wheel spacers on 996 cab?
#19
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front will rub
Good as the spacers look on the car, I don't think I can use 15mm on the front. When the steering wheel is turned to the stop, the tire is up against the fender liner. Probably try the next size down.
#20
Three Wheelin'
Chuck:
Porsche does not recommend spacers wider than 5mm front and back for any of their OEM rims. In addidtion, you probably know that you will need to get longer wheel bolts as well.
Personally, I think spacers are a bad idea. If you look at the stories on both this and on the funcarsonline board, you will find that there are many sad tales about folks with spacers and having stripped bolts and failed wheel bearings because of the stress that the altered offset puts on the hub and bolts. Another more reliable way of making your wheels stick out further is to get some rims that keep the proper offset, but are wider.
There are some great 13" gold faux wire wheel rims out there that allow you to stick your tires out way far! Team those up with some W rated whitewalls, and you will have a killer combo!
BTW: Love your color top combo. That was my first choice when I ordered my 02 Cab.
Porsche does not recommend spacers wider than 5mm front and back for any of their OEM rims. In addidtion, you probably know that you will need to get longer wheel bolts as well.
Personally, I think spacers are a bad idea. If you look at the stories on both this and on the funcarsonline board, you will find that there are many sad tales about folks with spacers and having stripped bolts and failed wheel bearings because of the stress that the altered offset puts on the hub and bolts. Another more reliable way of making your wheels stick out further is to get some rims that keep the proper offset, but are wider.
There are some great 13" gold faux wire wheel rims out there that allow you to stick your tires out way far! Team those up with some W rated whitewalls, and you will have a killer combo!
BTW: Love your color top combo. That was my first choice when I ordered my 02 Cab.
#21
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OE,
Thanks for the note, the color is awesome. I have had 4 928s over the years and 3 of them had spacers. My current GTS has a 1" spacer on the rears and I've had no issues nor, have I heard of other GTS owners with any issues. Didn't the 930 have spacers too?
Porsche recomends you don't do lots of things to your car. Is it really that big of an issue?
Thanks for the note, the color is awesome. I have had 4 928s over the years and 3 of them had spacers. My current GTS has a 1" spacer on the rears and I've had no issues nor, have I heard of other GTS owners with any issues. Didn't the 930 have spacers too?
Porsche recomends you don't do lots of things to your car. Is it really that big of an issue?
#22
Three Wheelin'
What year is your GTS? sounds like it is one of the last ones.
I prefer rims that have the correct offset, and are just deeper on the outside to make the rim stick out further.
I agree there are alot of things that Porsche says are no-no's , but I also see many folks that are singing the blues when they break their car becuase of some mod.
It looks like 996s have more problems with extra wide spacers than other models, especially on the front suspension.
The last thing I will bring up in trying to dissuade you from spacers is that with your wheels sticking out further, you will get more gravel and debris damage on your paint from stuff that the tires kick up.
I prefer rims that have the correct offset, and are just deeper on the outside to make the rim stick out further.
I agree there are alot of things that Porsche says are no-no's , but I also see many folks that are singing the blues when they break their car becuase of some mod.
It looks like 996s have more problems with extra wide spacers than other models, especially on the front suspension.
The last thing I will bring up in trying to dissuade you from spacers is that with your wheels sticking out further, you will get more gravel and debris damage on your paint from stuff that the tires kick up.
#23
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Hi OE,
My GTS is a 1995 model with 10,800 miles. It is one of 74 1995 GTSs built and approximately 23-27 with a 5-speed trans. I am a 928 fanatic, check out my web site:
928 site
I am going to have to put smaller spacers on the front because of the rubbing issue. I agree that some of the mods folks have done have contributed to problems down the road and that's why I've stayed away from extensive engine mods. Would very much like to keep the stock wheels and tires. I guess what I keeping thinking is how Porsche used to tell owners not to put 18" wheels on older cars.
I also agree with your last comment and as fanatical I am about keeping my cars in pristine condition this is definately a concern.
My GTS is a 1995 model with 10,800 miles. It is one of 74 1995 GTSs built and approximately 23-27 with a 5-speed trans. I am a 928 fanatic, check out my web site:
928 site
I am going to have to put smaller spacers on the front because of the rubbing issue. I agree that some of the mods folks have done have contributed to problems down the road and that's why I've stayed away from extensive engine mods. Would very much like to keep the stock wheels and tires. I guess what I keeping thinking is how Porsche used to tell owners not to put 18" wheels on older cars.
I also agree with your last comment and as fanatical I am about keeping my cars in pristine condition this is definately a concern.
#25
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Has anyone experienced negative impact on the wheel bearings and/or suspension components like Orient Express is concerned about? I certainly do not want to do something to my car that might induce other worse problems than the stock wheels not filling out the wheel wells to my liking.
#26
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This is a great question....
I too, would like some factual evidence to what spacers will due to your car. I am no mechanical engineer but do think that what I have heard to date on this forum and others is legend.
Stripped bolts is from over tightening.
The only thing that I can picture from all of this is that with the wheel further out you have increased the leverage point of the wheel on the suspension which would mean it will require less force to compress the suspension. This would be a negative (Some one technical might be able to tell us if this is negligable or not).
As for offsets, I have to imagine that you want to keep the center of the wheel close to the hub so that the geometry is not changed by a larger wheel.
Anybody care to explain if I am correct or totally off base?
Stripped bolts is from over tightening.
The only thing that I can picture from all of this is that with the wheel further out you have increased the leverage point of the wheel on the suspension which would mean it will require less force to compress the suspension. This would be a negative (Some one technical might be able to tell us if this is negligable or not).
As for offsets, I have to imagine that you want to keep the center of the wheel close to the hub so that the geometry is not changed by a larger wheel.
Anybody care to explain if I am correct or totally off base?
#27
Re: This is a great question....
Originally posted by 996/699
I too, would like some factual evidence to what spacers will due to your car.
I too, would like some factual evidence to what spacers will due to your car.
The main issue with spacers is that they change the scrub radius. Most modern car manufacturers advocate negative scrub radius (BMW being the notable exception), because it stabilises the vehicle under "split mu" breaking, i.e. breaking with right and left front wheels on different friction surfaces.
A 986 (I haven't got 996 data here, but I assume it's the same) has a scrub radius of -7mm. That's *negative* scrub radius which stabilises the vehicle under split mu breaking. Introducing spacers decreases this, i.e. if you use 5mm spacers, you are left with a scrub radius of -7mm+5mm=-2mm. You get very close to a positive scrub radius, and in real life with an asymetric contact patch you might already be there. If you fit 15mm spacers, you get a *positive* scrub radius of 8mm, which destabilises the vehicle under split mu breaking and is pretty much the opposite of what the manufacturer intended.
Cheers,
Uwe
#28
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Where is this scrub radius and how is it measured? How does a spacer change the radius? Do I assume the radius has something to do with the contact patch of the rotating tire?
#29