Tire stagger?

[911st]

I just had a thought.

If weigh determines the size of a tire contact patch, and if the rear of a 911 has 50% more weight on it than the front, then is there "effective tire stagger" even if the front and rear tires are the same size?

[VaSteve]

IIRC the larger tires in the back were to introduce some understeer into the car. "Stagger" must play into that somehow.

[old man neri]

Pressure also plays a role, thus you have higher pressures in the rear.

[BertBeagle]

Tire stagger is a circle track term and refers to left to right rather than front to rear. Tire stagger means that the outside rear is bigger than the inside rear on a circle track race car. The reason is that the outside tire has more distance to travel in a lap around the track than the inside tire. Stagger is also adjusted to affect handling. That adjustment was used more in the days of bias ply tires as they would stretch when more air pressure was used. Radial tires are built with stagger and are less affected by pressure.

[911st]

LOL.

So Bert, you thought I was talking about putting different size tires on each side?

[BertBeagle]

Originally Posted by 911st

LOL.

So Bert, you thought I was talking about putting different size tires on each side?

No, just saying that stagger might be the wrong term in your post.

Stagger is a function of circumference not roiling radius.

[Flieger]

Stagger also is used to refer to different width tires on the front and rear axles.

[equality72521]

Originally Posted by Flieger

Stagger also is used to refer to different width tires on the front and rear axles.

Yup.

[stlrj]

Originally Posted by VaSteve

IIRC the larger tires in the back were to introduce some understeer into the car. "Stagger" must play into that somehow.

This might explain why my 74 911 is now handling very neutral, now that I have all tires and wheels the same size. When I had the rears larger, it did understeer quite a bit.

Porsche must have known this when they made stagger standard from 1978 on, in order to increase understeer and safety from their perspective.


Cheers,

Joe

[Bill Verburg]

Originally Posted by BertBeagle

Tire stagger is a circle track term and refers to left to right rather than front to rear. Tire stagger means that the outside rear is bigger than the inside rear on a circle track race car. The reason is that the outside tire has more distance to travel in a lap around the track than the inside tire. Stagger is also adjusted to affect handling. That adjustment was used more in the days of bias ply tires as they would stretch when more air pressure was used. Radial tires are built with stagger and are less affected by pressure.

That is the way I have seen the term used.

Though I suppose it can describe f/r differences as well.

On a 911 you are not really looking for staggered rolling radii, you are looking for wider tires in back, usually w/ about the same height(especially on abs or awd equipped vehicles)

[Bill Verburg]

Originally Posted by 911st

I just had a thought.

If weigh determines the size of a tire contact patch, and if the rear of a 911 has 50% more weight on it than the front, then is there "effective tire stagger" even if the front and rear tires are the same size?

while weight is a factor of contact patch area it is not the only or even the most important one.

even more important than area is shape, because of the way a tire works a wide and narrow contact patch is the feature you are most looking for, along w/ the tire's compound

[BertBeagle]

Using "stagger" in this case to describe front to rear differences; with the same tire size F & R I wouldn't think you would have the effect of a wider rear tire simply because you had more contact patch due to weight. It would be the opposite because of the rear weight bias which, like posted above, is partly why they went with wider rear wheels in 78.

Sliding around in my 911 (same skinny wheels front and rear and small engine), my strategy was to subscribed to the long held theory that its more fun to drive a slow car fast than a fast car slow. The big ticket (first one) I got the other week is causing me to re think that plan of action and consider that what I really need is a track car!!!

[Zeke]

An article in Circle Track Magazine suggests that tire stagger is side to side with staggers used on both axles for various handling purposes including braking. Other sites indicate that "wheel" stagger would most likely refer to wider wheels in the rear. Or perhaps even lager diameter rims like a hot rod or drag car. Stagger can apparently mean a few things, but add a modifier and you get a narrower (sorry ) meaning.