Water and gearing

Took the jimny through some water today, was all fine besides getting a bit wet but I it doesn’t have the power to go over 4mph when the waters over the bonnet. I know I don’t need to go any faster but I’d like to have a bit more if I needed it as that was flat out. I have a 1.6 Liana engine  in it already, would changing the gearing help as its standard, eg VVT diffs or rocklobster box.
Cheers. 

Try 4WD-L at that depth the whole car will be starting to float up and you will be loosing enough traction over every surface to use low range.

You might also want to consider a high level exhaust pipe, if you stall it you might get some water back through the exhaust and the extra exhaust back pressure might be stifling the engine.

That was 4L. Wasn’t floating either as I had water up over the seats inside which wouldn’t have helped either power wise. But I didn’t think about the exhaust. Cheers

Depends on your tire size. original gearing should be limited to 215's or so.
Any smoke?
Studders?


But speed and water do not mix so well..
Should ideally be just right to make the bow wave in front of your car so the engine is in the valley behind the wave.

I got lower gearing and 235's and have not felt any powerloss in the deep except if there is mud on the bottom. I have not been deeper than the top of the bonnet though.

I do not think the exhaust pipe would help much to your power as my car idles just fine when submerged.

Yakuza, get your Jimny ready for some serious stuff, just seen this article about weather in Scandinavia. (OK it was mostly about Sweden, but that is close to you)

In pictures: Nordic states gripped by winter freeze
www.bbc.co.uk/news/in-pictures-67871751

Robin.

haha, yes I am on the west coast so I get mostly the british weather just two days after it blown passed you lot

At the coast here will get down to minus ten around the weekend so no more working in the garage after tomight. I will be waiting for the next thaw in a week or so.

Crazy snow in the south now, roads and schools and stores closed. Eastern Norway will get 30 below.

Wich brings me back to the all the water i drove thru in the summer that appearently still is inside my car and freeze up now during winter making my 4wd solenoids not work.
Hoping to have fixed it now, but will be testing in a few days.
 

When you say flat out what exactly do you mean? Flat out revs or flat out pedal to the floor? Because if it's giving maximum revs but it's only doing 4mph then I would suspect the clutch is slipping. If its pedal to the floor and not able to build revs then that's a power issue

He is driving through water that is flowing over the bonnet and has filled the motor to completely cover the seats. A basic calculation tells me that at 4mph he was displacing about 2.5 tons of water per second.

Roger

I don't do deep water anymore but never had a problem picking up speed in deep water 
Running 32's and lobster box 

Slightly different but my 1.3s have all been capable of gaining revs towing at full weight up a 20pc grade especially in 4x2 low and still in 4x2 high but obviously at a slower rate. Therefore I would suggest that a 1.6 in healthy condition should be able to gain revs even pushing a couple of tonnes of water. Therefore if it can't then something is wrong with the motor. Or the clutch is slipping especially if it was disengaged while under water which should be avoided at all costs. Into the water with room to exit with a suitable gear selected and motor across as smoothly as you can.

Yes gearing would help massively. With standard gearing at 4mph your engine is at very low revs, so power output is equally low. You probably have barely 20hp available to displace all that water. If you could have the engine spinning faster at the same speed you would have more power available. The Jimny has a very flat torque curve so the rise in power is very linear. Essentially double the revs = double the power. There is still a limit as the power needed to displace all that water rises exponentially with speed. Don't expect to be able to do 10mph, but with gear reduction you may get to 7 or 8mph which would feel rapid compared to 4.

Flat out pedal