Thread: Wheels and Tyres for a Puma

Hi Bobby,

Could you post a couple of photos showing the front & rear views.

I am about to purchase new wheels/tyres, still undecided on width and profile.

I do like those rims.

Cheers

No worries guys, I'll take ore photos on Sunday when I'm working on the big unit and I'll update with performance analysis once I've had more of a chance to drive it in various conditions.

So far the turning circle seems the same but I have a turning area at the bottom of my street that I know pretty well so I'll measure more accurately!

GPS - good idea, but alas I don't have one. I can't imagine an iphone app would be that accurate. I do have a tom tom but I'm rarely convinced by the accuracy of it - I often experience slight delays in showing exactly where I am.

Looks **** hot. Very nice looking vehicle.

Allan

to get the best turning circle you need to jack the front axle up and then turn the wheel to one lock and adjust the stop then repeat for the other side, you may need to two people. You can do this with the engine off as holding the steering over to the stop is not real good for the power steering, but ok when the engine is off.

Copy that Lambrover. Nice tip, thank you.

Interesting fact learned today regarding use of GPS as a measuring tool:

Bloke who owns the yacht which I race on is a former Navy man. Almost all his working life in the Navy and was Commodore too, so I was told. He rarely speaks of his time in the forces. Currently consults around the world working for an extremely large international organisation that makes cutting-edge military weaponry.
Knows his stuff, is the picture I'm painting here.

He mentioned to me this evening while enjoying a moist race out on the harbour, that measuring anything using GPS is entirely pointless on the basis that all GPS units effectively have an "accurate to x metres" variable in them....basically because the US military who own the bulk of the satellites up there, were never comfortable with giving the public or indeed any potential enemy a chance of being accurate to such a small distance, so every device has an inbuilt margin or error that's far larger than we think. He reckons all GPS units that say "accurate to 20 metres" are always up to 40 or 50 meres out, despite what they say on the tin. Unless you can get your hands on the military approved units, he said it's great for driving and finding your way around, but ultimately useless for measuring anything.

Total thread hijack. Appalling.....but interesting nonetheless.

Happy to hear differences of opinion. How should we really be testing the speed our Speedo says we're doing?

Originally Posted by The Cone of Silence

Copy that Lambrover. Nice tip, thank you.

Interesting fact learned today regarding use of GPS as a measuring tool:

Bloke who owns the yacht which I race on is a former Navy man. Almost all his working life in the Navy and was Commodore too, so I was told. He rarely speaks of his time in the forces. Currently consults around the world working for an extremely large international organisation that makes cutting-edge military weaponry.
Knows his stuff, is the picture I'm painting here.

He mentioned to me this evening while enjoying a moist race out on the harbour, that measuring anything using GPS is entirely pointless on the basis that all GPS units effectively have an "accurate to x metres" variable in them....basically because the US military who own the bulk of the satellites up there, were never comfortable with giving the public or indeed any potential enemy a chance of being accurate to such a small distance, so every device has an inbuilt margin or error that's far larger than we think. He reckons all GPS units that say "accurate to 20 metres" are always up to 40 or 50 meres out, despite what they say on the tin. Unless you can get your hands on the military approved units, he said it's great for driving and finding your way around, but ultimately useless for measuring anything.

Total thread hijack. Appalling.....but interesting nonetheless.

Happy to hear differences of opinion. How should we really be testing the speed our Speedo says we're doing?

As another former but probably more recent navy man who played with this stuff pretty frequently, my take on it is this:

That was the case for a long time. Some time ago (a few years) the US decided that there was little to be gained as we're all pretty friendly at the moment and plenty to lose by way of collisions at sea, lost trekkers, etc. so they dialled things back. You're now looking at 5yd or so error for commercial off the shelf units instead of the deliberate 50yd error. No need for crypto unless we go to war and the yanks pull the plug. But then I suspect our GPS will be one of the first things to go anyway, crypto or not, as it'd be a prime target.

Anyway, for this purpose you'll be fine. Heck, for pretty much anything you'd be fine. One or two PSI either way would make more difference to your GPS/Speedo differential.

I may stand corrected though...

GPS positioning may not be as accurate as it could be in a throw away unit, but the Speed reading is well within +- 1kmh , so for the purposes of speedo checking they are fine.

As for Positioning, You can buy a Trimble GPS with +- 100mm accuracy, avaliable to anybody if you have upwards of 15grand to spend on a GPS, They are the ones you see surveyors use with the domed antenna sticking up, Still use the same US millitary sattelites. The Google streetview truck use same.

Point of intrest my SPOT tracker is only +-5meters but when I look at my positions the always put pretty me bang onto where I am

For example heres a recent trip to Adelaide,
SpotWalla - Trip Viewer - LandRover Oct 11
zoom into Albury & go to the 108 tag at Tallangata caravan park, switch to satellite view, and that is exactly where we were camped,

Originally Posted by The Cone of Silence

Copy that Lambrover. Nice tip, thank you.

Interesting fact learned today regarding use of GPS as a measuring tool:

Bloke who owns the yacht which I race on is a former Navy man. Almost all his working life in the Navy and was Commodore too, so I was told. He rarely speaks of his time in the forces. Currently consults around the world working for an extremely large international organisation that makes cutting-edge military weaponry.
Knows his stuff, is the picture I'm painting here.

He mentioned to me this evening while enjoying a moist race out on the harbour, that measuring anything using GPS is entirely pointless on the basis that all GPS units effectively have an "accurate to x metres" variable in them....basically because the US military who own the bulk of the satellites up there, were never comfortable with giving the public or indeed any potential enemy a chance of being accurate to such a small distance, so every device has an inbuilt margin or error that's far larger than we think. He reckons all GPS units that say "accurate to 20 metres" are always up to 40 or 50 meres out, despite what they say on the tin. Unless you can get your hands on the military approved units, he said it's great for driving and finding your way around, but ultimately useless for measuring anything.

Total thread hijack. Appalling.....but interesting nonetheless.

Happy to hear differences of opinion. How should we really be testing the speed our Speedo says we're doing?

Are you ex military? with the "copy that" lol.

Yeah I am with the other guys, the yanks have settled down a bit and GPS is more accurate than when your mate was playing Navy. As mentioned when war breaks out the Yanks pull the plug and we go back to the old standard of GPS with bigger error. One could only imagine how good the Americans have GPS now though.