What is it exactly that causes a tranny to fail in high hp applications? Is it the heat factor? Is it the high load shifts? Is it the rotational stress?

Would a truck with a force fed engine producing 500rwhp create an equal amount of stress as a NA/No2 engine producing 350rwhp in 1st and 2nd gears and the No2 activated in 3rd to bump that number to 500rwhp?

 

hey bud, the 5.4 lightning engine puts out impressive torque even just off idle. Failures derive from many different realms, some are hard part failures meaning stub shafts or gear sets are not hard enough to take the loads. some from slipping (heat) burning up clutches, or shocks taking a toll overall. I talked some with my builder (Darrin Burch on these forums) about my application, he shared plenty of insight from what he has seen. From a standpoint of what he has seen done, what has worked or has not, and what he has done to put out a stout transmission himself that has gotten his name out there. Example aside from my truck, he built a trans for a fellow running a streetable mercury marauder, i believe the 1/4 time for that guy was in the 11's and was featured in MM&FF's magazine. very neat. I personally recommend you talk to Darrin and get what you NEED to handle the punishment, dont try to save a few bucks like i tried the first time. im still trying to get my money back from that yahoo.

Lets backtrack some again, a factory built transmission will not last the almost triple'd torque input from a NA motor to the force fed pigs. the problem here is soft shifts, usually mostly worn clutch packs that just couldnt hold that load if they were fresh for long. Most are using steel parts that can, and tend to separate, the stub shaft is a pretty common culprit for 3/4 failure and i found this out before i talked to Darrin. Also, in this world you absolutely have to couple a great transmission with a finely crafted torque converter. if you get a cheap converter and that separates, bye bye expensive transmission.

as far as the stress levels only really being similar in 3rd gear, i would say no and a forced inductions going to have more potential earlier IF you get it to stick.

 

Why is it that factory manual tranny's can withstand so much power? Is it because there are less parts? Why can you take a Mustang GT 5spd and give it tons of hp/tq and not have to replace anything but the clutch but with even the stoutest auto's you have to upgradethe whole damn thing after much smaller increases in power?

The reason I'm asking all of this is because I'm trying to figure out which direction to take my truck in. Contemplating a turbo set-up but a nitrous'd higher compression and possibly stroked engine are my 2 options at this point. The other looming question is the tranny, which is why I posted here. I rarely use my truck as a work vehicle and I have always been much more fond of manual tranny's.

 

You may be slightly mistaken on manuals, oh man they break and its just as bad or worse when they do fail. This gap your seeing is clutches burning up vs hard part failure, hard part failure from what i've seen as complaints have been less than clutches burning up and probably always will be. Also you have to consider how the person drives with the manuals, and remember manuals have come a good distance from the last 20-30 years.

I've seen as many manual trans failures in my family and friends circle as i have automatics. I'll tally them for you

My 97 f150 - Auto, clutches burned up just shy of 200k after i put the lightning in. then the new trans never worked
Brothers 98 chev 1500 before it was his burned the auto, again this was clutch and oiling problem.

friends fox body mustang, manual- obliterated the whole tailshaft section
dads 89 ranger, input shaft sheared.
thats it.


Now back to you, you mentioned swapping to a manual, you do realize the process involved with that? you'll need pcm and wiring harnesses to start, the other things would be mounts and other hard parts.

 

Yeah I don't know what to do at ths point. Mdcover has a monsterbox tranny for sale that I'm considering buying but I'm not sure if it will hold up to what I want out of my truck. I'm leaning towards a Modmax 1000hp short block and a custom Spyder single turbo kit pushed to like 25-30 psi eventually to reach close to the limits of the block. It's either that or a Paschal billet 6.4L stroker kit in a bored and sleeved aluminum 5.4 block with high compression and a decent dose of No2, 250-300 shot, to push to around the same output as the turbo set-up. Either set-up will have a worked heads, agressive cams, LT's and a free flowing exhaust.

Seems like from what everybody else says, I should be going with a Darrin Burch BC Automotive tranny. I'd really like to do a T56 though

 

Man, you are talking about a butt ton of power. I personally know of a much less powerful truck that had a Monsterbox(and 5 replacements) in it and it looked like it had reached the limit of the handling capacity of that transmission. At least according to Jasper the last time they replaced it.

You need to be REALLY careful about what choices you make in this department on this truck.

I am limited on what I can discuss in threads. It's not that there is some huge secret or that I don't like to give out info or anything, it's that I follow the rules of the forums I hang out on and doing so would break those rules. So if you ask me specific or certain types of questions in this thread be aware that they may go unanswered by me due only to that.

Darrin

 

Its your money, you do as you will. I'm just going to tell you I'm very satisfied with Darrins trans, I used my truck with his new trans to pull approximately 7k on my dads car hauler which weighs 1400# on its own. did numerous trips like this, never skipped a beat. still shifts like it did when i first got it, and let me tell ya when I say its go time, theres no beating around the bush. Lock and GO. 2nd gear from a 35-45 mph roll will lock, bark, and scream, while first is a joke and spins. im thoroughly impressed.

im honestly running a 10# pulley setup, not near your desired ratings but i did build the motor to be safe to your numbers your looking at.

Heads and cams, yeah, dont overlook your fasteners. be absolutely sure to use ARP studs, and consider a block girdle to stiffen up the bottom to be extra comfortable with the numbers you want to hit.

Oop sorry Darrin, we were typing at the same time. So what Darrin is saying is he cannot openly discuss things because of repercussions. Make it a private conversation and you can ask all kinds of questions, I did! just too damn bad i didnt talk to him until after i got hosed on one trans, and im blatantly advertising that negative fact in my signature.

 

The best bet would be to use a Dodge SRT 10 T56 and change the input shaft to the Ford 10 spline and use the Ford Bellhousing. Get a short throw shifter and weld a foot or two of rebar to it to lengthen the shift lever.
You will also need the pedal assy from a Manual F-150 and the Cobra hydraulics ect.... The Cobra T-56 will stand 450 ft/lbs but the Dodge is closer to 600. Don't forget the tranny delete in the PCM. Driveshaft length and tranny mount could be a concern.

If I had the $$$$ my next truck would be a Raptor with the 6.2 and a manual transmission.


.

 

That would be such a sweet truck

 

so lets say a fellow guy has a 01 5.4 and decides to throw on a eaton M112 supercharger on it. how would this do with the stock tranny? is there any real worries since there wont be tooo much power going to it...

 

I tried that. got 2k miles out of the trans.

 

how much would a better tranny cost?

 

depends on you... I tried twice, got really hosed the first time.
Paid around 2700 for Rods POS that never had 3rd or 4th for me, thank you ***** for not refunding my money...

paid around the same for Darrins trans. not one issue and absolutely love the way it feels.

 

Right on man Ya wanna play ya gotta pay!

Phil