LSONE

iTrader: (1)

I've been more and more interested in th400 cars lately, but unfortunately I know very little about them. I could just call and ask what a shop would recommend, but i like to do a lot of research before i make any decision so that I know what they are talking about. Anyone got any links that explain in detail what all the options do or how they work?

99Z28LS1

iTrader: (4)

it seems to me like the TH400 is an amazing tranny because a lot of the experienced people on this site have them, but man, i just cant get away from my M6 on the street. BUT, when i do a race car when i graduate college, it will def have either a TH400 or a glide. i like reading about the TH400's just in case i ever mught wanna switch my M6 later in the years to one. good comments on this thread and a lot of knowledge to be harnessed

Josh@KY-Turbo

iTrader: (120)

I have a TCI Competition TH400 in my car. RMVB, T-Brake, the works. I plan to hit the dyno several time since I dont seem to leave anything alone. I have been told several times to always leave the trans in 3rd after a pull and let the rpms fall before down shifting. Same goes for the street unless like said above you downshift from 3rd to 2nd on the throttle. I dont run a super huge stall, Just a Yank 3000. I hope it doesnt explode but if it does oh well. I will go back to a full manual 4L80E and get my OD back .

andereck

Powerglide. Ask for it by name. T400's are HP sponges and only slightly better than a C6.

Wonderbread

iTrader: (51)

Ive seen exactly that happen, a board member, GIMP98TNT had a M6 in his car with spray, the car with the M6 made 435ish RWHP NA and 650ish on the bottle,after the car was dynoed with he M6 the next year he changed to a TH400 and changed nothing else but the trans, put it back on the same dyno and the car only showed 350 RWHP N/A and 500 on the same nitrous shot/tune. Even though the numbers dropped, his best time with the 6 speed was 10.40, now with the TH400 and a brake the car has a best of 9.73.... a little more nitrous has help that number but the trans made a huge diff.

HAMRHEAD

iTrader: (8)

That's why dyno numbers only tell half the story. Plenty of people out there make claims off just dyno numbers.

99Z28LS1

iTrader: (4)

i would only use dyno numbers if i ran on the street primarily, which i do. then it becomes a game of traction, which i have. but if i were a track only car, there would have to be a POWERFUL *** clutch in there or an auto

99Z28LS1

iTrader: (4)

i dont see an auto destroy a rear end like the manual cars do. i could be very wrong though

iroctt

iTrader: (1)

Wonderbread

I'am curious he dropped from 10.4 to 9.7 ET how did the trap speed change?

Wonderbread

iTrader: (51)

He is at work right now so I cant ask for sure, Ill get him to chime in, but I dont think he picked up much MPHm aybe like 3-5, but I believe that is because of the converter on the big end.

6techniques

iTrader: (7)

yeah, but what about those guys in 3500lb+ cars...Weight isnt exactly the best friend of PG's...and the only one that I know of running one is Na$ty-TA and I think he'll swear by the PG but he's only one of the rare few that have enough confidence in one.

squealingtires

iTrader: (14)

curiosity has caught me. What exactly happens internally in the TH400 during the 3rd to 2nd down-shift? What is the failure? What is the fault?

blackz93

iTrader: (2)

You totally lost me there! What do the rods have to do with it?

andereck

Its not nice to take the load off of aluminum rods. You can deform the big end which can lead to bearing/rod failure. I personally won't let any engine drag down on decel.

engineermike

There was a guy on tm.com that was making 700+ rwhp on a 4.6 4v. He went from a 6 speed to an AOD and dropped 220 rwhp, but the et dropped. Not sure about the mph. I know my own car runs pretty good for "only" 695 rwhp. 146 mph at 3700 lb.

andereck

I ran a powerglide in my small block street car for quite a while and some of my buddies gave me **** and said the car would be even quicker with a 3 speed. I picked up a great deal on a fresh 400 and had a friend disasseble it for a TCI brake. The powerglide was already running a turbo spline converter and I borrowed a crossmember and driveshaft from a friend for the 400 in the Camaro.

Driving the car was a bit more fun with an extra gear but I didn't dig the reverse pattern and 2nd gear overrun was weird. The TCI brake will apply reverse in any shifter position, including park!

Dragstrip performance was disappointing but expected. The car went only .05 quicker and lost 1.5 mph. In my way of thinking what I gained in ratio I lost in parasitic drag. I just love the powerglide I suppose and they're dirt simple. Your mom could put one together.

YMMV

Mike: Wow! I had no idea your car was that fast.

andereck

Nothing happens on the downshift per se. The problem is shifting second gear with a braked 400, letting it overrun and rpm drop and then nailing it. The shock to the sprague race can cause it to split and take out the planetary set. This only happens if the band is removed or disabled by the valve body. Most reverse bodies are set up this way so you can have a neutral at the end of the run.

kp

iTrader: (34)

I could type this out but this is much easier

http://www.chevelles.com/forums/show...1&postcount=19

LSXNV

iTrader: (1)

guys, imo, dynos are for tuning. the 1320 numbers tell "the rest of the story".

andereck

Entertaining and informative. Thanks!