High Horsepower 4R70W

As some of you may know, I'm going to be building a new engine, and intend to make at least 550 - 600 rwhp and similar torque. What can be done to the 4R70W to make it withstand this amount of power on a daily basis?

Also, is there any way to make it "safe" to shift between 1-2-D or D-2-1 without slippage?

Is there any way to strengthen the trans to survive full throttle 3-4 shifts with that much power?

If there isn't a way, I might put a T56 in there.

Thanks!
 
I just put a performance valve body in and it shifts extremely fast now and does not slip at all. I also went with a 3200 none locking stall converter. I wish I did both mods as my first mod. They are amazing and the car is so much more fun to drive now. I also have a big transmission cooler. I think if you do the valve body and transmission cooler you will be good. I would wait on the stall converter until you have all the power mods done then call Lenny at ultimate converter to build one for your tq curve. I bought the valve body from Complete 4R70W Valve Body Kit
 
Flghtmstr1:

I suggest that you read "Transmissions 101" at TCCoA.com in their Tech Articles/Transmissions section. There are several sections in T-101 that describe how to bulletproof your 4R70W. The author is Jerry Wroblewski, former Ford Transmission Engineer. Yes, the same fellow who gave us the J-mod.

HTH,

Chris
 
Blackone, thanks for the link. It looks like that place will do / provide whatever I need.

Scupking, I already have a trans cooler, and I don't think a performance valve body would be sufficient for the amount of power I'll be making. It would be a good start as part of a general trans overhaul, though.

It looks like there are plenty of options for hardening my transmission, which is good. But nobody answered my question about the shift into overdrive. Does anybody know if that 2" carbon fiber O/D band would be capable of surviving?

Thanks for your help.

EDIT: nyuk, thank you for that link. I remember visiting that page years ago and perusing the J-Mod section, but for some reason I never bothered to read the rest. I am glad you prodded me to do so. It sounds like I'll actually enjoy this build, too. I'm looking forward to it.
 
... Does anybody know if that 2" carbon fiber O/D band would be capable of surviving?

Flghtmstr1:

You're welcome. The J-mod was one of the best mods I have done to the car.

I don't know about the band. It is stronger than stock but it might be more slippery (ironic, isn't it?). So, I would call Darrin at bc-automotive.com and ask him since he knows his way around these transmissions like few others do.

Chris
 
Chris,

I've heard about how aftermarket Kevlar OD bands are ill-advised in a street car due to the aforementioned slipperiness issue. I'm not sure whether the "carbon fiber" bands being sold are different from the Kevlar ones or if they are the same thing and the issue is being conflated by marketing terms (like "graphite" golf clubs).

I'll call that Darrin guy, and post back with what he says. I think this is an issue that should have much more information available than there is. What good is a transmission if you're not allowed to use all of the speeds?

Dave
 
With that amount of horsepower, you do NOT want to shift into or out of OD during WOT. If you are in OD and want to romp on it, flip the switch. If you are romping on it and are reaching the OD shift threshold, make sure you turn it off!

As for upgrades to the tranny...usually an extra friction in the direct drive assembly, a explorer wave ring for the intermediate, a spiral snap ring for the reverse (the stocker has a tendency to fling off at high rpms and hp) and some one piece teflon rings in place of the scarf cut unit's where applicable will allow you to handle the power. The kevlar OD band will simply be more forgiving if you get on it in OD. It will slip more, but will take more abuse before smoking.

Take a peak over at Click Click Racing - Click Click Racing for a TON of more info.
 
With that amount of horsepower, you do NOT want to shift into or out of OD during WOT. If you are in OD and want to romp on it, flip the switch. If you are romping on it and are reaching the OD shift threshold, make sure you turn it off!

As for upgrades to the tranny...usually an extra friction in the direct drive assembly, a explorer wave ring for the intermediate, a spiral snap ring for the reverse (the stocker has a tendency to fling off at high rpms and hp) and some one piece teflon rings in place of the scarf cut unit's where applicable will allow you to handle the power. The kevlar OD band will simply be more forgiving if you get on it in OD. It will slip more, but will take more abuse before smoking.

Take a peak over at Click Click Racing - Click Click Racing for a TON of more info.

So what you're saying is that basically, 4th gear is useless for anything other than putting around, and that the effective top speed of my (soon-to-be) 500+ rwhp car is about 122 mph (6000 rpm in 3rd)?

If so, maybe I'll just put a T56 in there, or sell the car and buy something else, because that's ridiculous.
 
So what you're saying is that basically, 4th gear is useless for anything other than putting around, and that the effective top speed of my (soon-to-be) 500+ rwhp car is about 122 mph (6000 rpm in 3rd)?

If so, maybe I'll just put a T56 in there, or sell the car and buy something else, because that's ridiculous.

check out some of the King of the Streets guys many run auto and trap well over 122mph
 
So what you're saying is that basically, 4th gear is useless for anything other than putting around, and that the effective top speed of my (soon-to-be) 500+ rwhp car is about 122 mph (6000 rpm in 3rd)?

If so, maybe I'll just put a T56 in there, or sell the car and buy something else, because that's ridiculous.

3rd gear is the same as a 5 speeds 4th (1:1 ratio). If you plan on making 500rwhp and still have a 6k rpm cap you need to drop your rear end ratio down to some 3.27's. Your top speed will end up being close to 140mph in 3rd which is more than enough when you'll likely be trapping less than 130mph in the 1/4.

FYI, the only thing a T-56 is going to give you gear wise is 2 extra OD's. 5th and 6th are still going to be the weakest gear-set.
 
I ran the 4r70w in my Terminator making around 560rwhp with a 2.2 KB on low boost....seemed to handle the power just fine, but it was built by PA Racing transmissions...lol...the only issues I really had were with converter slippage on the street, and I was running a P.I. setup which was supposedly top-of-the-line...just my .02
 
3rd gear is the same as a 5 speeds 4th (1:1 ratio). If you plan on making 500rwhp and still have a 6k rpm cap you need to drop your rear end ratio down to some 3.27's. Your top speed will end up being close to 140mph in 3rd which is more than enough when you'll likely be trapping less than 130mph in the 1/4.

FYI, the only thing a T-56 is going to give you gear wise is 2 extra OD's. 5th and 6th are still going to be the weakest gear-set.

I'm aware of the fact that 1:1 is 1:1 is 1:1. But in a manual trans, even if you don't want to hammer it through the 4-5 or 5-6 shift, you can still let off, ease it into gear, then get back on it. And there are plenty of fast Terminators, Vipers, Camaros, and Firebirds who can use 5th and 6th at WOT. The fastest 6-speed car in the world was at one point a Viper with its T56, and he used all six gears in his quarter mile runs.

I ran the 4r70w in my Terminator making around 560rwhp with a 2.2 KB on low boost....seemed to handle the power just fine, but it was built by PA Racing transmissions...lol...the only issues I really had were with converter slippage on the street, and I was running a P.I. setup which was supposedly top-of-the-line...just my .02

Did you ever do any WOT 3-4 shifts?
 
I'm aware of the fact that 1:1 is 1:1 is 1:1. But in a manual trans, even if you don't want to hammer it through the 4-5 or 5-6 shift, you can still let off, ease it into gear, then get back on it. And there are plenty of fast Terminators, Vipers, Camaros, and Firebirds who can use 5th and 6th at WOT. The fastest 6-speed car in the world was at one point a Viper with its T56, and he used all six gears in his quarter mile runs.



Did you ever do any WOT 3-4 shifts?

Unless you plan on going over 140mph on public roads, a set of 3.27 gears will do you fine. If you want ANY OD transmission capable of handling 500+rwhp WHILE in OD (or shifting into or out of), be prepared to shell out some coin. Keep in mind, most people running auto 1/4 mile cars don't even run an OD. If you want to have some fun, turn off OD...it's really that simple.

As for "easing" into gear...that isn't always the case. I "eased" into 3rd in my stock t-5 and blew out 3rd.
 
Unless you plan on going over 140mph on public roads, a set of 3.27 gears will do you fine. If you want ANY OD transmission capable of handling 500+rwhp WHILE in OD (or shifting into or out of), be prepared to shell out some coin. Keep in mind, most people running auto 1/4 mile cars don't even run an OD. If you want to have some fun, turn off OD...it's really that simple.

As for "easing" into gear...that isn't always the case. I "eased" into 3rd in my stock t-5 and blew out 3rd.

I have no desire to drive 140 mph on public roads.

However, I would like to be able to take my car to a track (road course) some day, seeing as its set up for being fun in the twisties as well as in a straight line. I'm pretty sure I would be hampered in any attempts to run a good time if I were limited to 122 mph (or even 140 mph).

I do want a trans capable of doing what you described, which is why I'm asking. I never said that money was an issue. I just want to know if it's doable, and if so, how.

This is also why I asked if it is possible to make the trans safe to shift manually through the gears (without getting a manual valve body), which nobody answered. An auto would be no fun on a road course if I had to just leave it in 'D'.
 
I have no desire to drive 140 mph on public roads.

However, I would like to be able to take my car to a track (road course) some day, seeing as its set up for being fun in the twisties as well as in a straight line. I'm pretty sure I would be hampered in any attempts to run a good time if I were limited to 122 mph (or even 140 mph).

I do want a trans capable of doing what you described, which is why I'm asking. I never said that money was an issue. I just want to know if it's doable, and if so, how.

This is also why I asked if it is possible to make the trans safe to shift manually through the gears (without getting a manual valve body), which nobody answered. An auto would be no fun on a road course if I had to just leave it in 'D'.

I don't know what to tell ya, an OD is an OD and not meant for all out WOT. This is the same case in an auto as it is with most any manual transmission. If you want to go faster than 140mph either up your cam and head combo to allow more RPM or drop the rear end gear ratio to allow more speed.

As for shifting, the electronic delay with an auto valve body is going to be a bitch to compensate for. The best you'll be able to do would be to pick up a baumannator TCS and hook up either your cruise control or some other button you choose and have a electronic sequential shift. While it may not be perfect, it still would be better than manually shifting with the lever which pushes a cable which then pushes a lever which finally sends the signal to shift.
 
Read everything, millhouse hasn't said anything I disagree with.

A few things I'd add:

Even with a tougher OD band, you're not going to solve the problem. That just means the input shaft gets turned into licorice instead of the band snapping. Like millhouse said, OD is for overdriving - not for accelerating.

As for gear command being safe and reliable w/out a manual valve body that's what I've attempted with my built 4R (built for 550) and come as close as I see worthwhile. You need to get creative with Jmod and valvebody kit selection. You can't avoid a aftermarket valve body kit because you'll have the problem of compromising clutch pack overlap in stock form. Line pressure's not going to be adequate on command.

As for lockup, I don't know why you'd choose to put a non locking converter in a road driven car in the 4R. There's no real downside to it specifically for the 4R and it's designed to use lock-up, so why not. If you're looking at a 3200 non locking, get a 3600 locking.

I forgot other points I was going to make. Just pm me if you have more q's as im rarely on here. Or just take my trans off my hands, lol. It's sitting on my garage floor.
 
Just curious if anyone here knows how much power a remanufactured 4r70w transmission can handle with slightly above stock components? I have an 02 with the same 4r70w transmission. I had to replace mine a year ago and got a remanufactured one instead of rebuilding after reading this article on rebuilt vs remanufactured https://5fa06d83b9d6f.site123.me/blog/4r70w-transmission. I contacted the company I got the transmission from about how much power it could handle and they gave me the run around... The reman trans only has 16k miles on it now