Wheel offsets and wider tires...Anyone have 225/50-16s on the rear...?

[Tremelune]

I have a 1970 911T that needs some new shoes, and I'd like to replace the wheels while I'm at it. I'm wondering if I can get a bit more tire under there by going with custom offsets. It seems like tires rub the fender lip but have room to spare inboard.

A fair amount of longhoods are sporting a square wheel and tire setup, or at least square wheels with slightly different tires. I like a square setup for rotation, but...it just feels weird on a 911 to me. My 2.2L engine isn't putting out much power, but that's liable to change in the future, and even still, the rear is ready to kick out some (no sway bars and ancient tires on 5.5x14 Fuchs—where'd these come from??).

I'm hoping to get a 205/55-16 up front and 225/50-16 in the rear, as that gives me access to more modern rubber. From what I've read, 7"-wide Fuchs in the stock offset will fit in the rear, and a 205-series tire probably won't rub (though some do). I'm wondering what it might look like to go 6" up front and 7" in the rear, or maybe even 7" up front and 8" in the rear.

Looking at this chart, it sure seems like I could squeeze an 8" rear (or at least a 7" wheel and 225 tire with room to spare) if the offset were something like 30-40mm (between the standard Fuch and the 911R):

[Arne]

Note that the 7R with 49mm offset requires 7-10mm spacers in the rear for clearance on the inside. So the max effective offset you can use on a 7" is really 42mm, which is 131mm backside. I doubt that will be enough to fit a 225 in back. The extra sidewall bulge will be problematic on both inside and out. If it was easy, more people would have done this by now.

[RickWhite]

Whatever inexperience I have, it is made up for with a similar fixation on maxing the meat underfoot.

As an owner of a '71 T with the comfort package, I highly encourage you to put the 14" wheels on the shelf. Also, the stock 15mm sway bars are a huge upgrade, probably better than the wider tires (I also have 930 torsion bars).

I've gone through great pains to keep my Targa "original" at least to all outward appearances, which means I run deep 6s and 7s. I refuse to roll the fenders, which means my tire size is limited to 185/70 in front and back. The fit in the front is quite tight, requiring some massaging of the protective plate for the oil cooler, and moderate tweaking of the front bumper (at speed, on a right hand sweeper, my tire was brushing up against the bumper horn).

This is the rear tire (get CN36s, the sprint classics are garbage, and no, I have no clue how to flip the orientation of this photo...sorry).



And yes, the 185/70 is pretty good, but not great, in performance driving. Here you can see the profile on front and back, under modest duress (emphasis on modest).



Check out the latest Esses (I think) for an article on the green T built by Longballa. It runs 205s (I think, from memory), but he has to do numerous things to fit the tire (including rolling the fenders, which is not allowed on my targa). Not that I have much standing to offer this, but when I contacted him with questions, he was extraordinarily graceful in giving me hints on set-up.

On the other hand, if you want real meat, get some new wheel arches! I am certain the board will be offended for about 26 reasons with this bastard of a long hood, but it is running 7j and 8jx15s (yes, I am restoring some fuchs so these are temporary), which allows 205/50 and 225/50 and the grip is nothing short of absurd. It also has quite a few tweaks to the suspension.

[Tremelune]

This is all rather interesting. I'm extrapolating from posts I've read and what's possible on an SC/3.2/G50...My understanding is that the front is the same as the impact-bumper cars, and you can fit an 8" front on them suckers—certainly 225s on a 7. Isn't the rear where the longhoods struggle...? I thought 7" with 205s on the rear was pretty well-worn territory. Maybe I need to go back through these tire threads...

The info about the 911R spacers is a valuable bummer. I thought that was my ace in the hole.

I'm not willing to add fender flares unless I need to paint the car for some other reason...I can live with skinny (and light) tires, I just don't want to deal with "vintage" tires and their higher cost and inferior performance (grip, noise, feedback, etc).

I'm kinda hoping my Fuchs aren't original to the car...'cause I don't want them in my yard for decades for the purpose of resale...

[RickWhite]

You can certainly fit 205s under, it just will require modification of the car. The difference between small modifications and slapping from RS flares....slippery slope.

If you don't care about looking period correct, some 16" with more modern tires might be the way to go. The 16" fuchs actually look OK on the cars.

[Jerry L]

Tremelune, I may not be answering your question exactly but hopefully helps. 71 Targa
I am running 215 50 16 Dunlop Diazza (sp) on 6x16 SC fronts on all corners, there is no rubbing issue and did not roll the fender lips. I am also a fan of getting more tire under the cars (also have a late 65 / 66 912 coupe with 205-55-16 on same wheels I had to add spacers to front 8 - 10mm and slightly rolled the rears) One of the reasons I went for the dunlop was having the 215 available. The dunlop has an offset at the bead pushing the sidewall further away from the rim (wider foot print) I also added 2 (I think) 2mm spacers on the rear. I had laser cut a bunch at work for fine tuning the look on the cars. I think your search for using 225 being 5mm wider per side (theoretically as overall width varies with manufacturer & tire design) "May" be doable.
I am attaching 1 pic had I had with me but not a great view of the fit. also the early Coupe. I am up on lake Superior but will be home by the 25th and can get you better pics & measurements if you would like. Also a blatant plug I have a near perfect set of 4 6x16 SC fronts in orig black that I will also be selling on my return.
Both sets were done by Al Reed, wishing him & Diane happy retirement today!!

Let me know if you would like more detail & pics next week.

Best Regards

Edit: on the 16 x 7's I played with them a LOT trying to fit them first on the coupe then the 71, finally sold them giving up on that plan.

[Tremelune]

Interesting. Am I making too big a deal of the staggered setup? I had a set of Direzzas on my '87 that I quite liked. It just...feels strange to me to have the same wheels and tires on the front and back on a 911, when the thing is like 60% heavy in the rear...

[Arne]

Porsche didn't make staggered sizes standard across the lineup until the 3.0L became the 'base' engine with the '78 911SC. Running square sizes is part of what makes the early cars feel more nimble, as the wider sizes just cause more understeer in normal driving. I love the look of big rubber on the back, but certainly won't go to the extremes necessary to make some fit. Not for street use.

[frederik]

You can fit 195/65 tires on standard 15x6" Fuchs wheels without rolling the fenders. I would also vote for adding sway bars -- I just added 15mm front and rear sway bars to my Targa and it makes a huge difference. Less understeer and way more stable in corners with easily correctable oversteer on throttle.

[Tremelune]

How did the sways affect the ride? I always fear they'll make potholes harsher, but I'm scarred from giant sways on a former race car I restored...