How do I make it go faster ?

[NZ Kubota Fan]

Greetings, all

Firstly thanks for all the great information posted here - I've been browsing from afar (well afar from most of you here in NZ) & found heaps of helpful stuff.

I've recently bought a 4WD B7000 (JDM) for towing our boat to & from the boat ramp. I've had a ball doing the normal refurbishment & getting sorted out with three-point hitch, brake lights, galvanised rims, road tyres etc etc - all good fun.

However, I'd really like to increase the road speed. I'm not doing any grunty agricultural stuff, it's flat from the house to the ramp & the boat ramp itself is a nice easy grade. Boat isn't enormous either (though as every bloke would, I'd like a bigger one). One day ....

Anyway - is an increase in road speed possible ? Given it's a 4WD I suspect it'd be a "pull the gearbox & machine a new drive shaft with suitable ratios" - which I'm not adverse to taking on (wife isn't watching over my shoulder ) - but just wondered if anyone else had tackled this particular challenge ??

Regards

 

[cabu]

Yeah, sometimes Vic is good for a joke...

But maybe he was trying to tell you, that the original speed is the maximum speed your Traktor should have, otherwise you will risk an accident.


The Slowspeed Carl

 

[NZ Kubota Fan]

Cheers, Vic & cabu

Yup - got those items under control.

And yes, appreciate that modifying one part of a system (say, a tractor) means that other bits need to be upgraded too. Seen too many modified cars over-powered to the max with nil attention to brakes, clutch etc etc.

However - I'm still curious about how you'd go about this. Having had our "maiden voyage" to & from the boat ramp, during which the B7000 performed superbly BTW, more speed would be very handy. Not silly faster, but a bit.

Regards

 

[joekimtkd]

Yeah, I'm hungry for the speed too.
but it will be almost impossible to change the internal gears with my capability.

Maybe a couple of suggetion~?!
First, Buy the truck or faster tractor...

Second, Change the tires. Bigger size. Bigger it is, Faster it goes...!!!
All you have to do and worry is the check the fender and frame that tires shouldn't touch~~~!

Good luck.

 

[stuart]

Actually it works the other way. Bigger tires mean more circumference speed for the same tire rpm, with less power. Therefore higher ground speed for same engine rpm.
On a truck you might get more ground speed with smaller tires, as there is more torque available to push the truck faster, but at significantly higher engine rpm. Like a .411 rear end will give more speed (due to increasd power) than stock, at the cost of gas mileage and engine wear. Your 'theoretical' top speed will be lower but achievable top speed it higher.

I doubt that wind resistance and such would be an issue on a kubota.

If you have 4wd, it gets a lot more complicated, as you would have to increase front and rear tires by the same percentage. Front and rear turn at different tire rpm due to different tire size.

In my experience, top speed on a small tractor on rough ground is fast enough, gives a very rough ride. Even on pavement the ag tires are very bumpy.

Changing tire size would be a huge can of worms - higher centre of gravity, go from 36 to 48 inch tires for a significant increase, frame clearances, cost, etc

Stuart

 

[joekimtkd]

Well~ Stuart explained whole thing~
Very smart person he is~~~!!!

As original question was, Just pulling the boat~
He is not even using Kubota for cutting grass or cleaning snow either. Lucky guy~!

So, he doesn't need much Torque. Just speed. so Changing internal gears and installing "Turbo Charge" isn't easy stuff. also, diesel engine is not design to have higher engine RPM. It provides low RPM but high torque. so installing bigger tire size will not affect too much of torque. and He doesn't need much of torque, although he could use LOW range gear to get the necessity torque... but HIGH range gear will give him a bit of speed increments... Still not much of increment though. unless he gets a huge big tires~~~

Also, changing tire will revoke the Warrany for sure~ and Dangerous~~~ So, Think twice...!

I had 70 Hp diesel tractor. and drive 13 Km to go to my farm to cutting the grass... it takes me exactly 1 hour to drive with that tractor.
Now, with 21 Hp B7510DT Kubota~~?! Perhaps an hour and a half~?

As any kinds of engines... running in Full speed is very crucial matter.
Keeping low RPM will increasing engine life and Oil life too...

One good example, Sea-Doo... I've seen many engines had to rebuilt.
Small impela try to pushing water to create propulsion~?! It has to run in full speed to keep up~ which is not the greatest idea. Of course, they make good engines too but keeping RPM down isn't the bad idea. That is what I'm saying. Also you could save a lot of Gas or Diesel money too~!
and Green planet~~~!!!

 

[stuart]

Well~ Stuart explained whole thing~
Very smart person he is~~~!!!
..........

Thanks, but more likely a miss spent youth at the race track.

..........

I had 70 Hp diesel tractor. and drive 13 Km to go to my farm to cutting the grass... it takes me exactly 1 hour to drive with that tractor.
Now, with 21 Hp B7510DT Kubota~~?! Perhaps an hour and a half~?

..........

Rated ground speed for my 17hp b7001 is 13 kph

Stuart

 

[NZ Kubota Fan]

Hi, folks

Apologies for the silence from NZ - been on leave & travelling extensively on business (which does mean no fishing).

Anyway - many thanks for the various contributions. In terms of tyres - yup - have been down that road & swapped the original rice-paddy super-aggressive tyres for truck & car tyres. Quite a process - I ended up getting the NZ Bridgestone agents involved (really helpful people) to ensure that I got the inter-axle ratios correct. So yes, it does roll down the road just fine & I do have sufficient traction for sand / boat ramp.

At the time I did look at increasing tyre diameters but it all got too damn hard, plus the incremental speed increase wasn't that great - speed increases linearly with circumference so there's not that much bang for buck (especially taking stability issues into account).

As far as increasing engine speed - the little two-cylinder is already revving it's heart out so I don't want to go there. No need for a turbo as power isn't the issue.

So there you go. Looks like 15 minute trips to the boat ramp are the way it'll be.

Regards,
Greg