Mating a 6.7 to a turbo-400 or lenco

Yea we have discussed several different options, with the lenco and clutch setup being the best probably. But I couldnt find a reason to try anything other than the 48 for an auto. The have evolved into what has to be the strongest auto on the planet now days.
 
Idk about the strongest, but they have evolved into a great transmission. Great thing about a TH400 is all the options available, but with no lockup its not preffered. Ive talked to 3 companys that made a TH400 lockup but shelved the idea after not enough interest. But theyre are still a few running the prototypes with success. We are working on a lockup unit for the th400.

I like a lenco w/ converter myself
 
We probably would have went to a lenco already if there was a good converter setup available. But after talking with all the converter companies as well as bruno, no one wants to step up and make one for it. Dirty Max is the only one I know of but I hear it isnt very dependable either.

But Im glad we have stayed with the 48. The only two issues we have ahd with it in the last two years is converter clutch linings and front band. And we have got around both those problems. Running same forward and direct clutches now for 3 years now and only lost one set of OD brake clutches. I cant imagine a 400 living that long at that power. But without lockup, its not even an option IMO. These engines need a load to work against.
 
A TH400 lives behind 3000+hp, Armor Inc runs a bruno/lenco and loves it after they found a converter that worked, converters will always take time to dial in with a setup like that. I can get a converter made for that setup no problem, (I sound like greg here ugh). I agree though i wouldnt run a TH400 with no lockup.
 
I think either a TH400 or Lenco would work, Jeff Dean seems to do pretty well, and I know Keating said he had 50+ 5.50 1/8th mile passes on his truck with a Lenco/clutch combo.

But.....considering it is a VP and rpm limited, and you already have a 48, I'd just do that.
 
MCForstenRacing said:
We are running a 9 inch with 40 spline moser axles and if I am remembering correctly Chris (our chassis guy) told us a 330 gear was the highest pro gear available. I hope this is correct.
Click to expand...

No, in a large dia. 35 spline Pro Gear there are several taller than the 3:30. Ive personaly seen; 2:50 2:70 2:90 3:00 3:10 and 3:25. I ran a 3:00 much of the time in mine and Chad ran a 2:50 in his Altered.


All the mopar stuff 46,47,48, etc..... to a tranny guy is nothing more than a old torqueflight 727. Ask any tranny builder [thats not bias and gets crazy money to build these way over priced diesel trannys] by design whats the beefer, stronger unit and better by design as well the GM based slush boxes IE glide, 400, 4L80 Or a damned ol TF 727, lol. Ive yet to see one behind a Top Sportsman, Pro Mod, Top Dragster, hell even a Super Comp car. Even the very few mopar muscle guys with crysler powerplants still have a GM tranny behind them for a reason. Nothing there to argue just the facts.
 
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Tranny

A 727 is one of the best trannies they make in comp style NA gas world. They are very trick pieces! They rob very little power and have a wide selection on gearing. A 400 or Powerglide will word in a diesel, and work well! Its all about the low gear and convertor. You just don't need all the low gear ratio that most trannies have. Most shops will laugh at you when you tell them the TQ and RPM you are working with. I found a company 15 plus years ago that will make it work and work with me no matter what! They custom make the stators and i'm very happy with what I have. I wanted the lockup at first. I just couldn't swing it and went with a normal glide. I'm not the fastest but I ALLWAYS FINISH!!!! It's not breaking every other pass! Sometimes it's not about setting records but going rounds and giving the people in the stands something to watch, a race with another car in both lanes. K.I.S.S for a tranny is the best move I have ever made. Jeff
 
The main reason I keep the 48 is because it relates to the every day diesel guy. My thoughts are if we can make it live in our truck, then it will live in about anything streetable. But I have always been curious about the glide and 400. thought maybe it was price, but the super awesome 400s seem to be in the $5k range without converter, so its no cheaper than a 48. Havent looked into a glide in a long time on price. But I cant imagine either without lockup in a heavy truck. I can see where it would work fine in a light car like Jeffs rail or the altered. I know without lockup and OD, our truck is MUCH slower.
 
Tranny

I agree with a heavy truck. I'm not sure at what point a 400 would work at. I would guess maybe 4000 to 4500 pounds. It would be fun to try.
 
I agree on much of that Jeff. The 2.48 low for the Black truck was great for getting 4500# off the line and with 1.32 60's at that weight Im still not sure if any other PS trucks have matched it. BUT in a sub 2800# Altered it was too much gear, looking back I wished I got the 2.10 low and left more off the brake. Off the brake with a 2.48 low I couldnt hit 2nd fast enough so I foot braked it much of the time in second gear [1.48] and could still 60' in the 1.18 - 1.19 range. I got a 1.09 once leaving off the brake in low and hitting 2nd just right but it was not consistant, it was ussually more like 1.15- 1.16 but it always layed over at the top of low ~5250 rpm.

A 2:10 low 400 in a light racer and the right converter is a fast combo. Lots of guys now building that 400 just leaving low gear out of it

I had a super good combo of parts and taylered my tune up around torque which always made it fun to drive and gave me great early numbers. I did lack the big killer top end power [single 71/73] and od for big fast 1/4 mile charges but 98% of my racing was/is 1/8th mile index and grudge racing. My point is its all about application, Id not recc. this setup to most due to our sport is run as 1/4 mile and gearing/weight is key to making this combo the best that it can be, because of it being fluid coupling ie. non L/U
 
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Ryan I always enjoy reading your Posts... You are defiantly right about a having the right combo of parts for what you have to work with horsepower, torque and rpm wise. My junk will never be as fast as you guys but it runs well for what it is. Tf727 and a 9in with a 275 gear...
 
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