Front track increase if using 7" fuchs

eurocarrera · 07-15-2003, 09:20 AM

Does anyone know what the overall track increase would be when switching from 16x6" fuchs in front to 16x7"? Thanks!

GeorgeK · 07-15-2003, 12:05 PM

1 inch
GeorgeK

Bill Verburg · Bill Verburg's Garage

George is correct 12.7mm/side adds up to 25.4mm(1"). However most folks are interested in the outer edges of the rims which are moved out 25.4mm(1") /side for a total of 2" increase.

eurocarrera · 07-15-2003, 01:18 PM

Bill, is that with running the same tire size of 205/55/16? Thanks!

So overall track increase would be 2" wow

Bill Verburg · Bill Verburg's Garage

I may be wrong here but I always considered track to be centerline to ctr. line of the wheels.

There maybe an alternate "official "definition. The distance form outer rim edge to outer rim edge

I think that the second def. which in this case is 2"(1"/side) is the more important one.

The tire is placed by the rim and so doesn't really enter into the calculations. The tire will be stretched wider and lower on the 7 than on the 6

Adman · 07-15-2003, 01:35 PM

I agree with Bill. Back spacing is identical for both wheels, 112mm. I am running 7x16's all around with 205/55/16 front and 225/50/16 rear. The fronts look like a perfect fitment to the rim and the rear rims look too narrow. They suck the tire bead in quite a bit, even if they are porsche spec tire wheel combination for the rear. The fronts use to look the same way.
Matthew

Wil Ferch · 07-15-2003, 05:15 PM

I mentioned before on this list that I too run 7" all around on my 85 Carrera...with 205/55 front and 225/50 rear tires. Back looks a "bit" narrow but with S0-2's...it's not so bad...looks actually pretty wide.

Car is much less understeering than before ( I have factory limited slip) and the car handles just great ( for me) at Watkins Glen on DE days...

---Wil Ferch

Adman · 07-15-2003, 07:06 PM

Quote:

Originally posted by Wil Ferch
I mentioned before on this list that I too run 7" all around on my 85 Carrera...with 205/55 front and 225/50 rear tires---Wil Ferch

Will...I knew that I got the idea from somebody on the forum.Thanks! Now I just need to get off my butt and sell the four 6x16 fuchs I have sitting in the garage.

Matthew

Wil Ferch · 07-16-2003, 09:12 AM

Matthew:
Be clever when you sell the 6"...normally they go for about $100 a pop...but some guys need these as starting points for 2 or 3 piece 17" rims with Fuchs "centers". So....these centers come from the 6" wheels....price them accordingly ( on the basis of "need"...hehe)...don't give them away.
---Wil Ferch

Adman · 07-16-2003, 10:27 AM

Quote:

Originally posted by Wil Ferch
Matthew:
Be clever when you sell the 6"...normally they go for about $100 a pop...but some guys need these as starting points for 2 or 3 piece 17" rims with Fuchs "centers". So....these centers come from the 6" wheels....price them accordingly ( on the basis of "need"...hehe)...don't give them away.
---Wil Ferch

Wil...appreciate the reminder. I have actually given thought to sending a pair to Lindsey to set up a set of 9" for the rear.
Matthew

n8marx · n8marx's Garage

Wil and/or Adman,

Are you guys using spacers on the rear of your cars to push the 7 inchers outward at all or just bolting them as intended? If so, what size? Just curious if it looks funky with the front wheelwells filled out and the rears standard. I am considering the same set up but am wondering about the spacers.

Adman · 07-16-2003, 10:45 AM

n8marx...I am using H&R 28mm Adapters. I know! Should be using spacers instead. Looks just right but my ride height is 26.5Fand 26R. If the car were lowered dont know about the fitment.
Matthew

KTL · 07-16-2003, 10:46 AM

While we're on the subject of track width...............

I just played around with this last weekend for kicks.

I swapped the 16x6's with 205/55 to the rear and put the 16x7's with 225/50's on the front. It really surprises me that folks can run the 16x8 951 on front with a 225/50 or 225/45 tire. Must have to crank up a large amount of neg. camber and narrow the fender edges to do this? My camber is pretty minimal at -0.5 deg. And it wasn't the top of the tire that concerned me the most. It was the forward portion of the tire at the fender-bumper interface. I dunno. Maybe my 225/50 Kumho MX's are taller (25.1") than your typical 225/50?

Like I said, just kinda suprised me to see the actual, in person fitment of a +23.3mm o/s wheel on the front with a 225/50 tire. At first glance one might think it would never work- and this is with only a 7" wheel. The 8" wheel fits too!

89911 · 10:50 AM

WheelEnhancement bought a bunch of our 6's at Hersey for $125 each. I can see the point of using 7's up front instead of 6's, but is the only advantage price when considering 7's over 8's in the back? I run the 225/45 up front with a 951 turbo 8 by 16". Yes, you need lots of -camber and I pinched the fender lips. The key was the 45 series tire. This lowers my car about another 1/2 inch due to the smaller size.

Adman · 07-16-2003, 10:51 AM

Quote:

Originally posted by KTL
While we're on the subject of track width...............

I just played around with this last weekend for kicks.

I swapped the 16x6's with 205/55 to the rear and put the 16x7's with 225/50's on the front. It really surprises me that folks can run the 16x8 951 on front with a 225/50 or 225/45 tire. Must have to crank up a large amount of neg. camber and narrow the fender edges to do this? My camber is pretty minimal at -0.5 deg. And it wasn't the top of the tire that concerned me the most. It was the forward portion of the tire at the fender-bumper interface. I dunno. Maybe my 225/50 Kumho MX's are taller (25.1") than your typical 225/50?

Like I said, just kinda suprised me to see the actual, in person fitment of a +23.3mm o/s wheel on the front with a 225/50 tire. At first glance one might think it would never work- and this is with only a 7" wheel. The 8" wheel fits too!

I guess the 125mm backspace helps things out a bit.
Matthew

Adman · 07-16-2003, 11:01 AM

Quote:

Originally posted by 89911
I can see the point of using 7's up front instead of 6's, but is the only advantage price when considering 7's over 8's in the back?

In my situation I already had 6's and 7's. I bought another set of 6's and 7's and just used the 7's. I still have 4-6's to sell and recover some of the cost. It was all about the Benjamins for me. Poor people and our poor ways...

Matthew

Wil Ferch · 07-18-2003, 08:30 AM

There is more...

I *don't* run spacers for my all-around 7's.

My point was to lessen some of the factory dialed-in understeer. One way to combat this is to widen the front track, and also to give the front sidewalls more vertical support with less distortion. Going to 7" in front with 205/55-16's does that. If I now add 8" or 9" rears ( or use spacers on the 7's)...I'd be widening the rear track and I'd be *right back* to where I was in the beginning !!!

As I said, you have to be a certifiable Porsche crazy to really see the "fill-out" difference, but yes, the rears are a bit pinched in, but the vehicle dynamics improvement ( for me) was more important.

I guess it depends if you're DE'ing or profiling

--Wil Ferch

KTL · 07-21-2003, 05:27 AM

Here's what a +23.3mm o/s 16x7 looks like on the front of my 87 Carrera.

The tire is a Yoko AVS ES100 205/55-16. The tire dimensions are
O.D. = 25.0"
Sect. Width = 8.3"
Tread Width = 7.5"

I'd go with a 205/50 next time. The ES100 is a wider than usual tread width 205/55. The tire looks kinda fat compared to the 245/45-16 on the rear. The rear is a 16x8 +23.3mm o/s. The phone dials do look kinda odd, but it's a cheap way to get a set of Porsche 16x7, 16x8 wheels.

eurocarrera · 07-25-2003, 12:29 PM

Well I just purchased another used set of 16x7's and I will be putting those on the car next week. From what I gather, it sounds like I should *not* run spacers in the rear.

Adam, how is the handling of your car without the spacers versus with them on? And, where can one purchase the H & R spacers? Thanks!

eurocarrera · 07-25-2003, 12:47 PM

KTL/Kevin, BTW, I am running the exact same tires - they're great!