Which auto for a 4 cyl turbo?

[justbrett]

Hi Guys

I've got a Mazda 1000 ute which is soon to receive a transplant courtesy of a 1.8 Zetec from a UK formula ford, plus a turbo. Aiming for 350-400 hp at the fly.

I want to drag and hill climb the beast (and the odd spin on the street) when it's done so I know whatever I choose would be a compromise at some point.

Problem is my left knee is screwed and even a light clutch causes me significant discomfort, so I want to use an auto. ( Yeah I know, harden up! : )

I figure a manualised 3 spd like a C4 would do the job but have also heard good things about 2 spd powerglides for similar applications. Or should I be looking at a 4 spd? I'm just not sure whether the extra gear(s) would be of much use.

Any trans experts on here care to offer some wisdom?

Cheers.

Brett

[Saraco]

Powerglide would be good for competition, the street part kills it though, you will need a very high stall speed on the converter for it to work. Not very practical on the street! So a C4 it is, turbo cars by nature use loose converters and reasonably tall diff gears, but the C4 converter will still be tighter than the 'glides. Either way you go they will need a trans brake, the only way to get a turbo to spool up at the start line at the strip. Makes a BIG difference to elapsed times!P.S. You must be careful with stall speed and the tall diff gears turbo cars require, since it will compound the problem of excessive stall speed.

[justbrett]

Cheers svov88.

I was also thinking the 3spd might be better for hillclimb work providing I have enough brakes so I'm not using the trans to slow the car too much. Couldn't be good for it in the long run?

[Saraco]

Auto transmissions don't like to be downshifted constantly without engine load i.e without kickdown/powering on etc. Puts loads on one way roller clutches /sprags etc. Don't ask how I know this! If your more worried about hillclimbs, consider a manual and see a physio/ chiropractor. For drags, manualised automatic is the go.

[justbrett]

Thanks mate

My knee's a bag of bones so there's sfa a physio or chiro can do. I'm up for a replacement when I'm old enough or when I can no longer walk (kinda ilke waiting to get your licence!).

What about the tiptronic autos ie. the BA 4 spd, do they need a complete ECU to work properly or am I dreaming on that front?

[rag top]

Originally Posted by justbrett

What about the tiptronic autos ie. the BA 4 spd, do they need a complete ECU to work properly or am I dreaming on that front?

justbrett :

The dude with the EH in the project section had a tiptronic setup in his steering wheel in a previous build.
http://www.fordforums.com.au/showthread.php?t=11247388

With $$ and the right computer guru, should be able to get you sorted.
Have you looked at the AOD box (non electronic 4sp Auto)
or a Gear Vendor's setup?
http://www.gearvendors.com/

Borrow Benny's gearbox. I won't tell him :

[justbrett]

Originally Posted by rag top

justbrett :

The dude with the EH in the project section had a tiptronic setup in his steering wheel in a previous build.
http://www.fordforums.com.au/showthread.php?t=11247388

With $$ and the right computer guru, should be able to get you sorted.
Have you looked at the AOD box (non electronic 4sp Auto)
or a Gear Vendor's setup?
http://www.gearvendors.com/

Borrow Benny's gearbox. I won't tell him :

Cheers Mick, and : backatchya!

Gonna look into a C4 and talk to specialists about building one that's a bit of an all purpose job. The gearvendors thing just has me asking more and more questions (one of which being how much is a kidney worth these days?).

[f6speedster]

You should give Al's Race Glides in Sydney a call as he has done many auto transmissions for 4 cylinder turbos especially C4's. He is also the Australian agent for Gear Vendors. We have done alot of development for him with the C4 behind a 358ci Ford and he can build a tough box. Speak to Al or Brad.

Cheers.

[Saraco]

There are stand alone computers with optional steering wheel paddle shifters for some US electronic transmissions, none that I know of for Aussie stuff, but I'm a bit of a dinosaur, so who knows?!

[atec77]

Originally Posted by justbrett

Hi Guys

I've got a Mazda 1000 ute which is soon to receive a transplant courtesy of a 1.8 Zetec from a UK formula ford, plus a turbo. Aiming for 350-400 hp at the fly.

I want to drag and hill climb the beast (and the odd spin on the street) when it's done so I know whatever I choose would be a compromise at some point.

Problem is my left knee is screwed and even a light clutch causes me significant discomfort, so I want to use an auto. ( Yeah I know, harden up! : )

I figure a manualised 3 spd like a C4 would do the job but have also heard good things about 2 spd powerglides for similar applications. Or should I be looking at a 4 spd? I'm just not sure whether the extra gear(s) would be of much use.

Any trans experts on here care to offer some wisdom?

Cheers.

Brett

Because of the way the turbox4pot works you need lotsa gears
I suggest you look at the chev/holden4 speed auto manualized with a custom housing or a suitable 5 or 6 speed manual with an altered clutch , I also have a shagged knee but it handles a low preasure clutch just fine
(4wd MKIII golf 2Lturbo)and trust me there is NOTHING like the fun of powerband in a manual

[justbrett]

Thanks f6, I'll give Al's a call.

Cheers for the input atec77. I've even thought about trying to adapt a hydraulic clutch lever onto the shifter or something but I'm not sure my co-ordination would be up to the task : .

It's not the resistance that causes me dramas but the action itself, if that makes any sense (I am a bit special : ).

I think a 3 speed auto should do the trick if I can get one built to cope with a bit of engine braking, probably be lucky to get out of second gear on our local hillclimb track anyways.

The next challenge would be to find an auto shifter that allows easy up and down shifts. I assume 99% of the performance shifters are designed for fast and easy upshifts with little thought given to downshifts. Anyone?

[ebxr8240]

UMMM ?? How about a Subaru auto ???
Obviously take the transfer case off the front...
Mrs has STI equipped WRX auto.. Shifts up and down manually etc...
Few klrs on it now but its working fine...
A Jatco auto is another top box...
Turbo converter are not set as high as high rpm N/A engines...
Just enough to spool turbo depending on turbine size??

[dat_40l]

my mate has a jatco behind a methanol sr20 turbo they are a good box, then i have the bigger jatco RE4R03A full manualised in my xr6 turbo. they were both built by KEAS transmissons.