[Sausager]

Hey guys. I've owned an AW4 vitara for a few years now, and done a fair bit of offroading with it too. I used to be a "manual is best offroad" sorta guy, but after driving this vehicle offroad I realise this was unfounded and I am sold on offroading the auto. Left-foot braking adds a lot of utility.

I don't know the limits of the AW4 though, and I am keen to understand it better. What can I do with this gearbox, and what can I not? For example, can I build revs in N and then whack it into D to try and get a quicker start where I may have a short run up?

Do you have any driving tips? Tips, tricks, your experience, please share. I am keen to learn what I can

[Gwagensteve]

That’s called a “neutral drop” and you can do it but it’s very hard on the transmission.

The bigger issue with the Suzuki application of the AW-4 is it can’t be made to start in second gear so it’s hard to build wheel speed in low range without loosing a lot of track. I have details in my build thread about how I have resolved this.

[fordem]

ummmm - this might depend on which TCU you have - I think the later TCU supports a Normal/Power switch and if you have it in Power & Second, it will start in second.

[Gwagensteve]

I have the normal/power switch and can’t say I’ve ever noticed it starting in second in power mode.

That’s a convenient but well hidden feature if it’s correct. Also tallies that most AW-4s have a 2nd gear start or “snow” mode and that wasn’t present on the Suzuki application.

[fordem]

Attachment:

PN switch.JPG

[Brenno]

That's very interesting, nice work Fordem.

I have an aftermarket TCU controlling my re4 and have a switch that allows me to start in any gear and its the best feature especially with really low gearing. Typically start in 2nd in most scenarios

[fordem]

Can you share the details of that aftermarket TCU please, I didn't know such things were available. I did, somewhere on the internet, come across a basic program (basic as in the computer programming language) for a DIY controller for the AW4, but never tried building one.

[Sausager]

Thanks for this gem Fordem.

I tried this on my commute home this afternoon, and yup, works a treat. For what it's worth, car is a 1995 LWB 1.6 Vitara.

Does starting in 2 actually have a real life advantage though for us in non-snow climates?

[fordem]

Sausager wrote:

Does starting in 2 actually have a real life advantage though for us in non-snow climates?

I'd say yes, but, it will depend on circumstances - too much torque, or rather more torque than you need on ANY slippery surface can cause a loss of traction - it can be mud, it doesn't have to be ice or snow.

[Brenno]

fordem wrote:

Can you share the details of that aftermarket TCU please, I didn't know such things were available. I did, somewhere on the internet, come across a basic program (basic as in the computer programming language) for a DIY controller for the AW4, but never tried building one.

It's from shiftkits Australia. I don't think they have one for the aw4 and they are 1.5k so pricey but I had no option as the gears wouldn't change on their own even with the factory TCU as the speed signal went from AC to a 5v DC after being converted in tge factory dash which I couldn't fit. Tuned it myself after getting re4 base map. It's a great bit of kit.

[Gwagensteve]

Sausager wrote:

Thanks for this gem Fordem.

I tried this on my commute home this afternoon, and yup, works a treat. For what it's worth, car is a 1995 LWB 1.6 Vitara.

Does starting in 2 actually have a real life advantage though for us in non-snow climates?

My reason for starting in second is I can’t build wheelspeed in low 1st so even if I stall the car up (or even neutral drop it) I get 5’ or so of crawling before it pulls second and I start to get wheelspeed. Makes it impossible to bump an obstacle if you’re close to it.

I’m very low geared though.

The idea is less torque at the wheels makes it easier to maintain traction in low traction environments but that’s not relevant for my use.