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Need Race Rear Suspenion help

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Old May 4, 2005 | 05:45 AM
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Question Need Race Rear Suspenion help

Someone who has a track prepped 2nd gen should be able to help me.

After a couple of years of not gaining much towards completing my car, its all very near raceable. The problem i have is..........

I have Koni adjustables all round, and they are short. like the bottom off the diff is just over 4 inches off the ground. Its LOW, which is all well and good BUT, I cant suss my rear camber out, I have a rear camber link, and its wound up soo much i'm at the point of needing to bash the floor to get more adjustment but there HAS TO BE something else i can do to be able to tuck the wheels in more. My 'eyecrometer' says i currently have about 5 degrees camber on the LHR and about 4 on the RHR. I'm thinking I really need about 1.5 degrees perhaps 2 degrees max (negative camber that is). The fix is probably something obvious but i cant seem to work it out. ALL HELP GREATLY APPRECIATED.

thanks
Shane
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Old May 4, 2005 | 07:44 AM
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Well I an going to ask the obvious question. Are the spring perches adjustable? The shocks don't normally dictate the ride height. The spring length and perch point on the shock do that. Once the height is adjusted you should be able to dial in your rear camber properly.
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Old May 4, 2005 | 01:41 PM
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You make the camber rod longer to take negative camber out. Sounds like you're adjusting it backwards.
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Old May 4, 2005 | 05:27 PM
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Also, the AWR camber adjusters if you're going to run that low. Your front arms may bind a well, go to AWR.com and ye shall understand. Otherwise, raise the car, and eliminate some of the camber gain. Also, as I explained in RX7Ben's question, you will get even more negative camber on launch. Carl
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Old May 4, 2005 | 06:50 PM
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Originally Posted by PaulyDee
Well I an going to ask the obvious question. Are the spring perches adjustable? The shocks don't normally dictate the ride height. The spring length and perch point on the shock do that. Once the height is adjusted you should be able to dial in your rear camber properly.
Yes they are adjustable and i have it set with my ride height about where I require it.
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Old May 4, 2005 | 06:53 PM
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Originally Posted by C. Ludwig
You make the camber rod longer to take negative camber out. Sounds like you're adjusting it backwards.
My camber rod was at 265mm and i put it out to 300mm and i HAD INSANE negative camber, must have been bordering on 10 degrees negative!!!!!!!

I'll have a look at that webpage. thanks guys
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Old May 5, 2005 | 04:52 AM
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From: The Sunny B.O.P, New Zealand
is it by lengthening or shortening that little 'link arm' that one gets less negative camber?
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Old May 5, 2005 | 08:19 AM
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Originally Posted by HWO
Yes they are adjustable and i have it set with my ride height about where I require it.
Don't take this wrong but where you require your cars ride height may not be where it works best. When you lower a car there is a point of diminishing returns especially if you stick with most of the factory components. You may have gone past that point. I'm suggesting you raise the car a little bit also just to see if it helps. Its free and reversible if your not happy with it.
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Old May 5, 2005 | 10:44 AM
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Originally Posted by MPM
Don't take this wrong but where you require your cars ride height may not be where it works best. When you lower a car there is a point of diminishing returns especially if you stick with most of the factory components. You may have gone past that point. I'm suggesting you raise the car a little bit also just to see if it helps. Its free and reversible if your not happy with it.
Basicly, lower is better, so long as you can maintain proper suspension geometry. You, cannot, so, raise the car up until you can get to ~2* negative in the front, and ~1.5* in the rear. Alternately buy the AWR Camber adjusters. there are a ton of threads on FC alignments, here, and in the suspension section. Carl
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Old May 5, 2005 | 06:52 PM
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Yeah exactly i raised the car in the rear by 5mm, not much, but thats about as much as i can raise it and still have enough downwards travel left in my suspenion to make it work effectively. I have got some pieces on the way so i can make up my own rear camber adjusters on those link arms.
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Old May 6, 2005 | 09:35 AM
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so what is so unique about your car that you need that setup? lots of other successful racers don't seem to have experienced this. not trying to be rude so don't take it that way.
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Old May 6, 2005 | 09:57 AM
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I'd suggest a real deal alignment not just an eyeball one. You might find you have something totally different than what you think you see.

-Jack
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Old May 6, 2005 | 10:19 AM
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Originally Posted by HWO
is it by lengthening or shortening that little 'link arm' that one gets less negative camber?

One more time. You lengthen the rod to achieve less negative camber.
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Old May 6, 2005 | 02:16 PM
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Shane, for us to help you, you have to be open minded to our changes, like raising the car. Raising it 5mm will not make a difference given the amount of camber change you need to achieve. There are alot of succesful 2nd gens that race at, or near stock ride height. Also, raising the car increases travel, not the other way around. Regards, Carl

Last edited by Carl Byck; May 6, 2005 at 02:18 PM.
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Old May 6, 2005 | 02:17 PM
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Just figured it out, He's in New Zealand
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Old May 6, 2005 | 08:52 PM
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read what i said again........
Originally Posted by HWO
still have enough downwards travel left in my suspenion to make it work effectively.
Raising the car by winding the springs further up the pearches means the car sits higher right......... that also means that there is now 5mm less DOWN travel (not upwards travel which is what you are thinking) in the suspenion from ride height.

Is it because i am in the southern hemisphere that my camber link works backwards???? I have no idea but the longer i make my subframe camber link, the MORE negative camber it gives me.

My koni's dont extend long enough to make my car sit even CLOSE to standard ride height. Are you's forgetting that race shocks are SHORTER than standard? and that is is total shock length which gives you total ride height??? My koni's cost me nearly $3K NZ for all four, are around 40 mm shorter than standard struts are.

I have jigged up my rear suspension temporarily using racing beat adjustable sway bar links in the position of those little trail arm to subframe links, they are approx 7-8mm shorter than the standard link arms, and it seems to be enough to get me in the ball park of where i need my camber to be.

I have an open mind about this but I know what is physically possible to do with my are and raising it by say 10 or 15mm is NOT possible. To get my car to the current ride height in the rear, i jacked the rear up, took the wheels off and wound the spring pearches up as high as I can make them go, any higher and i'll be damaging my shock due to the force being exerted by the spring trying to pull it past its usable length.

What is unique about my car???, pass, possibly the ride height or the length of the shocks i am running i'll take some pics of stuff it peoples cant understand what i am saying.
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Old May 6, 2005 | 11:12 PM
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Just measured my rear struts, they are 460mm long from top mounting face to the centre of the eye that goes onto the hub.
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Old May 9, 2005 | 05:16 PM
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AWR.com is an accounting firm!
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Old May 9, 2005 | 06:31 PM
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Originally Posted by designfreak
AWR.com is an accounting firm!
This is the correct link.
http://www.awrracing.com/

You will see a TON of the things they make are sold through Mazdaspeedmotorsports
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Old May 10, 2005 | 07:37 PM
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You sure you have the right Konis for the rear??? My Koni SAs are plenty long enough, won't come near maxing out the shock at anywhere near a normal ride height. Hell, when I jack up the rear, the shock hangs down a good 10", leaving the spring totally loose.

PaulC
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Old May 13, 2005 | 09:39 PM
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Anything below about 4"-4.5" at the rocker in the rear is going to work against you with stock control arms. I made custom arms to correct the problem and work better at that height. Making the camber link longer creates more neg. camber. If you use the AWR camber links you MUST also use their control arm bushings or the stock bushings. If used with the derlin bushings or anything that only moves in a linear plane the trailing arm will bind
John
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Old May 15, 2005 | 12:08 PM
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John, exactly which bushing must be stock? Can you ID it an a mazda Micro fiche? I know I have replaced almost everytghing with urethane, or Delrin, and I am using the AWR pieces. Also, are the AWR toe adjusters required, or just convenient when running at these heights? Sorry about the bad link guys, I was just lazy I guess. Well, back to the garage with me
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Old May 15, 2005 | 02:11 PM
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I believe (correct me if Im wrong John) that he is referring to the trailing arm bushing that attached the trailing arm to the car near the end of the door... is the closest I can describe.. (My manuals are all in the garage sorry I dont have a part number)
Think about it... if you are twisting the trailing arm along with all the associated hardware to give negative camber.. you will eventually get a bind. It may not bind when it is static or even under mild travel.. but it will bind under extreme travel with a solid or delrin bushing in it.
You have the camber adjusters or asjustable dog bones at the other side of the "Y" of the trailing arm.. that are adjustung things.. as well as the camber link adjusting the whole subframe's position..
Eventually it will bind if you go delrin or solid. Even poly will start to bind.
For my EP I will be following the prod world and specifically John's advice and going with a Aurora to replace the end of the trailing arm. I believe there is one that will fit INSIDE the bushing hole.. and with proper spacers etc.. it can be centered and pressed into place. Hence ZERO binding.
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Old May 15, 2005 | 07:16 PM
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Got it, Just had to look at the car. of course i just ordered, and recieved the Mazda comp bushings for there. LOL. Just about have the turbo oil system redone, should be firing up the car in an hour or so...
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Old May 16, 2005 | 07:29 AM
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how r u guys gettibg more than -1.2 degree camber in the front. i maxed out my ground control plates and that gives -1.2 max.
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