Wheel size poll. :)

[Darrin]

I'm curios as to the wheel size folks here are running. The original GT40 used odd ball 1960's sizes, but roughly they related to

F: 245/60/15 = 26.57" tall
R: 325/60/15 = 29.4" tall

The 2006 Ford GT used the following:

F: 235/45/18 = 26.7" tall
R: 315/40/19 = 28.92" tall

Most here seem to run much shorter tires than that I think.

What do you run?

 

[Mike Telow]

Did the MKI and the MKII run the same size tires? I would think there would be clearance issues with the MKI running a 29.4" tire in the rear.
I have Goodyear 27X14X16's on the rear and 23.5X10X16's on the front.

 

[Darrin]

Did the MKI and the MKII run the same size tires? I would think there would be clearance issues with the MKI running a 29.4" tire in the rear.
I have Goodyear 27X14X16's on the rear and 23.5X10X16's on the front.

The sizes I mentioned were for the MkII.

Based on this page: Tire sizes Ford GT40 Mk I (Street Version) (1965 since middle 1964 for North America U.S.)

The MkI had a total wheel diameter (in): 27.4

 

[Mick Ridley]

I have

Front 225/60/15
Rear 295/50/15

not sure of their diameter, I have a MKII rear clip

 

[Darrin]

I have

Front 225/60/15
Rear 295/50/15

not sure of their diameter, I have a MKII rear clip

That comes out to be 26.6 in the rear.

 

[Cliff Beer]

The original (~'64) narrow body GT40s didn't wear a 325 on the rear.

With the original Borranis in the early days, the tire width was more in the range of 255, and grew somewhat as both the rear flares grew and with the increase in availability of wider Halibrands and BRMs. Original wide body cars I've seen appear to be running 295's (roughly). Of course, the original tire widths were measured in inches not mm.

 

[Dave Hood]

Darrin:

My SPF Mk1 uses
Front: P225/60R/15
Rear: P295/50R]15

 

[Al Jones]

215-60-15 front, 295-50-15 rear, MK 1 with no flares.

 

[Mike Telow]

I wonder if there is any chance an Avon 14X27X16 would run on the rear of a wide body without clearance issues? It's actually 27.1" tall with a cross section of 16.7" I'm thinking the width would be the issue.

 

[Brett James-McCall]

Darrin,
See here: http://www.gt40s.com/forum/gt40-tec...841-thoughts-tyre-size-please.html#post289157

 

[Bob Putnam]

I wonder if there is any chance an Avon 14X27X16 would run on the rear of a wide body without clearance issues? It's actually 27.1" tall with a cross section of 16.7" I'm thinking the width would be the issue.

15.5" is about as wide as you can go without interference, and I prefer to stay below 26.5" OD to keep within the working range of the suspension.

 

[Darrin]

Most seem to be around the 26.6" to 27" height in the rear.

That's a good bit shorter than either the original narrow body at 27.4 or the MK2 at 29.4.

I'm having a hard time finding the kind of rubber I like in sizes that will work and if I stay narrow (have the flares to go Gulf if I choose to use them) I am thinking either in the rear:

285/40/18 (about 27" exactly)
or
295/35/19 (27.125" tall)

If I go Gulf then who knows.

I've seen folks gasp as the thought of a 19" wheel on the GT40 but coupled with a low profile tire it's no taller than the donuts they tend to use. It's also a lot easier to get very high performance rubber in the sizes needed to get to about 27" in height going with the taller wheel.

 

[Jim Cowden]

Nothing like donuts on a 40

 

[Brett James-McCall]

Darrin,
Personally I think 18s and 19s will look oversized on a GT40. They look OK on a GT (the recent one), but that is because that vehicle is larger overall so there is better proportion.

I know I am using 17s (as a lot of other people are), but an extra 12-25mm on the radius makes a big difference. Trust me I know having seem the variants int he design centre here at work.

As an aside, have you chosen your wheels that you are going to use yet?

BTW you can get a lot of high performance rubber in 17s...

 

[Darrin]

Hi Brett,

I hear you with respect to the GT being larger and that's why the wheel size on it (19" in the rear) looks better to you. Others may agree with that as well. Doing the math, the GT40 is about 91% of the height of the Ford GT. SO, the wheel size that would be equivalent based on that height would be just a bit over 17".

I have done many searches, and you just cannot get 17" tires wide enough and in the proper aspect ratio to get around 27" in height from what I can find.

If I could get a a 295/45/17 for example then I'd go with the 17s but you just cannot do it in any major manufacturer of tires that I have seen. It's even tough in an 18" wheel these days where a 19" gives you almost anything you want in the very high performance category.

No I've not decided on the wheel yet. Need to decide if I will be adding the Gulf flares or stick with the original width. If I stay original, then I am leaning to going with an 18" wheel.

 

[Phil]

Darrin:
I prefer 15" wheels even though it is difficult to get rubber for them. I am using Avons 12.5 X 27 X 15 rears which actually measure at slightly over 26" tall. Front is 9.5 X 23.5 X 15 which actually measure about 22 3/4" tall. Wheels are 15 X 14 rear and 15 X 10 front.
Everything fits but as Bob said things can get a pretty tight with big rubber and you wouldn't want to limit suspension travel or rub on the body so most guys go smaller.
I think 16's are OK, but bigger than that gives a "Tuner car" look.
Cheers
Phil

 

[Brett James-McCall]

Hey Darrin,
So I refer back to my link above. A well respected member of the community told me the tyres were 24" front and 26" rear to make it sit right. If you do the math on the 295/50 15 comes to about 26.6". That's pretty easy to get in a 17", both in the US and here in the UK, even having a quick scan on Tire Rack

Just to give you another thing to mull over - you are saying you want to get the height right, so the look is right, but the larger the wheel, you will minimise the amount of rubber you have, so it could start to look a bit 'West Coast'. Also, then there's the ride to consider. Just my $0.02 for your planning stage.

B

 

[Brett James-McCall]

Darrin,
Another thing to consider, especially with the narrower body, see here: Ford Press Release, January 1966. Ford GT40 Web Site Index GT 40 Replica Kit Sports Cars Le Mans Racing Sundt

WHEEL AND TYRES
Wheels - Borrani wire-spoke, light alloy
Front - 6.5 x 15 in.
Rear - 8.00 x 15 in.
Tyres (Dunlop)
Front (size) - 5.5 x 15 in.
Front (loaded radius) - 13.00 in.
Rear (size) - 7.25 x 15 in.
Rear (loaded radius) - 14.75 in.
Tyres (Goodyear)
Front (size) - 5.5 x 15 in.
front (loaded radius) - 12.4 in.
Rear (size) - 7.00 x 15 in.
Rear (loaded radius) - 13.4 in.

 

[Darrin]

Hey Darrin,
So I refer back to my link above. A well respected member of the community told me the tyres were 24" front and 26" rear to make it sit right. If you do the math on the 295/50 15 comes to about 26.6". That's pretty easy to get in a 17", both in the US and here in the UK, even having a quick scan on Tire Rack

Just to give you another thing to mull over - you are saying you want to get the height right, so the look is right, but the larger the wheel, you will minimise the amount of rubber you have, so it could start to look a bit 'West Coast'. Also, then there's the ride to consider. Just my $0.02 for your planning stage.

B

I agree Brett in that I really don't like the "tuner" look either.

Looking at Tire Rack, there is only one tire available in the 295/50/15 size. What happens when they discontinue that? Also, to me, that much rubber makes driving turn in kind of sloppy...lot of play.

Maybe I'll just paint the outside rim black to match the rubber! LOL Joking of course. I wish they had the 17" sizes I wanted. Continental does have the Extreme Contact DW in a 285/45/17. That's a bit more narrow and only 26" tall which affects my gearing plans a bit though.

Well, looks like I'll just see if I can roll it to the Discount Tire shop a couple miles from me on anything that will fit and have them mount a couple options when the time comes.

Thanks for the feedback!