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4bt bowtie
09-12-2011, 04:30 AM
I am planning to put a 4bt in to my 1990 Chevy s10 4WD. I am looking to get roughly 350- 400hp out of the engine which, as a general rule of thumb, should land me in the 700-800 ftlb of torque range. I plan on doing an SFA swap in the truck and I am thinking of using a T-56 transmisson coupled to a divorced NP208 t-case.

My reasons for using a T-56 are thus:

-better gear ratios than an NV5600 and G-56

- The extra overdrive will allow me to run a lower spool (thinking 4.11:1 with a 33 or 35 inch tire)and still run highway speeds at a near perfect 1700 rpm.

-considered using a ZF-6 but from what I've seen the parts are considerably more expensive and the T-56 would shift faster which would be nice at the drag strip.

-I know a stock T-56 will come apart very quickly behind that kind of power but I have seen a few rebuild kits for around $1400.00 that claim to put the torque rating over 600 ftlbs. I have seen used T-56's go for around $400 so in total I would be in roughly $2500 by the time the plumbing and installation is all said and done.

Any opinions and info on this would be greatly appreciated. If anyone has any better ideas I would love to hear them. :thankyou2:

pinky49
09-12-2011, 08:27 AM
they break pretty easily behind a LS2 gasser at about half the torque. they seem pretty light duty to put behind a diesel in my opinion.
ed

LReiff
09-12-2011, 08:33 AM
The easiest and simplest would be an NV4500.

SHughes
09-12-2011, 08:53 AM
I think there is a reason they didn't put the T-56 in trucks...just sayin.

4bt bowtie
09-12-2011, 06:28 PM
How do the ZF transmissions compare to the NV4500 as far as longevity? I have heard people swear by the ZF 5 speed but I know the NV4500 is cheap and easy to find.

jaybuller
09-12-2011, 06:51 PM
just for your info on the 1700 cruising rpm.... id recomend running the 4bt at wround 1800 to 1900 if you plan on running 70 or so crusing sped a lot. 1700 the 4bt dosnt pull to well and the rattle will tear up those little overdrive gears. At least my 4bt did. It got better mpg and felt smoother and ran better at 1900 than it did at 1650(where my cruising rpm used to be.)

in my hounest opinion the 6bt does great cruising at 1500 to 1700 but the 4bt does not.

4bt bowtie
09-12-2011, 11:43 PM
Thanks for the info. I was basing the 1700 rpm off of the peak torque. According to a fuel consumption chart I found for the 4bt it theoretically consumes the least amount of fuel at 1700 but of course that is in a controlled dyno room not in the real world. As we all know, lab results and real world rarely coincide perfectly.$.02

littleboy
09-13-2011, 07:54 AM
If you actually are gonna end up with as much power as you say , you are definately gonna need to raise your cruising rpm!

bh10
09-13-2011, 08:46 AM
That np208 will go boom quick.

jaybuller
09-13-2011, 09:14 AM
the more i think about it in all hounesty i dont think that even a built t56 will handle the 4bt tourque pulses down lower in the rpms(under 2000) i think it will destroy the gears fast and as you might be saving a little money up front going with the t56 i dont think it will be worth the hassel of rebuilding every few months... i think if it were me and i wanted to go with a manual 6 speed i would just use a nv5600. but if you plan on racing with it a lot at the strip i would be saving my money for a auto and be money ahead in the long run becasue i think that even a nv5600 when drag raced will need to be rebuilt quite often...

haloman
09-13-2011, 09:17 AM
Auto is the easiest if you wanna go faster than 13s everytime. Trust us on that one.

4bt bowtie
09-13-2011, 02:34 PM
I agree that the T-56 is probably not the best way to go. I was looking at the T-56 because of the two overdrive gears. Yes, the NV5600 and ZF 6 are six speed transmissions but they do not have a double overdrive. They have an extra gear before direct drive to make towing easier. I will probably go with the tried and true NV4500. This truck is not going to be a drag truck, it is a daily driver that will see occasional track time. I would prefer to keep with a manual trans for ultiamte longevity. I have known some people swear by the ZF5 transmission, any opinions on it versus the NV4500?

LReiff
09-13-2011, 02:37 PM
Allison 1000 6 speed has double OD.

4bt bowtie
09-13-2011, 08:32 PM
I thought about that, but then I would have to get a standalone computer to run it and the cheapest standalone I’ve seen is close to $800. I still would prefer to run a manual trans.

4bt bowtie
09-15-2011, 04:13 AM
Does anyone know of a good link to go to in order to find the physical dimension of an NV4500 and ZF-5? A friend of mine (who has more experience with the NV4500) thinks that I would never be able to fit the NV4500 in my S10 without some serious tunnel surgery. I’m fairly certain a ZF-5 will fit with a small body lift because I have seen it done on a late 90’s Ranger.

:ft:

Scooter's Roofing
09-15-2011, 07:02 AM
47RH will be cheaper/stronger in the long run than anything you've listed above

4bt bowtie
09-20-2011, 02:57 AM
Personally, I prefer shifting the gears. That and if I keep it a stick the wife can't drive it. :lolly: But all joking aside, what would I have to do and how much money would I have to put in to an NV4500 in order to make it handle 700ft lbs reliably?

jaybuller
09-20-2011, 07:26 AM
a new one with a 1 3/8 input will handle it reliably. you just cant speed shift it or lay into the fuel before the gear is 100% engaged... 700 isnt much for that trans just make dam sure each gear is engaged before stepping into it.

4bt bowtie
09-21-2011, 02:14 AM
So I wouldn't need to upgrade to billet shafts or anything along those lines?

4bt bowtie
12-20-2011, 08:24 PM
I know I'm kind of beating a dead horse here, but other than fixing the 5th gear issue that I have heard about, what would I need to do in order to make sure that when I mash the trottle off road I will not have to worry about destroying my trans?

TMONEYDIESEL
12-20-2011, 08:40 PM
Nothing

SHughes
12-20-2011, 08:57 PM
use an NV 4500

LReiff
12-21-2011, 05:55 AM
So I wouldn't need to upgrade to billet shafts or anything along those lines?

I know I'm kind of beating a dead horse here, but other than fixing the 5th gear issue that I have heard about, what would I need to do in order to make sure that when I mash the trottle off road I will not have to worry about destroying my trans?

No matter how you build a NV4500 3rd and 5th gears will always be weak. A built 47rh/re will handle torque better.

Cumminsfever
12-21-2011, 07:34 AM
No matter how you build a NV4500 3rd and 5th gears will always be weak. A built 47rh/re will handle torque better.

Care to explain why my completely stock nv4500 has held up to the daily beatings and horsepower that I've subjected it to??

homewrecker
12-21-2011, 08:10 AM
^^^^^ You're lucky? Lol

tapatalking from droidx

Signature600
12-21-2011, 08:15 AM
No matter how you build a NV4500 3rd and 5th gears will always be weak. A built 47rh/re will handle torque better.

Gotta disagree....it's a 4BT. I've beat the tar out of my NV4500's grossing 40K+ lbs with 1000ft lbs on tap, and other than 5th gear coming off once, thy never cared.

I even welded that gear back on and ran it for 3 years until I found a replacement 2wd tranny.

With a 850+hp sled puller, I could see a problem...but in a 4K lb S10 with a 4bt, that tranny will be so overkill, it won't be funny. Fix 5th gear so it can't come off, and go with it.

Chris

LReiff
12-21-2011, 08:30 AM
The 5th gear syncro cone becomes the weak part once the nut and shaft issues are fixed and 3rd will wipe the teeth right off the gear. I also know people with NV4500s that never had problems. Maybe it's abuse, maybe it's not.

Cumminsfever
12-21-2011, 01:30 PM
The 5th gear syncro cone becomes the weak part once the nut and shaft issues are fixed and 3rd will wipe the teeth right off the gear. I also know people with NV4500s that never had problems. Maybe it's abuse, maybe it's not.

How many of those with problems had the nv4500/4bt combo?



I have personal experience with 3 nv4500/4bt setups. Each had plenty of power, and 2 of them are daily drivers that get BEAT. Transmission has been the LEAST of their problems. The third one is my own. There too the transmission has NEVER given a problem.
while I agree there are weak spots in the nv4500, behind a 4bt, it won't give a minit of trouble if 5th gear nut if properly fixed and proper oil is used.

LReiff
12-21-2011, 01:36 PM
How many of those with problems had the nv4500/4bt combo?



I have personal experience with 3 nv4500/4bt setups. Each had plenty of power, and 2 of them are daily drivers that get BEAT. Transmission has been the LEAST of their problems. The third one is my own. There too the transmission has NEVER given a problem.
while I agree there are weak spots in the nv4500, behind a 4bt, it won't give a minit of trouble if 5th gear nut if properly fixed and proper oil is used.

You don't know the definition of beat! LOL I know for a fact that you've never raced 0-60 with your 4500 and if you had it would have broke something. Easing into the power and shifting the trans with care will go far!

Cumminsfever
12-21-2011, 02:34 PM
You don't know the definition of beat! LOL I know for a fact that you've never raced 0-60 with your 4500 and if you had it would have broke something. Easing into the power and shifting the trans with care will go far!

I wasn't aware the OP wanted to race...

Signature600
12-21-2011, 03:39 PM
You don't know the definition of beat! LOL I know for a fact that you've never raced 0-60 with your 4500 and if you had it would have broke something. Easing into the power and shifting the trans with care will go far!

They aren't all bad. I put 375K miles on mine with the abuse mentioned before, DD clutch, trying to shift it fast, everything. Never a problem except 5th gear. There are probably thousands of other tranny's out the in trucks that aren't being hot rodded and beat to death that hold up fine...if they are ALL as bad as you think, there should be Dodge's and Chevy's littering the roadways with broken NV4500's.

There's not;)
Chris

4bt bowtie
12-21-2011, 09:01 PM
Thanks for the input. I have known guys to run built 12V with 400-500 horse and do nothing to the trans but blow out the stock clutch. And again these are full sized trucks. My thouht is that, even if I get lucky and I am able to push 700ft lb out of the 4bt, the s10 is light. As long as I fix the 5th gear issue, put a quality rebuild kit in it and am aftermarket clutch such as a south bend or something like that, I should be ok. Even with larger tires, rough terrain and a very heavy right foot. Is my thinking in the ball park or am I way off?

LReiff
12-21-2011, 10:10 PM
You'll be fine! Some days I get the blues of fixing broken trannys.... The light weight truck will be a big plus!

fire power
12-22-2011, 10:35 AM
How many of those with problems had the nv4500/4bt combo?



I have personal experience with 3 nv4500/4bt setups. Each had plenty of power, and 2 of them are daily drivers that get BEAT. Transmission has been the LEAST of their problems. The third one is my own. There too the transmission has NEVER given a problem.
while I agree there are weak spots in the nv4500, behind a 4bt, it won't give a minit of trouble if 5th gear nut if properly fixed and proper oil is used.

Using the correct oil in the nv 4500 goes a long way mobil 1 75 90 synthetic DOES NOT WORK!!!!

Cumminsfever
12-22-2011, 10:43 AM
Using the correct oil in the nv 4500 goes a long way mobil 1 75 90 synthetic DOES NOT WORK!!!!

Hey. Your junk don't count :lolly: bif :shake: LOL

fire power
12-22-2011, 11:22 AM
LOL

black06
12-31-2011, 08:56 PM
I think there is a reason they didn't put the T-56 in trucks...just sayin.


SRT10 Rams came with a T56...... and they make a lot more hp/tq with factory 22" wheels and a viper V10 than the little breadtruck engine

TMONEYDIESEL
12-31-2011, 09:17 PM
SRT10 Rams came with a T56...... and they make a lot more hp/tq with factory 22" wheels and a viper V10 than the little breadtruck engine

Yep because the little bread truck engine has never made 800+hp LMFAO

TMONEYDIESEL
12-31-2011, 09:21 PM
Something like this would be better.................. :evil

4bt bowtie
01-03-2012, 09:14 PM
And that would be a fully billit NV4500? lol I am no where close to being in the right tax bracket to afford that. I am a big supporter of the overbuild it and it won't break concept, but I think that is a little overkill. I have been toying with the idea of a t56 but I am building this truck to be a daily driver/ adventure rig and it would be a hell of a lot easier to find parts for an NV4500 in the middle of no where than a T56.