TCC lockup - which scheme would give better performance?

[Bruce Plecan]

-----Original Message-----
From: David A. Cooley <n5xmt at bellsouth.net>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Saturday, January 09, 1999 12:24 PM
Subject: Re: TCC lockup - which scheme would give better performance?


>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.

Then explain why his tranny is working long after the others would have
failed.

>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.

Yes, and once done was right.  The 200R was designed to do a WOT
high gear shift, and the 700R took 5 years of deployment to get that.

>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.

I've never heard of a GN thou with that sort of failure rate.

>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...

And most are trailer queens at that stage.  Or of limited street use.
I'm talking street car, not race car/trailer queen stuff.

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

An 11 sec GN with a stock other than govenor 700R, I would have to see, to
beleive.
>
>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).

Then why at 300HP did I start killing them so often, and then deleting
the TCC instantly it lived.

>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.

I'd had mine out several times, and appart and never saw any
evidence of even an accumulation of anything there.

I still stand by what I said, to avoid failures, don't lock it at WOT, or
run a non TCC converter, period.
Bruce
>
>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...
>===========================================================
>           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.
>===========================================================
>