Outer Limits 4x4 Board

I had a tricked 308 powered RR with a T400 and Topshifter ( I think cant quite remember the shifter). I loved this thing off road, downhills were great would happilt travel at a k or 2, long and varying uphills were easily managed, you could bump shift gear up or down or set Drive so it was best of Auto or manual.
Im not sure Id want the auto setup on a low tech deisel though.
Im also not sure Id go the T400 again, much rather the overdrive on road

i have driven both off-road....... the auto is bloody brilliant!! i was one of those "auto's are crap" kind of guys until i got the Patrol. After reading thoughts from guys who went from manual to auto and raved about it..... i thought i would do the same. I'm glad i did!!! Sure, decents can be a bit of a pain..... but i have never had any problems with brakes yet. All i need is to regear my diffs to better suit the big tyres and keep the transmission cooler......

Gwagensteve wrote:They're only easier once you have learned how to drive thsm, which many people don't think you have to do. That was my point - they are hard to learn how to drive off road because you have to teach your left foot to do the braking, otherwise they suck.

Steve.

That's just riding the brakes though, which is basicly riding the clutch but a clutch would handle that better than brakes.

I couldn't stand to use 2 feet at the same time, manual for the clutch is fine but I think it's not needed at all in an auto.

That's me though.

Dump the auto and the manual get a triptronic

i know which one id rather be replacing between brake pads and clutch after a year or so...............

zagan wrote:

I couldn't stand to use 2 feet at the same time

That's just riding the brakes though, which is basicly riding the clutch but a clutch would handle that better than brakes.

I couldn't stand to use 2 feet at the same time, manual for the clutch is fine but I think it's not needed at all in an auto.

That's me though.

Dump the auto and the manual get a triptronic [/quote]



Are you for real? You can delicately and accurately slip the clutch to control speed on an obstacle off road without rolling back or cooking the clutch, (oh, hang on- clutches were made to be slipped) but can't use two feet to drive an auto because its bad for the brakes and shouldn't be neccessary????

The only way to even get close to an autos drivability off road is with around 100:1 gearing and a hand throttle on the gearlever. Juggling a hand throttle, steering, gear selection, clutch engangement and brakes makes you pretty busy. I know, I have tried to do it.

Tiptronic is a Porsche trademark for an auto with shift switches on the steering wheel. It's still a torque converter gearbox and so responds best to controlling the converter and load via braking.

If you mean DSG, no-one is using them in an off road application as yet. as they offer no torque multipication and cannot be started or stopped in gear, they will be very tricky to drive off road. I have driven DSG cars.

Steve.

gwagensteve, i dunno bout struggling with hand trottles, i just stick mine on 1000rpm, and shift when i need to, and put the boot in when i need to. i rarely touch the accel, and i can usualy sit in 2nd or 3rd on most tracks, and if ya know ya truck well, ya dont even need the clutch to change gears!

gotta agree with gwagen here.... i bought my first auto fourby recently and promply headed off to well known areas and went home thinking 'what a pile of power sapping shite this is'... after some advice from this site and some practice with two foot driving (and a plan to upgrade the valve body in future) i am sooooo in love with the auto...

i couldnt believe that i would have to learn how to drive an auto but i did and i wont ever look back...

by the way upgrading the valve body wont be that much more expensive than a heavy duty clutch in a manual really so i am happy to do this.

auto all the way... manual it and put a ratchet shifter of some sort if yhou really feel the need to 'be in control' if you have to but it will still be an auto box and it will still be awesome....

I prefer an Auto and loss of powers not an issue with 6.5 liters of grunt

But the down side as I see it

Auto suck going down steep hills
Auto can over heat.
Auto can’t be roll started
Auto have lower crawl ratio
And biggest problem for me, DONT STALL AN AUTO ON A HILL as you lose you power booster for your breaks:?

Eric

This is assuming you have a stock set up.

scout392 wrote: Auto have lower crawl ratio
And biggest problem for me, DONT STALL AN AUTO ON A HILL as you lose you power booster for your breaks:?

I have had the stalling problem, but that's not really the auto's fault. It gets it pretty exciting. (car drops about 5 feet before I can pull it up)

The torque multiplication of the converter means you don't need to be geared as deep. That's why autos can get by with less gears. My Gwagen (whilst with 88hp needs far more power) will run 36" tyres in extremely steep terrain with stock gearing. A manual would be very undergeared in the same circumstances.

Steve.

Gwagensteve wrote:

scout392 wrote: Auto have lower crawl ratio
And biggest problem for me, DONT STALL AN AUTO ON A HILL as you lose you power booster for your breaks:?

I have had the stalling problem, but that's not really the auto's fault. It gets it pretty exciting. (car drops about 5 feet before I can pull it up)

The torque multiplication of the converter means you don't need to be geared as deep. That's why autos can get by with less gears. My Gwagen (whilst with 88hp needs far more power) will run 36" tyres in extremely steep terrain with stock gearing. A manual would be very undergeared in the same circumstances.


Steve.

The crwal raito going UP a hill yes spot on but down a hill the "torque multiplication" dose not help.

Eric

Actually, it does if the gearing is right. My G descends about as well as a factory geared petrol manual - I can do most moderate descents without braking.

CJ has to descend in 2nd low with crawler gears (4:1... nothing huge) in his vitara.

Sure, It won't match a 100:1 manual, but it all comes back to gearing them right for the job, and getting the converter right.

Steve.

I personally find driving Auto's very boring, Although my next road car will be auto because of stop start traffic.

Maybe in 10 years time I'll change my mind, however if I had alot of power or did alot of rock crawling I'd take an auto

Luxo wrote:I personally find driving Auto's very boring,

Me too and that'll always colour my preference.

Some interesting arguments either side here.

But i must say, Gwagen steve, you seem a bit too biased towards the autos! Are you trying to make yourself feel as though you made
the right decision going to an auto! But yes you have made some good points.

No, not at all. I just know how good they can be.

I also think that autos are boring on the road, I looked pretty hard at DSG, but wasn't convinced that was the answer either.

As I said, I am currently building a manual car because auto isn't a viable option for the motor I am running, but I'm building that car for sh!ts and giggles. I know it won't outdrive an auto.

Steve.

I recently bought a 3.0l auto surf and after a few trips offroad i was impressed enough to get an auto for my 40 series project. Very well matched to the vehicle, very tractable and even on very steep downhills I just lock it in low-low and it idles its way down comfortably.
Not 100% sure but i think it locks the torque converter up when slipped into 4 lo.

I just hope the t700 auto in the shorty works aswell as the surf one.

Cluffy wrote:I recently bought a 3.0l auto surf and after a few trips offroad i was impressed enough to get an auto for my 40 series project. Very well matched to the vehicle, very tractable and even on very steep downhills I just lock it in low-low and it idles its way down comfortably.
Not 100% sure but i think it locks the torque converter up when slipped into 4 lo.

I just hope the t700 auto in the shorty works aswell as the surf one.

The surf is diesel ?? if so autos and diesels work very well i assumes its to do with the narrow power band an oiler makes so the auto keep the motor in the sweet power spot.

No sure if thats exactly true tho.

Eric

autos and diesels make very good friends. Mostly, it is due to to flat torque curve and limited revs that seems to make them work nicely.

Also, with turbo diesels, the stall speed of the converter covers the doughy off boost reponse- Small engined cars like Disco's are better in auto than manual because of this - they won't pull at all when off boost, but the auto ensures they don't fall off boost on gearchanges and always pull away on boost.

Steve.

Gwagensteve wrote:autos and diesels make very good friends. Mostly, it is due to to flat torque curve and limited revs that seems to make them work nicely.

Also, with turbo diesels, the stall speed of the converter covers the doughy off boost reponse- Small engined cars like Disco's are better in auto than manual because of this - they won't pull at all when off boost, but the auto ensures they don't fall off boost on gearchanges and always pull away on boost.

Steve.

Do you think this may change with the new comon-rail T/D running 26000 psi fuel press and veriable turbos??

Eric

Eric

My (limited) experience with more modern, electronically controlled diesels tells me it will be worse.

Emission controls are forcing manufacturers to back fuel out of turbo diesels at low revs to stop the smoking. They often feel very doughy down low where even low powered old school diesels feel crisp.

The ML270 CDI merc has a 2700rpm stall speed in the converter and a 4500rpm rev limit. I'm sure it goes hard off the line

Steve.

PS modern petrols are as bad - my cooper S was terrible to free rev and doughy down low for the same reason.

KiwiBacon wrote:

Luxo wrote:I personally find driving Auto's very boring,

Me too and that'll always colour my preference.

Me too. I have an auto car for everyday road driving and i prefer it that way as it's so much easier in traffic. However i crave getting into the jeep on the weekends and on trips and just having a ball with the gearbox throwing the stick around. That bloody 40 year old engine suits the gearbox so well that i could (and i have ) drive around all day without touching the brake pedal. It's a lot of fun

I only spend 15mins on the road to get to work (2 traffic lights ) but if i had to drive the jeep everyday and in heavy traffic i'd have probably gotten an auto.

Gwagensteve wrote:My (limited) experience with more modern, electronically controlled diesels tells me it will be worse.

It will get better, it just takes time for the good technology to reach this part of the world.
Variable vane turbos were for a long time pneumaticly controlled (vacuum actuator, computer controls the valve to that). The new ones are oil pressure driven which gives a lot more grunt and fine control to the vane movement.

There are good autos and bad autos.
Bad autos suck at everything.

KiwiBacon wrote:

Gwagensteve wrote:My (limited) experience with more modern, electronically controlled diesels tells me it will be worse.

There are good autos and bad autos.
Bad autos suck at everything.

well i have the torqueflite 727 auto.
Super strong but 3 speed and 2.45 to 1 1st gear.
what defines a goog/bad auto??

eric

i read in nams post he dislikes the auto due to constant load. theres a solution to this if your running the right box. I'm using the th350 in mine and on the top of the box there is 2 bumps that look like they could be drilled and tapped if done right u can drill and tap these and run hydraulic lines off to a line locker. with the line locker blocked off it runs normally but when u hit the button it bypasses all the fluid from the clutchbands( well this is how i understand it) and it works like a clutch, but on a button. has any else had this done? mine is drilled and tapped just have to setup the lines and switch

Manuals would be perfect, if they didn't have a clutch! Autos would be perfect if you could control them.
A well setup manual shift auto is about the best compromise. It gives exact gear control. Lock the torque converter and then there's no run away downhill (as long as you have the right gearing)
The big thing is you have to drive an auto. You can't just stick it in gear and steer. You have to do more BUT the control they give is brilliant.
It takes quite a bit to learn how to drive one and anyone getting out of a manual will hate them as they won't know how to make it work. It is well worth learning how to drive them and untill you have, you don't know what you are talking about. It's saying something is bad when you've never experienced it.
I have a GQ with a turboed 4.5 Nissan V8, it has the Patrol auto (same as for the V8 anyway) with an Extreme manual valve body. Not cheap to setup but then we are talking about what is best not what is the best value for money etc

the Ambos down here in tas have an auto clutching manual. theres no clutch pedal, but you still change gears like a normal manual vehicle, just the computer will engage the clutch a moment before the gears engage... not 100% sure how it works, but it makes fast shifting a breeze!

I have had a man and auto in the same vehicle without changing anything else and had 68 to 1 crawl ratio. The auto made the vehicle twice the vehicle it was in the bush. With the convertor and the torque multiplication, climbs and crawling was grouse. As for power loss, I didnt feel any different and the convertor now made it EZ on the driveline.
I then changed the crawl to around 140 to 1 and it was another world.
On road driving at hi speed I still do like changing gears myself.
My new rig is auto also, 1/ it has alot of power and want to be as soft on the driveline as Poss. 2/ Its a turbo and want smooth power without rev drop between gear changes 3/ matching my stall with my turbo's will help with dealing with lag. 4/ refer to what I first wrote.
Cheezy

macca81 wrote:the Ambos down here in tas have an auto clutching manual. theres no clutch pedal, but you still change gears like a normal manual vehicle, just the computer will engage the clutch a moment before the gears engage... not 100% sure how it works, but it makes fast shifting a breeze!

What vehicle is that in? sounds like the Mercedes benz system like they use in the smart and A class. Merc call it "funshift" in the A class. It might be available in the Sprinter van.

IMHO any mechanised clutch manual won't work off road because you don't get the softness and the torque multiplication, you also loose momentum on changes, and they hate "creeping" which autos love.

Steve.

yeah its a merc