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> Track car alignment, new content
falcor75
post Apr 27 2017, 01:05 AM
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QUOTE(Racer Chris @ Apr 25 2017, 11:04 PM) *

QUOTE(falcor75 @ Apr 25 2017, 09:30 AM) *

Do you use anything to leverage it inwards/backwards or how do you do it?

A big ass screwdriver. (IMG:style_emoticons/default/biggrin.gif)


Raising the front wheels off the ground and a BF rubber mallet works too... (IMG:style_emoticons/default/biggrin.gif)

Doing an alignment on mine this afternoon and hopefully geting Close to the following for my 95% street and 5% slalom/autocross usage:

Front
Camber: -1,5
Toe in: 1 mm on each side
Caster: 5,5-6 somewhere

Rear:
Camber: -1
Toe in: 1 mm om each side.
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ChrisFoley
post Apr 27 2017, 04:29 AM
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QUOTE(falcor75 @ Apr 27 2017, 03:05 AM) *

QUOTE(Racer Chris @ Apr 25 2017, 11:04 PM) *

QUOTE(falcor75 @ Apr 25 2017, 09:30 AM) *

Do you use anything to leverage it inwards/backwards or how do you do it?

A big ass screwdriver. (IMG:style_emoticons/default/biggrin.gif)


Raising the front wheels off the ground and a BF rubber mallet works too... (IMG:style_emoticons/default/biggrin.gif)

Doing an alignment on mine this afternoon and hopefully geting Close to the following for my 95% street and 5% slalom/autocross usage:

Front
Camber: -1,5
Toe in: 1 mm on each side
Caster: 5,5-6 somewhere

Rear:
Camber: -1
Toe in: 1 mm om each side.

Those cambers are very aggressive for a street car and will result in rapid tire wear on the inside shoulder.
Even 3/4 degree all around will result in significantly shortened tire life.
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falcor75
post Apr 27 2017, 05:12 AM
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QUOTE(Racer Chris @ Apr 27 2017, 12:29 PM) *

QUOTE(falcor75 @ Apr 27 2017, 03:05 AM) *

QUOTE(Racer Chris @ Apr 25 2017, 11:04 PM) *

QUOTE(falcor75 @ Apr 25 2017, 09:30 AM) *

Do you use anything to leverage it inwards/backwards or how do you do it?

A big ass screwdriver. (IMG:style_emoticons/default/biggrin.gif)


Raising the front wheels off the ground and a BF rubber mallet works too... (IMG:style_emoticons/default/biggrin.gif)

Doing an alignment on mine this afternoon and hopefully geting Close to the following for my 95% street and 5% slalom/autocross usage:

Front
Camber: -1,5
Toe in: 1 mm on each side
Caster: 5,5-6 somewhere

Rear:
Camber: -1
Toe in: 1 mm om each side.

Those cambers are very aggressive for a street car and will result in rapid tire wear on the inside shoulder.
Even 3/4 degree all around will result in significantly shortened tire life.



And here I thought I was being a bit conservative. (IMG:style_emoticons/default/biggrin.gif) I've got two sets of tires to alternate between and I probably wont drive more then 2000 miles over one season from April to September so I'll start with this and see what happens.

The added caster I dialed in yesterday really helped the front end feel less twitchy and sensitive to bad roadsurfaces.
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ThePaintedMan
post Apr 27 2017, 06:55 AM
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Racer Chris really knows his damn stuff. Everytime I post and he posts afterwards I question whether I was giving the right information, lol.

Mats - the other thing I noticed, at least on my car, was that when maxing out the caster, I could get another millimeter or two by leaving the bolts all the way loose. There is a "lip" that you can push the bottom caster/camber plate over, that normally one wouldn't be able to do unless they're all the way loose. I think it could be ground down too, but I didn't have to do that. It's been awhile, so I may not remember this correctly.

I know you can also elongate the holes to gain even more caster/camber, to a point. But I'm sure that's clearly not necessary for your purposes. As I told Shane, it seems to me that most people probably think they need more camber than they actually do anyways.
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falcor75
post Apr 27 2017, 07:10 AM
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Thanks for the tip George.

Just back from the alignment shop and I cant seem to get toe in on the left rear wheel. Right side is at 2 degrees toe in but the right side is at 2 degrees toe out despite that I have elongated the holes in the outer trailing arm bracket as much as possible.

I did check the mounting hole dimensions according to the underpan picture here on the World and it seemed spot on. Starting to suspect I have a bent trailing arm...
Does anyone have good dimensons to check it for straightness?
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mepstein
post Apr 27 2017, 09:00 AM
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QUOTE(falcor75 @ Apr 27 2017, 09:10 AM) *

Thanks for the tip George.

Just back from the alignment shop and I cant seem to get toe in on the left rear wheel. Right side is at 2 degrees toe in but the right side is at 2 degrees toe out despite that I have elongated the holes in the outer trailing arm bracket as much as possible.

I did check the mounting hole dimensions according to the underpan picture here on the World and it seemed spot on. Starting to suspect I have a bent trailing arm...
Does anyone have good dimensons to check it for straightness?

If it turns out you need a new one, I'll send you one for the cost of shipping.
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naro914
post Apr 27 2017, 11:48 AM
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QUOTE(falcor75 @ Apr 27 2017, 09:10 AM) *

Thanks for the tip George.

Just back from the alignment shop and I cant seem to get toe in on the left rear wheel. Right side is at 2 degrees toe in but the right side is at 2 degrees toe out despite that I have elongated the holes in the outer trailing arm bracket as much as possible.

I did check the mounting hole dimensions according to the underpan picture here on the World and it seemed spot on. Starting to suspect I have a bent trailing arm...
Does anyone have good dimensons to check it for straightness?


Does the console (the 'mount' where the elongated holes are) hit up against the chassis? Is that's what's stopping you from getting more toe in? That's what was wrong with ours, we had to grind down on the console until we could move it enough...both sides. Did it at the track.
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falcor75
post Apr 27 2017, 12:26 PM
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I've got Chris's outer brackets on the car and I've filed the mouthing holes up around 5 mm, might get another mm in there but then the round part will start to hit the body. Then again that is solvable by reducing the camber to make the mount sit lower. But then I start running into interference between my 195/55 tires and the inner lip of the fender.

I'll borrow a fender roller this weekend and see if I can gain more clearance....
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ChrisFoley
post Apr 27 2017, 02:08 PM
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QUOTE(falcor75 @ Apr 27 2017, 02:26 PM) *

I've got Chris's outer brackets on the car and I've filed the mouthing holes up around 5 mm, might get another mm in there but then the round part will start to hit the body. Then again that is solvable by reducing the camber to make the mount sit lower. But then I start running into interference between my 195/55 tires and the inner lip of the fender.

I'll borrow a fender roller this weekend and see if I can gain more clearance....

Is there a GT stiffening kit on the chassis? If so, the piece which goes on the back side of the outer console will cause the same trouble you're experiencing.

I just completed an alignment on a 95% street/5% autocross car. We ended up with 0.5 deg front/0.6 deg rear, and about 1mm toe in all 4 corners.
Stock front A/S bar, although I'm recommending to the owner that he purchase a 19mm adjustable bar.
205/55 tires on Fuchs alloys and no issues with fender clearance.
I went through my test curves on a local road, comfortably - as fast as I dare drive a customer car through there.
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falcor75
post Apr 27 2017, 10:16 PM
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Yes I have your full stiffening kit with the rod braces on the car.



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ChrisFoley
post Apr 28 2017, 04:39 AM
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QUOTE(falcor75 @ Apr 28 2017, 12:16 AM) *

Yes I have your full stiffening kit with the rod braces on the car.

My kit doesn't have the surface mounted plates that the GT kit has so that's not part of your problem.
It may be that you have a bent trailing arm.
The angle between pivot and axle in the horizontal plane is 12.5 degrees IIRC.
There is also a built in camber of 1.5 degrees.
There are no other measurements that I know of, although I think I've seen a picture of a go-no go fixture used to verify a trailing arm.
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falcor75
post Apr 28 2017, 12:53 PM
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I'm thinking I might need to take down both rear trailing arms and put a suitable diameter pipe thru the pivot axis on both together and then measure the angle to the hub plane and see if there is a difference.
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falcor75
post Apr 30 2017, 11:55 AM
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Didnt want to spam this thread with more questions so I started my own...

http://www.914world.com/bbs2/index.php?sho...=309230&st=
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Jetsetsurfshop
post Apr 30 2017, 07:16 PM
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QUOTE(jmitro @ Apr 24 2017, 07:33 PM) *

QUOTE(Jetsetsurfshop @ Apr 17 2017, 02:17 PM) *

My car is behaving differently through Bishop Bend since the accident we had last year. Ill work on posted the video here in a few. The old alignment number are in this post. From those numbers I also added decambered ball joints. Suppose to add 3/4 more negative camber. I never got it on the alignment rack to prove that, but they certainly looked like they did.
We now have 2.3 negative camber in the front. (Rears are same as before) I have adjuster plates maxed out. Was awesome at Homestead at that setting.
Check out the steering wheel angle in the comparison video. First part is from before the crash, second part is after.
Guess I'm looking for any ideas here. Might have nothing to do with my camber?
I also changed my front bumper from a 916 to a stock looking set-up. I can't imagine that has anything to do with it.

https://www.youtube.com/watch?v=DGLmx5AEvwg




Hope you don't mind me entering your thread; I've never raced a 914 but raced 3 series BMWs for several years.
I'm confused by your comments above. You said you never got the car on the rack to check camber, but yet you quote -2.3 F camber. Are you using a portable camber gauge?
Also, how is it behaving differently? Understeering? oversteering? Feel sluggish or loose? I think the tire temps are useful only for setting camber, nothing else. The temps should be within 10 degrees of each other across the inner, middle, and outer tread.
RE correct toe and caster settings, that's probably based on how the car feels. IE is it understeering on corner entry or oversteering? Understeering on corner exit or oversteering? I tend to see the front end as contributing to corner entry and the rear end as corner exit, so if you want the car to behave a certain way on entry or exit, you set up the front or rear appropriately.

Sorry, I'm not familiar with the track in question, but my comment about the change in steering wheel angle is this may indicate the car is either pushing or oversteering more than before. If you now lift off the gas where you used to be flat out, maybe the increased negative front camber is causing more front grip, making the rear end seem a bit looser? Just a wild guess based on knowing very little about the track or your driving style.

QUOTE(naro914 @ Apr 20 2017, 11:52 AM) *

Front toe in makes the car squirrelly at high speed...


Do you know something I don't? I've always heard the opposite. Front toe in makes the car more stable at high speed due to drag pulling the tires backwards. BUT racecars usually run slight front toe out to help with initial turn in



Let me try and clear up what you asked me about.
I didn't put the car back on the alignment rack after added the de-cambered ball joints. Elephant Racing says the add 3/4 more negative camber. It was measured prior to adding them. I tracked it after the addition and like how it handled. I never measured what was accomplished with the new ball joints.
It looks like you comments are on point. I agree the car was pushing slightly. It was just to different. I fixed it now.
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Jetsetsurfshop
post May 2 2017, 06:31 AM
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All better now. Turned my fastest lap this weekend on some beat tires.
FYI, My alignment was not correct. My Dad left me to get it right and I messed it up. Now I'm 1/8 in. Huge difference.
(IMG:style_emoticons/default/beerchug.gif)

https://www.youtube.com/watch?v=dFnQIlb23ZQ
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jmitro
post May 4 2017, 10:42 PM
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(IMG:style_emoticons/default/aktion035.gif) (IMG:style_emoticons/default/beerchug.gif)
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