TCC lockup - which scheme would give better performance?

[David A. Cooley]

At 08:52 AM 1/9/99 -0500, you wrote:
>
>Don't lock the TCC under full throttle!.
>The TCC is much softer than the other clutches in the tranny to prevent it
>from chattering.  I've gone thru 4 or so tranny overhauls in my 700R4.  Last
>guy said ditch the TCC, and you'll never break it again.  Well put 50,000
>on it, and it's still alive.  Cording to him what kills the 700's 4L60's is
>the
>TCC fllaking off and contaninating the fluid, and at a microscopic level,
>getting embedded in the other clutches, and then they fail so like the 3-4
>clutch problem is really caused by the TCC.  I will admit, that I'm hell on
>trannies,
>with all the calibration testing I was doing, but going to a non-lock up
>converter was the best tranny money I've spent.  If you don't drive hard
>often, or mileage is your primary concern ignore the above.
>  Also, comparing the 700 to the GN 200 isn't a good comapro in my book.
>The 200 as installed in a stock gn is light years ahead of stock 700, in
>my opinion.  Very early in the gn program, it was looked at to haul 4
>guys with misc hardware at WOT in pursuit situations.  The 700 was
>never really successful at that, from what I've seen/heard.
>  Bruce

Bruce,
The trans guy is dead wrong.
The GN 200-4R trans was a beefed version of the Auto OD trans slated to go
behind a normally aspirated 160HP V6...  Buick had to do some fancy dancing
to get turbohydramatic to allow them to put the trans behind the turbo 6.
I had a non-intercooled 85 Buick T-Type, only 200HP and fried 9
transmissions, including snapping off the input shaft on one at 80,000 miles.
It was never designed to be used for extended High HP functions... (racing!)
The 700-R4 wasn't used because it would have taken a new case with the
proper bellhousing bolt pattern... it was a chevy/corporate bolt pattern.
Of all the GN's racing, the guys are running lock up converters, and
locking them up at WOT until they get into the 11 second bracket with no
problems...But the trans they use is a MUCH modified version of the stock
GN trans.  After that they go to the non-lockup 9 inch converters for
higher stall speed and no lock up is used only because the 9" has no room
for a clutch to handle the HP.  The factory lockup converter is a piece of
junk that comes apart, but the aftermarket Torque converters with lockup
are lightyears ahead of the factory parts.  There are a few GN's with 700's
installed that used adapter plates and they are really happy with the
combo... No internal trans mods (except the governor weights/springs to get
the trans to shift at the proper points for the turbo-6) and they are
running in the 11's

The 700 trans is strong enough to be used behind some very healthy V8's
with lockup without any mods but a trans cooler (external).
The problems that arise is if the TCC solenoid becomes plugged.  then the
TCC slips and will destroy itself... this happens in any trans with TCC.

Not sure where you're located, but the best person to ask about the 200-4R
and the 700-R4 is Mike Kurtz at PMAC in Houston, TX.
He's had the 200-4R living in 9 second cars!... I had asked him about the
700 for my buick and he said it wasn't necessary unless I really got up in
the HP...
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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
       I am Pentium of Borg...division is futile...you will be approximated.
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