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Max forward wheel size
#1

Wish to get 265/18/35s in forward to balance 295s at the rear (these can be bought 2nd hand at low prices from GT3 owners). I have 10" wheels ET 47. I tried these on last year and it looked tight but OK. What is te max forward size used in US racing?

//TL
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#2

be very careful about increasing up front - i have a lightweight 9" rim (20lbs) up there with a 255/35 on it, but i won't race that on the stock hub and spindle - the load would be too much - the stock ones are known to break with even an 8" rim and wider tire

if i were to race, i would definitely upgrade the hubs and spindles so i could run wider rims
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#3

Upgraded spindles? What upgrades are available beyond the M030?
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#4

lol - as far as i know, M030 is the only spindle upgrade currently available - there are a couple of different hubs out there
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#5

Upgraded hubs on their way. What is the max size used by US drivers up fronn? Considering to go as far as 295s here as well due to the cheap supply of second hand tires. Right now I have a bunch of 265s to consume so that will be the first step.
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#6

the biggest i've heard of so far is a 265 on a 10" -

thing to think about:
to run that much tire up front, you will need to reduce the front negative camber - the contact point changes so much relative to the hub that when the car goes into a turn, you actually end up with less net contact patch, and because the decrease is on the inside tire, you add roll

the lower brace will help this, but still plan on resetting the front angles

also, watch the wheel weight - going wider in tire adds weight - you will need to make sure you don't add wheel weight too - target a net combination tire/wheel weight of a max of 52lbs

you can also expect your braking and acceleration to suffer a bit due to the increased mass at the outside, but that might be offset by being able to carry more speed into the corner due to the increased traction and thereby not needing as much braking or acceleration
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#7

17x11 with 315's on all 4 corners has been done.

http://www.tonygarcia.org/944V8/
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#8

I'm running 275's on 9.5x17 fronts and 275 on 10x17 rears. I'm limited to 10 inch wheels for the class I'm running but I think I could get 295's to fit all around.
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#9

i really need to make a road trip up there to see that car
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#10

Erik,

That's impressive! No rubbing?
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#11

I need to get my car down to some California races some day.

Scott - no rubbing. The fenders have been rolled a bit and I'm running 2.25" diameter springs.

Here is a picture by Renalicious from this weekend in Mission BC.
   
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#12

soooooo.... what would be the ideal specs (offset) for a front 18" at 9.5" to 10" wide with rolled lips, -3.3 camber, to accommodate a 265 to 275 R6? Since we are on the subject... how about the rear for a 10.5"?
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#13

that would depend on a LOT of things, like chassis bracing, weight and weight bias, spring rates, sway bar rates, yada yada - i'm starting to do the design layout now for my toy, and with all the number crunching of spring rates, corner weights, etc, i don't think i will be going past -1.75 up front and -2.25 in the rear - but, i am also seriously changing the lower structure of the car
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#14

I leave the calcs to you more applied guys... I tend to take the easy slacker route and follow the pyrometer, lap times, and overall buttometer indicated car attitude.... And when all else fails, I just call Pete and complain until he gives up and gives up a track secret....
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#15

I have run 285/30/18's on 10" wheels front and back with no problems. That is the current fast setup for NASA GTS2 944 S2's and 968's. I know lots of guys that are running that setup with no issues.
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#16

i've been very concerned about the spindles and/or hubs failing on my car, as we've all heard of so many failures on the track - i'd love to find out that it was over nothing

i'm curious - of the guys who are not having issues:

what spindles and hubs are these guys running?

what are the tire/wheel combination weights?

what are the front corner weights?

what is the overall car weight?
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#17

I'm running billet hubs and M030 spindles. I think most of the other guys are running billet hubs, but there is probably a mix of M030 and regular spindles. Stock hubs will fail with any size racing tire. I've seen it many times. I've never seen a spindle failure.

Everyone runs lightweight 18" racing wheels and Hoosier tires. I don't have exact weights.

I don't have corner weights, but overall car weight in GTS2 trim is 3,100 lbs with driver for me. For the other guys car weight ranges from 2,850 to 3,150.
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#18

well, that's sort of good news - the weight part is encouraging - at least i can feel safe once i change spindles and hubs
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94 Midnight Metallic Blue Cab Porsche 968 w/deviating cashmere/black interior and WAY too many mods to list - thanks to eric for creating www.968forums.com



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#19

I have run 285/30/18's on 10" wheels front and back with no problems. That is the current fast setup for NASA GTS2 944 S2's and 968's. I know lots of guys that are running that setup with no issues.

-------------------------

What ET are you running for the 285s forward? I have a rather low car which now sits on 265s forward on 10x18 ET 47 wheels. The assymetry of the car is evident, the left side looks good but I am bringing the car to have the right side wheel arches rolled monday which is needed at the rear where I now have 11x18 ET 45 with 295s . The rears are 996 Turbo items with hollow spokes. Very light and a recommendation if you are looking for second hand wheels.

The car is rather low (will get an exact number when next time on a suitable flat surface) with close to four degrees of camber forward and something like 3 at the rear. I have not managed to wriggle the correct number out of my chassis guru who set it up.

Interrested also in what angles you are running on your car.

Interresting that you have not heard about spindle failures, makes life a bit easier, have not heard about any failures this side of the pond. I have seen a hub failure so this will be a priority change.

Best

TL
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#20

I'm not sure what the offset is, but I do know that the ones on the front are identical to the ones I run on the back. My camber is -3.25 front and -2.25 rear.
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