Transmission question

[RedDragon777]

Seeing as more people are getting this turbo kit, i have a question for the ones running it on an auto.

What type of torque converter are you running and are you seeing any problems with 5R55S and the turbo kit? What do you recommend to upgrade first to keep up with the turbo as you move up in PSI?

i am starting to make a list of everything i need to make this a reliable car and i know the 5R55S is not made to handle huge numbers like the 6 speed on the new cars.

 

[JeremyH]

We have not had an auto car yet. About to have a 4r70 though. Seeing as the kit is geared for 600hp+ dont believe the 5r55 will fair too well based on its track record.

 

[TexasBlownV8]

I would not put this on a car with a 5r auto in it. As jeremy noted, they simply are not that strong. And, with higher torque being applied, it will have to be able to handle it.

So, first before anything, what are your goals for the car in terms of power? Is your engine forged or stock?

If you intend to stick with the 5r55s, you would be better off obtaining a less-potent setup, such as a single turbo or some other supercharger. Even so, the 5r will hold up only to so much power. And in stock form, there are a few things that should be upgraded before hand, such as the input shaft and the two servos. The 5r I had held up to 500 rwhp without any problems.

I'll be installing the twin kit with a 4r70w in the car, and we'll make sure everything fits.

 

[RedDragon777]

My plans are to go with a single kit, Boss 5.3L shortblock, and i was considering a Level 10 transmission rebuild. The rebuild kit would include, valve body, oil pump, new servos, clutches, bands, and a new input shaft. Would that be enough or should i be looking at just keeping it under 8psi. i would love to be around 600-700HP but in reality i would be fine with 500RWHP

 

[retfr8flyr]

A built 5R55 will handle 500 rwhp just fine but that's about it's limit. Before you put all that money into the 5r why not look at the other options that will give you room to grow? Believe me you say 500 will be fine you are kidding yourself, you will want more power very shortly. HP is addictive.

You can build a 4R70 to handle 1000 hp and, with an additional programmer, have it shift automatically just like your 5R. There is also the option of the GM 4L80E, which is basically a TH400 with an OD. Hughes Transmissions http://www.hughesperformance.com/index.php?option=com_content&view=article&id=61&Itemid=63 , as well as others, make a setup for the modular engine and you can also get an automatic controller for that trans. I wish I knew back when I built my 5R, what I know now. I would never have spent all the money on the 5R setup in the first place. I am running 600 rwhp with my street tune, so I know I am on borrowed time with my 5R.

Now is the time to make your decision because you have to get a new converter and build the 5R anyway, if you go that route. So the change to a different transmission type will not cast that much more. When, not if, my 5R fails, I am planning on going the 4L80E route myself.

 

[RedDragon777]

Thats what troubles me. With Bobby already pushing the single kit to 450+ RWHP on sub 8PSI it makes me wonder what i should do. I have been looking into many built 5R55S transmissions and most of them do not post any numbers as far as torque and HP. I think only one says it can go up to 800HP and Level 10 says you can run almost any set up and get away with it. But have any of them really punished a trans to the point of breaking or just done a couple of dyno runs at that HP and said its good?

 

[retfr8flyr]

TCI and Level 10 can claim what they want about power capability but the truth is the 5R's internal parts just don't have the physical size, no matter how you build it, to handle big power on a regular basis. Sure you can most likely get away with some dyno pulls and a few blasts on the street at high HP levels but there just isn't any way the trans will hold up, at high Hp levels, to the regular abuse all of us give the car.

It all depends on how much power you want to run. If you don't plan on big power, then go ahead and build the 5R and get a good Circle D converter. If you think you will go forged bottom end and bigger power in the future, then save yourself some money, in the long run and build a trans that will handle that power. There are several options out there for a trans that will handle big power. You just need to decide if you want a trans with OD and automatic shifting capability, or the manual shifting non OD versions. I have also heard that a company will soon be marketing a standalone computer setup for the new 6R trans. It's all up to you.

 

[RedDragon777]

If they make a computer for the 6R then i will wait for that. I do a lot of highway and some long distance drives and having the 5 speed is nice, a 6 speed would be even better. I really do not plan for more than 500-600 RWHP because i do not see myself needing any more than that.

 

[retfr8flyr]

In that case I would just build the 5R and put in a good converter like the Circle D. I have been running mine with that setup for several years at 600rwhp and the trans is holding up. I don't really abuse the car and only go the the track a few times a year, so I haven't had any problems with mine yet. The way you describe your driving ad desired power levels, I think you would be fine sticking with the 5R. The new 6R and the standalone computer, when it ever comes out, I am sure will be an expensive swap.

If you want a 6 speed you can always get this setup. http://www.tciauto.com/tc/6x-six-sp...-bolt-crank-bellhousing-outlawtm-shifterhtml/

 

[RedDragon777]

That is good to hear. I was looking into this set up earlier today, seems interesting but i do not know how it would hold up.

PATC 6 speed 4L80-E