tire size on 60's Grand Prix cars

[masraum]

OK, I've been searching for a couple of days for info on the tires that were used on the F1 Grand Prix cars in the 60's. Does anyone know what sizes were the norm for what years?

Not the Pontiac Grand Prix.

[RallyJon]

I have an amazing book at home: The Grand Prix Car 1954 to 1966 by LJK Setright. If no one else knows, I'll be happy to dig through it tonight.

In general, the early '60s were the transition period from 80-series narrow treaded tires to lower profile slick(er) racing tires.

[masraum]

Yes, it seems that the late 60's is where we went from skinny to fat, about the same time that aero was added. I can't believe that I haven't been able to find it online. I can find any other info, just not tire sizes. It's just for my personal info. If you remember tonight that would be great. Thanks

[Rot 911]

Internet: It's on computer now!

1965
PONTIAC GRAND PRIX
2-door, 4-passenger sport coupe


OPTIONS ON CAR TESTED:
Turbo Hydra-Matic, air conditioning, power steering-brakes-windows-antenna, radio, whitewalls, misc. access.
BASE PRICE: $3498
PRICE AS TESTED: $4868.78 (plus tax and license)
ODOMETER READING AT START OF TEST: 2300 miles
RECOMMENDED ENGINE RED LINE: 5200 rpm

PERFORMANCE
ACCELERATION (2 aboard)
0-30 mph....................................3.0 secs.
0-45 mph....................................5.3
0-60 mph....................................8.3
PASSING TIMES AND DISTANCES
40-60 mph...................................4.9 secs., 359 ft.
50-70 mph...................................4.9 secs., 431 ft.
Standing start 1/4-mile 16.6 secs. and 84 mph
Speeds in gears @ 4300 rpm
1st..................42 mph 3rd..................100 mph
2nd..................75 mph (observed) @ 4500 rpm
Speedometer Error on Test Car
Car's speedometer reading.....30 48 54 65 76 89
Weston electric speedometer...30 45 50 60 70 80
Observed miles per hour per 1000 rpm in top gear...........22.5 mph
Stopping Distances -- from 30 mph, 45.5 ft.; from 60 mph, 202.0 ft.


SPECIFICATIONS FROM MANUFACTURER



Engine
Ohv, 90-degree V-8
Bore: 4.06 ins.
Stroke: 3.75 ins.
Displacement: 389 cu. ins.
Compression ratio: 10.5:1
Horsepower: 325 @ 4800 rpm
Horsepower per cubic Inch: 0.83
Torque: 429 lbs.-ft. @ 2800 rpm
Carburetion: 1 4-bbl.
Ignition: 12-volt coil
Gearbox
3-speed automatic (Turbo
Hydra-Matic); floorshift

Driveshaft
1-piece, open tube

Differential
Hypoid, semi-floating
Standard ratio: 3.08:1

Suspension
Front: Independent, with upper
and lower control arms, coil
springs, direct-acting, 2-way
tubular shocks, and stabilizer bar
Rear: Rigid axle, 4-link pivoted
control arm, coil springs,
direct-acting tubular shocks


Steering
Recirculating ball bearing,
with power assist
Turning diameter: 42.8 ft.
Turns lock to lock: 4.2

Wheels and Tires
5-lug, steel disc wheels
8.55 x 14 rayon whitewall tires

Brakes
Hydraulic, 2-shoe, self-
adjusting; cast-iron drums
Front: 11-in. dia. x 2.75 ins. wide
Rear: 11-in. dia. x 2.00 ins. wide
Effective lining area: 188.5
sq. ins.
Swept drum area: 328.9 sq. ins.


Body and Frame
Welded steel body, perimeter-
type frame with swept hips
Wheelbase: 121.0 ins.
Track: front, 63.0 ins.;
rear, 64.0 ins.
Overall length: 214.6 ins.
Overall width: 79.6 ins.
Overall height: 53.9 ins.
Curb weight: 4360 lbs.

[masraum]

Kurt, thanks. Actually I was talking about F1 type grand prix cars, not the Pontiac Grand Prix.

[hardflex]

1962

[hardflex]

1965

[hardflex]

oops

[hardflex]

whats wrong

[hardflex]

the pic won't go, but 1967 is on wide tires.

[hardflex]

once more with a different name

[masraum]

damn those cars are hot, anybody got specs on sizes?

[Tervuren]

http:/forumrscnet.org

They are a major place that players of Grand Prix Legends hang out(most late 60's F1.) You are probably likely ot find an answer to your question there.

IF you like the cars, try finding a copy of GPL, get a racing wheels, and go at it! Blast of a racing simulator.

[masraum]

I've got GPL, great game, but really hard. I find it difficult to drive when my butt can't feel what's going on.

[Tervuren]

Originally posted by masraum
I've got GPL, great game, but really hard. I find it difficult to drive when my butt can't feel what's going on.

I first started with sim games at the young age of 4 at a freind of my Dad's house. So obviosuly its where I got most of my "seat time" as I never drove a full sized car until 14. (Game was Indy 500 btw, Copyright 1989 I think, I last played it just a few months ago, havne't tried it since my old computer died, will one day though, love it!)

GPL was given to me by a man is his mid 20's as he could not get around the track, and said I might have more fun with it. He was right. I thin I started GPL at not less then 12, probably 13 or 14, but not older then that. could check by seeing when it came out and know.

[masraum]

Yep, GPL has been around a long time. I can get around a track, but being consistent is hard.

I also used to play Indy 500, and yes, it's been out since the late 80's or early 90's.

I've also played GTR, a couple of the F1 200x series games, all of the "Test Drive" series, some of the Need For Speed, Live for Speed, and a bunch of arcade games. I have the hardest time with the F1 200x games. I get little to no feedback about what's going on with the car with them, and I get a bit bored. GPL is really fun, but not easy. I find consistency the most difficult part. Probably because I'm always trying to go faster. GTR is similar, but not quite as hard. For a computer "game" I prefer something that's got realistic types of reactions in response to unrealistic situations, ie NFS - Porsche Unleashed. Pure sims are great for training but not as "fun". I don't want to think or work that hard when playing.

[RallyJon]

Here you go (1.9MB pdf): http://www.rallystuff.com/images/gpc_tyres.pdf

[masraum]

Very cool, thanks.

So it appears that in 1954 the rear tires were approx 27" tall, 6.5" wide, with a 4.5" tread width, and then in '66/67 they were 22" tall, 12" wide with a 10" tread. So actually pretty big.

So, in the mid to late '60s the cars were running 375-450hp, around 1100-1200lbs and 10" wide tires.

I bet that was a whole lot of scary fun.