Wheel Spacers and Lug bolts

[Rennsource]

I did a quick search and just ended up more confused... I've got 18's and have a set of H&R sport springs on the way... I've read that a popular 996 mod is 7mm front and 17mm rear spacers to push the wheels out .. I don't know where to get 17mm rears, (I've only found 15 and 18?) My question is though, how do you figure out what size lug bolts go with what size spacer? thanks!

[Loren]

The correct spacers will depend on your existing wheel offsets. Porsche approves only 5 mm front and 17 mm rear spacers for the 996 series cars.

The wheel bolts will depend on the width of the spacer and the design of the spacer. Some spacers are designed to use standard wheel bolts and some (i.e. Porsche 5 mm spacers) user wheel bolts that are 5 mm longer than stock (stock 45 mm so 5 mm spacers would need 50 mm wheel bolts).

[Rennsource]

Is the offset printed on the wheel? (you can see the 18s I have in my avatar) My owner's manual says: 8jx18h2 50mm and 10jx18h2 offset 65mm....

thanks...

[Loren]

Yes, on most of the 996 wheels the offset and wheel width is printed next to the tire valve.

[Rennsource]

Got it.. Thanks.. reads 50 front 65 rear...

[Loren]

Porsche approves only 5 mm front and 17 mm rear spacers for the 996 series cars and they sell both of them.

As i recall if you but the 5 mm spacers from Porsche they include longer wheel bolts. The 17 mm spacer use standard bolts but they attach to the wheel hub via included special bolts.

You won't likely want to go wider than these as that will cause road debris to be throw up on the sides of the car.

[RFM]

17 mm spacers are fitted with the Original wheel bolts on the hub, the wheels are mounted with the supplied lug nuts on the spacer/hub assy as the 17 mm spacers are fitted with studs. I would recommend to use OEM spacers since some after market ones has been shown cracks after time.

[1dmurrray]

I put sport technos (18x8/50 front, 18x11/63 rear) on my 2001 C4, and I was wondering if I could add 5MM spacers to the front. The TSB does not list this as an option. Any thoughts?

[Loren]

I put sport technos (18x8/50 front, 18x11/63 rear) on my 2001 C4, and I was wondering if I could add 5MM spacers to the front. The TSB does not list this as an option. Any thoughts?

Porsche does not recommend spacer on just the front or just on the back.

You could do 5 mm all the way around or 5 mm front and 17 mm rear.

[1dmurrray]

I put sport technos (18x8/50 front, 18x11/63 rear) on my 2001 C4, and I was wondering if I could add 5MM spacers to the front. The TSB does not list this as an option. Any thoughts?

Porsche does not recommend spacer on just the front or just on the back.

You could do 5 mm all the way around or 5 mm front and 17 mm rear.

Thanks Loren. I guess I will leave well enough alone. The 11s are plenty wide in the back as is.

[KapCoupe]

Loren,

Regarding your last comment about going with 5mm spacers all the way around, how does that square with your previous comment about 5mm on the front and 17mm on the rear being Porsche's recommended sizes? I'm asking with regard to a stock 40th Anniversary model. Thanks in advance for your feedback.

[Loren]

Porsche also allows 5 mm on all four wheels - the 996 GT3 came with that as standard.

[KapCoupe]

Thanks for the clarification, Loren. We appreciate all your help.

[bzguy]

Any idea about the part numbers for the OEM spacers & bolts ?

I'd like to install 5mm OEM spacers (front) & 17 mmm OEM spacers (rear) on my 996 MK1 (with MK1 GT3 wheels).

[Loren]

Your car shoudl

Any idea about the part numbers for the OEM spacers & bolts ?

I'd like to install 5mm OEM spacers (front) & 17 mmm OEM spacers (rear) on my 996 MK1 (with MK1 GT3 wheels).

5 mm spacer kit for all 4 wheels. (new part number 997-361-605-90).

The 17 mm kit is for two wheels and is 000-044-500-41.

[Coloradocurt]

This thread seems to focus on guys wanting to space their stock-offset wheels out to fill the wheel well a bit more. A different situation is when replacing the stock wheels with aftermarket ones with more (negative) offset than the stock ones, and spacers are needed to bring those wheels out to where the stock wheels would have been.

Loren, do you know whether the factory's recommendations of those 5/17mm spacers is related to (1) the most you can move the stock wheels out before encountering fender rub, or (2) the mechanical limitations of even thicker spacers and ever-longer wheel bolts? I would imagine that extra long wheel lug bolts might have undue bending/shearing forces on them.

[Loren]

This thread seems to focus on guys wanting to space their stock-offset wheels out to fill the wheel well a bit more. A different situation is when replacing the stock wheels with aftermarket ones with more (negative) offset than the stock ones, and spacers are needed to bring those wheels out to where the stock wheels would have been.

Loren, do you know whether the factory's recommendations of those 5/17mm spacers is related to (1) the most you can move the stock wheels out before encountering fender rub, or (2) the mechanical limitations of even thicker spacers and ever-longer wheel bolts? I would imagine that extra long wheel lug bolts might have undue bending/shearing forces on them.

On some of the early cars (1998 and 1999) the rear fenders need to be cut to use the 17 mm spacers. So I would say with the stock offset that is the main reason for the recommendation.

Not sure there is much room at the front as the fenders are factory rolled already.

The 5 mm spacer get 5 mm longer bolts - the 17 mm spacers use adapters the screw to the wheel disc/hub so they use the stock length fasteners.

17 mm spacer on left - 5 mm on the right

[bzguy]

Thank you very much for this information Loren !