Auto Swapped Cobras TH400 vs 4R70W

[99 GT vert]

I need some input from those of you that have auto swapped cobras, what trans are you running, why did you choose that trans, and how do you like it? and what size stall do you have

I have people telling me to go TH400 and others telling me to go 4R70 and i seem to go back and forth on which one to go with on a daily basis,

Plans and use of the car, mixed city and highway driving only plan on 2-3k miles a year with the occasional drag strip visit once or twice a month during the summer, mods currently are upgraded pistons, mach 1 intake manifold and hp performance twin turbo kit


4R70 Pros: overdrive, built to mate to a ford motor, i already have a 4r tore apart in my garage ready to be built

4R70 Cons: Cost more to build, Heavier, Requires extra shields and covers to make sfi approved, not as strong,

Th400 Pros: Really easy to get parts, no extra gaurds or shields needed to be sfi approved with aftermarket bell housing and case, can be built for less to handle the same if not more power than the 4r, weighs less

TH400 cons: Only a 3 speed, going to take a little more work to make it fit in the car,

 

[99 GT vert]

wow i would have figured with as many auto swapped cobras someone would have some input on this

 

[fs308]

just to add more to this what about a c4 or maybe a power glide?

 

[gt347mustang]

I would advise against the glide being a street car.

I too have a 4r sitting in my garage waiting to be built. I didn't know the th400 weighed less than the 4r.

Looking to hear from people running autos.

 

[GhostRiderblk]

mvb 3500 stall and 4r70w held good but id only recommend to about 650hp... depends how much power you want to throw

 

[AntiHeightPunk]

i have a th400 in my car....had a 4r70w and knew i was going to blow that 4r70 up at some point so i sold it while it was in one piece
i have 3:27 gears and a 28 inch tall tire and it works fine on the interstate

 

[Juiced46]

The no OD is not a big deal at all. Its not like you are driving it to work 15 miles each way on the highway at an 80mph cruising speed everyday.

I had a TH400 and loved it. 3800 stall on a turbo car. Drove the thing everywhere with alot of highway driving. With the correct gear choice and tire size having no OD is a non issue. 75mph was a tick under 3000 RPMs. My 6 speed 2013 BMW 535 cruises @ 80mph @ over 3000 rpms so who cares? lol

There is nothing really special about making the TH400 fit into the car aside from drilling 2 holes into the factory transmission mount and a custom driveshaft. That is it.

The TH400 will hold ALOT more power, pretty much bullet proof and very very reliable.

TH400 all the way IMO

 

[99 GT vert]

i have a th400 in my car....had a 4r70w and knew i was going to blow that 4r70 up at some point so i sold it while it was in one piece
i have 3:27 gears and a 28 inch tall tire and it works fine on the interstate

this is the exact gear and tire combo I am planning on going with what is your rpm range at 70 mph? the goal with the car is 7-800 rwhp once I get the motor a little stronger

 

[99 GT vert]

just to add more to this what about a c4 or maybe a power glide?

thought about the c4/c6 just havent looked into it enough yet

mvb 3500 stall and 4r70w held good but id only recommend to about 650hp... depends how much power you want to throw

that is my worry the over all goal is 7-800 rwhp on the current turbo set up and maybe more in the future if i go with bigger turbos

The no OD is not a big deal at all. Its not like you are driving it to work 15 miles each way on the highway at an 80mph cruising speed everyday.

I had a TH400 and loved it. 3800 stall on a turbo car. Drove the thing everywhere with alot of highway driving. With the correct gear choice and tire size having no OD is a non issue. 75mph was a tick under 3000 RPMs. My 6 speed 2013 BMW 535 cruises @ 80mph @ over 3000 rpms so who cares? lol

There is nothing really special about making the TH400 fit into the car aside from drilling 2 holes into the factory transmission mount and a custom driveshaft. That is it.

The TH400 will hold ALOT more power, pretty much bullet proof and very very reliable.

TH400 all the way IMO

what kind of gear ratio did you run in your setup? did you ever see any heat issues when you would drive in on the highway for a longer period of time?

 

[AntiHeightPunk]

he ran the same as me 3.27 and 28 inch tall tire (i based my trans/gear/tire setup off his car)

 

[Wicked46]

Built 4R70W here... Love the trans with the MVB and its a blast to drive. OD is awesome to have when street driving. Can't go wrong with either transmissions so it's really up to you. I chose the 4R because it literally bolted right up. No modification at all.

 

[AntiHeightPunk]

but how much power will a 4r70w really hold thats the question

 

[Wicked46]

My Lentech “Strip Terminator” 4R70W is rated for 1500HP. Honestly, I think that’s a spoof and I certainly wouldn’t push it quite that hard (not that I’d EVER see that kind of power anyway).

I've been at the 650HP range for a while now and the trans has performed flawlessly. I’m in the middle of an engine build so my power level will be up and I’m still confident that the 4R will hold it.

 

[AntiHeightPunk]

no way it holds 1500hp
is it warrantied for 1500 is the real question....

 

[crfrider16]

The no OD is not a big deal at all. Its not like you are driving it to work 15 miles each way on the highway at an 80mph cruising speed everyday.

I had a TH400 and loved it. 3800 stall on a turbo car. Drove the thing everywhere with alot of highway driving. With the correct gear choice and tire size having no OD is a non issue. 75mph was a tick under 3000 RPMs. My 6 speed 2013 BMW 535 cruises @ 80mph @ over 3000 rpms so who cares? lol

There is nothing really special about making the TH400 fit into the car aside from drilling 2 holes into the factory transmission mount and a custom driveshaft. That is it.

The TH400 will hold ALOT more power, pretty much bullet proof and very very reliable.

TH400 all the way IMO

Dave, I may have to respectfully disagree. With the TH400, I felt it was screaming at highway speeds. At least in my opinion. Now granted, if you were on a flat road, you were around 3K at 70ish. But I was never even comfortable with that. Also, I think one thing you have to consider is that if you hit even a small incline in the road, the RPM's go up a lot if you try to maintain your speed. All the sudden, your 3K just jumped to 3,800 just to maintain 70 MPH.

I never really even considered hitting the turnpike or parkway and just cruising somewhere at 80 with the TH. Now I have a Fred Brown 4R70W. To me, the car is a different car. SO MUCH more fun to drive. I can hit a big highway, click into O/D, lock it up, and I'm cruising at 2,000 RPM, watching the trans temp gauge go DOWN.

OP, for me, O/D was a necessity. You just need to decide how important it is to you. As an experiment, go hit a highway and keep your car in 4th gear. Also keep in mind that even with that, your trans is locked up. Consider that as you drive with TH400, RPM's will go even higher than that as you hit inclines.

I'm not knocking the TH400. It's a stout trans. I just know that for me, going from that to a 4R opened up a world of cruising possibilities.

 

[Wicked46]

no way it holds 1500hp
is it warrantied for 1500 is the real question....

Trust me, I wouldnt debate that argument one bit LOL. Who knows what its warrantied to but i've been hard on this thing since i've owned it. Before me, it was in a turbo cobra making more power then my car. It's held up great and its been flawless! :burnout:

 

[badcobra]

I've debated this auto thing a lot in my mind. Would love to have a 4l80, but don't have gazillions of dollars to do it. I just decided im going to do a th400 and a couple years down the road put a gear vendors OD on it because it's still a 100% street car. The 4r is not reliable enough for my tastes, especially because I plan to turn my shit up to 33lbs after I finish the fuel system. Looking for a good th400 core right now.......

 

[Juiced46]

what kind of gear ratio did you run in your setup? did you ever see any heat issues when you would drive in on the highway for a longer period of time?

3.31s with 28" DRs on the street. Never once had a heat issue on the street. The converter size, cooler, and fluid type is key to keeping heat down.

Dave, I may have to respectfully disagree. With the TH400, I felt it was screaming at highway speeds. At least in my opinion. Now granted, if you were on a flat road, you were around 3K at 70ish. But I was never even comfortable with that. Also, I think one thing you have to consider is that if you hit even a small incline in the road, the RPM's go up a lot if you try to maintain your speed. All the sudden, your 3K just jumped to 3,800 just to maintain 70 MPH.

I never really even considered hitting the turnpike or parkway and just cruising somewhere at 80 with the TH. Now I have a Fred Brown 4R70W. To me, the car is a different car. SO MUCH more fun to drive. I can hit a big highway, click into O/D, lock it up, and I'm cruising at 2,000 RPM, watching the trans temp gauge go DOWN.

Jim that is very strange. I can honestly say I NEVER saw RPMS like that cruising on the highway. @ 75mph-80mph it was always just below or above 3000(3200 max @ 80ish). If it was at 3800 on steady throttle @ 80mph I would say HELL NO and agree with you totally lol. I am trying to think why it would do that for you. Did you ever change the trans fluid after I sold you the car? I was running the Hyguard fluid in there which tightened things up. If you switch to just a straight ATF I think it would cause the RPMS to be much higher the highway. But I never saw RPMs that high while cruising.

Was that with the same 28" M&H tires as well?

 

[crfrider16]

Yeah Dave, it was the same driveline setup. Like I said, the big thing is inclines. You have to get into the pedal a little bit, and rpms will definitely rise. It's just so much funner for me with o/d. But there's no doubt that a 4r is more expensive to build. Definitely pros and cons to each.

I gotta take you for a ride one day!

 

[GhostRiderblk]

thought about the c4/c6 just havent looked into it enough yet




that is my worry the over all goal is 7-800 rwhp on the current turbo set up and maybe more in the future if i go with bigger turbos



what kind of gear ratio did you run in your setup? did you ever see any heat issues when you would drive in on the highway for a longer period of time?

from experience and 830hp through the auto. its hard to make it last. the 4l80 would be a great maybe the best trans to run on the street as its basically a th400 with overdrive so you get both of best worlds. i never ran o/d on the 4r70 just so i wouldn't fry the bands if i nailed it and forgot wasnt bad around town on high way i just stayed in the slow lane lol but the th400 is a heavyer trans and puts more load on your motor there is plenty to factor do you research pricing and dont be manipulated by trans builders be open minded on both setups write a pro and con list will help greatly. good luck! ill sell you my 4r70 if you want it