[Hammered]

I am trying to understand what Pontiac did to make the 69-72 GP have a wider track width in the front. The A-body cars of the same era have 59" front track widths whereas the GP had a 62" track width. They share A-arms, spindles and rotors and from what I've found elsewhere online, the frames are the same width in the front. Finally, the wheels across the different platforms seem to have about the same offset. How did they do it?

Similarly, the '68-72 GTO has a 2" wider track in the front than all of the other A-bodies.

['ol Pinion head]

Not sure what source you are referencing in regards to track widths. Can pull the front wheels off a GP & measure wheel mtg surface to wheel mtg surface. I measured three original wheels, a '69 14x7 IF, & both an 14x7 HC & a 14x6 HF for my T-37 Coupe & noted the same back space (4 7/16").

[Hammered]

Thanks for the quick response. Track width is the distance from the middle of one tire to the other and if the wheels have zero offset, then that measurement would equal the hub-to-hub distance. As you say, the GP frames don't position the wheels out any further and all else being equal, it seems the difference would be in the wheels. A wider wheel alone would not change the track width unless the offset was different. I have see offsets of 1/4" and 1/2" reported for factory rally wheels, but don't know which direction the offset is in. Even so, I don't see how Pontiac could achieve a 3" wider track with only wheels.

['ol Pinion head]

Hammered, I'll measure both bodystyles. I've removed the front stub section from several GrandPrix frames & have a '71 GP partscar w the front clip & engine removed, it should be the easiest to measure if there was any widening in the center area of the front frame "stub". The front of the frame horns are def in the exact same spot.

[Hammered]

Here are A-body GTO dimensions, but they are the same as a set I found for a Chevelle.

[b-man]

If the ‘69 -‘72 GP frame was wider in the front or wherever (which it isn’t) the GP spindles wouldn’t interchange with A-body cars.

In order to have the correct Ackerman the steering arm length/angle would have to different from G to A-body to maintain the correct geometry for the wider frame.

[Nobuddy]

I thought "wide track" was only engineering by the marketing department and advertising agency.

[mrennie]

Originally Posted by Nobuddy

I thought "wide track" was only engineering by the marketing department and advertising agency.

Me too. I thought it was more about the illustrations that stretched the look but which were not accurate.

[Hammered]

From what (little) I've read, the original Wide Track cars, starting in 1959, had significantly wider track widths to improve handling. However, I am beginning to believe that in later years, it was a marketing slogan ostensibly backed by fudged numbers.

[b-man]

Looking at the track of a 1959 Chevy (or Canadian Pontiac) compared to a 1959 Pontiac it’s easy to see the wider stance of the Wide Track Pontiac.

Surely in later years is was mostly a marketing slogan.

The 14x7” wheels that were standard on the GP for 1969 and not available on the Pontiac A-body which only had 14x6” wheels would qualify as a wide track feature in some sense.

[besserspat]

Im the later years it was through the wonderful magic of Marketing.... There was also no really tiger under the hood of a GTO...just sayin.

Peter

[Keith Seymore]

Originally Posted by Hammered

From what (little) I've read, the original Wide Track cars, starting in 1959, had significantly wider track widths to improve handling. However, I am beginning to believe that in later years, it was a marketing slogan ostensibly backed by fudged numbers.

Not to improve handling, but to push the wheels out to match the larger body style (for aesthetics).

Bunkie Knudsen's comment was that, without doing that, the cars "looked like football players wearing ballet slippers".

https://disaffected-musings.com/2021...track-pontiac/

https://club.shannons.com.au/club/fo...track-pontiac/

K

[WQ59B]

Yes; starting in '59, the front & rear track were considerably wider than the other Divisions. My '59 Buick is 63/60, a '59 Pontiac is 64/64. Chevy was the narrowest. Wide-Track was a very real feature thruout the '60s. I cannot say without checking how it was in the '70s.

But the '70 sales brochure only lists a 1" difference in the GP & GTO, not 3 :

[Joe's Garage]

Since the 'track' measurement is from 'center of tire to center of tire' it's easily explainable.

The 1969-72 Grand Prix used 7" wide wheels. That's 1" wider than the 6" wheels on the same year GTO.

Most of that extra width is to the outside of the rim, so the tires moved outward.

I haven't gotten out a tape measure, but I'd speculate that the extra wheel width, which would move the tires themselves further apart, is how the track got wider.