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johnc

Alignment Settings

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Where would you measure if your entire rocker panel is rusted off?  We are talking z-cars!

 

Seriously, does anybody have a suggestion for rear suspension tricks for drag racing?  I wonder if the rear toes-in under heavy accelleration?  Static camber recommendation to account for squat on launch?

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Are there no race shops in Dubai? I would try and find one and then give them the specifications that you want and tell them to try and hit them. You'll need adjustable suspension to do anything though. With a stock Z the only adjustment is front toe, and maybe shimming a tiny bit of caster.

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Are there no race shops in Dubai? I would try and find one and then give them the specifications that you want and tell them to try and hit them. You'll need adjustable suspension to do anything though. With a stock Z the only adjustment is front toe, and maybe shimming a tiny bit of caster.

Hey John, couldnt find any shop who can sort it out on its own, they reply more on the data in the machine to start with. So how do usually guys measure from scratch the camber and caster? in my last attempt they read it on basis of 73 skyline kenmeri as thats the only datsun or nissan they had in their system.

 

I have coilovers (done by yourself) and TTT camber and traction arms so there is room to play around. But then in last attempt couldnt move the front camber mor eon negative side then -1.1 in the front toe arms came out

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Your coilovers probably came from John Coffey, definitely not me.

 

Adjusting the control arms for camber is a bit tricky because of the tie rod length issue. There have been some threads on that in the past, and bjhines and I made our own tie rods with 5/8" rod end outers. You could do the same or get camber plates for the top to get the camber you want without running out of steering arm length.

 

Here is another article on DIY alignments. Obviously the adjustments are not the same on a Miata, but it tells you how to set up the strings: http://www.quadesl.com/miata_alignment.html

 

I have a related question: caster is checked by measuring camber and then moving the wheels x degrees and checking camber again, and then doing some math to figure out the caster setting. In theory though, the caster angle on a Z is just the angle of the strut tube fore/aft, because the top of the strut is one of the determinants and the ball joint which is directly under the strut is the other. So wouldn't it be possible just to stick an angle finder on the strut tube and take that measurement directly instead of having to figure out how many degrees you turned the wheel? Seems like it should be more repeatable and easier for the at home alignment, if it works...

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I was a suspension/brake tech at a ford dealer for many years.When I would have a track day coming up for my car I would do a track day set-up -Basically a special 4 wheel alignment just for the weekend .Then on monday or tuesday the car would go back on the rack for a daily driver alignment.This was basically just pulling out negative camber to a more street based setting.Having a nice laser alignment rack to use makes things easy.Where I live its hard to find any shops interested in doing anything close to custom work.Most of the employees at auto repair shops in my town get less than $20 /hr and are brain dead zombies that dont care about anything.

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Your coilovers probably came from John Coffey, definitely not me.

 

Adjusting the control arms for camber is a bit tricky because of the tie rod length issue. There have been some threads on that in the past, and bjhines and I made our own tie rods with 5/8" rod end outers. You could do the same or get camber plates for the top to get the camber you want without running out of steering arm length.

 

Here is another article on DIY alignments. Obviously the adjustments are not the same on a Miata, but it tells you how to set up the strings: http://www.quadesl.com/miata_alignment.html

 

I have a related question: caster is checked by measuring camber and then moving the wheels x degrees and checking camber again, and then doing some math to figure out the caster setting. In theory though, the caster angle on a Z is just the angle of the strut tube fore/aft, because the top of the strut is one of the determinants and the ball joint which is directly under the strut is the other. So wouldn't it be possible just to stick an angle finder on the strut tube and take that measurement directly instead of having to figure out how many degrees you turned the wheel? Seems like it should be more repeatable and easier for the at home alignment, if it works...

 

I don't think the numbers are an exact match but if you get the caster numbers from a correct alignment you can measure the strut tube as mentioned above and use those numbers as a relative reference.

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I have my first autocross (in years) in two weeks.  I'm trying to duplicate johnc's recommended race settings as closely as possible.  But, because my EMI camber plates have holes for adjustment instead of slots, I am unable to achieve johnc's alignment specs exactly.  Here's where I am in front:  Either -2.5 degrees negative or 3.5 degrees negative.  The car is currently mocked up at -3.5.  The back is more adjustable due to Modern Motorsport adjustable LCAs, which I currently have mocked up at -2.5.  I don't really want to go more in back due to my drag racing setup (today's question is only about autocross). 1" bar in front with none in back due to exhaust/CV/driveshaft flange clearance PITA.  Tires are 225/50/15 BFG R1 on 15X7 wheels. Springs are 225F and 250R coilover with hypercoils from betamotorsports, shocks are Illuminas set at 3F, 4R. Sorry to be so specific, but my questions are pretty simple.....I just want to get things as close as possible before taking it to the alignment shop-I know there is no "right" answer.  I'm not looking to be national champion, just don't want to make a fool of myself in front of strangers.  I'll try to keep the hood closed.

 

2 specific questions for the forum:

1) Do you think I should keep the -3.5 up front, or decrease back to -2.5?

2) To set tire pressure, do you measure tire temps across the tread: 1) after a run around the track, or 2) do I need a constant turn radius like a skid pad?  I was thinking about starting at 26psi F/R and playing with my pyrometer.

 

Moderators, if this should be in the general suspension forum, please move it.

Edited by RebekahsZ

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