I also think diagnosing mechanical issues is easier with a manual. Plus, one of the first things people look at on my car is that handshaker in the middle of the floor and just smile.

Sent from my SCH-S960L using Tapatalk

Totally. I'm a real computer guy so my main focus is fiddling with the computer controls. I have a B&M Megashifter in place right now which makes ratchet shifting for racing nice and easy on the C6, should work well with a 4R70W.

As far as theft deterrent goes, that's just BS. Everyone I know knows how to drive a manual. My wife is from England and they don't even sell vehicles there with automatics. Most people in countries aside from the US do not know how to drive an automatic! In any case, I've got a switch with a setting that disables the EEC-V computer as well as a detachable Grant steering wheel... those are true deterrents!

 

[Tubo]

Totally. I'm a real computer guy so my main focus is fiddling with the computer controls. I have a B&M Megashifter in place right now which makes ratchet shifting for racing nice and easy on the C6, should work well with a 4R70W.

As far as theft deterrent goes, that's just BS. Everyone I know knows how to drive a manual. My wife is from England and they don't even sell vehicles there with automatics. Most people in countries aside from the US do not know how to drive an automatic! In any case, I've got a switch with a setting that disables the EEC-V computer as well as a detachable Grant steering wheel... those are true deterrents!

Mezzo as you know the EEC-V CPU has a 4R70W trans control built into it.

I use original Bauman TCS in our 73 and the newer Quick 1 in the 65 2+2, to control the 4R70W's in them.

The Quick 1 has a circuit for the paddle shifters.

I'm looking into adapting a Hyundai Genesis 5.0 cable shifter into the cars and use it's "select shift" to hold trans in a specific gear or use the shifter to up and down shift. Instead of paddles.

http://www.becontrols.com/

 

[Mesozoic]

Does anyone have an opinion on torque converter manufacturers for a 4R70W? I'm going to need a minimum 3000 RPM stall converter and of course, I want the PWM controlled lockup. Dirty Dog recommended that I use a 3500 RPM stall speed. I'm currently using a Hughes 3000 RPM stall unit in my C6 and it works really admirably, but the cost of these converters is astronomical!

There's quite a few options, just not sure what's going to be the most reliable at my power level. I definitely do NOT want to have to touch it once it's in place!

B&M Racing Holeshot 3000

TCI Super Streetfighter

Dirty Dog Performance

Hughes 3000 stall

Hughes 3500 stall

FTI billet 9.5" lockup

Found some more manufacturers that people on the Corral seem to like:

Edge Racing Converters

PTC converters

Ultimate Converter Concepts

 

[c9zx]

Given the torque number cited, why do you need a 3000-3500 stall convertor for street car with a 3.55 rear gear ratio? From the B&M site, "Stall speed listings are based on engines producing 230lb. ft. of torque at 2,500 rpm. More torque at 2,500 rpm will give you more stall speed, less torque at 2,500 rpm will give you less stall speed than the stall speed ratings indicated." If you drive a lot below the actual stall speed of the convertor (without a lock-up) you will be heating the fluid unnecessarily. High fluid temps kill automatic transmissions, 175 degrees being optimal. If you install the automatic transmission, consider the largest transmission cooler you can realistically fit as well as an extra capacity pan. You might want to contact this company for detailed information and convertor recommendations. http://www.broaderperformance.com

Just an opinion. Chuck

 

[Mesozoic]

Given the torque number cited, why do you need a 3000-3500 stall convertor for street car with a 3.55 rear gear ratio? From the B&M site, "Stall speed listings are based on engines producing 230lb. ft. of torque at 2,500 rpm. More torque at 2,500 rpm will give you more stall speed, less torque at 2,500 rpm will give you less stall speed than the stall speed ratings indicated." If you drive a lot below the actual stall speed of the convertor (without a lock-up) you will be heating the fluid unnecessarily. High fluid temps kill automatic transmissions, 175 degrees being optimal. If you install the automatic transmission, consider the largest transmission cooler you can realistically fit as well as an extra capacity pan. You might want to contact this company for detailed information and convertor recommendations. http://www.broaderperformance.com

Just an opinion. Chuck

The Hughes 3000 stall converter in front of my B&M Street/Strip C6 works very well on the street and cruising, minus the highway. My revs are at 3500 RPM on the highway though, it's pretty bad. I've added some serious cooling for my transmission using a stacked plate aluminum cooler in conjunction with a large aluminum radiator and twin computer controlled electric fans. I've also got a B&M 3 qt deep aluminum pan for the 4R70W. The cam doesn't produce peak torque until 4000 RPM and generates over 450 ft-lbs of torque at 2500 RPM.

Unfortunately, Broader Performance doesn't have a converter for a 4R70W. I'm basically at the point now where I need to commit to a torque converter and not sure which way to lean. The Hughes unit in the C6 has served me well... Dirty Dog Performance seems to be the best bang for the buck, though.

 

[Luke]

I would go with the TKO option or a Jericho but I am a fan of stick shifted cars

 

[Qcode351mach]

Agree with chuck..2400-2500 should be pretty close to where you want to be with the 4r70w...Heres a great reference for all the stock converters you could use http://www.tccoa.com/articles/tranny/transmission/page2.shtml

If you need a new one custom configured try these guys

http://converter.com/stallion.htm

 

[Mesozoic]

Just curious why everyone is suggesting such a low stall speed... I've called FTI, Hughes, TCI, B&M, and Dirty Dog and all of them have suggested a 10" converter with a stall speed between 3000 and 3500 RPM, and this is for a 4R70W.

 

[c9zx]

I can share my reasoning. The transmission has a .7:1 top gear ratio. With the 3.55:1 rear gear at 70 MPH with a 26 inch diameter rear tire the RPM would be 2,248 RPM. 27 inch tire = 2,165 RPM, 28 inch tire = 2,087 RPM. All way below the 3500 RPM stall speed. Because of the slip caused by being well below the stall speed, the fluid is heated excessively and energy transfer efficiency is reduced. From the Jeg's site: http://www.jegs.com/tech-articles/torque-converters.html Light throttle, low RPM responsiveness is also reduced when the RPMs are well below the stall speed. From your posts it seems you intend to use the car on the highway and your are concerned about fuel usage. Granted, when in overdrive and RPMs are at 2100, the engine will be making way less horsepower/torque than was used to determine the converter's stall speed. So the effective stall speed is reduced at 2100 RPM. I suppose that if the power, gear ratio, and tire diameters are a "match", the 3500 stall converter could work out OK. With converter prices being what they are, I wouldn't want to risk having to buy two. I would suggest contact a person that custom builds converters and discuss the pros and cons of various converter stall speeds. The people that answer the phones at companies like TCI and others are more salesmen than subject matter experts. They usually assume the car will be used for drag racing. I talked to two different people at TCI and got two different recommendations for stall speed separated by 500 RPM for the same car. I went with the lower one and I'm glad I did because the actual stall speed is about 200 RPM higher than the rated stall speed because the rated stall is based on an assumed power level and RPM. From Precision Industries site: "Is stall speed the only consideration in selecting a converter?

While stall speed is very important it is by no means the only consideration when selecting a converter. Torque multiplication at launch and high end efficiency are equally important. Stall speed can be attained in many ways that cripple the converter in other ways. Stall speed can be obtained at the expense of looseness at low speeds and loss of performance at higher speeds after launch. You want a converter that produces the right stall without sacrificing performance down the street or down the strip." All of the above is just an opinion based on my reasoning and personal experiences. In the end it is your car, your money, and your decision. I hope the swap goes well.

Chuck

 

[Don65Stang]

... but I want to cruise on the highway at reasonable engine speeds.

Just curious why everyone is suggesting such a low stall speed... I've called FTI, Hughes, TCI, B&M, and Dirty Dog and all of them have suggested a 10" converter with a stall speed between 3000 and 3500 RPM, and this is for a 4R70W.

Cruising at 70 mph you will be turning roughly 2,250 rpm (assuming 26" tall tires) with a 3.50 rear gear. At 80 mph your rpms would be around 2,500.

Personally I would go with a 2400 rpm stall and enjoy the ride.

 

[Don65Stang]

Ha! Chuck beat me hitting the enter key.

 

[Mister 4x4]

Don't know if this has been answered yet or not, but if the 4R70W is [dimensionally] around the same size as the AOD, then Hooker Competition or Hedman Headers should fit just fine.

 

[Mesozoic]

Guys, the 4R70W has a computer controlled (PWM) torque converter solenoid to control lockup duty cycle. I would expect it to go into lockout under low load cruise conditions, so I don't think that's an issue that should affect the converter stall speed selection.

Here's what Hughes Performance had to say about converter selection over email:

Thank you for submitting a tech card with Hughes Performance. I recommend installing torque converter part number 53-30L-DB. This is our Pro Series billet 10" lock-up torque converter, and will be custom built specifically for your combination. This converter should provide 3,000 - 3,200 RPM of flash stall speed with your combination, and is ideally suited for all street and track use. Features of this converter include the following:
Billet steel front cover

Billet steel lock-up piston with wide heavy duty clutch lining

Custom stator

Heavy duty sprag with heat treated races

Heat treated turbine spline

Heat treated pump hub

Roller bearings

Brazing of fins

Pressure tested

Computer dynamic balancing

Cost on this converter is $869.00. Build time

If you have any other questions or concerns, please feel free to contact me at any time. Thank you for your interest in Hughes Performance!

I responded with some more detail:

Thanks for the response. My power/torque curve looks like this:RPM HP Torque

2000 160 419

2500 214 449

3000 273 478

3500 344 515

4000 401 526

4500 455 530

5000 494 519

5500 518 494

6000 521 456

6500 506 409

I am currently using a Hughes 3000 RPM stall converter in front of a B&M Street/Strip C6 transmission. It has been a wonderful and reliable combination for many years, but I am now trying to set the car up for Pro Touring (17" wheels, large disc brakes, improved handling, etc.) and would like to be able to cruise on the highway at high speeds (potentially road race) as well as tool around on the street. I do not envision any track time aside from establishing some baseline numbers at some stage. The primary vision is for a superb handling car, capable of carving corners in the canyons and blistering top speed on straights.

Is the torque converter you suggested still relevant for my application after considering the above description?

To which I got another prompt response:

Thank you for the additional information. Based on this new info I feel that the 53-30L-DB torque converter is an outstanding choice for your combination, and will provide a very good blend between drivability, efficiency, and performance. I am confident you would be very pleased with the performance and driving characteristics of this converter.

 

[Totalled]

Yeah, but you make over 400 ft lbs at 2,000 rpm. It's not like it's a '73 Q code that has trouble getting out of its own way... It makes the torque to pull itself around with a lower stall. Which translates to higher in town fuel economy, when the converter won't be locked up.

 

[cazsper]

I have read that the T56 requires tunnel mods; even in the '71-'73's. I plan to put one in my '68 and '73 Mach-1. But the funds aren't available right now. However, for my '68 Coupe, I did swap the 302 and c4 for a 393w and the TKO-600 with the cable clutch setup. I purchased it as a kit from Modern Driveline. It came with the trans, bell housing, shifter and all the bracketry. For headers, I'm running Hedman mid length and my motor has a Canton 9qt. Road race oil pan. There is less room in the '68 than my '73 but it was still pretty straight forward. If you're interested, I can send some pictures of the finished product.

As for an automatic with an overdrive, have you considered a GearVendors unit?