dan_t

I know that a lot of you on this section won't have much expereince with an Auto out on track, but its what I got so I use it....

One thing that I am struggling with is the firmness of the manual downshift, 3-2 mainly as I can do without first on most places.

Is there anyway I can avoid the abrubt, firm change as I shift the lever? It really up-sets the car and its really slowing me down. In a Manual I'd Heal-Toe but obviously thats not an option here!

Any help or advice greatly appreciated!

Slalom4me

What road speed is this occuring at?

This thread may have relevant reading.
As a follow-up to the discussion within, lock-up values were
changed and flashed to a new BIN on an aftermarket chip
capable of storing multiple BINs.

In conjunction with a remote switch that permits BIN changes
on the fly from the cockpit, the arrangement permits me to
retain TCC lock-up and switch between road and track speed
lock-up settings.

A simpler approach might be CFI-EFI's suggestion (in the link)
to add a toggle switch to defeat TCC and simply run un-locked
during an event. A caveat to this is that I did not pursue clairification
about the comment "that the GM 700R4 (4L60) transmission does
not route fluid to the cooler unless the TCC is locked." Our
respected C4 Tech 700R4/4L60 guru, Pete K replied at the time
that his test indicated there is SOME fluid flow. Since I altered
rather than defeated TCC and I have a t-fluid temp gauge, I
did not feel any need to investigate the fluid flow statement further.

I also bought a converter with a higher stall. Installation is pending
further news about availability of some other transmission parts I am
interested in.

.

Aardwolf

I use an auto too, I unwind the wheel a little right before the shift so the car is less likely to step out. I don't ever get first either, just 2-3 up shifts. I don't down shift with it, by 3-2 shift you are downshifting it before a corner? Does the rear skid?

dan_t

Will check that link out - thanks...

yes I want the downshift before the corner. I've watched your vids and see that you let the downshift come after but it doesn't feel right to me. Also maybe cause my power-band has been pushed up the rev range somewhat!

dan_t

I dont think that link would help as I'm above my stall speed anyway? - When I drop to 2nd I want to see around 4000rpm's

Slalom4me

My vote is that there is potential for slippage when the converter is
unlocked and above the stall speed. Otherwise there would seem to
be little need for the lock-up feature.

From post #16 in the link
As always, there is usually more than one way to achieve an end.
Hope to follow along to hear what turns out to work well for the
OP's circumstances.

.

dan_t

when you say a loose and tight converter are you talking about the lockup or actual kind of mechanical slip the the converter allows?

Slalom4me

The context of the original post #16 was in reply to #14 and was
referring to looseness in terms of higher and lower stall speeds.
I feel it is relevant in this thread to illustrate that when the TCC
clutch is disengaged, the engine and transmission are decoupled.

An OEM converter w/ an 1,800 RPM stall may not have much slippage
at 4,000 RPM, but there will be more than there is when the lock-up
is engaged. My vote is this provides an opportunity to better match
engine RPM with transmission input shaft speed upon downshifting
and thus reduce unsettling of the car with unwanted engine braking.

.

dan_t

I found a fix for this - I've pulled the 700r4 and done a deal on a ZF-6! I cant wait!!!

Slalom4me

Does the deal include the D44 rear end and C-Beam that were OEM
with the ZF6?

If not, be prepared to undertake some modifications to your 700R4-to-D36
C-Beam in order to accomodate differences. I am not well versed in
the details, but I believe that the center-to-center distances from the
tailshaft to the differential housing vary.

Perhaps a new thread in C4 Tech will draw out comments from those
who are more familiar with the fine points of this swap.

Two other considerations - the D36 supplied with the 700R4 is noteably
more fragile than the D44. Some people have reported that cryo treatment
extended part life. Usage is a factor.

Also, a popular swap for 4+3 owners is to move to one of the Tremec
aftermarket transmissions. Keisler offers kits for this conversion and
they also offer one for replacing the 700R4. Forum regular LD85 is
currently considering the Keisler package, Carl Johansson and others
have already gone down the path.

Keisler TKO 600 experiences

I realize that your location may influence the decision criteria. Doesn't
hurt to look into the matter, though.

.

dan_t

they don't know but I've got me eye on a D44 thats for sale over here in the UK, unfortunately its a 3.07 but at least it would have the strenth issue sorted and I can do a ring a pinion later on down the line.

I beleive that the C-Beam just needs the holes re-drilling...