[urq] re-quattro-ing a quattro - ALSO

[Chris Miller]

Mass determines the size of the contact patch, in general, so a wider tire
only alters the shape of the contact patch.  Skinny tires have a long front
to back patch; wider tires make it more rounded.

With new tire technology, today's tires are much grippier and last much
longer than those when the urq was designed.  Probably are getting more grip
on the stock early size modern tires than can be used.

That's also ignoring things like change in suspension geometry in
cornering...

Optimizing the unsprung weight is also helpful in keeping the tire in
contact with the road surface.  With a heavier tire and wheel, it takes
longer for the suspension rebound to put the tire back onto the road.
That's why stiffer suspensions are popular; keeps suspension geometry the
same and tires in contact with the road.  Fine for racing, but bad for
fillings and road feel.

-----Original Message-----
From: urq-bounces at audifans.com [mailto:urq-bounces at audifans.com] On Behalf
Of Jon Archibald
Sent: Thursday, December 15, 2011 3:05 PM
To: Keith Lloyd
Cc: urq at audifans.com
Subject: Re: [urq] re-quattro-ing a quattro - ALSO

It seems that in all but the most extreme dry pavement cornering, less width
may really be more. Amazing how hard it can be to override that visceral
desire for "big claws," when the pluses so rarely outweight the cons...

On Thu, Dec 15, 2011 at 11:32 AM, Keith Lloyd <spotatashleys at hotmail.com>
wrote:
> Because from now on I'm looking after the old girl better (my quattro) 
> I'm not going to be using her in the bad weather this year so I've put my
6"
> ronals and snow tyres on my '98 A4 Avant. It was a tight fit between 
> the stick-on wheel weights and the calipers but after cleaning off 
> corrosion on the calipers with an angle grinder/wire brush there was 
> no more interference. Are they compatible with the A4? They are the 
> same offset as the stock wheels. The wheel and tyre size was an option 
> at the time and the are specified size for winter tyres for the A4, so 
> yes they are. And guess what? They improve the feel and ride of the A4 
> hugely. Great stuff. Might leave them on all year.
>
> Keith
>
> '87 WR
>
>
> -----Original Message----- From: Jon Archibald
> Sent: Wednesday, December 14, 2011 6:04 PM
> To: j.koenig
> Cc: Thatcher Hubbard ; Keith Lloyd ; urq at audifans.com
>
> Subject: Re: [urq] re-quattro-ing a quattro - ALSO
>
> It's an interesting observation. I have heard that Porsches at least 
> are extremely sensitive to the correct tire size being used for proper 
> alignment. In addition to the probability that a suspension that's 
> been lowered more than 1/2"-1" just won't work like it was designed 
> to, wider wheels with different offsets than the original design must 
> surely also have the potential to reduce optimum response. It makes me 
> wonder if Audi thought much about this when they switched to the wider 
> and further-outboard offset 15x8s. I've always loved the aesthetics of 
> wide tires and there is no questioning the firm grip on flat, dry 
> pavement, but when I rolled with 6" wheels and 195-width snow tires 
> for a few weeks with my car, I was amazed at how much more normal 
> everything felt and how much less I had to fight with it over bumps 
> and rutted roads. My embracing of the rugged "well it's a sports car 
> and needs to be wrestled with" atittude has given way with age to "it 
> would be nice if this drove like a normal car"...
>
> It would be super interesting to have a back-to back test from the 
> same driver of lateral grip, braking, and slalom handling of a car 
> with stock ride height and 205-width tires on stock 6" rims vs.
> lowered with wider-stance 225's and see if the perceived benefits of a 
> lower car with wider tires and stance actually equate to real world 
> performance increases. I would not be entirely surprised if the former 
> actually "danced" more nimbly.
>
> On Wed, Dec 14, 2011 at 8:49 AM, j.koenig <koenigj at comcast.net> wrote:
>>
>> There is such a thing as out-teching an older suspension design with 
>> modern tire sizes.  I bet the period tarmac rally cars changed out a 
>> lot of bearings and bushings and hubs back in the day.
>> My two-cents worth...
>> John
>>
>>
>> ----- Original Message -----
>> From: "Thatcher Hubbard" <thatcher.hubbard at gmail.com>
>> To: "Keith Lloyd" <spotatashleys at hotmail.com>
>> Cc: <urq at audifans.com>; "Jon Archibald" <talisman05 at gmail.com>
>> Sent: Tuesday, December 13, 2011 5:09 PM
>> Subject: Re: [urq] re-quattro-ing a quattro - ALSO
>>
>>
>> John, my own experience is similar to yours, I just hadn't got to the 
>> built engine yet.
>> Now I just want the 20v for reliability and smoothness.
>>
>> FWIW, my car had 17x8 wheels on it when I got it.  I bought a set of 
>> nice Fuchs for Winter tires and I've ended up putting all seasons on 
>> them and leaving them on for 5 years now.
>> They look better on the car, and feel better on most roads.
>>
>
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