wheels needing insane spacers

[DucktailCTR]

how big of problems am i looking at for premature wear for using wheels that need 3.25 inch spacers?

[Evan Fullerton]

If it is just to correct offset then none (though I haven't heard of any ~90mm offset wheels). If it is to correct the offset some and fill out a turbo fender then probably some extra wear will occur but not enough to worry about it. The bigger issue is that you will need something like 125mm studs to do it right (I don't like bolt on wheel spacers) and I haven't seen anything over 100mm for sale. Not to mention adding a 3.25" spacer and accompanying studs will weigh several pounds and be quite expensive. I would imagine that unless they are some super funky cheap wheels that you would be better off money and performance wise selling what you have and buying appropriate size and offset wheels that don't need spacers or longer studs.

[DucktailCTR]

Originally Posted by Evan Fullerton

If it is just to correct offset then none (though I haven't heard of any -90mm offset wheels). If it is to correct the offset some and fill out a turbo fender then probably some extra wear will occur but not enough to worry about it. The bigger issue is that you will need something like 125mm studs to do it right (I don't like bolt on wheel spacers) and I haven't seen anything over 100mm for sale. Not to mention adding a 3.25" spacer and accompanying studs will weigh several pounds and be quite expensive. I would imagine that unless they are some super funky cheap wheels that you would be better off money and performance wise selling what you have and buying appropriate size and offset wheels that don't need spacers or longer studs.

theres a set of 18x11 5x130 te37s with 41 mm offset for sale for 1500 brand new. got plans for flares to accomadate them. pretty sure i could get the spacers fabbed. not sure where to look for studs. would 930 trailing arms or a substitute for them be required to prevent extra wear?

[DucktailCTR]

also calculationg that the approiate offset for 11 inch wide wheels would be around -30 and the wheels are +41, an approx. 70mm spacer is called for. and i guess some insanely long studs too

[Evan Fullerton]

A 70mm spacer is probably doable with 100mm studs depending upon the thickness of the wheel. SwayAway sells studs for Porsches/VWs. To fit a 11" wheel you have to have right around that offset to get it to fit and there are plenty of people who have done it that also track their cars on slick so you should be fine. Search for the the Pelican user Ted as I believe he is currently running 15X14" wheels on his street/track car with RSR body work and he uses regular 911 trailing arms. Wheel bearings on 911s are tough. I wouldn't be surprised if the ones on my '75 are original at 150k miles so even if they wear out 4X as fast that still is pretty decent life.

[DucktailCTR]

Originally Posted by Evan Fullerton

A 70mm spacer is probably doable with 100mm studs depending upon the thickness of the wheel. SwayAway sells studs for Porsches/VWs. To fit a 11" wheel you have to have right around that offset to get it to fit and there are plenty of people who have done it that also track their cars on slick so you should be fine. Search for the the Pelican user Ted as I believe he is currently running 15X14" wheels on his street/track car with RSR body work and he uses regular 911 trailing arms. Wheel bearings on 911s are tough. I wouldn't be surprised if the ones on my '75 are original at 150k miles so even if they wear out 4X as fast that still is pretty decent life.

how thin or thick does the wheel need to be for that to work?

[Evan Fullerton]

Depends on how one measures 100mm studs. If it is 100mm for the threaded length then with a 70mm spacer you will have 30mm remaining. Steel open ended lug nuts need about 20mm for full engagement so the wheels thickness would have to be around 10mm. However, I think most studs are measured as total length not threaded length and if that is the case you would need ~120mm studs or so.

[DucktailCTR]

Originally Posted by Evan Fullerton

Depends on how one measures 100mm studs. If it is 100mm for the threaded length then with a 70mm spacer you will have 30mm remaining. Steel open ended lug nuts need about 20mm for full engagement so the wheels thickness would have to be around 10mm. However, I think most studs are measured as total length not threaded length and if that is the case you would need ~120mm studs or so.

any idea where to find 120-125mm studs?

[Evan Fullerton]

Nope. 100mm seems to be as long as any I have seen.

[ratpiper71T]

I've wondered also the effects of this. Have you seen Chop Shop:London Garage or Bangla Bangers on Discovery HD? Not porsches here but in almost every case they use massive spacers to fit the offset for larger fenders on the hotrodded beaters they fix up. But we're talking like 11 inches! Obviously, the ones your using are much smaller. I would imagine this increases the Centrifugal mass of the rolling wheel and cause great stress to the wheel studs and bearing regardless of the setup(ie.- long or short studs) used? Sorry if I've misused these terms- I'm not an engineer..

[911-32]

After many years on Pelican and being around the track day scene, I cannot recall ever seeing a failure of the bolt on type spacers. There are hundreds of negative comments on Pelican for sure and I think that comes from the racing forum where tech inspectors don't let you run them because checking the tq of the spacer involves removing the wheel.

I am running 70mm bolt on spacers on the rear of my 3.0RS-type track car so I can run 8+9x16 Fuchs on narrow body suspension. The only extra load on the bearings compared to a deeper dished wheel of equal size and weight is the weight of the spacer and that is the same whether its bolt on or slip on over longer studs.

[Joe Bob]

The reason you haven't seen any failures is that the bolt ons are banned by most race sanctioning bodies.....at least this side of the pond.

[Evan Fullerton]

With the bold on spacers instead of having the stud flange captured by the steel hub you either have just a few threads into the aluminum spacer holding it in or the same size flange on the stud being held in by a similar thickness of aluminum as the steel hub, both are much weaker than the stud being in steel. H&R spacers seem to be of the bolt on variety and they have a good reputation for making quality parts but out of personal preference I have avoided bolt on spacers but then I have never needed more than a 1" spacer.

[911-32]

Originally Posted by Joe Bob

The reason you haven't seen any failures is that the bolt ons are banned by most race sanctioning bodies.....at least this side of the pond.

Fact remains, these are on probably thousands of cars all over the planet. Where is the evidence of failure? If even one failed in the wider Pelican community, we would know about it.

I am not aware of them being banned over here. As Evan notes, all the German bolt ons, like H&R, will be TuV approved and of high quality.

[DucktailCTR]

would wheel adapters and wheels with a better offset be suggested instead?

[JeremyD]

Yes!

I thought mine were bad at around 2.25" and longer studs

[DucktailCTR]

here are my alternative ideas (all would need adapters)

rota boost 18x10 +20 hub bore 73mm

rota grid 18x10 +15 hub bore 73mm

tsw nurburgring 18x10.5 +27

anyone see any problems or have any suggestions?

[DucktailCTR]

bump?

[Kevin Stewart]

an 18x10 needs roughly a -23mm for the rear so with a +20 you will need roughly 43mm spacer whats that come out to 1 3/4, the best way is obviously you want a negative off set or the lowest + offset, mout the tires/wheels place them under the fender and measure the air gap, Kevin

[DucktailCTR]

Originally Posted by Kevin Stewart

an 18x10 needs roughly a -23mm for the rear so with a +20 you will need roughly 43mm spacer whats that come out to 1 3/4, the best way is obviously you want a negative off set or the lowest + offset, mout the tires/wheels place them under the fender and measure the air gap, Kevin

they all need adapters so wouldn't the spacers needed be smaller?