Here are a couple of videos and link that I just ran across.

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https://en.wikipedia.org/wiki/Ackermann_steering_geometry
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Thank you Husker, nice videos!

y'all, this has turned into a WEALTH of good info in this thread!
Thanks, and keep it coming!!!

Paging maytag - What was your final alignment spec? And did you ever get rear toe links?

I'm conflicted on my rear toe. Some shops telling me to add more rear toe, some tell me to leave it. By virtue of adding more (this is where I'm confused) I would need a rear toe link kit.

For what it's worth, this is my alignment:
Front:
Camber - 3.14 (left) / -3.32 (right)
Caster: 8.58 (left) / 8.69 (right)
Toe: -0.06in (left) / -0.06in (right)

Rear:
Camber: -2.34 (left) / -2.51 (right)
Toe: +0.05in (left) / +0.06 (right)
Total Toe: +0.10in
Thrust Angle: -0.01 degrees

Seems ok but quite aggressive on front neg camber. Im assuming you are running r comps/hoosiers/toyo rr?

Id personally dial out the front toe but rear seems ok

Any recommendations on front toe?

Currently running a street tire - looking for R-comps later. If track days get cancelled beyond the summer, I'm going to dial back the front camber in a month or two (agreed that its too aggressive.)

just to add to this thread with my new alignment today and new H&R sway bars - I got rid of the understeer I previously had mentioned in my other thread http://986forum.com/forums/performance-technical-chat/77430-those-whove-adjusted-front-bumpsteer.html. The car is fairly predictable and seems more evenly balanced on corner entry/ exit

I have a hair of toe out, but neutral (zero'ed) is good

Just my $.02:

1- That much front camber is probably sacrificing some braking grip. There is always a trade-off between front camber and braking grip. The front suspension on our cars has poor camber in roll, but stiffening the front bar can overcome that to a degree.

2- That front to rear camber ratio looks pretty high. Wider front tires might help if you haven't maxed those out.

3- I would reduce front toe to zero, and use solid bushings. Some people like toe-out in front to combat corner entry understeer but if you trail brake that is probably unnecessary.

4- I would change that rear toe-out to very slight toe in, again with solid bushings. Toe out in the rear is unstable.

Good luck

Got this all figured out. That short session at the track the other day made some things become very clear.

It's getting new uprights and toe links as we speak. When I get a minute, I'll update what I did wrong, and what the "race shop" (I'm using that term loosely now) failed to identify / catch. In fact, they misdiagnosed, charged me a grossly inflated amount, and then shrugged their shoulders and said I just don't know what a race setup is supposed to feel like.

::sigh::



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Please do tell what the "experts" missed ...

No wonder the Huracan's are so dangerous to the lowly NASA club racer.

yeah, so... check this out.... I'ma take a beating here for my mistake. I already am on JT's FB page, haha. People like Brad Roberts are being a little "merciless", but I'ma forgive that because the way it was posted, it appears a "professional" did the work.

I did it.
I jacked it up.
But the "Professionals" exacerbated the problem.

So you'll see in the photo below, that there's a clear "mismatch" between the rod-end and the hole it's going into. (This is my adjustable toe-links in the rear.) The mismatch is because there's a steel insert that's cast into the upright, which apparently is known for coming out with the toe-links when they're removed incorrectly. Some are saying you can see obvious signs of a hammer used on it.... meh, I don't see it. It wouldn't have been the upright you're beating on anyway, it would've been the rod-end / link itself. Regardless: I've been known to handle stubborn ball-joint removal with a "larger hammer". I usually start with my pickle-fork, and if that doesn't work, I've got a ball-joint separator that I've NEVER had work on a ball-joint before. So very commonly, I'll put a jack under the bottom knuckle to support "firmly", and then put the castellated nut back on the threads til it's flush with the top of the bolt, and then I'll smack the piss out of it with a 4lb single-jack. So while I have no specific recollection, this is very likely the method I used to remove these. Yeah.... sue me. :D

So anyway; ya run that rod end up into the hole and it fits "snugly" enough that it gave me no warning to re-inspect. I'ma also blame the twenty-minutes-here, twenty-minutes-there approach to my garage time last winter. :cool:

Ok, so now I've made my excuses; flame me if you must. Apparently this is a common enough mistake that many of the respondents say they collect these inserts to fix the problem when a customer-car comes in.

In the meantime; what this meant was that as you tighten-up the nut, it just keeps sucking-up the tapered joint further and further into the hole. Ya torque it and it feels great, and then ya drive down the road, turn, the joint goes further into the hole and it's loose again. Make sense?

So anywho: I installed the parts this way, and took it to my local "race shop" to do a complete track setup; 4-corner balance and alignment.

That brings us up to the bottom of this thread, I think, but in a nutshell: should've been one day; took 3 or so. Immediately upon leaving their parking lot, I knew something was wrong, so I took it back to them. They drove it and agreed with me, so back on the rack it went, where they said they discovered a bad wheel bearing and that's what was causing the problem. The symptoms fit what I'd felt, so I didn't doubt them (though I found it odd I hadn't discovered that myself, as those are things I check.) We eventually agreed that this should've been discovered BEFORE doing an alignment (they didn't love that, but conceded the point eventually). I told them I was sensitive to the fact that they were going to have to RE-DO their work, so I told them I'd pay them to replace the wheel bearing, where typically I'd have done that myself. (They charged me a little over $800 for the wheel bearing replacement. I have no idea how this compares to other shop-rates, but I suspect poorly) I also told them I'd find a couple other things they could do to recoup some $$ on this.
I mean; I thought I was being really generous.

So I picked-up the car again. It was still bad. not AS bad, but still bad. (in hindsight, this improvement is surely because they stacked-up the washers to make it "tighter"). They convinced me I just didn't know what a good track alignment was SUPPOSED to feel like. And I guess I shrugged my shoulders a bit and thought I'd try it at the track.

Now, at this point, let's be clear: They'd had BOTH toe links off. We know this because they did a wheel bearing on one side and I SAW the upright on the floor in the shop. And on the other side, they had stacked washers under the nut, trying to get it to tighten-up some more.

So I get to the track last Wednesday, and as I said: some things became much more clear. It was no longer a "vague twitchiness". The best way to describe it was just about the time the rear is about to begin to rotate, the giant 200lb bowling ball in the rear trunk slides over to the outside.

So Friday afternoon, I jacked-it up and started looking at things. Sure enough, I found what at first glance appeared to be a bad wheel bearing on the other side from the one they replaced. Except, on closer inspection, it became clear it WAS NOT the wheel bearing, but in fact the movement was in the ball-joint on the toe-link. Which suggests to me that the wheel bearing they replaced was also NOT THE CULPRIT, and I paid them to replace it just for fun.

So yeah; I'm frustrated, I'm pissed and I'm relieved.

I'm frustrated that I screwed-up the installation. That's on me, and I'm typically a very good mechanic. This is a learning moment. And I'll be paying the price for it both financially and with my ego. :ah:

I'm pissed that I paid over $500 for a 4-corner balance and track alignment that are JUNK because they didn't check the parts BEFORE they aligned it. I'm pissed that I paid them over $1400 in other services, including an $800 wheel bearing which I now suspect was not bad, that I could've done myself for under $200, in the name of being generous and loyal.

I'm relieved that the good guys at Tatum Racing are all over it now and will get it all correct for me. (I gifted them a car a while back, with a lot of good parts including two good uprights, so I'm hoping that is reflected in the eventual bill, haha.)

Anyway:
PCA has a DE in 10 days that I should be Good-To-Go for. I'm excited to really drive what I built. I mean, REALLY drive it. :dance:

I'll keep y'all posted.


http://986forum.com/forums/uploads02...1590596007.jpg

It's admirable that you freely admit your mistakes, Maytag.

I hope that everything gets resolved properly and you can enjoy your car fully.

Are you still selling it? If you have the time of your life, will you keep it? Are you gong to do any track days with your new car?

I'm not sure.... that first sentence might be you mocking me, and I probably deserve it. ;) It might not be the dumbest thing I've ever done.... but it ranks up there. If I can't laugh at myself, well then, I've missed the point.

It's uncertain whether I'll sell it. If i could find some off-site storage that made sense, it might be "outta sight outta mind" for a minute, and I won't feel pressured to unload it.

Yes, I'll have the new car out at the PCA DE at least one of the two days. the car just WANTS it. :dance:

But here's the thing: with the Boxster, I feel like I can push it HARD. I'm a good enough driver that I can mostly stay out of trouble with that car. It's fun to brush up against some of the car's limitations, and know that there's still more I can squeeze out as I keep learning. And, it fits the first rule I always tell newcomers: if you take it on the track, make sure you'd be okay if you had to leave without it.

With the new car, it's much more car. MUCH more car. And it may require a MUCH better driver than I am to get the same enjoyment out of it at the racetrack. I'm going to find out. I'm not going to be rallying across the curbs as I do in the Boxster. I'll probably leave the TC on most of the time (it's surprisingly effective at helping you go fast, at least in my so-far limited experience with it). With about 550hp begging for me to tap on it, driving the line out of the apex requires a much more judicious application.
But I need to hear it all full scream down the straight, and in the back-throttle-burble in the hard braking zones. :dance:

Glad you got it figured out. I was not aware of a steel insert so I’m glad I can learn from your mistakes 😁

What’s your new car?

Did you inspect the ball joint on the side the bearing was replaced? What did the current shop say about the work they did... their charges... their sloppy diagnosis?

Lets get back your money... ;)

you must've missed that thread, haha. http://986forum.com/forums/uploads02...1590604582.jpg

Both sides are the same. both major FAILS.

Here's my thinking:
First, the problem was CAUSED by me. I did the install.
Yes, they should have caught it.
Yes, there's no way you could accurately align that and not fight with the rear toe numbers over and over. (let alone the thrust angle!)
No, I can't definitively demonstrate to them that the bearing was NOT bad, and they might argue that it was in fact bad and that's why it was improved when I picked it up. I'd disagree, and then what?
Did they overcharge me for the bearing? I think so, but I didn't ask them to quote it to me, because I thought we were trying to be fair with each other, so after explaining my hope to them, in good faith I simply told them to do it.

And the other side of this: The owner of the shop is a good person. I haven't brought this situation to his attention because the fair thing to expect of him is to make it right... which would mean going back into their shop. You think they did poor work on it BEFORE I went and "told on them" to the owner? Wait and see how it goes now. I really don't want them NEAR my car. I've ZERO confidence that they'd get it right. Whether because they don't care enough, or aren't experienced enough, or because now they're vindictive; they've demonstrated that they can't get it right.
IF I were going to take it to a shop where they CLEARLY can't get it right, I'd just pull it back into my own garage where the faulty install started to begin with! haha.

And finally: this community is pretty small; even more-so in a small market like Salt Lake City environs. I don't need enemies at the racetrack. I do this for fun, and I'm not going to suck the fun out of it by adding that dynamic to the situation.

But if they care, they WILL notice that I quit tagging them on FB when people are looking for a referral, and that those referral tags are now going somewhere else. But I don't suspect they care that much. a "boycott" is never as satisfying as you want it to be. :(

Uhh, seriously..?

Congratulations!! I am happy for you (and jealous too) ..ha ;)