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Anybody care to educate me a bit on crash bolts? I'm trying to figure out ways to get a bit more negative camber in the front of my car, and right now, it appears that the only camber plates available for my car are uber expensive, not to mention, I really have no desire to adjust camber day to day, or to adjust caster, just to dial in 1.5 -2 degrees of negative camber and be done with it.

I can't seem to find crash bolts listed as a part anywhere, but does that mean they aren't available for my car? Are they a vehicle specific application, or are there generic kits available that can be made to work (I'd assume its just a question of the size hardware isn't it?) What bolt do they actually replace?

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2012 MX-5 Sport SUV

Crash bolts are bolts that hold the upright on the car. Usually you need two of them. The term "crash" comes from the fact that often times after a "crash" you need a small alignment tweak to make up for mildly bent suspension attachment points. So manufacturers will make a bolt available that has a thinner neck than normal and thus allow you to tweak the upright position because of the new slop.

They're only legal in stock class if the manufacturer has them listed in the FSM or has a tech bulletin of some type suggesting their use. I think different manufacturers have different ways of talking about them...I think with Toyota it's something like "one dot" and "two dot" etc and the amount of "dots" (marks on the head of the bolt) tells you how much slop they have and thus how much camber you can change.

Those are the generalities. For specifics on what you can use legally for autocross, see the rulebook on your class as well as the FSM and tech bulletins for your car (or just ask others who autocross the same car in your class and then decide if you "trust" their response enough to not look it up yourself).


--Donnie

If you drive over a 6" curb straight-on at 45 MPH, your control arms and subframe will flex a little and give you a few degrees of extra camber. All the fast guys prep their car like this.

If you're going to try it, let me know, I'd like to come by with a lawnchair and a sixpack to watch.

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Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

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Todd Breakey
STS 42 - 1992 Sunburst Miata
Dammit!
"You souldn't play leap frog with a porcupine. You might get hurt." - Eliza

What kind of suspension is in the front of the Mazda3? Is it strut-based or a double wishbone? Since you mentioned camber plates I'm guessing it's struts but for some reason I thought I remembered those things having wishbones up front.

And what class are you in? That could make the difference in legality.

Jim

thanks for the pointer Mike, although wouldn't hitting a curb like you describe likely give me positive camber?

edit: Jim, its a strut suspension, and I'm running STS (where I'm getting WHOOPED by BMW's)

As far as legality, I know its legal (for STS), I'm more asking about the bolts themselves, and whether they are available for my car. I'm not running stock class, so thats not a huge concern for me, I'm just trying to find a cheap way to get some camber. Camber plates are legal for my class even, and available, but they are pushing $400 (and have to be shipped from australia from what I can tell, unless there is a local KMAC distributor) and I don't really want/need adjustable camber/caster, as I will simply set it on the alignment rack and leave it. I know from a previous discussion I can slot the strut mounting holes if necessary and be legal, but I'd prefer something that I know won't "slip".

I was just curious if this is a make/model specific part, or whether "crash bolts" are available in a bunch of different thread sizes/diameters and used where needed. I seem to be able to find camber adjustment stuff for the rear of my car, but nothing for the front. I've tried searching for crash bolts for my car and not found anything, but I'd imagine that since its been out since 2004, maybe there are enough people who have wrecked them that there is a market for "crash bolts".

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2012 MX-5 Sport SUV

After reading your follow up, I'd start with your local Mazda dealer. Give the parts department a ring and see if they are available. You can probably get them cheaper elsewhere but at least it will give you an idea of what to look for.

Jim

H and R sells different size camber bolts. You might be able to match up the size you need. http://www.hrsprings.com/site/index.html Eibach also sells them but they don't list an app for your car. [/url]

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"Never let life be shaped by fear of its end"

No, you're a towel!

Also, if the dealer doesn't have what you need, I would pull one of the bolts and measure it for length and thread pitch. Then I'd try to find a car that matches (hopefully in the Mazda family to make it easy) and see if crash bolts are available for it.

I would also loosen all the strut bolts and see if there is any "slop" in there. On some cars, you can gain nearly an extra 1/2 degree of camber by pushing in the top of the strut while tightening the top bolts and pulling out on the strut while tightening the bottom bolts.

If you need some help sometime messing with it and you're not too far away, let me know.

Edit: Marcus suggested the same matching idea while I was typing...

Jim

Thanks for that info!

Eibach makes a +/- kit for my car - hopefully I can get it in by Danville.

Right now I have -1.2 front, -1.8 rear.
Should I go for more neg camber at both ends, or would an extra -1deg in front be the most important thing?

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One of those LeMonHeads...
91/95 Miata, 02 Focus SVT, 01 Ford F250, 09 Suzuki SV650SF
rusty 84 C4 Vette, tiny piece of the General Lei
Irish Sport Horse - 1hp NA!

I'd only get more up front. You have plenty in the rear, if not too much already. - AB

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'14 Toyota Sequoia Platinum 4WD
Super Westerfield Bros - '93 Integra - LeChump Du Jour
STX 93 - Scion FR-S

With those current numbers, I'd leave the rear alone and try to max out the front. I wouldn't start thinking about the rear unless you can get the front past -2 degrees.

Edit: Aaron types faster than me...

Jim

Brice i have some eibach camber bolts for my corrado that i never installed if you would like to try and see if they will work for you??!?!?

It is up to you

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From a good history with crash bolts on the multiple Celica's I've run, when you get them installed and get the alignment, once you get the car home, re-torque them and check them before every event. We only had one slip once, and it due to the bolt being about a year old (20-25 autocrosses). Most of the bolts are designed to stretch, thus after enough alignments/autocrosses, you might consider replacing them out.

I'm sure Jim F. can remember driving Pastorius MR2 and having them slip, even with new bolts. The problem? The nut can slip as well, so replace them as a pair. - AB

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'14 Toyota Sequoia Platinum 4WD
Super Westerfield Bros - '93 Integra - LeChump Du Jour
STX 93 - Scion FR-S

Yea, Aaron's once again dead on with that one. Jim P regularly overtightened the bolts as a precautionary measure and they would still slip from time to time.

I also remember Jim P and I trying to loosen one of the bolts to make some adjustments and we couldn't do it. We were both simultaneously nearly standing on his 1/2" breaker bar + extension and it wouldn't budge. You should have seen the flex in the bar-- it was crazy! I guess it was good that it didn't budge otherwise the resulting force may have tossed both of us though the garage wall. Those bolts were tough!

I believe he had to take that one to a shop with some big air tools to finally get it loose but you'd have to ask him for the details.

Jim