converting a bw35 to modern 4 speed autobox, anyone?

[englishbull]

Cheers, Harvey,

I hope you'll keep us updated on the evaluation process...

Best regards
Thorsten

Yes I would be keen to do this to Thorsten.............

[sorbs]

I always fancied fitting an overdrive to my 2000 BW35. The idea was scoffed at at the time so it's nice to hear it's been done!

I never got round to it and just bought a car with a 4 speed auto instead........

I'd always liked the idea of the overdrive being automatically engaged which would have needed a speed signal, load or throttle position signal and a little programmable control unit to get it to switch in and out as required.

[Andy Thompson]

There is an Aisin Warner 4 speed auto - fitted to some Volvos and the Toyota cressida
My mate has one on his Stag - so it can be made to fit

A40D
Four speed automatic
Applications:
1977-1980 Celica Supra
1983-1986 Celica Supra (Australia)
1981 Corona
1981 Toyota Cressida


The AW70, 4 speed auto (without lock up clutch - controlled 4th gear 'overdrive') 240 series, B23F engine.

http://v1800reg.org/pages/AW70%20CONV.PDF this might help

[Alan Chatterton]

a company called tate and lewis off the ZF 4 speed auto (22HP I think) into the stag. Simple ish conversion with a special adaptor plate.

a friend of mine enquired about a saloon, it could be done but there might have to be some minor tunnel "mods" (big hammer!) to make it fit.

Driven a stag with this box and its very nice indeed.

Problem is the cost, £2500.

Dave Hosegood fitted a AL4D box from a Granada Scorpio to his car, full write up including all the tech details on how he did in Sixappeal a few years back?

[CAR]

Dave did indeed do the conversion and a write up in SIXappeal a while back, he lives close to me although I haven't seen the car. It was said to be very good.
The Stag conversion at £2.5k seems a bit steep, a gearbox out of a later BMW would seem an excellent choice, Dad's '96 323i has a 5speed ZF switchable box that does just under 2000rpm at 80mph. He manages to get a true 39+mpg from that 2.5L car coming up to visit us at a steady 70mph.

There must be loads of those E36s in the breakers now, all it needs is someone with an engineering background to prototype a conversion. The box, electrics, mounts and prop ought to be £150 tops from a scrapyard.

Colin.

[TR7Driver]

Dave did indeed do the conversion and a write up in SIXappeal a while back, he lives close to me although I haven't seen the car. It was said to be very good.
The Stag conversion at £2.5k seems a bit steep, a gearbox out of a later BMW would seem an excellent choice, Dad's '96 323i has a 5speed ZF switchable box that does just under 2000rpm at 80mph. He manages to get a true 39+mpg from that 2.5L car coming up to visit us at a steady 70mph.

There must be loads of those E36s in the breakers now, all it needs is someone with an engineering background to prototype a conversion. The box, electrics, mounts and prop ought to be £150 tops from a scrapyard.

Colin.

Hi Colin, Don't 'spose you could get Dave to repeat the write up or attach it to the forum?

Cheers,

Jim

[TR7Driver]

Just got back from Reigate, via M4. Speedo shows 78/80mph, rev counter shows 5000rpm, tomtom shows 70mph! TR8 would be doing about 2100rpm. Is the autobox at fault? or do I need to change the diff?

Cheers,

Jim

[Thorsten]

Jim, of the back of my head I reckon the the engine speed/road speed ratio in auto 3rd should be somewhere around 20mph/1000rpm in a 2000 (3.7:1 diff), a 2.5 even better I suppose. So if your rev counter is correct, there's something wrong... I'm not sure how far off a 4.1:1 diff would get you?!

Rgds
Thorsten

[kevinw]

if someone can identify approximately which issue of SIXappeal the original article appeared in, I could reprint it. I have the "official" archive, but the problem is that only the last 3 year's worth are electronic and the preceding 27 years worth are on hard copy - and that takes up the best part of a filing cabinet - so a lot to search through.

They are all indexed, so if I know approximately which issue, it is much easier to find for a reprint.

Kevin

[sorbs]

I think a 2000 with direct drive (4th on a non overdrive manual) gives about 16.7mph/1000rpm? So a true 80mph (probably 90 on the speedo) would give 4800rpm. That's with a 4.1:1 diff.

A 2000 auto should have a 3.7:1 diff giving 18.75mph/1000rpm so 4250rpm at a true 80mph.

All 2500s should have a 3.45:1 diff giving around 20mph/1000rpm in direct drive top, 3rd on an auto, 4th on a manual.

5000rpm at a true 70mph tends to indicate a problem with the rev counter reading, diff ratio or maybe a slipping transmission.