Need Info on auto cobras

[Zimmer0924]

Hello,
I'm new to the idea of putting an auto in my 03 cobra. From what I read I really like the idea of having a auto with a manual valve body, 3 or 4 spreed with overdrive, a trans brake, and maybe a lock up. I would like this all to be in a 4R70W trans so I don't have to mess around with mocking it up to my engine.
I really don't understand the idea of having "lock up" as an option when getting a built auto, what does this really do. Also how do you know which stall converter to go with. If some of you guys could please explain this and any other help full advise that would help.

Thanks to all.

 

[Chuckler3]

bump for wisdom

 

[Chuckler3]

ttt

 

[Chuckler3]

someone's gotta be trans smart...

 

[BADASS03SVT]

Hello,
I'm new to the idea of putting an auto in my 03 cobra. From what I read I really like the idea of having a auto with a manual valve body, 3 or 4 spreed with overdrive, a trans brake, and maybe a lock up. I would like this all to be in a 4R70W trans so I don't have to mess around with mocking it up to my engine.
I really don't understand the idea of having "lock up" as an option when getting a built auto, what does this really do. Also how do you know which stall converter to go with. If some of you guys could please explain this and any other help full advise that would help.

Thanks to all.

my first question would be...why? and whats the goals for the car?

going auto (the right way) is a big chunk o change.

first off...a 4r70w is a 3 speed with OD. if you dont want OD you go C4 or Th400.

trans brake....are you going to run slicks at the track? thats the only real way it will come in to any use

lock up....its for the street. saves some gas mileage...drops the rpms a little in OD...my car is faster locking the converter on the track too

converter....if/when you do this, talk to a few companies people recommend and pick one. they will set it all up for you but its usually set to your peak tq which on our cars with roots blowers is usually 3500ish.

 

[Zimmer0924]

lets say my goal is to get as close as possible to 800hp. Now this will be helped along with a 2.8H KB and a 50 or a 75 shot of the juice. With that much power I will be running slicks at the track. Now with a manual valve body from what I understand i will not be needing a computer controller (I hope).

 

[BADASS03SVT]

lets say my goal is to get as close as possible to 800hp. Now this will be helped along with a 2.8H KB and a 50 or a 75 shot of the juice. With that much power I will be running slicks at the track. Now with a manual valve body from what I understand i will not be needing a computer controller (I hope).

correct..no controller....you upshift and downshift and lock the converter

 

[Chuckler3]

Say your goals are closer to the 500hp mark.. Trans brake is for the fun of launching. just looking for more consistency. what kind of highway feel am i getting from one of these? my car would remain a DD, just wondering what kind of rpm i can expect at highway speeds..

hijacking threads for the good of slower cars

 

[BADASS03SVT]

Say your goals are closer to the 500hp mark.. Trans brake is for the fun of launching. just looking for more consistency. what kind of highway feel am i getting from one of these? my car would remain a DD, just wondering what kind of rpm i can expect at highway speeds..

hijacking threads for the good of slower cars

depends on the rear gear really. Id onyl suggest an auto for a low to medium hp car if you race alot/bracket race. your WILL lose gas mileage...you WILL lose top end run speeds....so if your worried about highway runs or gas mileage...I dont recommend it.

on my car....4.10s and stock size tires I see 2500 at 65mph in OD.

remember too guys..these trannies only go in 1, 2, and 3...Overdrive CANNOT handle any type of power...its a cruising gear only.

 

[Zimmer0924]

You should just change your user title to " All Knowing".

 

[Chuckler3]

is this just a matter of the ratios in the tranny? for rear gears i'd be looking at 3.73's or 4.10's this winter when i start in on it.

i'm all about the manual tranny and don't really like the feel of an auto. I'm exploring my options as far as trannys go right now because mine is well weathered having nearly 80k on the stock 5 speed. I heard about these trans that take away computer control completely, retain a "manual feel", while taking out the hassle of a clutch. that and i find the idea of using a trans brake in a street car, light to light to be amusing. are there any other options for me to consider? i'm not very savvy on the transmission side of things.

 

[shhak]

The RPM's when cruising depend on your rear gears and whether or not you've got a lockup converter. Mine had a 3500 stall. At 60 mph, with 3.55 gears I would turn about 3000 RPM's. Once I locked the converter, it'd drop to about 2200 or so.

With a manual valve body, the computer doesn't control anything. You shift every shift manually. (both up and down). The trans brakes are cool, but unless you're running slicks and heating them up, you won't be using it much on the street unless you just like blowing the tires off. I was making about 685rwhp with mine and at the track on 335 Hoosier slicks, if I'd leave on the trans brake at about 7# of boost, I'd just completely destroy the tires. The trans brake is only beneficial if you're at the track on slicks.

Look at some of the Lentech or PA 4R70W's. I've ran both and had good luck with them. They are pretty pricey though. Don't go into this thinking you're going to do the swap for $2500... I did alot of shopping and did all the work myself and still ended up with about $5500-$6000 in my setup.

 

[Chuckler3]

Alright.. that will be considered.

Are there any other options i should be considering when looking into other transmissions?

my fallback plan is to swap in a T-56. and 4.10's.

 

[Chuckler3]

The RPM's when cruising depend on your rear gears and whether or not you've got a lockup converter. Mine had a 3500 stall. At 60 mph, with 3.55 gears I would turn about 3000 RPM's. Once I locked the converter, it'd drop to about 2200 or so.

With a manual valve body, the computer doesn't control anything. You shift every shift manually. (both up and down). The trans brakes are cool, but unless you're running slicks and heating them up, you won't be using it much on the street unless you just like blowing the tires off. I was making about 685rwhp with mine and at the track on 335 Hoosier slicks, if I'd leave on the trans brake at about 7# of boost, I'd just completely destroy the tires. The trans brake is only beneficial if you're at the track on slicks.

Look at some of the Lentech or PA 4R70W's. I've ran both and had good luck with them. They are pretty pricey though. Don't go into this thinking you're going to do the swap for $2500... I did alot of shopping and did all the work myself and still ended up with about $5500-$6000 in my setup.

was yours an OD? or did you just have the 3 speed with lock up?

 

[JB]

my fallback plan is to swap in a T-56.

Don't you have an '03 Cobra?

 

[Chuckler3]

nope.. i hijacked that guys thread.. i've got a lowly 01 cobra...

 

[Zimmer0924]

I've got the real cobra. He's just a thread terrorist.

 

[Chuckler3]

i prefer the term pirate.. i boarded this thread and have claimed it as my own..

 

[Chuckler3]

bumping for more knowledge and suggestions.

 

[dragonlightning]