Wheel offset/alignment question

[solamanda]

I've got an obscure wheel question. I'm sorting out some spare wheels for a track car to use with wet tyres. The front wheels are offset ET36 verses the dry wheels ET25. The outer dimensions of the tyre will be identical. I can get a 5mm wheel spacer to push out the wet wheels (it doesn't seem like 10mm is possible/available). Would having one set of wheels 5mm out affect the geometry?

I have checked clearance isn't an issue.

Thank you

[brillomaster]

thats really weird you could get a 5mm spacer but not a 10mm... what car is it?!?

but no, doubt very much you'd notice having some wheels that sit 6mm further in than the others, if everything else remains the same.

i've recently fitted 7mm/15mm spacers to my boxster, and can i honestly say i notice a difference in how it drives? probably not. it does definitely look better though.

[solamanda]

It's a Vauxhall Vx220. Someone else at a trackday said it might screw up the geometry. I think my solution is to use two 5mm spacers if necessary. Not ideal but it's hardly a big spacing.

[Master Of Puppets]

You are thinking this the wrong way round, if you put a 10mm spacer on your ET25 wheels the offset will then be even smaller
at ET15, adding spacers decreases your wheel offset, resulting in them sitting out further on the car.

[solamanda]

I think I've confused you! I want to fit spacers to the ET36 wheels to bring them closer to the ET25 wheels.

[braddo]

Won't a VX220 have a very common PCD? In which case finding 10mm spacers should be easy.

The spacers will change scrub radius / ackermann angle slightly but not enough to be an issue, especially if you're already using another set of wheels with less offset. If you can't feel any difference between the two sets of wheels now, you won't notice any difference after the spacers either.

[solamanda]

It's 5 x 110 pcd with 65.1mm bore. I've not found 10mm spacers with a 65.1mm bore.

I've not fitted the wheels yet, I'm going to be running an unusual setup, so trying to get my research done before I go all in with new tyres/refurb on the wheels.

[braddo]

If the inner bore size needs increasing, a local machining shop can do that (one in south london did similar for me)

[Den Den]

Try https://www.superforma.co.uk/ they'll make any size/offset/pcd you can think of, and at very reasonable prices.

[solamanda]

Thanks Den Den, they say the wheel centre bore needs to be 75mm