[Provoste]

Ok guys, I’ve passed along this DIY instructions to a few guys on the 1LE forum, but I thought it might be helpful to put this DIY out there for everyone.

After burning through my front OE Goodyears in my SS 1LE the first weekend I took it to the track (with front camber maxed out), I decided to look at how I might achieve more negative camber up front. I know there is some variability between cars, but my car maxed out around -2.2-2.3 front camber. After this mod, I’m at -2.9- 3.0 up front (tire wear perfectly even on track now).

This mod to the front struts if very straightforward, and should only take about 30-45 minutes. I have a good friend with a lift, which made this easier having everything at eye level when standing. The only tools needed are a carbide bit/Dremel and some flat black spray paint. There are 2 parts to this mod: (Obviously first you need to put the car on jack stands with the front wheels removed, and remove both lower strut mount bolts)

1. Mildly elongate the existing camber adjustment range on the upper hole of the lower strut mount. This is how you are able to achieve more negative camber. Do not remove much material, a little goes a long way here. I used the imprint of where the camber bolt had previously been tightened as a template for material to remove. See top photo.

2. Grind down the ridge above the lower strut mount. If you don’t grind down the ridge on the strut, the inner barrel of the wheel will make contact with the strut ridge with the increased negative camber value. You might need to do a test fit or two to make sure at max negative camber the wheel clears the strut ridge. Also, don’t be alarmed if the strut bottoms out at the knuckle at max negative camber, mine did.

I did this mod in April of 2017, have 8k road & track miles/ 25+ days on track. This was the best mod I’ve done to my car, front tires now wear evenly.

[JRL1LE]

Thanks for posting this!
With maxed out 2.3 neg camber I've been wearing out the front outside edges.

[Norm Peterson]

Nice, thanks.

Guys, you should be able to estimate how much to grind from the center to center distance between the upper and lower holes and using a little trig. They're pretty close together, so a little (like maybe 1.0 mm) really does go a long way (maybe a whole degree).

I did a very similar modification on a Mazda 626 that I used to autocross.


Norm

[RUQWIKR]

I wonder how much is parts variation vs. alignment rack variation vs. combo. I showed -2.76 / -2.78 up front without elongating the holes. My front wear on both G3's and G3R's show I need more. Rear wear at -1.80 has been very even on both tire types as long as I rotate side-to-side frequently.

I have camber plates laying on the shelf but haven't had the time to install and realign. Thought about doing the old elongating trick before to see if I could get another degree negative out of my fronts. Will post if I do.

For the stock ZL1 1LE front wheels on my SS, I had to profile grind like you show. Will have to probably take additional material off if I elongate the struts. I did grind enough to get ~4-5mm clearance without having to use a spacer.

Provoste: Appreciate you showing the folks, too.

[travislambert]

I'm doing this mod this weekend. What I noticed was the top of the knuckle contacts the strut with almost nothing removed from the elongated holes.

I'm shaving a tiny amount of material from the back of the knuckle just above the threaded adjustment hole (where it contacts the strut restricting the camber).

Don't worry. I'm test fitting as I go to ensure the wheel won't rub.

I was at -2.2 before. I'll report back once I get the car realigned. I'm thinking anything -3.0 or better will make it worthwhile.

[Provoste]

Originally Posted by travislambert

I'm doing this mod this weekend. What I noticed was the top of the knuckle contacts the strut with almost nothing removed from the elongated holes.

I'm shaving a tiny amount of material from the back of the knuckle just above the threaded adjustment hole (where it contacts the strut restricting the camber).

Don't worry. I'm test fitting as I go to ensure the wheel won't rub.

I was at -2.2 before. I'll report back once I get the car realigned. I'm thinking anything -3.0 or better will make it worthwhile.

No need to remove knuckle material. Yes, the strut will bottom out at the knuckle, but that’s fine. I didn’t touch my knuckle... -2.9-camber currently, tire wear is great at -2.9.

[travislambert]

Originally Posted by Provoste

No need to remove knuckle material. Yes, the strut will bottom out at the knuckle, but that’s fine. I didn’t touch my knuckle... -2.9-camber currently, tire wear is great at -2.9.

I'm not sure what the tolerances are on the knuckles, but I don't think that I could have gained anything without removing a little material from the back of the knuckle. My knuckle was basically touching the strut before I started. Maybe there are slight differences which might help to explain why different people get different max camber values in the stock configuration.

[travislambert]

I thought I'd add some more pictures to the thread.

Before modification:


Here's one of the test fits. Be sure to leave enough room for wheel weights to clear. I removed a little more material from the strut after this test.


After the modification:



After first coat of paint:

[travislambert]

Provoste, thanks for taking the time to do this write-up. I found it very helpful.

I have an appointment for an alignment on Thursday. I'm switching to R7s so I'd like to get at least -3.0 up front. I'll report back with my results.

[Provoste]

Originally Posted by travislambert

Provoste, thanks for taking the time to do this write-up. I found it very helpful.

I have an appointment for an alignment on Thursday. I'm switching to R7s so I'd like to get at least -3.0 up front. I'll report back with my results.

Awesome! Glad you found it helpful, please post alignment #’s when you have them. Very clean job too- looks completely factory!

[Move_Over]

Originally Posted by travislambert

I thought I'd add some more pictures to the thread.

Before modification:
Attachment 949442

Here's one of the test fits. Be sure to leave enough room for wheel weights to clear. I removed a little more material from the strut after this test.
Attachment 949443

After the modification:
Attachment 949445
Attachment 949446

After first coat of paint:
Attachment 949444

Very nice, did you use a standard carbide bit with a dremel or something different?

[travislambert]

Originally Posted by Move_Over

Very nice, did you use a standard carbide bit with a dremel or something different?

I used a Dremel with the 9901 tungsten carbide cutter. I used two bits although one would have done the job.
https://www.amazon.com/gp/product/B00004UDJJ

To clean it up, I used the Dremel EZ407SA with a 60 grit band followed by a 120 grit band.

For the slots/holes I did all of the cutting with the 60 grit band (no cutter). For consistency I checked periodically using a digital caliper to remove 1.5mm of material from each slot. If you don't plan to remove any material from the back of the knuckle, 1mm is probably plenty.

[travislambert]

Originally Posted by Provoste

Awesome! Glad you found it helpful, please post alignment #’s when you have them. Very clean job too- looks completely factory!

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.

[Move_Over]

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.

Attachment 950133

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.