Suzuki Jimny power improvements

[XJ Junkie]

Fitting bigger diameter tyres reduces torque on the ground in direct proportion to the percentage increase in size. So a 10% bigger diameter tyre will result in a 10% reduction in power traction. So in such an instance re-gearing the diffs to accommodate the bigger tyres will be the best money you ever spend.

Weight of off-road bumpers can be overcome with the right bumper manufacturer because there won’t be a huge weight difference. They can also be made from aluminum for the Jimny. The best winch is your mates winch.

Once the traction is sorted with tyres & gearing then it may need only a little more power, but adding too much power brings its own set of problems wrt strength of components.

I think the idea of exhaust mods is a good suggestion. Maybe find someone that knows what he’s doing that can build you some bespoke headers for off-road use. I found this made a massive improvement especially for low down torque. Money well spent.

Only play with the engine if the relevant mod is a recognized one with proven results on other cars, especially off-road.

[BushWacker]

Heinrich stated above that it increases power, which is technically incorrect.

It will increase power to the wheels.. the engine power stays the same

yes ... by increasing the wheel size the same power output is faced with driving a bigger turning diameter ... yet drive train is designed for std diam ...
... if you change the gear ratios , then engine may be more up to the challenge ie lower gearing ... maybe like those cunning Series Land
Rover guys you even add a Fairey Overdrive to beat the Jimney , on tar, to trail start !
Chucking heavy stuff like bumpers etc also doesnt increase the power but it does change the Power/mass ratio and so reduces the challenge the engine faces...
... to increase the power need to approproately forcefeed the engine w fuel and air and improve the efficiency, reduce friction etc ...
... what ever happened to skimming heads, polishing ports , domed pustons etc etc ...
or is that no-no to tamper with modern delicate engines?

[KurtG]

It will increase power to the wheels.. the engine power stays the same

Winner winner chicken dinner

[HeinrichC]

Heinrich stated above that it increases power, which is technically incorrect.

It will increase power to the wheels.. the engine power stays the same

Correct and a detailed expansion of the point I made.

In example; lets take Manny and put him on a bicycle with only one gear in the front with the pedals and one at the back wheel. If you add an additional larger gear at the back wheel and an additional smaller gear at the pedals then Manny would be able to cycle uphill even though his skinny legs have the same useless power output. But his maximum achievable speed on a flat piece of road will decrease (Or should as Manny cannot cycle fast with his skinny Gru legs).

[XJ Junkie]

Torque is decreased at the wheel with bigger tyres. It’s measured at the wheels & doesn’t exist in the absence of traction. Kw is constant at the flywheel.

[BushWacker]

I dont know anything about Jimny engines but have watched the evolution of LRover engines...
In my opinion the Kalahari “Kanniedood” Defender 300TDi was probably the best Landy of all. They then went and made/adapted this great engine TD5 and then constrained and spoilt things to achieve emission compliance and
environmental acceptability....
... as far as power and performance etc goes this was a bad thing so first thing a Defender guy does is undo all that stuff : Exhaust boxes, wastegates, mapping, regulators etc and it can definitely unharness underlying potential of what is a pretty good motor.

There must be similar ‘unwanted’ constraints and hindrances built into Jimney engines ???

[HeinrichC]

Correct and a detailed expansion of the point I made.

In example; lets take Manny and put him on a bicycle with only one gear in the front with the pedals and one at the back wheel. If you add an additional larger gear at the back wheel and an additional smaller gear at the pedals then Manny would be able to cycle uphill even though his skinny legs have the same useless power output. But his maximum achievable speed on a flat piece of road will decrease (Or should as Manny cannot cycle fast with his skinny Gru legs).

Apologies, I need to make a correction - In order to get Manny voluntarily on a bicycle one would need to remove the seat.

[XJ Junkie]

[XJ Junkie]

In my opinion the Kalahari “Kanniedood” Defender 300TDi was probably the best Landy of all.

A mate of mine did the Richtersveld with a broken crank in his 300 TDi & then drove it back to Cape Town like that.

[Saxj]

I dont know anything about Jimny engines but have watched the evolution of LRover engines...
In my opinion the Kalahari “Kanniedood” Defender 300TDi was probably the best Landy of all. They then went and made/adapted this great engine TD5 and then constrained and spoilt things to achieve emission compliance and
environmental acceptability....
... as far as power and performance etc goes this was a bad thing so first thing a Defender guy does is undo all that stuff : Exhaust boxes, wastegates, mapping, regulators etc and it can definitely unharness underlying potential of what is a pretty good motor.

There must be similar ‘unwanted’ constraints and hindrances built into Jimney engines ???

The only unwanted constraint that you can really remove is the catalytic converters, which nets around 5% gain in output.