TH-400 "Automatic" ?s
03-07-2005, 04:04 PM
#1
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TH-400 "Automatic" ?s I have searched for info on the th-400 and I found a lot of good stuff. I will build my future car up for street only and I'd like to get 800 rwhp out of it. I like the idea of having a th-400 with gear vendors OD but I would also like the idea of having a tranny that is as "automatic" as the 4l60e. The only question I have that hasn't been answered is if the th-400/GVOD can be fully automatic for street racing and normal street driving. Can I have this combo and not have to shift it myself and still reliably support 800 rwhp? If not, I might as well get a M6 with the g-force upgrade with a strong clutch. I just don't want to have to shift it because I prefer autos but I also need one that can handle 800 rwhp. Please let me know what I should do. Also consider that this car will hopefully be my daily driver.
T.J.
T.J.
03-08-2005, 01:07 AM
#2
The Gear Vendors O/D has an "AutoDrive" mode that is sort of automatic. It will engage the O/D at about 48mph and disengage at about 18. The TH400 has to be calibrated to shift by using the throttle valve cable and governor.
I think the best results for a fully automatic drivetrain would come from a 4L80-E. The 80 can reliably support 800HP if built for it, just like the TH400.
I think the best results for a fully automatic drivetrain would come from a 4L80-E. The 80 can reliably support 800HP if built for it, just like the TH400.
03-08-2005, 04:21 PM
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Thats good to hear because I want to buy an automatic tranny for a reason, consistency. If I wanted to shift it myself I'd just get a M6, lol. Does Rossler build a strong 4l80e for our f-bodies? Thanks for the help,
T.J.
T.J.
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03-08-2005, 09:00 PM
#8
I think most people that swap to a TH400 set them up to a reverse-pattern manual valvebody with an aftermarket floor shifter. The pattern ends being P-R-N-1-2-3 instead of P-R-N-D-2-1.
For a fully-automatic TH400 line pressure is vacuum-modulated and the kickdown cable and governor determine upshifting and downshifting based on throttle position. Not much to adjust here and you definately cannot choose specific settings for each gear.
The 4L80-E is fully electronic and can be programmed in your stock computer (if the year PCM supports it) for shiftpoints based on speed and manifold pressure. Line pressure can be set for every gear based on manifold pressure.
With an aftermarket controller like, like TCI's, the setup is based on throttle position instead of MAP for all those parameters and tables. The TCI also has the ability to paddle-shift by just adding some simple switches of your own design.
With either a supported stock PCM or the TCI you can set up a 4L80-E to shift silky-smooth at light throttle with stock characteristics AND have it snap your neck up top. It can be refined to whatever you desire in terms of shiftpoints and firmness and will be consistent 100% of the time.
-James
For a fully-automatic TH400 line pressure is vacuum-modulated and the kickdown cable and governor determine upshifting and downshifting based on throttle position. Not much to adjust here and you definately cannot choose specific settings for each gear.
The 4L80-E is fully electronic and can be programmed in your stock computer (if the year PCM supports it) for shiftpoints based on speed and manifold pressure. Line pressure can be set for every gear based on manifold pressure.
With an aftermarket controller like, like TCI's, the setup is based on throttle position instead of MAP for all those parameters and tables. The TCI also has the ability to paddle-shift by just adding some simple switches of your own design.
With either a supported stock PCM or the TCI you can set up a 4L80-E to shift silky-smooth at light throttle with stock characteristics AND have it snap your neck up top. It can be refined to whatever you desire in terms of shiftpoints and firmness and will be consistent 100% of the time.
-James
03-08-2005, 10:27 PM
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Wow, thanks for the info guys. I think I'll definitely get the 4l80e, even if it does run me over $5,000. I found a thread on it earlier today and some guy said that his whole setup, fully automatic and capable of over 800 rwhp, will run him about $5,000. Hey, you gotta pay to go fast and be reliable, right?
T.J.
T.J.
03-10-2005, 10:32 PM
#10
4l80
Originally Posted by FLeXNuTZ
I have searched for info on the th-400 and I found a lot of good stuff. I will build my future car up for street only and I'd like to get 800 rwhp out of it. I like the idea of having a th-400 with gear vendors OD but I would also like the idea of having a tranny that is as "automatic" as the 4l60e. The only question I have that hasn't been answered is if the th-400/GVOD can be fully automatic for street racing and normal street driving. Can I have this combo and not have to shift it myself and still reliably support 800 rwhp? If not, I might as well get a M6 with the g-force upgrade with a strong clutch. I just don't want to have to shift it because I prefer autos but I also need one that can handle 800 rwhp. Please let me know what I should do. Also consider that this car will hopefully be my daily driver.
T.J.
T.J.
