Things to admit / Getting smarter??

So as most of you guys perhaps know I've always been a firm believer that due to the Jimny's low weight, small size and low power 31" tyres are the biggest tyres needed. Anything bigger is just silly... or is it? :blush:

For the last 3 years I've been running 30" Special Tracks in competitions here in Denmark, meaning only mud, sand and gravel. And it's been working out very well for us. Never had a problem keeping up with the Patrols, Cruisers and Defenders on 35-37" tyres.

I've always liked the idea of small tyres for low powered vehicles as this means little rotating mass = easy to spin and keep clean.

But now, after having attended this years Wild Boar Valley Challenge as co-driver in Croatia back in october I may have learnt a thing or two. Mainly to keep the diff clear of rocks, which is one thing we don't have in Denmark And as I next year will bring my own Jimny it's now time to think about making it ready.

So now I'm considering putting on 32-33" tyres.
But how much needs cutting. I am not interested in putting on a 3" body lift and 5" suspensionlift. In thinking perhaps 3" suspension lift and 10-15mm bodylift, but mainly for easier cleaning.

Even now with the 30" tyres I had to cut the outer corners at the foolwells. I also had to cut the outriggers under the headlights as they cought the tyres on full articulation.

So does any of you have any ideas?

The problem you have is the amount of effort for a small gain.

I am sure you know that the difference between a 30" and 32" tyre is 1" of diff height. The rotating mass of the tyres is higher so any sudden "stop" of a spinning tyre (ie when it contacts the ground) takes out the CV joint. Its a slippery slope to a lot of work.

On this event, does the co-driver sit in the car or does he walk/spot the rocks, if the latter then learning to direct the diff around problems might be the way forward.

Martin

I will of course have to take the CV's into consideration as well. But this event in particular is not nearly as hard on CVs as we thought. As mentioned here in Denmark it's all very much sand and deep mud with lots of grip which is generally very hard on the CVs and shafts. Even with uprated ones I've broken them. But luckily on warranty.

The terrain down in some parts of Croatia is very different. Where we'll be racing it's much more rocky and very slippery clay.
The whole week we were down there we saw only one racetruck having to fix a broken CV joint/shaft. Not sure which part.
But with much less traction in general it is not nearly as hard on the CV's/shafts.

The event is not suitable for the Co driver to walk outside the car as spotter. We're driving way too fast and with daily roadbook distances of 80-90 km's it's just not possible

First inch of clearance you can get by shaving axles housings.

For 31 and bigger wheels, you have to advance front axle.
And everything changes: steering, panhard, springs support on the frame

I am in the transformation process of a Jimny in order to participate next year to Romanian Offroad Campionship.

Not a bad idea actually, shaving a bit off the bottom of the diff housings.
www.pirate4x4.com/forum/suzuki/603216-shaved-samurai-axle.html

Regarding tyres, I've been doing some research. My initial plan was to use 32" TSL SX Super Swampers, but since these have gone out of production I had to look for something else. Then came across standard 32" TSL tyres. But these just looked a bit too narrow for my liking compared to Simex/Silverstone tread pattern, and also not as aggresive on the sidewall.

So now just found out that 31/10.5 R15 Simex Extreme Trekker actually stand about 32" tall. So I think these will be my tyres of choice.

Also considering upgrading to 26 spline shafts in the front axle. Either just getting 26 spline shafts to fit the RCV joints. Or swap the whole RCV thing for a complete set of TG shafts and joints.

Using large wheels, the front axle definitely will bend.
Axle housing is soft and there is no solution to this.

I replaced the Jimny front axle with a Samurai one, with air locker and HD RCV.