Date: Tue, 11 Feb 2014 04:54:18 -0800
Reply-To: mark drillock <mdrillock@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mark drillock <mdrillock@COX.NET>
Subject: Re: Silly idea?
In-Reply-To: <QvHf1n00p1P0Ebw01vHwUx>
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If you are going to use a hunting rifle that always shoots high to the
right it is useful to know that it does so even if you might also have
to factor in range, wind, air density, etc. It is true that most people
don't use the results of their gearing calculations for anything real
and thus accuracy doesn't matter so much. But some people spend serious
money on gearing and tire changes and they should at least be aware of
the degree of known error before doing so based on flawed tools. In this
case someone proposed that he could achieve the same gearing effect with
a specific tire change rather than using a different tranny that had a
specific gearing. He was pretty far off and I first proposed a program
error as a possible cause. I don't know what the actual source of his
error was and as I already said the difference is greater than that
which could be readily explained by the common flaw of various programs.
I don't see how any of the other possible factors you mentioned would
have much to do with his specific case of comparing the effects of a
tire change to an internal tranny case on the same vehicle being use the
same way and under the same conditions. The fact that we can't know
everything or factor in everything makes a pretty weak argument for
ignoring the errors that are apparent on the face of it.
Mark
OlRivrRat wrote:
> I suppose that If one is indeed trying to acquire Exact info on the Rev's/Mile of a specific Combo of Tires & Gears then using the TireSpecs supplied by the Manufacturer would be the Ideal way to go ~ But in defense of those that might only be trying to make a RelativeComparison between 2 or more Diff' TireSizes &or Tire&GearingCombos I would submit that Most if not All the Calc's on the web are quite sufficient ~ Especially in cases where the Manufacturer does not provide the necessary info which can & does happen ~ Also ~ Considering the Fact that VehicleWeight, TirePressure, VehicleSpeed/TireRotationSpeed, Vehicle Aerodynamics & Road Surface Type & Temp & Condition all should factor in to the equation, Exactness could be deemed a waste of effort ~
>
> ORR ~ DeanB
>
> On 10 Feb , 2014, at 1:02 PM, mark drillock wrote:
>
>> There are a lot of garbage calculators on the web.
>>
>> Tire companies tell you how many rev/mile their tires turn. That is the
>> spec to use for calculating gearing. If your calculator used a raw tire
>> size instead then it is probably garbage.
>>
>>
>> BFG says their 195/75/14 tire is 815 rev/mile
>> BFG says their 215/75/15 tire is 748 rev/mile
>>
>>
>> Mark
>>
>>
>>
>>
>> Ralph Meyermann wrote:
>>> It was showing me that the only ratio difference of the two was the ring
>>> and pinion. The tire size is 27.8 on the bfg and 25-26 on my 195/75/14?
>>>
>>> Velma 82 1.9L AAZ td westy
>>> On Feb 10, 2014 1:17 PM, "Ralph Meyermann" <ralphmeyermann@gmail.com> wrote:
>>>
>>>> I was using the transaxle ratio/tire size calculator thing to make my
>>>> reference from. Is it not that accurate?
>>>>
>>>> Velma 82 1.9L AAZ td westy
>>>> On Feb 10, 2014 1:14 PM, "mark drillock" <mdrillock@cox.net> wrote:
>>>>
>>>>> Stock DK tranny and 195/75/14 tires in 4th at 3500 is 65.6 mph
>>>>>
>>>>> Stock DZ tranny and 195/75/14 tires in 4th at 3500 is 51.4 mph
>>>>>
>>>>> Stock DZ tranny and 215/75/15 tires in 4th at 3500 is 56.1 mph
>>>>>
>>>>> Mark
>>>>>
>>>>>
>>>>>
>>>>> Ralph Meyermann wrote:
>>>>>
>>>>>> Hi Volks, I may have another silly idea. I am planning on having my
>>>>>> diesel
>>>>>> ratio transaxle rebuilt with a 1st and second ratio change to a 4.13 and
>>>>>> 2.25 if my memory is correct to aide pulling my small fishing boat out of
>>>>>> the water. My silly idea is that with 215/75/15 bfg all terrains matched
>>>>>> to
>>>>>> my diesel ratio transaxle is about the same as my dk transaxle with my
>>>>>> 195/75/14. I was thinking that when I'm bringing the boat camping I will
>>>>>> run the 14" wheel package to take some load off the engine/transaxle and
>>>>>> when I am not bringing the boat Ill use the big wheel package to gain
>>>>>> some
>>>>>> hwy speed? It's so crazy, it just might work??
>>>>>> Velma 82 1.9L AAZ td westy
>>>>>>
>>>>>>
>>>
>
>
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