Question about spacers and track driving

[kboy]

So I have yet to bring my Atom to the track. Unfortunately the events I looked into require fenders, so here's the setup I'm trying to make work:

- 949 Racing wheels - 15x9 fronts with 205/50R15 and 15x11 rears with 275/35R15 Hoosier A7's
- Skunkwurx 225mm front fenders and brackets (supposed to be good up 205's but mounted on the larger wheels they are too small. Might order a set of the 245mm rear fenders and mount them up front. If so I'll have a set of 225mm available for sale soon.
- Skunkwurx 295mm rear fenders and brackets

The problem I'm running into is that in order to mount the wider wheels and fender brackets together I'll need wheel spacers. 25mm up front, 15mm rear. Because the Atom's lug posts are welded directly to the hub, you can't swap out longer posts, so you have to run a spacer that bolts to the hub and then the wheel bolts to the spacer such as this:

https://www.summitracing.com/int/par...0291/overview/

My question is how safe is high performance track driving with this type of spacer, or with spacers in general? If anyone has any experience with this or has any ideas on other ways to clear the fender mounting brackets, I'd love to hear from you!

(Also I'm not sure if posting that link breaks any forum rules. I'm not trying to advertise, I'm just showing what I'm trying to work with, but I can edit the post if necessary.)

[jeff8407]

Quality-wise, you will not have a problem with the spacers. I have seen sprint cars with 800hp use those exact brand/style of spacers to adjust offset/tire width/stagger....

[Frank Orozco]

You will alter the scrub radius of the car with spacers, changing handling characteristics. Can't you modify the fender instead?

[sector: 4]

The problem I'm running into is that in order to mount the wider wheels and fender brackets together I'll need wheel spacers. 25mm up front, 15mm rear. Because the Atom's lug posts are welded directly to the hub, you can't swap out longer posts, so you have to run a spacer that bolts to the hub...

So you're saying that the wheel studs are welded to the hubs? Are you joking? Are you sure? They should be using splined studs pressed into holes so that they can be replaced. Are they using regular bolts instead of regular headed wheel studs or something? How dumb!

[sector: 4]

You will alter the scrub radius of the car with spacers, changing handling characteristics. Can't you modify the fender instead?

Usually yes, but the wheels are being changed. If the new wheels have an offset that is too positive, then a spacer can bring the scrub radius back where it belongs, which may be the case here if the aim is to center the wheels under the fenders.

[cvjoint]

So you're saying that the wheel studs are welded to the hubs? Are you joking? Are you sure? They should be using splined studs pressed into holes so that they can be replaced. Are they using regular bolts instead of regular headed wheel studs or something? How dumb!

Yes, they are welded on. However, I have talked to TMI about this and they are quite accommodating: they are willing to provide the stock hub and studs separately. That way you can use different studs on stock hubs. That's what I would do. I'm using 5mm spacers on my street car but I would not on the Atom for the track.

[Phoenix Atom]

You don't need to buy new hubs. Take the old hubs, grind off the welds and press the studs out. Any competent shop can do it. Finding the studs was a challenge but if TMI will sell you the longer studs, you're all set on that.

You'll need to remove the bearings, as I recall, and you'll destroy them in the process, but bearings are cheap. B32 is the size, I think. You'll need seals, as well. All of which will be much cheaper than buying new hubs.

[jeff8407]

A tack weld on the back of press in studs was the proper, "factory", install method for most OEM's up until the 1990's on cars with a live rear alxle . You remove the axle or hub, grind the tack weld flat, then press the stud out. I have done it dozens of times....

[cvjoint]

My Atom SRA has really long studs that work with the Keizer wheels. The previous owner of the wheels had an Atom 2, which has the same bolt pattern but short studs. So I bought studs and bearings but never had to do the job.