I have an auto box and I think its very sluggish not sure but i think first and second gears are higher ratio than the manual? because 1st gear on take off is just slow then onece it gain speed it hits 2nd were the revs drop considerably which looses you power.
will be converting to a 4 speed manual very soon.

Yeah mate, full aware how hi stalls work. Had them in my daily drivers for about 6 years straight . I live in the middle of a city and constantly find that I'm regularly shifting above 4 grand to keep up with the metropolitan traffic Golf Gti's ect.(Stock A12)So rev wise wouldnt be all that different. I also do a lot of higway driving usually sitting smack on 4000rpm in 110kph zones, so no difference there. I have a H89 head which I find struggles on the mountain roads I frequent at lower revs, so would be helpful there also by keeping the engine in the torque band. As far as taxing power is concerned some autos are a lot worse than others. For example the fords FMX taxes in the vacinity of 65hp compared to the C10 @ 35HP which is only slightly more than the manual top loader box. The 4N71B box sounds interesting. Hi stall that are too slippery are pigs to drive. Good convertor shops are able to match build convertors to engine specs for a more progressive torque transfer. There are also locking convertors now which are a Rad idea for street cars. Check out Taipan convertors. Not sure that I would want a Hi stall behind a stock a 12, but I think behind a built A series engine it could be a bit of fun. Something different too.

Comparing it to other brands of autos doesn't mean much.

The A12 automatic is a 71-series big unit. Same size as used in the six-cylinder Datsuns, although not necessarily as beefy internally, it's plenty strong for 1200cc.


Quote:It feels even more doughy with a high-stall converter. But if driving at full throttle it will be very responsive. Keep it above the stall speed and it will be pretty responsive. It will cruise below the stall speed, but you'll see the tach jump up every time you touch the accelerator pedal (like a lot of new cars do).


Quote:Sure it does. That's what a high-stall convertor is for. If you put a 4500 stall converter in, put it in Drive, let off the brakes, rev the engine to 4000 RPM and the car doesn't move (more or less, it will creep). If that's what you want go for it. But at 4500 RPM, you have the A12's full torque put to the diff. It's like revving up and dumping a clutch. All the time.


Anyways that's my (limited) experience with high stall. I never had a 4500 stall converter but had a 2500. If someone has more experience, let us all know.


If you want an automatic that's just as efficient as a manual, swap in a 4N71B. 4th gear is direct drive just like a manual for similar fuel economy at highway speeds. Plus 3 other gears for more get-up-and-go.

I agree. The lil 4 speeds can take some punishment. So DD, the the A series auto doesn't tax much power compared to the manual box?? Does anyone know if shift kits and decent bands are available for these autos. Would be interesting if old mate with the dyno could do a comparison. In stock form the auto's feel prety doughy. The only problem I have had with the various autos, wearing out not included is snapping off the bands next to the clips next to the clips. That was my own fault doin 7000rpm 1st to 2nds in an XC falcon with manualized C10. Only happened twice. Other than that no drama's. Point being, I have had less breakages with auto than manuals overall ? So, draw through turbo A15, 4000rpm convertor, manual valve body, locked diff.... would be like a mini pro street traffic light bandit, bigs n lils, Im starting to like this idea way too much lol

and unless you have the inabilty to use the clutch a series boxes are tough as, smashing gears only happens when you dont get it to go into gear

thats what happened to the last 2 boxes ive had ,both had #OOPS#ed syncros so they would clunk going in if i revved it out in every gear ,till one day a tooth broke off and went through the gear set ,destroying the gear set but leaving everything elsi in good nick

Yes people have done it. No it doesn't drain power, but it doesn't drive the same afterwards.

Blowing up the box? It'll blow up faster with a hi-stall converter.

I've been wanting to do the same thing.. The auto boxes are probably stronger.. I keep blowing a series boxes.

A built a12 with a 4500 stall would be fun. Ive had stall behind V8's never heard of ANYONE DOING IT TO 4 BANGER. mAYBE THE POWER DRAIN OF THE AUTO IS STILL TOO MUCH ???

I was thinking the same thing!

Has anyone ever put a hi stall behind an auto A series ?