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looking at doing some upgrade over winter and i am curious what is all needed to withstand 800-850hp running through a th400. the car is 3800lbs with driver. trans will have a trans brake as well.. thanks
 

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Sorry for the vague response. Yes mostly stock parts and an aftermarket steel hub. Of course the stock parts have to be the right ones. If you want a detailed list I will find time but it won't be now.


Hutch
 

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3800+ 800hp on motor 1000-1100 on nitrous same th400 for 6 years, over 10,000 street miles and well over 100 passes, this is what works for me.

8 bolt pump, straightcut planetary set, steelhub, 34 element sprag, directfed drum, alto red clutches, selesct manual valvebody with a internal brake. i dont have any of upgraded shafts or real bigmoney stuff. infact i still use 5/16 hardline i perfer it over steelbraided but thats me
 

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3800+ 800hp on motor 1000-1100 on nitrous same th400 for 6 years, over 10,000 street miles and well over 100 passes, this is what works for me.

8 bolt pump, straightcut planetary set, steelhub, 34 element sprag, directfed drum, alto red clutches, selesct manual valvebody with a internal brake. i dont have any of upgraded shafts or real bigmoney stuff. infact i still use 5/16 hardline i perfer it over steelbraided but thats me
.

nice camaro.
 

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In my experience a naturally aspirated car @3800 and 800 to 850 horsepower will live with a properly built th400 with a good oem smooth style drum and Borg Warner 34 segment sprag clutch and a quality brake valve body w/170 to 180 psi line.If the engine is making 800 to 850 w/n2o ,supercharger or turbocharger then the addition of an aftermarket steel forward clutch hub or the factory 4l80e hub will be a better choice as they both are made from better materials than the OEM 400 hub.You also should be using a press in sun gear shaft to keep the sprag and drum on center.If you dont the drum and sprag are all over the place.Even in high gear with everything that rotates from the converter turbine hub to the differential pinion locked together the slip fit between the direct clutches and the direct clutch hub will allow runout and wobbling.And Green Loctiting the sun gear shift isnt going to do anything so dont waste your time.Therefore your hard parts list should include a 34 element drum,and possibly a billet or 4l80e forward hub and press in sun gear tube.Any reputable shop can access these parts and be able to get you what you need.
 

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Adding Chris's post would be all aluminum pistons , some form of case lug protection , a rear case to output shaft bearing ,deep oil pan (pref a GM deep pan and pickup tube), surface ground pressure plates , proper sprag retainer snap ring or spiroloc, 4 port direct drum and at least a 7 bolt case using an 895/896 pump also with a minimum of 7 retaining bolts.


Hutch
 

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3800+ 800hp on motor 1000-1100 on nitrous same th400 for 6 years, over 10,000 street miles and well over 100 passes, this is what works for me.

8 bolt pump, straightcut planetary set, steelhub, 34 element sprag, directfed drum, alto red clutches, selesct manual valvebody with a internal brake. i dont have any of upgraded shafts or real bigmoney stuff. infact i still use 5/16 hardline i perfer it over steelbraided but thats me
LEAVNON3RD,

What engine is in your Camaro? I am going to put a 3-speed in my car for next year and was trying to decide between a TH-400 and a TH-350. My car has a 800+ HP SBC in it.

Thanks
John
 

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LEAVNON3RD,

What engine is in your Camaro? I am going to put a 3-speed in my car for next year and was trying to decide between a TH-400 and a TH-350. My car has a 800+ HP SBC in it.

Thanks
John
my car has a mild pumpgas 555 init(built back in 2004). Alot of friends use th350s because they liked 3 speeds, but the 350's didnt last very long( even behind 600hp street cars) and from my exp even with big money spent they still cant hold a cnadle to a good th400. 99% of my friends who had th350s went to PG's and its been a mixed bag, some lost a little e.t. and some picked up 2 tenths. for me a th400 is the only option for a heavy weight street car like mine.

and thanks for the comments on the car, its rocking 28" radials now, that .gif it still was a big tire car and had centerlines.
 

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my car has a mild pumpgas 555 init(built back in 2004). Alot of friends use th350s because they liked 3 speeds, but the 350's didnt last very long( even behind 600hp street cars) and from my exp even with big money spent they still cant hold a cnadle to a good th400. 99% of my friends who had th350s went to PG's and its been a mixed bag, some lost a little e.t. and some picked up 2 tenths. for me a th400 is the only option for a heavy weight street car like mine.

and thanks for the comments on the car, its rocking 28" radials now, that .gif it still was a big tire car and had centerlines.
Thank you for the info. Some companies said the TH350 could hold the horsepower I have but didn't say for how long. Probably long enough for them not to be responsible lol. After what you told me and what I heard from a friend in the transmission business, I'm going to go with the TH400. I have a powerglide now but with the weight of my car, the RPM that I turn with the engine, the size of the engine, and because I footbrake it I need the 3-speed. I need more low gear and the smaller span between shifts to keep the engine in the upper RPMs longer. My transmission guy said the same thing you did. The TH400 is much more durable than the TH350 and once the TH400 is lightened it won't lose much, if anything, in ET compared to a TH350.

Thanks
John
 
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