A wider tire proposition for a narrow body??

Zeke · 11-07-2005, 05:53 PM

I got to chatting with a gentleman in the parking lot today at OSH. He had a '70 with some pretty big meats on the stern. The wheels were 17's so the tire size is irrelevant for my purposes. Let's just say he had the equivalent of 225/50/15's or 16's. Those are easily a 9 inch tire and then some for some brands thru the mid-section. Not too many people have been successful in mounting this size to an early narrow body w/o some significant work including rolling and stretching the fenders. Or using a fairly high ride height.

So, I looks this thing over and ask him how he got so much tread under there. And he tells me he moved the hubs inward.

Move the hubs inward? "How does one do that?," I ask. He says he machined them.

OK, before I get a brain hernia trying to figger this one out, someone tell me if they have ever heard of such a process by which the hubs, stub axles or anything else besides the trailing arm, can be moved in. He maintains that the trailing arms and spring plates are stock and in stock position.

One last thing, I looked at some hubs I have for the early model and could see where one could possibly get 1/4" off the shoulder that rests against the bearing, and then correspondingly take an equal amount off the end, but I'll be damned if I would do that and then take the car to the track. Not enough left there for my butt to be in the seat.

Any thoughts?

ianc · 11-07-2005, 06:12 PM

It might look better with larger tires, but by moving the wheel center inward, you are giving up some of the inherent stability of the wider track...

ianc

Shuie · 11-07-2005, 06:49 PM

'Hubs' as in the fronts only, right? I cant imagine how you could machine the rears for more clearance. I think a lot of our cars could run a custom offset (say 40mm) 8" wheel with a 225 tire on the rear.

Randy Blaylock · 11-07-2005, 06:58 PM

Assuming wider tires, the outside to outside track could be the same. The question I have is how did he accomodate the movement of the brake rotor (that mounts over the hub) towards the inside, and corresponding caliper alignment? Possibly shimmed the caliper inwards?

Todd Simpson · 11-07-2005, 07:02 PM

I don't know how or if this could be done, but why not just use wheels with more offset?

vntgspd · 11-07-2005, 07:06 PM

I wouldn't go machining the hubs. The little extra tire isn't worth the risk of catastrophic failure IMO.

Here's a pic of my car with some 225/45/15 Hoosiers mounted on 8" wide wheels. These tires are every bit of 9" wide at the tread area. I have aluminum banana arms with rolled fenders but the body is otherwise stock. I get light rubbing on the inside fender under sustained heavy cornering but this may go away when the bushings are replaced as there seems to be ample static clearance.

Also, large tires definitely look great but don't always translate into the fastest lap times. For example, the Kumho V710 are usually faster than the Hoosiers but are also typically narrower when the same size is compared.

Good Luck and keep us posted...

Charlie V · Charlie V's Garage

Moving the rear hubs is impossible. Just think about it for a minute. The guy has got to be smoking something.

Wider rims and rolled fenders are the only option to get big meats on the back of an early body.

Todd Simpson · 11-07-2005, 07:29 PM

There was a recent Excellence feature car that had modified steel trailing arms to fit wider wheels.

Tyson Schmidt · 08:05 PM

If you use the hubs from a '74 and later on your steel trailing arms, then you will bring it in by 5mm.

The later hubs are deeper by 5mm to fit the wider wheel bearings on the later cars, so if you use them on your narrow bearings, it will bring them in. (I've never done this, but I think you'd have to make sure all the e-brake shoes, etc. will clear the inside of the rotor's inner drum. Look at an old rotor to see the witness marks from the shoes to see if there'll be room)

You can also shave the rotor hats down by about 3mm.

I've got 225's on 944 Turbo 8X16's under my '69 at the moment. I'm running 3 degrees negative camber, but could easily get away with -2.5 without rubbing due to a top-secret mod I did, which I could PM you.

Tyson Schmidt · 11-07-2005, 07:59 PM

Here's a couple shots of it with the 944T 8's and 225/50/16's

Jeff Alton · 11-07-2005, 09:15 PM

That pic has -3 degrees of rear camber? I will take your word for it but it sure looks like less..

Cheers

ischmitz · ischmitz's Garage

I am running with Tyson's evil mod and about 2.5 degrees negative camber in the rear. 225/50/16 on 944 8/16 Fuchs in the rear on my narrow-body. I am pretty much touching my fender lip and my oil lines ever so slightly under heavy cornering. Shaving hubs wouldn't do me any good. I need to widen the ass of my car or narrow the engine and the engine bay....

Ingo

PcarPhil · 11-08-2005, 03:28 AM

Quote:

Originally posted by Tyson Schmidt
I've got 225's on 944 Turbo 8X16's under my '69 at the moment. I'm running 3 degrees negative camber, but could easily get away with -2.5 without rubbing due to a top-secret mod I did, which I could PM you.

Tyson,

PM sent! Thanks for the help,
-Scott

awis321 · 11-08-2005, 04:30 AM

building his ultimate 911. I believe it was a yellow, early body with a 3.8. He wanted to fit the biggest meats under the wheel wells without adding flares so he made up a jig and sectioned off parts of the rear suspension until it was right width. I think he was in the auto industry so he had access to the tools he needed otherwise he wouldn't have tried doing it.

Jim Richards · 11-08-2005, 05:28 AM

I'm running 225/50/15 Toyo T1-S street tires on 7" Fuchs in the bacl of my skinny 73E. My track setup is 225/45/15 Toyo RA-1's on the 7" Fuchs. The RA-1's in this size are a little short for my taste, but they fit with ~2.5 degrees of neg. camber. Tyson, I'll PM you for your secret mod. Thanks!

}{arlequin · }{arlequin's Garage

yes, there are no problems running 225/45-15's on a 15x7 all around.

but for the "Holy Grail"--
the real trick is to fit 245's in the rear. who's gonna be first???

Tyson Schmidt · 11-08-2005, 08:22 AM

Quote:

Originally posted by }{arlequin
yes, there are no problems running 225/45-15's on a 15x7 all around.

but for the "Holy Grail"--
the real trick is to fit 245's in the rear. who's gonna be first???

As soon as I get the money to buy a new set of tires, it'll be ME!

As you can see by the pic, I've got the room. Those are 225's on 8's.

If I need a little extra fender lip room with the 245's, I still have the option of shaving the rotor hats.

Tyson Schmidt · 11-08-2005, 08:23 AM

Quote:

Originally posted by catca
That pic has -3 degrees of rear camber? I will take your word for it but it sure looks like less..

Cheers

It's the angle of the camera. Straight from the back, you can tell.

911SCfanatic · 911SCfanatic's Garage

Quote:

Originally posted by Tyson Schmidt
If you use the hubs from a '74 and later on your steel trailing arms, then you will bring it in by 5mm.

The later hubs are deeper by 5mm to fit the wider wheel bearings on the later cars, so if you use them on your narrow bearings, it will bring them in. (I've never done this, but I think you'd have to make sure all the e-brake shoes, etc. will clear the inside of the rotor's inner drum. Look at an old rotor to see the witness marks from the shoes to see if there'll be room)

Does this also apply if you just use an aluminum trailing arm straight up? I'm using aluminum arms from a '77 on my '72 and then swapping in the four bolt flanges from my steel arms. Will there be any net effect on the hub placement?

Tyson Schmidt · 11-08-2005, 11:27 AM

Quote:

Originally posted by 911SCfanatic
Does this also apply if you just use an aluminum trailing arm straight up? I'm using aluminum arms from a '77 on my '72 and then swapping in the four bolt flanges from my steel arms. Will there be any net effect on the hub placement?

No it won't work. You have to use the later hub on the early narrow bearing.