1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Cambering Solid Rear Axel

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Old 09-18-09 | 03:08 PM
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Old 09-18-09 | 03:09 PM
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The more negative camber you run...the faster your car will be.

The proof:
http://www.youtube.com/watch?v=HtJ0i5ilyyg
Old 09-18-09 | 05:19 PM
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The specs for factory alignment probably take into consideration that adding weight (ie:people, cargo) compresses the suspension and adds a small amount of negative camber. When you add weight the camber changes. Ever seen a pic of a car with no engine in it, and the wheels sit with a ton of positive camber \----/ like that. It's just the way MacPherson struts work.
Old 09-18-09 | 05:46 PM
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Originally Posted by orion84gsl
The specs for factory alignment probably take into consideration that adding weight (ie:people, cargo) compresses the suspension and adds a small amount of negative camber. When you add weight the camber changes. Ever seen a pic of a car with no engine in it, and the wheels sit with a ton of positive camber \----/ like that. It's just the way MacPherson struts work.
We're talking about solid axles...
Old 09-18-09 | 07:46 PM
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Hey, if you want real negative camber on a rear axle, it can be done without destroying bearings. What you'll need to do it is to go to a full floater rear end arrangement with crowned axle shafts. This is a fairly common setup for circle track / NASCAR. There are lots of benefits from a full floater -- chief among them is the safety aspect. If you snap an axle, the wheel retains its composure and you retain control.

This will, however, require some serious surgery to your rear axle -- or a new rear axle altogether. Check out Speedway Engineering. They'll be happy to mod your axle for a stack of cash.
Old 09-18-09 | 08:54 PM
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guru made FB full floating kits with torsens. Set you back about $3500 AUD when they were available.
Old 09-19-09 | 12:09 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by ray green
Thanks for helping me figure this out Kent, the little diagrams on my alignment readout are confusing me. So what we see in this picture is negative camber?

Having the wheels splay out like that would seem to make more sense than having them splay the other way. And if that's negative camber and that's good, why do the stock settings call for positive camber in front? It seems like this would make the front end kind of pigeon toed. Why is it one way in front and the other way in back?
negative camber is when the wheel/tire assembly tilts in at the top, positive is when it tilts out at the top, when looking at the car from the front/rear/top.

basically the tire will have maximum grip when it is planted into the ground with some slight negative camber as its not solid. if you think about it when you turn, the car leans, which to simplify, adds positive camber, so simply to maximize grip some negative camber is needed. on a strut suspension car like the SA/FB we need to run some negative camber when the car is stationary, as the strut does not add much in its normal range of travel. a double wishbone suspension can add (more) negative camber thru its travel, due to the upper arm. all the suspension arms/links swing in arcs.

just about every OEM car will have more negative camber at the rear than the front, as the car will naturally understeer that way, and this is considered safer.

there are TONS of good articles if you wanna learn more/get some specifics
Old 09-19-09 | 01:39 PM
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Originally Posted by Hyper4mance2k
guru made FB full floating kits with torsens. Set you back about $3500 AUD when they were available.
Yes, I remember those. Don't think they are willing to make them again -- probably not enough demand to justify continued production. The nice thing about their kit was that it was bolt-on. Anything else will involve some cutting, fabrication, and welding.
Old 09-19-09 | 02:01 PM
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Thanks J9, now the camber makes sense. Although if it was me I would have labeled the good stuff "Positive" camber.

If I could ask another question, why is the toe-in in the rear overall positive (toed out, right)? And why is it slightly positive on the left and slightly negative on the right?
Old 09-19-09 | 03:41 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by ray green
Thanks J9, now the camber makes sense. Although if it was me I would have labeled the good stuff "Positive" camber.

If I could ask another question, why is the toe-in in the rear overall positive (toed out, right)? And why is it slightly positive on the left and slightly negative on the right?
yeah the positive and negatives on the alignment angles are kinda weird.

since its a solid rear the toe in in the rear, with it different side to side means its slightly off centered, its pointed slightly to the right, but .15 is pretty slight. possibly you could loosen and re tighten the bolts and get it centered (or off the other side!)

and actually a little toe in in the rear is good

http://farnorthracing.com/autocross_secrets.html
Old 09-19-09 | 04:58 PM
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then... is -3 degrees too much camber on the front? i mean, what do you consider a little bit of camber?
Old 09-19-09 | 06:07 PM
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-3 is about where most are set for autocrossing. Too much for street use, way too darty at highway speeds. Also tends to get jerked around by any imperfections in the pavement.

But with the camber plates, it just takes a second to make the adjustment. You need a jack to reduce the camber for street use, but setting the camber to race mode you just loosen the bolts and kick the tire. lol.

Makes a hell of a difference too. You can really feel the car "carve" the corner, really just digging in to it. Very nice...
Old 09-20-09 | 07:59 AM
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-2 was factory setting in the front. I daily drive and autoX religiously. I run -2.75 camber with .125" toe out in the front and experiance no abnormal tire wear.
Old 09-20-09 | 11:47 AM
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yea, i'm probably closer to -2.75, but stock settings is 1 degree +/- .5 degrees

i'd rather not keep on changing it too much, i'll just keep it where it is and live with it. it makes for one helluba car
Old 09-22-09 | 09:23 AM
  #40  
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To bring this back from the dead, rawr! I'd like to point out front camber adjustments at the track are a bad idea unless you reset the toe afterwards because any adjustment in the front end will affect toe, and several other things but for now we will stick with just toe.

I believe the word the OP was looking for is "demon camber" its the look I'm going for and how i found this thread in the search. Its argueably a style only thing. Some people like to argue more is always better but from experience I know there is such a thing as to much camber. Usually the demon camber thing is popular in the drifting crowd where its all about style and no so much function. If the car will still go sideways, its good to go. Its usually done with very agressive wheel fitment stretched tires and a low offset and IMO looks awesome!

Do a quick google search for demon camber and you will see what i mean.

I really dont like the thought of having to replace axel bearings all the time. Someone earlier in the thread mentioned an FC rear end set up. How does the FC and FB compare track width wise? I'll have to go find some pics of an FC rear end set up to see how feasable this is, but anything can be done with a welder, some fabrication and a little ambition.
Old 09-22-09 | 10:10 AM
  #41  
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Originally Posted by ray green
Thanks J9, If I could ask another question, why is the toe-in in the rear overall positive (toed out, right)? And why is it slightly positive on the left and slightly negative on the right?
Originally Posted by j9fd3s
yeah the positive and negatives on the alignment angles are kinda weird.

since its a solid rear the toe in in the rear, with it different side to side means its slightly off centered, its pointed slightly to the right, but .15 is pretty slight. possibly you could loosen and re tighten the bolts and get it centered (or off the other side!)

and actually a little toe in in the rear is good
guys most US spec cars have a real slight offset in the rear to keep the car running straight on a crowned road...... it it was the smae on both sides the car would try to find its way into the ditch when you release the steering wheel as most US roads are slightly crowned for water runn off.

kenn
Old 09-22-09 | 12:53 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by kenn_chan
guys most US spec cars have a real slight offset in the rear to keep the car running straight on a crowned road...... it it was the smae on both sides the car would try to find its way into the ditch when you release the steering wheel as most US roads are slightly crowned for water runn off.

kenn
they usually do that with caster (too)

around here our roads are actually too bad to tell if the car pulls
Old 09-22-09 | 01:43 PM
  #43  
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Originally Posted by kenn_chan
guys most US spec cars have a real slight offset in the rear to keep the car running straight on a crowned road......

kenn
Not to pick holes in your theory cause you are right but i think you worded that wrong. what do you mean by offset in the rear? When i hear that I think of wheel spacing and that does nothing to direct the car in a strait line.

Did you mean toe in? Because that is one of the main factors in strait line stability and determining how darty the car is when on the road. On the opposite end of that, toe out would cause it to want to follow that crown in the road but is better for racing purposes. And like said above, caster is a big factor in that as well.

But we are getting off topic, this is susposed to be about rear camber.
Old 09-22-09 | 02:15 PM
  #44  
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that demon camber looks like crap on this car. I like an agressive stance, theres no proformance gain from that. and the bozoku (Sp?) look is kinda dumb.
Attached Thumbnails Cambering Solid Rear Axel-camber.jpg  
Old 09-22-09 | 03:09 PM
  #45  
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-2.8 degrees camber looks awesome on the front for first gens. it doesn't look overkill. but yeah, i don't think the car would look great with rear negative camber. the stock -.5 looks perfectly fine
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