I am getting contact between my front driver's side tire and the inner wheel well. This happens on a hard corner or when I hit a dip in the road. It is a brief rub but has already worn a small hole in the fender liner. I had my local miata specialist check the alignment and it had not deviated from its settings which are approximately the 949 rated dual use:

Front camber: -2.5°
Caster: +3.5 ~ 4.0°
Front total toe: 0

Rear camber : -2.0°
Rear total toe: + 1/8", .06"

The shop said that the dampening needed to be increased. I did this and it still rubs . I am also running XIDA CS coilovers with 550 front springs and Bauer front ball joints. Handling feels fine, and there is no evidence that the coilover is leaking. Wheels are 15x8 6ULs running 205-50-15 tires.

What am I missing here?

Thanks

 

You have much travel (This is a good thing). If you're worried about your inner fender liner, you need to limit that travel. You can sorta do this with heavier springs (wouldn't actually limit travel, but maybe limit the amount of times you are able to compress that far), or with longer/stiffer bumpstops.

 

thanks for the reply. I need to take a close look at this coilover. I did not see any evidence that the dampener was leaking (no dust collecting below the shaft etc). Have not heard of hyperco springs losing their rate. Wondering if a degraded bumpstop could cause this? Lots of travel that can no longer stop on a bump stop.

 

Degraded bumpstop sure, or the car is just that much heavier on that side. Or you're driving the car harder as you get used to it.

This isn't something that's happening on normal sedate commuting, right?

 

It is happening on when I am at least going 45 mph , straight road with a slight dip in the lane. I hear the tire scrub the wheel well. I am not any heavier (actually lighter) so something has changed that is allowing the car to rub. Will shoot 949 an email about the bumpstops.

 

What's your pinch weld height?

 

Pinch weld is a bit bent on the driver's side so I measured on each side of it to the ground . Both measurements gave me 4.6".

 

So it would be 4.6" minus how "proud" the pinch weld is?

That's a bit low for those rates IMO, but doesn't explain why it was good before, but not now. Sorry i don't have a magic bullet. :(

 

Definitely a proud pinch weld! I need to bend it back with some vice grips. Measurement was taken just on the other side of the pinch weld where the rail was straight. So how low do you think the front should be?

 

If it were ME, i'd probably run 4.75-5" at pinch weld with those rates if fender liners are a concern.

 

Xida Race + remove liners = profit

 

Fender liners are definitely overrated

In all seriousness, Id say try to come up a little bit, but if you're rubbing that easily (at least it sounds like you're hitting the dip too hard), then even raising a little is still going to rub when driving aggressively. Either going to have to go up quite a bit to be safe, or look at a higher spring rate (which is going to have its own drawbacks)

 

Trade in allowance for XIDA CS?

 

Same shock & springs. https://supermiata.com/xida-mount-miata.aspx

 

Making them wet won't improve the situation.

The correct answer though is stiffer or longer bump stops - they should be what limits travel at max compression, not your tire. As others have mentioned stiffer springs or more ride height might stop you getting there as frequently too.

 

Thanks for the comments everyone. First step will be a small increase in ride height.