Want to convert from T5 to auto transmission.

[G_Edmonds]

This has been my experience and your car at be totally different as they say. I used the oil cooler opening with a cooler right inside the hole. Bad idea. The problem with that is the tranny cooler won't get enough air flow at slow speeds when it really needs it, unless it's ducted better than mine was.
Keezling brought up a good point about the road course. I've tried running on a course in auto. This track had a high speed curve that my tranny wanted to up shift on. That's not a place that you want to break the rear tires loose.

[Tom Wells]

landmass,

Here's a picture of my shifter: the hat - Club Cobra Photo Gallery

The original 427s that Shelby put automatics in had this shifter - it's a contemporary Mustang unit from around '64-'66 I think - it has been a while. It does have the original appearance and is hooked to a C6, same as the originals. It is intended for a 3-speed auto and would work as is with a small block C6 or C4. Perhaps it could be used with an AOD but might need some tweaks?

As to cooling, I use mine on road courses and it is definitely needed there. Drag racing, I don't know - I would guess it depends on the number of runs you make and how soon after each one the next one happens. If you did one every 10-30 seconds like the road courses require, you'd definitely need a cooler. If there's a half hour or so between runs, probably a cooler isn't needed. After incinerating three transmissions I tend to think a cooler is necessary even for spirited street use. Most street vehicles come with some kind of cooler built into the radiator tank at the least. Owners add them if the vehicle is used for towing and doesn't come with a tow package. They are relatively cheap especially when compared with renewing the trans and converter.

As far as shifting, I put mine in D and go racing. It doesn't upset the car if it downshifts under power - something that seldom occurs. If I'm exiting a really slow corner, the downshift happens at part throttle so it doesn't try to break the rear tires loose. With lots of HP, one gets an education quickly about the meaning of the term "roll on the throttle." If you stomp it you'd need to take a compass reading first so you might have some idea where the snap spin is taking you...

The trans builder can probably take care of the downshift behavior. In drag racing, get a trans brake and see how far you can carry the front tires when you stomp it

As far as the upshift behavior is concerned, mine (and likely most others) behaves like a street car: The upshift speed can vary with throttle position, so if you accelerate gently it will upshift at low speeds. As you increase throttle and load, the upshifts move to higher speeds.

Some of the shift point behavior is adjustable with the "kickdown" lever and linkage found on the C4/C6 - the AOD can be adjusted too I think but I have forgotten how. Sorry. I dimly recall a TV (throttle valve) rod for the earlier all-mechanical version of the AOD - the caveat there was that if you adjusted it incorrectly you were likely privileged to buy another trans.

Whatever you decide, have fun with it!

Tom

[landmass]

Tom, thanks for the photo. It appears to be located in the same position as the T5 shifter. You have a very nice looking car. I'll check into a trans brake and I think I'll go with a cooling system on the front of my vehicle(where the oil cooler would fit). Also, I'll check into another radiator with a tranny fluid cooler incorporated into it. Thank you for the information. I'll be checking into all of this starting Monday morning.

[EarlsflyinCobra]

Very interesting.

[Tom Wells]

Earl,

Oh, no you don't!



Tom

[Tom Wells]

landmass,

Earl just (tangentially) reminded me of another relevant item: The length of the auto trans.

It needs to be no longer than the existing trans probably. I say probably for this reason: I have IRS so the driveshaft can be really short.

With a live axle as you and Earl have, it probably needs to be a little longer than mine or it may bind when the rear suspension deflects. If the auto is the same length as your present trans or shorter, there should be no problem.

The driveshaft may or may not need a slightly different front U-joint which should be readily taken care of.

Just another little thing to pay attention to before you commit to a swap!

Tom

[twin turbo]

With my AOD I can make 3 drag passes in a row with no break in between before my trans starts to get warm to where I would let it cool down, I'm using a separate cooler in front of my radiator. For a track day, I would need a larger trans cooler if I was being very aggressive. On the street, which is 99% of my driving, it never gets over 185 degrees. FYI, overdrive in an AOD is for mileage/cruising only and cannot handle a lot of torque. You have to push a button to allow it to activate, I rarely use it, but I have 2.73 rear gears.

I use a manual valve body which requires me to shift every gear, and that keeps it fun for me and allows more precise traction control. If I had drive mode and it kicked down coming out of a corner rolling into full throttle, it would not be pretty. Perhaps if I was normally aspirated, this wouldn't be as much of an issue.

I absolutely love running an auto trans and IMO it makes big power much more controllable, besides ease of drivability if you get stuck in traffic or are starting out on a steep hill. Cheers.

[cobrajeff]

You might not expect to find a built C4 automatic under this shifter.....



However, having a bum leg has forced me to have to have to convert a number of my cars (including my HiPo Mustang, BOSS 351, and ERA 289 FIA) to automatic trannys. I've had very good results with a C4 (I used a small-block C6 in the BOSS 351, and had an AOD built for my ERA that I never got around to installing).

I shift my C4 with a 289 Cobra shifter grafted to a standard C4 shifter....



The rusty looking part is where they are welded together (with the boot installed, it doesn't show). The original lockout mechanism is functional. I had the two shifters welded together with an angle to the left, so that when the shifter was in "Park" position, it would look like a 4-speed parked in "Reverse". I have no shift indicator, I shift it by feel only.

I believe your best bet is a built C4. The C6 small-block is big and heavy, and uses up a lot more horsepower to operate. The AOD or AODE is big (an inch longer than a C4 and a good bit bulkier), heavy, and may require the addition of electronic controls.

After experimenting with a number of different setups, I finally have my C4 shifting exactly like I wanted it to, which is the firmest, hardest, tire-screeching shift into each gear. Along the way, I tried a full-manual reverse-pattern valve-body, a fully automatic valve body, a semi-automatic valve body, and eventually the one I have now which is a forward-pattern full manual valve body. My preference leaned toward full manual due to the complications of plumbing vacuum lines to the Webers for the automatic shifts.

I bought my stall converter and full-manual control valve body from Broader Performance Broader Performance in Texas. Your desire is a bit different from mine, as you want to be able to shift automatically in Drive, and override manually when you want to. For that type of functionality, I have had very good luck with using shift kits from Trans-Go TransGo-Home Page. Their kit will allow full automatic operation with manual override whenever you want it. With that kit, you do not get automatic downshifts, as you eliminate the downshift control cable, which also prevents "surprise" downshifts in a corner.

I have run these C4s in open track and autocross events with good results. Maybe not quite as exciting as rowing the gears of Top-Loader, but, they will get the job done.

Jeff

[landmass]

Tom Wells, good point that I'll be checking on, thank you.
Twin Turbo, I've read where the AOD tranny is quite large, maybe reguiring enlargement/expansion of the tranny tunnel, also much heavier than the C4 or C6. Did you have any problems installing the AOD? Your manual valve body requires that you shift every gear? You mean if you put it in "D", it goes into(and stays in) 3rd gear-even at low speed? When racing, do you start in "1rst" then "slap" it into 2nd and 3rd when you want it to shift?
Cobrajeff, You have a very nice setup there, and gave me a ton of good information. Wish you had pics of the engine compartment in your profile....Thank you very much.

[cobrajeff]

Landmass -

Clicking the photo icon beneath my profile picture should take you to a bunch of pictures of my car, engine compartment, and build.



regards,

Jeff

[twin turbo]

Originally Posted by landmass

Twin Turbo, I've read where the AOD tranny is quite large, maybe reguiring enlargement/expansion of the tranny tunnel, also much heavier than the C4 or C6. Did you have any problems installing the AOD? Your manual valve body requires that you shift every gear? You mean if you put it in "D", it goes into(and stays in) 3rd gear-even at low speed? When racing, do you start in "1rst" then "slap" it into 2nd and 3rd when you want it to shift?

The AOD did not require any tunnel expansion on my car but I did have to grind down some tabs on the case itself. The AOD was the same length as my manual transmission so the installation was relatively straightforward on my FFR.

The AOD is quite a bit heavier than a C4, although I don't remember off hand the actual amount, probably 40 lbs or more. The C4 wasn't a good option for me due to my end torque and tall gearing (low numerically), they don't hold up well in turbo cars with this set-up, plus I wanted the OD option for high speed cruising. For a non-turbo car a built C4 is a great option, although a built C6 would be stronger, but heavier. If you don't want or need overdrive, no reason not to go with a C4 or C6.

Yes, I have to shift every gear with the full manual valve body. If I put it in drive, it's 3rd gear. The MVB is a lot of fun going thru the gears, I love it. Bonus is it really frees up room for your feet. Cheers.

[Harley753]

I also have an AOD - I had it built by Hughes Performance Transmissions and use lights on the dash to tell me what gear I am in

[landmass]

I have a 3.89 rear gear. In 4th gear at 80mph I'm at 4K on my tach, in 5th gear at 80mph I'm at 2800rpm on my tach, just at the beginning of my power curve and "smooth running". This being considered, do you guys think I need an AOD? Also, how to do correlate the gear ratios I have in 1rst, 2nd, 3rd and 4th, to a 3 speed automatic? How do I get the auto to run like the manual in terms of speed through the gears? Also, can I detune my auto tranny(can't go below 11secs) so it shifts at a lower rpm at the track, then change it back when I'm on the road? How does an MSD rev limiter affect shifting, since the rev limiter would be a logical way to reduce my track hp to stay above 11 seconds? Thank you.

[joyridin']

It sounds like you might be better off with an AODE trans from a 94 or later Ford. Same basic trans as the AOD, but it is electronically controlled. Then you can hook up one of these controllers and program it however you want. You can go auto shift or full manual and change the shift points to wherever you want.

MSD Atomic Transmission Control Modules 2760 - Free Shipping on Orders Over $99 at Summit Racing

[landmass]

joyridin' - I checked that out, and it sounds perfect. I'm going to talk to some transmission people tomorrow and ask them about that as well as other options. May pay a visit to cobrajeff(he's only 25 miles from me). We've been emailing each other and he is very knowledgeable about transmissions - I think he's had them all!

[Tom Wells]

landmass,

Let me know when you go - I'm about 1-1/2 hours from there. If I'm in town I'll come down for a look too!

Tom

[landmass]

Estimating going this week was optimistic on my part, as the work on my car is going slower than normal. I'm working on a possible clutch problem that I have to finish first, prior to working on the brakes. I've been working on it all day, and I am still at it. It could well be the following couple of weeks before I can go. Weather is predicted to be rainy for the rest of this week anyway.....I'll email Cobrajeff and let him know. You could email him, too. I'd like for the three of us to get together, especially with our cars.

[Tom Wells]

You have a PM

[Tom Wells]

Well, here's some thread creep - so sue me!

We had a great short cruise today, hosted by CobraJeff, including David, Carl and yrs truly; later Charles with his GT40. For a few photos, go here: Cruise to Edgewater FL Mon May 23, 2016 anyone? - FirstCoastCobraClub

Thanks, CobraJeff!