Launching an auto?
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never use overdrive if your racing, the weak overdrive band cant handle even stock horsepower. IF THE auto is stock the best way to launch it is to probably leave it in drive, press the break and bring up the R's right till before the tires break loose, then when you wan to go, floor and release break at the same time. Or you could just simply leave it in drive and floor it when you want to go, which would flash the converter. but since you probably have a stock converter it wont benifit you much.
Ya I'd like to save my transmission its already been rebuilt once... Drive is quicker than overdrive right? Cuz I'm almost always in overdrive to save gas so I don't really compare the 2 much...
When I still had OD in my 93 I used it on the highways only. Around town I would just leave it in D.
The big prob with the AOD is that the OD band is really too narrow. I believe that it is 1.5" and the AOD in the mustang has the "B" servo. The servo is what hold clampin force on the band so it doesn't slip. There are a few things that can be done with the trans still in the car. You can install a shift kit which is pretty straight forward but messy. You have to pull the pan and drop the valve body. If you plan on putting a shift kit in it then I would also install either and "A" or "A+" servo. They have more clamping force and will help your AOD last longer under some abuse.
If you want some really good tech and advice on the AOD check out www.clickclickracing.com. They have a section on auto transmissions over there with some GREAT tech in there.
The big prob with the AOD is that the OD band is really too narrow. I believe that it is 1.5" and the AOD in the mustang has the "B" servo. The servo is what hold clampin force on the band so it doesn't slip. There are a few things that can be done with the trans still in the car. You can install a shift kit which is pretty straight forward but messy. You have to pull the pan and drop the valve body. If you plan on putting a shift kit in it then I would also install either and "A" or "A+" servo. They have more clamping force and will help your AOD last longer under some abuse.
If you want some really good tech and advice on the AOD check out www.clickclickracing.com. They have a section on auto transmissions over there with some GREAT tech in there.
I run a transgo shift kit in my car and love it. With the stock converter i always had the best results launching at 1000 rpm's. Always in drive at the track and around town. If you dont already have an external tranny cooler i would highly recommend it.
ninety15.0
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Ok we need to get a few things straight here. First off, the only difference between D and OD is the one more gear...OVERDRIVE! Besides the different shifter position, the car will drive/shift no differently in D or OD, except that it will have one additional gear (4th gear AKA overdrive) Overdrive is not part of the planetary gearset in the trans, its a 1.5" composite belt/band clamped/controlled by a servo, and a weak one at that!
If you leave the car in OD and launch it, you will still be launching in 1st gear!!!!!!! The same is true for launching in D. The tranny will HAVE TO run up through 1st, 2nd, 3rd gears before it even thinks about shifting into overdrive! This speed is generally around 110mph with stock gears...maybe higher?
You can go to the track and leave the car in OD and launch the hell out of it and run it all the way down the 1/4 mile in "OD" This does not mean the tranny will actually get into overdrive...it most likely wont with a stockish car and stock rear gears.
Roll racing is a different story. If the TV cable is properly adjusted and the trans is in good operating condition....then when you floor it from a highway roll it will immediately kick out of OD down into 2nd or 3rd gear depending on your speed. However, i would not risk heating up that OD band...and if i were roll racing i would toss it in D just before you hit it. This will put the trans it at least 3rd gear and when you punch it you will either drop into 2nd or stay in 3rd depending on speed.
Do not do the 1-d-1 shuffle to hold second gear...dont really mess with the shifter much at all. get in the car, put it in OD and PAY ATTENTION. It should become pretty apparent what gear you are in by the speed you are going and the revs you are turning. Dont beat on that OD band...everything else will take care of itself. If you want to shift gears...get a stick car!
If you leave the car in OD and launch it, you will still be launching in 1st gear!!!!!!! The same is true for launching in D. The tranny will HAVE TO run up through 1st, 2nd, 3rd gears before it even thinks about shifting into overdrive! This speed is generally around 110mph with stock gears...maybe higher?
You can go to the track and leave the car in OD and launch the hell out of it and run it all the way down the 1/4 mile in "OD" This does not mean the tranny will actually get into overdrive...it most likely wont with a stockish car and stock rear gears.
Roll racing is a different story. If the TV cable is properly adjusted and the trans is in good operating condition....then when you floor it from a highway roll it will immediately kick out of OD down into 2nd or 3rd gear depending on your speed. However, i would not risk heating up that OD band...and if i were roll racing i would toss it in D just before you hit it. This will put the trans it at least 3rd gear and when you punch it you will either drop into 2nd or stay in 3rd depending on speed.
Do not do the 1-d-1 shuffle to hold second gear...dont really mess with the shifter much at all. get in the car, put it in OD and PAY ATTENTION. It should become pretty apparent what gear you are in by the speed you are going and the revs you are turning. Dont beat on that OD band...everything else will take care of itself. If you want to shift gears...get a stick car!
Another quick question what does a stock geared aod run at at 55 mph(rpms please) in drive not overdrive.
Thanks for clearing that up ninety15.0. Now that you mention the OD bands being weak and 3rd topping out around 110. I'm shooting for low to mid twelves and I'm sure I'll be trapping a little quicker than 110 so I'm gonna need the extra gear. What would be the best solution for where I'm headed? Better OD bands if they make those? I'd like to do it with just the factory AOD and maybe some better parts for it internally. But the way its lookin a Lentech tranny might be my only option.
rd
Founding Member
Not sure I follow all of this...
An AOD works the same in D and OD, except that it won't shift to 4th or od in the D position.
Overdrive is in fact done by a planetary gearset, the od band closes via actuation of the od servo and stops and holds the od drum or outer ring gear from turning, forcing the planet carrier to turn faster than the sun gear, and driving the output faster.
Yep, the od band is probably on the narrow side for the amount of load it sees.
An AOD works the same in D and OD, except that it won't shift to 4th or od in the D position.
Overdrive is in fact done by a planetary gearset, the od band closes via actuation of the od servo and stops and holds the od drum or outer ring gear from turning, forcing the planet carrier to turn faster than the sun gear, and driving the output faster.
Yep, the od band is probably on the narrow side for the amount of load it sees.
There is no option of shifting into overdrrive no matter what transmission you have.
JGT
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ninety15.0
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25thmustang
Mustang Master
Why would you want to shift into OD in the 1/4 mile??? In the 1:1 gear (the 4th gear of a T5, the 3rd gear of an AOD) is where you want to finish the 1/4. If your going into OD your not running the right motor/tire/gear set up and should change it immediately.
Maybe I was misunderstood. What I meant is the top of my 3rd gear gonna be enough to get low to mid twelves in the quarter. I was under the impression that 3rd tops out around 110 in the AOD and my only choice to would be to run in OD to carry on down the track so I don't run out of gear. I haven't been to the track in a while but it seemed most cars running low 13's already trap around 105-110 which is why I was worried about runnin out of gear in 3rd to meet my goal. I didn't mean to switch into OD while running the car down the track either, but to start out in OD. Its still gonna be a while before I get there I still got a few more suspension things I wanna do, then move on to transmission and rear end. I'm just plannin ahead on my best route for the tranny right now.
25thmustang
Mustang Master
How fast a car goes in a certain gear is determined by the tire height, gear ratio, how high the motor revs, and even the weight of the car...
A low 12 second car will rev higher and have the right gear to run the mph needed at the right RPM in the 1:1 gear. Our low 12 second car traps 110 (T5 but the same 1:1 gear as an AOD) and still has TONS of RPM to play with. This is with a 3.55 gear and a 26x9 slick.
A low 12 second car will rev higher and have the right gear to run the mph needed at the right RPM in the 1:1 gear. Our low 12 second car traps 110 (T5 but the same 1:1 gear as an AOD) and still has TONS of RPM to play with. This is with a 3.55 gear and a 26x9 slick.
Yea I'm tryin to do this without the use of slicks. I know gears and tire height all play a roll. As far as that setup goes I was thinkin runnin a 3.73 gear already got my rims and tires which are 17x9 03 cobras with 245x45x17 tires. I'm not sure how high my motors gonna rev to meet its peak power yet. I intend on staying with the 302 maybe make it a 306 upon rebuild which I hear doesn't do much but I figure what the hell everyone else does it. I don't want anything to bizarre of a setup I'm shootin for simplicity and still easy to work under the hood so no forced induction or juice for me.
25thmustang
Mustang Master
Low 12s on a street tires 302 or 306 with no power adder, your going to be revving that car pretty high, so you shouldn't have to worry much about running out of gear, or going into OD.
