[Bennyzarb]

Hey people I have a gti powered Sierra and wanted to put an auto in her what autos could I put in and how hard is it to make it work with the gti ???

[Fatzook]

A G13BB auto will bolt up, but there will be some electrical madness to overcome, and I'm not sure how long it would last with the savage Gti motor in front of it.

A vitara AW4 would be my choice. But you will need an adaptor, and the same electric work as the BB auto.

You'll also need to widen the tranny tunnel, make new crossmembers, add a bearing or shaft support at the back of the auto.

Its plenty of work.

[Bennyzarb]

Hmmm I don't mind work it's just concerning me about the auto cause the gti revs so high I would think the auto would shift gears to early before you got all the power hehe and what about transfers and stuff

[Bennyzarb]

Does anyone have any pics of there aw4's they can post plz

[Bennyzarb]

What is the bennifet of having an auto over a manual

[atari4x4]

i'm copying & pasting Steves post cause he writes pretty words. :pompoms:

Gwagensteve wrote:

suzpect90 wrote:

what makes the auto better then a manual box ? are there things that make having a auto better apart from the having to change gears?

And I'll weigh in with the more technical reason.

Because an auto is like hydraulic drive- by using left foot braking, you can separate torque at the wheels from wheel speed. That's really valuable- it means you can crawl over obstacles very slowly but in perfect control. Never roll back when pulling away regardless of how steep the hill is. Stop the car with absolute precision- like anything else with hydro drive, like a Bobcat.

And wot they said

Steve.

stolen from this thread...

viewtopic.php?f=5&t=38326&hilit=torque+wheel

[Bennyzarb]

Hmmmm ok I want an auto now
How to I make the autos computer work with the computer on my gti ?

[SierraDan]

If you use a 3spd itll be fine. Or there is a tech thread on using the AW4 without a G16B.
(on phone, atari will get the link im sure )

[Gwagensteve]

I was thinking the same thing- No need for an AW-4 if it's primarily a trail car. The gearing compromises of a trimatic are far less of a concern on a trail car, and there's no wiring (other than the start interlock and reverse lights)

Steve.

[JrZook]

Bennyzarb wrote:

Hmmmm ok I want an auto now
How to I make the autos computer work with the computer on my gti ?

AW4 to GTI can be solved

[Gwagensteve]

I'm sure it can JR, but if the end result is the car can't ever pull OD because it's revving too low, then it was all much ado about nothing.

My understanding is Bennyzarb's car isn't a daily, so the cruise RPM and/or added refinement of the AW-4 might not be required, making the shorter, looser, and computer-free trimatic more viable. I could be wrong though.

Steve.

[mudboy]

t700 in it like mine lol

[Gwagensteve]

And the advantage of a T700 over a AW-4 is?




Nothing.

They have the same gearing, (near enough) the same converter ratio (near enough) and both have a deep OD.

Steve.

[Bennyzarb]

Mine is a daily ha it is running hilux diffs 4.88 gears 35" tyres 6.5 transfer gears
What is this trymatic auto what is it out of and how would it go onoad?

[Bennyzarb]

How does a tri-manic auto work?

[atari4x4]

tryed da sirch?

[Gwagensteve]

Bennyzarb wrote:

Mine is a daily ha it is running hilux diffs 4.88 gears 35" tyres 6.5 transfer gears
What is this trymatic auto what is it out of and how would it go onoad?

A trimatic is a vacuum shifted three speed auto used in the carby auto vitara, along with all sorts of GM product (like kingswoods and commodores) I have put two in sierras, one running a Baleno, and one running a carby G16B. They work find offroad but they are tough to gear on road due to the direct (1:1) top gear, equivalent to 4th in your manual gearbox.

OK, if you're legitimately daily driving this setup you can't run a trimatic. 100km/h = 4800rpm with a 1:1 top gear.

If you dropped to 4.3 diff gears I get 4233 rpm, and with 4.1's 4036 rpm @ 100.

I wou'd have thought you'd want to be around 4K @ 100 km/h with a GTi and 35's.

The problem is, that's hard to achieve with a AW-4 too.

With your setup now, an AW-4 spins 3603rpm @ 100. I'm not sure a GTi will have enough torque at 3600rpm to hold the converter locked. my guess is you'll be swinging between converter locked/unlocked/thrid gear, which will bump revs back up 4800. There's a BIG step between third and 4th, and without the torque of a 1.6 to cover the gap, progress might be frustrating.

Stepping up to 5.29 diffs would help - that takes you to 3900rpm @ 100, where the GTI is most likely going to be happy.

Steve.

[Bennyzarb]

I want to put an auto in my Sierra what is the best or easiest auto to put in ?

[Gwagensteve]

Easiest? Jimny.
Best? AW-4

Get searching and ask a more considered/detailed question and you'll get much better answers.

Steve.

[Bennyzarb]

Will the jimney auto bolt up to Sierra transfer without moving transfer ? And what's involved in putting in a jimney auto ?
And aw4 auto can you bolt a twin hilux transfer on the back ?
Couldn't find much Im probably not searching properly
Could you plz put a link up would be super helpful

[atari4x4]

you asked this question only a few months ago & it was answered pretty good viewtopic.php?f=5&t=39146

[Scrawny]

I think I'm slowly decending into Royce's frustrations with this place

Bennyzarb, why do you need to keep starting threads about the same thing?? If you have more questions or need a better explanation of something then go back to the first thread you started!! I moved your last thread and I'll be doing the same with this one

[atari4x4]

i was wondering where that thread went from the other day.... just wish i could go Grimbo & tell muppets to search with the fear of bannage.

[Bennyzarb]

What are the steps to make it work in my Sierra ?

[Bennyzarb]

Would I still be able to have a tourk converter lock ?

[Bennyzarb]

Ahh sorry I couldn't find it so I started a new one

[Bennyzarb]

I like the idea of a trimatic auto the engine is getting boosted anyway later on so power won't matter
Do you have any pics of the trimatic in that zook ?
I think I will give it a go

[jono165]

You can edit you posts instead of making 3.

Trolley Tug build with G16B and Trimatic: viewtopic.php?f=4&t=14025&hilit=trolley+tug

If being power by a GTI you will need a reversed engine adapter plate, hook up the vacuum hose, starter lockout and reverse lights, widen tunnel, shorten jackshafts, adapter bearing/bush in the back and make some mounts.

The trimatic doesnt have a lockup torque converter unless you find a rare TH180C.

AW4 you will need to do all of the above + more wiring + you will probably need one of JRzook's kits if the GTI ECU doesnt have the correct outputs for the TCM.

[Gwagensteve]

If the car is geared properly there won't be any advantage to having a converter lock. The AW-4 only locks the converter when in overdrive, and whilst I'm sure it's possible to manually switch the lock in in other gears, I'm not sure there's much to be gained. I know Patrol users use the converter lock to improve engine braking, but I have so much engine braking in 1st low with my AW-4 that I generally descend in 2nd low - 1st is just too slow.

As for power not being an issue with a trimatic, and a boosted GTi, it's not how much power there is that's important, it's where it is in the rev range. I reckon stall speed in the converter in a trimatic is around 1800rpm. if you're not producing enough torque at 1800rpm to accelerate the car strongly, it doesn't matter if you have 400hp at 6000rpm, it's still going to be a pig to drive. It's always possible to experiment with stall speed in the converter though to get the car to pull the way you want.

One of the disadvantages of deep gearing and stock torque converters is that the car drive strongly at very low revs. This is great for crawling, but it's bad if you want to stall the car up and get it to spin wheels (the equivalent of a clutch dump in a manual) It is possible to do a neutral drop to mimic the effect of a clutch dump, but it's pretty hard on the auto.

If you really want a converter lock with a trimatic, the TH180C gearbox (the three-speed trimatic with a converter lock) might be available from a JDM Escudo - I think they were used with the throttle body injected 8V motor. but as Jono pointed out, they are rare, and my understanding is that the converter lock solenoid is troublesome and often fails.

Steve.

[Bennyzarb]

Wow thanks heaps that explained alot um could you tell me how the trimatic auto works I am kinda guessing when you put your foot down the vacuum of the engine tells the gearbox how fast it is spinning and changes gear also depending on the strain on the gearbox ?????
But how does it know if it doesn't have a computer ?
Does it have an overdrive ?