[Move_Over]

Also, are you guys removing the whole spindle/hub assembly while you are doing this? I noticed travis took the struts out of the car, and Eric left them in, but removed the hub assembly?

[Provoste]

Originally Posted by travislambert

Here's my alignment sheet. I'm not sure how accurate it is. The side-to-side caster difference makes me suspect. Maybe someone can help me understand this?

So It looks like I needed to remove a little more material from the left strut knuckle. I did my best to get them even, but that's something that's hard to measure without the proper tools.

Anyway, assuming the numbers are right, it looks like -3.3 of front camber is completely doable via this mod. I'm sure there's more room left in it, but I'll probably never try to go any further than that. If I ever have the need, I'll be looking into camber plates and/or completely different struts.

I drove the car at PittRace yesterday after the alignment and it drove awesome. I was running R7s for the first time and ran a 1:55.26 which is respectable for that track. On street tires, my best time was a mid 1:59.

Caster difference is normal, I'm sure the alignment is accurate.

You don't need any more camber, espeically if you liked how it handled. Adding any more camber will only wear your street tires faster. My street tires still wear fine @ -2.9 up front.

Your toe values make absolutely no sense though... you should NEVER have more toe IN on the front axle vs. rear axle.

I wouldn't touch your camber #'s, but i'd have the car re-aligned to address toe.

Shoot for 0 total toe up front, .10-.14 total toe IN in back.

[Provoste]

Originally Posted by Move_Over

Also, are you guys removing the whole spindle/hub assembly while you are doing this? I noticed travis took the struts out of the car, and Eric left them in, but removed the hub assembly?

No, I just pulled the upper knuckle bolts/lower strut mount bolts.

[travislambert]

Originally Posted by Move_Over

My caster measurements were very similar to yours. about .7 degrees off from each other. (however i have not done the mod).

I have a question on when you are talking about removing material from the knuckle, what exactly are you talking about, i get the slots and the grinding, but am confused as to where the knuckle is you (and others) are referring to? I am attempting to achieve about a -2.9 - 3 with NT01, so should 1mm of material in the slots be good?

Do you recall exactly how much material you removed from the struts? Thanks in advance.

The steering knuckle is the piece that bolts to the bottom of the strut. The material is removed between the very top and the top of the threaded adjustment hole. Each car could be ever-so-slightly different, so you'll probably want to test fit to see if/how much material to remove. In any case I wouldn't think you'd need to take away more than 1 mm from the knuckle.

In the slots, 1mm might be enough, but I'm not sure. There's no harm in removing 1.5mm, so I'd probably just target that. It'll probably save you some time.

Not sure about the measurements on the struts. I was just eye-balling those using test fits to check. After I did one, I made the other one match.

[travislambert]

Originally Posted by Move_Over

Also, are you guys removing the whole spindle/hub assembly while you are doing this? I noticed travis took the struts out of the car, and Eric left them in, but removed the hub assembly?

I left the hub. I took my struts out because I was doing a spring replacement at the same time. Otherwise I probably would have left them on the car.

However, removing the strut from the car is pretty easy. It makes grinding on the strut much easier and keeps metal shavings from getting all over the suspension. The downside is the test fits take more time.

[Move_Over]

Originally Posted by travislambert

I left the hub. I took my struts out because I was doing a spring replacement at the same time. Otherwise I probably would have left them on the car.

However, removing the strut from the car is pretty easy. It makes grinding on the strut much easier and keeps metal shavings from getting all over the suspension. The downside is the test fits take more time.

Cool, interested to see which springs you went with. I'd be worried about messing with spring rates. Feel free to PM me directly so we don't muck up this thread.

[Norm Peterson]

Originally Posted by travislambert

Here's my alignment sheet. I'm not sure how accurate it is. The side-to-side caster difference makes me suspect. Maybe someone can help me understand this.

So It looks like I needed to remove a little more material from the left strut knuckle. I did my best to get them even, but that's something that's hard to measure without the proper tools.

Both of these items can be tied to the car's build being subject to tolerances - there is no guarantee of precise symmetry.

Removing identical amounts of metal from the strut holes with the cambers starting out unequal (and all of the bolt to hole clearances taken up in the 'most negative direction') would leave you with about the same amount of cross-camber after you're done. As would happen in the case where before you got started one side's bolts were bottomed out max-negative but the other side's wasn't, and you bottomed both sides max-negative upon reconnecting everything.


Norm

[travislambert]

Originally Posted by Move_Over

Cool, interested to see which springs you went with. I'd be worried about messing with spring rates. Feel free to PM me directly so we don't muck up this thread.

I just installed the newer revision of ZL1 springs. Around April of 2017 all new ZL1s got the springs that I now have. My car was built in March of '17, so it had the gasser style front that was higher than the rear. Now the stance is perfect.

[travislambert]

Originally Posted by Norm Peterson

Both of these items can be tied to the car's build being subject to tolerances - there is no guarantee of precise symmetry.

Removing identical amounts of metal from the strut holes with the cambers starting out unequal (and all of the bolt to hole clearances taken up in the 'most negative direction') would leave you with about the same amount of cross-camber after you're done. As would happen in the case where before you got started one side's bolts were bottomed out max-negative but the other side's wasn't, and you bottomed both sides max-negative upon reconnecting everything.


Norm

I bet you're right. I was using a digital caliper to keep the material removal consistent between sides, but that won't necessarily result in perfectly even camber when both sides are maxed. There's probably some margin of error within all cars, plus with new springs all bets are off until they settle.

The caster is what made me most suspicious. I was thinking my last alignment (same alignment machine) showed the caster the same for both sides. Since it's nonadjustable, I was expecting it to be the same this time too.

[Move_Over]

I completed this mod this weekend, just put the car back on the ground and will be getting an alignment next week.

I used a mixture of carbide, grinding wheel, 60 and 120 grit all dremel tools. Drivers side came out much better than my passenger side, but i am happy with both.

Apex 10.5 et22 with NT01 305/30/19. Looking forward to getting on Sebring next weekend with the added front grip.

[Move_Over]

-3.0 is achievable both sides with no knuckle grinding. Here are my results today.

[TRZ06]

Originally Posted by Move_Over

-3.0 is achievable both sides with no knuckle grinding. Here are my results today.

How does the track alignment feel compared to stock?

Turn-in better? more grip in corners? How's the straight line stability with zero toe? Does it follow ruts more? Is it twitchy?

[Move_Over]

Originally Posted by TRZ06

How does the track alignment feel compared to stock?

Turn-in better? more grip in corners? How's the straight line stability with zero toe? Does it follow ruts more? Is it twitchy?

I can’t really give you an accurate answer until i get on track. I found the -2.2 and -1.5 twitcher than this go around though.

Does not seem to follow ruts, and straight line feels pretty good. I am on sticky R comps too, not to mention 305 up front. I’ll follow up on Sunday after i have another track day on this alignment

[Provoste]

Originally Posted by TRZ06

How does the track alignment feel compared to stock?

Turn-in better? more grip in corners? How's the straight line stability with zero toe? Does it follow ruts more? Is it twitchy?

Yes: better turn in, more grip. Excellent straight line stablity with 0 to -.08mm toe OUT up front. No, it doesn't follow road camber any worse than -2. Not twitchy.