[BruceWilkie]

Anyone know anything about the Chevy HD case? I have one that came out of a U-Haul truck. Truck had heavy duty cooling package including factory deep pan. I'll have to swap tailshaft out as it has a fixed yoke. Bolt pattern is not an issue for me.

[Half-Inch Stud]

Have had several truck cases, and not convinced i've found the "HD case" so either they are unimressive vs Big Car, or i've not had an HD case,


TH400 tech and DIY builds are fun & rewarding

[BruceWilkie]

Originally Posted by Half-Inch Stud

Have had several truck cases, and not convinced i've found the "HD case" so either they are unimressive vs Big Car, or i've not had an HD case,


TH400 tech and DIY builds are fun & rewarding

Maybe the HD on the casting is simply ID?

I'll have to disect it and compare to my other case(late 70's Buick short tail with now illegible code tag).

Want to help? Maybe some rainy weekend ? Call me sometime.

[RA462]

I use the big car case that I installed the short tail housing on. Here is a couple pictures of the forward drum splines from CK. Their website says it is good to 1000HP but I am not sure of the material the shaft is made from. It's good to read something technical here without the cylinder head wars.

Dragncar since I know you have been such a Mike Leech fan here is just a little side story for you. Mike called me one day and wanted to know if I would come up to his shop and help him change out the gear set in his TH400. He had worked on transmissions before but it had been a while. My dad and I went up there and spent the day with him and his boys. We took out the 2.10 and installed a I believe is a 1.97. Everything else still looked like new inside. I remember Mike saying "Don't drop that. Your holding like $2500". That is what he used his last year of racing. We had a great time talking Pontiacs and he was going to help me get to my 1000HP goal. Sadly we all know what happed later that year. Below is a like to Coan kit in Mike's transmission. Transmission eye candy.

http://www.coanracing.com/coa-22871-...-kit.html.html

[taff2]

Ah, so in the XLT , Coan has downsized the drums to reduce rotating mass but upped the clutch count to get the necessary friction area.

[Dragncar]

Originally Posted by RA462

I use the big car case that I installed the short tail housing on. Here is a couple pictures of the forward drum splines from CK. Their website says it is good to 1000HP but I am not sure of the material the shaft is made from. It's good to read something technical here without the cylinder head wars.

Dragncar since I know you have been such a Mike Leech fan here is just a little side story for you. Mike called me one day and wanted to know if I would come up to his shop and help him change out the gear set in his TH400. He had worked on transmissions before but it had been a while. My dad and I went up there and spent the day with him and his boys. We took out the 2.10 and installed a I believe is a 1.97. Everything else still looked like new inside. I remember Mike saying "Don't drop that. Your holding like $2500". That is what he used his last year of racing. We had a great time talking Pontiacs and he was going to help me get to my 1000HP goal. Sadly we all know what happed later that year. Below is a like to Coan kit in Mike's transmission. Transmission eye candy.

http://www.coanracing.com/coa-22871-...-kit.html.html

Thanks for that 462. I was just getting to know him and really looking forward to the relationship, if only over the phone. Just liked the guy man. He was also going to help me with meeting my goals. Tell you what, inspired me to get off my @$$ and do it. Life is short, have fun while you alive and can share it with others.
Trying to get back ahold of Jake. And get more of the details with his Stage 3 kit. He said my engine was pretty basic tranny wise. 1000 or so HP and under 8000RPMs. Said its the high RPMs where cost skyrocket. I told him that was exactly why I am not building a high RPM/cubic dollar engine. Not for me.
I have a feeling Jake is where I am going to get the most value for what I want to do. He has all the high end components but there is not a big company's name stamped on it. Bet a lot of them come from the same place. Like a lot of things do. Same product, different name and price.

[Dragncar]

Jake Shoe called back, very busy guy and his time is valuable so I did not want to hold him up.
But I got the general prices and what you get for his Stage 3 Components. He said these trannys hold up to 1200HP at the wheels without issue as long as they are not sky high RPMs. And mine is not.
850$ for aluminum direct drum with steel spines and 36 element Pro Mod Sprag. 350$ for modified factory forward drum with S300 input shaft. 150$ for billet forward hub. Thats the basic hard parts for his Stage 3 trannys and I can use the rest of my parts and put it together. I have a bunch of clutches, steels, gaskets and seals.
the next thing I could upgrade to is a S300 intermediate shaft. But do not really need it. I asked about a center support upgrade and that is more complicated. There is special machining involved and end play clearances that are not by the book. So he said it always ends up costing more to do that mod yourself by the time the paid by hour tech calls are done. I think I could get that done, but might tike me more time but I will differ to his expertise on that one. Dont need it. Tells me when you get into those 10,000+ RPM Fords running T400s the cost goes way up.
I asked him if his stuff was the name brand parts without the name. He told me there are a LOT of Chinese parts out there and all his stuff was quality made in the USA parts. Good enough.

[Half-Inch Stud]

Yea, sounds good and all. rA462 photos look fantastic too.

I think a fella can beef the input shaft, FWD Pack, DIR pack and leave the Mainshaft as the fusible link as it splines into the Rear Planet cup.

It's all feel-good to me, but there is advantage to knowing where the fail point will be FOR SAFETY. Putting my geek-hat and going DEEP;

The TH400 input is a quill shaft, and so is the Mainshaft. When a fella stiffens the input to super stiff with diameter increase and 300m, then the Mainshaft quill is definitely doing all the instantaneous quill & rear shock absorbing, so it will bust with spectacular crystal brittle cleave and your run is done; you just gotta drop the trans.

I'm a bit out of the high-end gambit, but if you are gong to replace TH400 "hard parts", please run the TQ @ rpm vs HP equation for your combo, and decide based on THAT.

[BruceWilkie]

Originally Posted by taff2

Ah, so in the XLT , Coan has downsized the drums to reduce rotating mass but upped the clutch count to get the necessary friction area.

That's an interesting approach.

Todd thanks for the link.
All things considered Coan's kit price isn't unreasonable.

[Half-Inch Stud]

Downsized drum diameter is going in the wrong direction for holding TQ.

I would prefer a maximum hub diameter, just clearing the case, (windage scraper..), and using the next higher Standard Friction diameter. So we're talking a 1/4" increase. MOOT
huh No need to play with hub diameters. Just play with hub materials.


Are All those folks spinning stock diameter hubs to high rpm looking silly?

[Stan Weiss]

Originally Posted by Half-Inch Stud

Downsized drum diameter is going in the wrong direction for holding TQ.

I would prefer a maximum hub diameter, just clearing the case, (windage scraper..), and using the next higher Standard Friction diameter. So we're talking a 1/4" increase. MOOT
huh No need to play with hub diameters. Just play with hub materials.


Are All those folks spinning stock diameter hubs to high rpm looking silly?

Mark,
Remember I am coming from a clutch / manual trans back ground. Isn't about maximizing surface area and minimizing MOI?

Stan

[BruceWilkie]

Originally Posted by Half-Inch Stud

Downsized drum diameter is going in the wrong direction for holding TQ.

I would prefer a maximum hub diameter, just clearing the case, (windage scraper..), and using the next higher Standard Friction diameter. So we're talking a 1/4" increase. MOOT
huh No need to play with hub diameters. Just play with hub materials.


Are All those folks spinning stock diameter hubs to high rpm looking silly?

Smaller OD can more than be made up with extra clutches/steels. So if drum is significantly smaller it could still be lighter and made to hold better. I saw no reference to the new drum using stock sized frictions/steels.

[Dragncar]

Went all though the Coan T400 site. Its great, full spectrum of aftermarket and modified stock parts. Prices are not high either, for what you get. 100$ is not bad for a billet forward drum. The 2700$ price for the kit Mike had is pretty good really. If you can install it and have a Trans like a 5-6K Rossler I belive that a good deal.
Not sure if I even need that kit. Think I will give them a call and see if they have something in-between that suits my needs.

[Dragncar]

Originally Posted by BruceWilkie

Smaller OD can more than be made up with extra clutches/steels. So if drum is significantly smaller it could still be lighter and made to hold better. I saw no reference to the new drum using stock sized frictions/steels.

On Coans site I seen references to C6 clutches. Maybe they use them. I believe Lencos are based on them too.

[Stan Weiss]

Originally Posted by BruceWilkie

Smaller OD can more than be made up with extra clutches/steels. So if drum is significantly smaller it could still be lighter and made to hold better. I saw no reference to the new drum using stock sized frictions/steels.

Bruce,
Even if it weighs the same. If the mass is closer to the shaft center line it takes less energy to accelerate / deaccelerate .

Stan

[Dragncar]

CK has a great site too. Better prices than Coan for what I want to do.

[Dragncar]

Called up CK, talked to Chris. He says I do not need any aftermarket drums of any kind for what I want to do. Pro Mod sprag either. He gave me 4 part numbers. I looked one up and it is a OEM forward drum with aftermarket input shaft. The rest I can not find on their site. I will give them a call and clear it up tomorrow.
Very nice guy. Says this stuff handles 1200HP. I have two of the 34 element sprags already. One thing, I am pretty sure I have extra clutches in direct and intermediate (4) right now. He told me that is hard on a 34 element sprag, can roll them. Says run 3 or the OEM paper clutches in direct. They have more than enough torque capability and they have a built in cushion that will make the 34 element sprag live. And need to get the billet Koleen cover.
If I do not have to buy the 850+$ Pro Mod sprag and it all lives, fine with me.

One thing, he asked what rear gears I have, weight and torque. I told him 750tq. But that is a guess. Say I get the 900HP, how much tq would it have ? 4.5" stroke. 750 a good guess ?

[t money]

I can’t add anything to this post. But just throwing this out there Lou Gach has a well build turbo 400 for sale on this site and his. Maybe email him and see what parts he has in it. Maybe save some time and money

[Stan Weiss]

Originally Posted by Dragncar

Called up CK, talked to Chris. He says I do not need any aftermarket drums of any kind for what I want to do. Pro Mod sprag either. He gave me 4 part numbers. I looked one up and it is a OEM forward drum with aftermarket input shaft. The rest I can not find on their site. I will give them a call and clear it up tomorrow.
Very nice guy. Says this stuff handles 1200HP. I have two of the 34 element sprags already. One thing, I am pretty sure I have extra clutches in direct and intermediate (4) right now. He told me that is hard on a 34 element sprag, can roll them. Says run 3 or the OEM paper clutches in direct. They have more than enough torque capability and they have a built in cushion that will make the 34 element sprag live. And need to get the billet Koleen cover.
If I do not have to buy the 850+$ Pro Mod sprag and it all lives, fine with me.

One thing, he asked what rear gears I have, weight and torque. I told him 750tq. But that is a guess. Say I get the 900HP, how much tq would it have ? 4.5" stroke. 750 a good guess ?

Dragncar,
I have no said anything as people have talked about the HP that parts will live to. But you are finally talking with someone that understands that it is torque that will brake them.

Now to answer your question.

900 HP @ 7500 RPM = 630 Torque

900 HP @ 6300 RPM = 750 Torque

Stan

[BruceWilkie]

Torque x RPM ÷5252=HP

750×6500÷5252=@928.21HP

750×7000÷5252=@999.61HP

675×8200÷5252=@1053.88HP

These are just math samples that you can determine HP from tq and rpm. You can change number positions and determine tq from HP or find rpm the tq or HP point. 5252 is always the factor.

Hope this helps.