Seeking some PowerGlide transmissionwisdom. Convert from track to street.

Here is the deal.

I am re-powering the Molvo from Ford 302 to GM LS power.

I want to use a powerglide autobox because I have one already.  The two speed thing does not bother me as there should be plenty of torque to drive the car around. The  engine will be spinning 2900 rpm at 60 mph, I will live with that. For now.

The problem I have is that the powerglide I own is highly modified for quarter mile racing. It has a transmission brake and it shifts very hard. Great for 1/4 mile launches and ET but not something I want to live with on the street.  The good news is that the spiny bits in the transmission are supposedly bbullet-proof; whatever that means I do not know but the previous owner spent like 6k on having it built and it was working as designed right up until the car crashed.

The hope is that I can get my hands on a stock powerglide and harvest the valve body and all the racecar shifting goes away to give me the powerslush shifting that I want, with a box whose internals are capable of living with the LS power. Is that a reasonable assumption or is there going to be some interdependncy between the 1/4 mile valve body and the internal spiny bits that makes this all not work?

Just an idea....find some drag racing FB groups over there and see if someone would trade a  stock TH350/400 or a 700R4 for it.

Edit: What converter do you have to go with that 'Glide? Some really high stall thing?

I would probably throw a regular valve body and governor back in and see how it goes. But its probably easier and less $ to sell it and get a regular th400 or 4l80e and get another gear or two if you plan to street it. 

Paul_VR6 (Forum Supporter) said:

I would probably throw a regular valve body and governor back in and see how it goes. But its probably easier and less $ to sell it and get a regular th400 or 4l80e and get another gear or two if you plan to street it. 

Forgot about the governor. I do have a spare one of those around. Is the governor possibly responsible for the box not shifting until high rpm and then hitting like a golf club on the ball? Or is that on the valve body?

The torque converter is not a super high stall; as a matter of fact the PO complained that it was way too low for the Hot Rod it was being used in. 

I am doubtful that a 4L60 will fit in the Miata tunnel space. The powerglide seems to fit with lots of space to spare. Maybe time to see if I can find a 4l60 core for reasonable $$$. They are about 3k to rebuild but maybe worth it if it can be made to fit.

Isn't the 200-4R a bit smaller than the 700-R4/4L60?  I think the gear is more appropriate as well vs. that truck-gearing-deep 1st on the 700.  Have to find a 200-4R though, which isn't bad if you don't mind just buying one outright...

In reply to pres589 (djronnebaum) :

I have never heard of that box. 

Seems to have better gear ratios but still needs a TV cable that will take out the gearbox and some way to deal with the lock-up feature. That last one I have no insight into. yet.

For converter control of the 200-4R, you can get kits like this one; Painless Products 200-4R Transmission Torque Converter Lock-Up Kit    -note that I do not have direct experience with this

It looks like there are TV cable kits for cable-controls throttle bodies on the LS.  Having to deal with a TV cable in a non-stock application does seem like a hassle. 

It seems like you'll probably want to do something like this eventually anyway so there's a bit of buy once cry once to it.  I also understand wanting to get a more simple setup going first before stepping up to a higher cost and more complex solution.

In reply to pres589 (djronnebaum) :

The reality is that I expect the auto to last exactly one driving season and then go spend $$$$$ on a TKX 5 speed. Mrs NOHOME said she wants to drive the car if only it had an auto. Methinks the novelty will wear off. and I can gauge the level of interest with a something I already own.

Also why I should have just bolted the C4 that I have on to the back of the 302 that was in the car, rather than dive into a whole LS swap. But what else to do when you have a winter to kill?

NOHOME said:

 But what else to do when you have a winter to kill?

Curling.

NOHOME said:

In reply to pres589 (djronnebaum) :

Mrs NOHOME said she wants to drive the car if only it had an auto. Methinks the novelty will wear off.

With a drag oriented Powerglide, I guarantee it.  

In reply to Russian Warship, Go Berkeley Yourself :

Hence the need to de-dragify the thing. The only reason I want to use the powerglide is that I know it drove to the scene of the accident that killed the car and it worked well right up to the tree-crunching event. If I bought a 350 or 400  on marketplace I would have to have it rebuilt; if I can even find a shop that touches them. Getting kinda hard to find people who will.

Without knowing anything about what was done to it, "de-dragifying it" is going to be really tough.   You would have to basically pull it apart, which is the same as rebuilding it.   Every single part of the Powerglide has drag upgrades available, including the case, gears, drums and clutches...

Sounds to me like it should basically just need the line pressure dropped a bit.

Or shift it manually and let off when you shift?

Check out bowtieoverdrives.com for plenty of 200r4 and 700r4 info on tv cables etc. 

Yeah, I'd sell the 'glide and use something else.

Pete. (l33t FS) said:

Sounds to me like it should basically just need the line pressure dropped a bit.

 

Or shift it manually and let off when you shift?

Ya know...this might just be the answer; mod the driver and not the transmission.