Trials Truck - Auto or Manual

[SirGerald]

Time for a bit of a survey and advise prior to making some decisions on an upcoming Trials Truck build.

Looking at mounting a Toyota (or similar) front wheel drive 2 litre fuel injected engine to a Suzuki Chassis and Hilux Running Gear for a Trials Truck.

Not looking for anything that is going to win a class, and even don’t really care about which class I end up in, so basically an open forum for ideas as I want something that is going to not break and will be able to still throw around.

Before purchasing the engine I need to decide to go manual or auto. I have never driven an auto off road, so am unsure as to their performance and would like your thoughts.

I can see that the auto would be good for being able to left foot break easier, along a smooth transfer between gears, however feel that a manual would give me more control and use of the power.

I assume that there are people out there that are using autos or have used one in the past and would appreciate your thoughts.

[spanky]

i am doing same sort of thing as you but sr20 nissan 2ltr ,moded vitara chassis and hilux diffs .mine is a manual but if i dont like it i can put the auto box on to it and try that. after looking at lots of trial trucks they are mainly auto but the donar car was manual and with a spare box ,plus i love being able to dump the clutch .
vaughan

[cool__bananas]

i think that auto is best because you can hav it in a low gear and left foot break when doing a big sidelean and then turn up the hill with your foot down and it changes up gears whereas manual once your in a gear you cant really change, and i would imagine its really hard to change gear in a hazard because as soon as you put the clutch in you hav no drive so it wud be much easier to stop in a hazard. But if youve got bulk hp and big rev range then its all good, and with a manual if you are going up a hill steep as hill climb and your about to go over backwords its much easier to just put the clutch in rather than try find reverse on just put your foot on the break, so thats my thoughts, my next truck is probably going to be a auto unles i get a bulk hp motor with atleast 10000 worth of revs. (supercharged 4.5l nissan v8 )

Mitch

[sig]

i reckon a manualised auto would be the go ,it only changes gear when you want it to

[cool__bananas]

the auto/manual dont have clutches though ae sig???

[KiwiBacon]

I'd say custom built auto.
The options are endless and only really limited by your budget. You could even get an auto fitted with a manual clutch if you spent enough.

[Heath]

Thought long and hard about this and after watching a few trials trucks (and talked to a few drivers) and if you have horsepower to burn then auto all the way. For a std 1.6 vitara I will go for a manual so the little power I have (or will have) can be sent to the wheels and not lost in the slush box. Of course I still want to try an auto so maybe if I can find a cheap one later on (when all set up) I will swap it in and see how it works.

Heath

[tpft]

years ago b4 hill stall converters drag racers used too fit a manual clutch in place of the converter, easy enuff too do.
sometimes a big rev and dropping the clutch is whats needed, and then threw the hazzard change gears like a normal auto.
less hp loss too, best of both worlds.

speedway guys just run a coupling and a on/off hydro tap in place of convertor and a manualised auto.

one day hydro motors instead of diffs and gear box/clutch would be possible for this sport too

[Heath]

can we use a hybrid like this in A class?

Food for thought...

[tpft]

think so?
have too check, by memory rules for a and b are mainly wheel and diffs/suspension, u are allowed too mod or exchange engine and gearbox

[lilpigzuk]

can change engine, gearbox and transfer in A/B class. So yeah a "selecatable auto" or what the name for it would be allowed

[yorick]

can change engine, gearbox and transfer in A/B class. So yeah a "selecatable auto" or what the name for it would be allowed

I think the phrase would be Power-Shift. You'd want the shifter arse about I would think though so R N L 2 3 D. That way you can hit the Panic slot real easy. I wonder if that would be possible to rig on a conventional trans like a GM400 for instance. I'm not that au faix with the internals of a Car type Automatic

[turoa]

I had the idea (well maybe I stole it) of putting a latch just in front of reverse so you can quickly bang it in reverse from drive without hitting park. You then lift up the latch and push foward to go into park.

Auto all the way

[4x4wntab]

I've got a home built "C" class with a sr20 and auto box and I luv it. I have by-passed the auto computor and hard wired it which means it stays in whatever gear I hold it in, if I put in 2nd it starts in 2nd and stays there until I change it. I have even rewired it so I can start while in gear which paid off on a steep downhill when it decided to die for some reason. If you have a long mud run up to a hill climb it is nice to high speed it in 2nd and then pull 1st as you start to loose ground speed without having to clutch it. With these east west conversions in A or E class though be carefull of having to cut dash enough to get motor far enough back to get the front drive shaft in.

[WACKO]

you said a frontwheel drive box, so no transfur. id say auto. makes the gear stick set up alot easier aaswell. with low power id want a man, as its harder to get the acceleration. but if you have enough power then even with an auto, put ya foot on the brake, build the revs, foot off the brake and you should either take off or light the tyres. not very easy if you only just have the power to turn the tyres.

Sam

[Heath]

One of the guys in our club is running an east west engine complete with gearbox and dif in a north south configuration. Weld up the front wheel drive diff, short shaft to the transfer case and you have even lower gears (because of the diff in the with the engine). Not sure about cutting fire walls etc to stay in A class.

[spanky]

I had the idea (well maybe I stole it) of putting a latch just in front of reverse so you can quickly bang it in reverse from drive without hitting park. You then lift up the latch and push foward to go into park.

Auto all the way

i think youll find B+M did this about 30 yrs ago any of the ratchet shifters allow to select and hold gears, i might try an auto later when i turbo the sr20 cause 150hp aint enough for a auto for me.
vaughan

[DieselBoy]

I had the idea (well maybe I stole it) of putting a latch just in front of reverse so you can quickly bang it in reverse from drive without hitting park. You then lift up the latch and push foward to go into park.

Auto all the way

i think youll find B+M did this about 30 yrs ago any of the ratchet shifters allow to select and hold gears, i might try an auto later when i turbo the sr20 cause 150hp aint enough for a auto for me.
vaughan

THats basicall what i have had done to my THM400 trans.

I got them to install a manual shift kit into it (cost $200), so that it only changes gear when i move the leaver, and i can set off in what ever gear i choose, as opposed to having to always start in 1st. No automatic shifts and no kick down.

I have a Toyota style auto selector leaver set up, that with a little bit of trickery, have made it so that there is no gate between any of the positions, apart from park, where you do have to depress the button to push it through. The rest of the positions between 1st and reverse you just give the leaver a quick flick and its in.

Its just a matter of getting the position of the locking leaver that runs down the center of the shift leaver into a semi depresed position and holding it there with the shift knob in place, but also still alowing it to be able to be depressed fully so you can get it into park