The stock tire was 185 in section width, 15" wheel diameter. When
these cars were first made, tire makers didn't refer to the aspect
ratio. However, I've heard it would be approximately equal to
185/80-15.
The concept you've alluded to (big wheels using tires with small aspect
ratios, yielding the same overall tire/wheel diameter) is called "plus
sizing". You can read about it on www.tirerack.com. You need a tire
that has an overall diameter of about 26.4 inches (this is the stock
diamater).
The formula to calculate tire diameter is (tire width/25.4) * aspect
ratio * 2 + wheel diamater.
For this formula, tire aspect ratio must be entered as a decimal (ie.
65 series tire would be .65).
So, your formula to calculate your wheel or tire size (while keeping
same overall diamater) is
(26.4 - wheel diameter) / (aspect ratio * 2) * 25.4 = tire width
Fill in two of the three variables (wheel diameter, aspect ratio, or
tire width), do some simple algebra, and you get your answer.
Tim Holbrook
1971 TR6
--- Mark Holveck <mholveck@princetonpower.com> wrote:
> From: "Mark Holveck" <mholveck@princetonpower.com>
> To: <6pack@autox.team.net>
> Subject: Re: 16" wheels and tires
> Date: Wed, 26 Jun 2002 15:08:27 -0400
>
> Please pardon me for asking a question that I'm sure everyone here
> knows the
> answer to, but what are the dimensions of the stock tires for the
> TR6. They
> have such large sidewalls, I wouldn't be surprised if they were
> xxx/100-16
> or something like that.
>
> I really like how the stock looks with the large outer diameter of
> the tire.
> Has anyone seen an example of a wheel/tire combo where the outer tire
> diameter is the same as stock, but the sidewalls are short, thus
> requiring
> like a 19-20" wheel or something like that? I just love the look of
> the big
> wheels filling up the whole wheel well like they do on a stock car.
>
> -mark
>
> -----Original Message-----
> From: owner-6pack@autox.team.net
> [mailto:owner-6pack@autox.team.net]On
> Behalf Of Timothy Holbrook
> Sent: Wednesday, June 26, 2002 2:13 PM
> To: 6pack@autox.team.net
> Subject: Fwd: Re: 16" wheels and tires
>
>
> I would think that 205/55-16 or 205/60-16 is the way to go for tire
> size on a 16" wheel. There's a lot of tire selection in 205/55-16
> because that's an OE size on many sporty cars. I really don't think
> a
> TR6 needs more than a 205 width tire. But that's just my opinion.
> Plus I'm wondering if you would get rubbing problems in the rear with
> wider tires if you had tube shocks... I run 205/65-15 on my car.
> These tires are a bit shorter than stock, but I think it looks really
> good. Makes it look more aggressive, without giving the car that
> floating look that can happen when you go to a tire that's too short
> (yielding a giant gap between the tire and the fender).
>
> Jorge Lozano, a fellow lister, also has the Goodparts springs and 16"
> Panasports. He had some rubbing problems up front, but I believe his
> tires were taller than 205/55. Care to share, Jorge?
>
> Tim Holbrook
> 1971 TR6
>
>
> --- Chuck Arnold <Chuck.Arnold@oracle.com> wrote:
> > Date: Wed, 26 Jun 2002 08:24:31 -0700
> > From: Chuck Arnold <Chuck.Arnold@oracle.com>
> > To: Ryan Miles <rjhmile@yahoo.com>, 6pack
> > <6pack-digest@autox.team.net>
> > Subject: Re: 16" wheels and tires
> >
> > Are these both front and rear springs? What is the height of the
> > front
> > springs before they are in the car? The ones I got from Moss were
> > 9.5",
> > stock is about 10.0x. My rears I got too long ago to know the
> > unsprung
> > height, but the rear of the car is 1" lower than the front. So I
> got
> > advice from Bob Lang. In summary, here is what he said:
> > 1. The rear should end up a little higher than the front so when
> > accelerating and "squatting" the height is about neutral. To get
> the
> > rear higher you can lower the front [to some extrent] or add
> spacers
> > to
> > the rear [TRF sells 1/2, 3/4, 1 inch spacers, around $22/pair].
> > 2. To lower the front:
> > a. Shorter springs [but the ones I have are the shortest I
> could
> > get];
> > b. Do not use the rubber or plastic caps on the top and bottom
> of
> > the springs, will give up to 1/2 inch lower [I shaved mine, but am
> > now
> > going to remove and see where we are]
> > c. Lower the perch the spring sits on in the lower A arm by
> > making a
> > spacer to sit between the arm and the bracket [the one held by 6
> > bolts]. Note, the inner most ones are studs and only about 1/4"
> > spacer
> > can be inserted and still get a nut on the studs; the studs could
> be
> > replaced by a bolt to get more length]. I am going to investigate
> > doing
> > this.
> >
> > You will also have to pay attention to the camber resulting from
> > shorter
> > tires and may have to add shims in the front and flip/change
> brackets
> > on
> > the rear trailing arm.
> >
> > The 45/205/16s are almost two inches shorter than the 205/65/15s I
> > had
> > on the front. They are 23.25 diameter. I got 205/45s all the way
> > around. In retrospect I wish I had gotten the wider [225/50/16's]
> on
> > the rear. They would be 24.86 in diameter. This would have made
> the
> > back about a half inch higher than the front without spacers which
> > would
> > have been perfect. As you stated, the 225 look too big for the
> > front,
> > but they would fit well in the rear I think. Note, stock diameter
> is
> > about 25.25, so no matter what you do the speedo will be off [mine
> is
> > way off due to the tranny I have anyway, so I get mph from the rpms
> > --
> > got a little cheat sheet pasted to the speedo showing speed by rpm
> by
> > gear].
> >
> > The 205/45/16's look very short. Can hardly wait to get them on
> the
> > track. Got to get the brakes right and the suspension geometry
> > worked
> > out first.
> >
> > Hope that helps.
> > Chuck
> >
> > Ryan Miles wrote:
> >
> > > Chuck,
> > >
> > > I have Richard Good's springs which are supposed to lower the
> > car
> > > 1 to 1 1/2 inches, and I have no idea what size tires to get so
> > that
> > > the car dosen't look bad. You are the only other person I have
> seen
> > > with a lowered car and 16" panasports. How do the 205/45/16's
> look?
> > I
> > > was worried that a 45 series would look too small... What do you
> > > think? Right now I have the 16's on my TR6 which has stock
> > suspension,
> > > and my tire size is 225/60/16. These appear to be a little too
> wide
> > in
> > > the front, but about perfect in the back. I think I will probably
> > try
> > > 215's next, I justhavn't decided on the sidewall yet.
> > >
> > > Thanks,
> > >
> > > Ryan Miles
> > > Sign-up for Video Highlights of 2002 FIFA World Cup
> >
> > [demime 0.97c removed an attachment of type text/x-vcard which had
> a
> > name of Chuck.Arnold.vcf]
> Yahoo! - Official partner of 2002 FIFA World Cup
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