Modify strut hats for camber adjustability?

[tsmith25]

yes...its on both forums...

One of these days I might make an intro/journal thread...

I have a 98 with pretty trashed strut hats. They are currently swapped which put me at about -4 deg per side. I think a previous owner slotted the upper bolt hole on the bottom of the strut and I didn't notice when reassembling resulting in the higher than usual swapped sides camber. I am going on a road trip in the M3 so I plan to bring my camber number back down to avoid shredding my tires during the couple thousand mile highway trip.

I'm planning to get some 95 hats and anticipating that putting me around -2 to -2.5 deg.

I am a mechanical engineer at a metal fabrication shop. I was thinking that camber plates are basically a slotted strut hat with a bolt carrier plate that keeps the bolts in place and clamps the hat to the tower when tightened. Both of those are things I could do in the shop.

Has anybody made their oem hats into adjustable camber plates? If so, how was the process and result?

[pbonsalb]

My 08M3 has slotted holes in the tower. Maybe 1/4 inch extra. From the factory, the extra room is filled with pins. Some of us pull the pins and move the struts to gain about 1/2 degree negative. On the E36, people shim the lower strut bolts and use a thinner upper bolt to gain negative camber. Have plates on mine. Have not made my own.

[Moron95M3]

That is essentially what the KMAC plates are (what I run).

ring with studs coming up (carrier), then the strut mount with a lot of slop around the 3 studs (like 2" arc length by .75" radially sized cutouts).

So yes I think you could do that with stock, but guessing stock is a bit larger all around and that space claim my limit your adjustability.

Try it!

Take a look at the KMC's here, you don't 'need' the top piece (hell, mine are on the bench because I have a strut bar).
https://www.ecstuning.com/b-kmac-par...FUa4wAodmeMK-Q



PS if you do this, please send me the dimensions/DXF so I can go get it lasered for my lemons car! :P


PPS, you may want to use nonM mounts (?) as they seem to have more meat around the strut mount. If you cut a large amount away on the '95M mount you may not have much metal there to actually sandwich.

EDIt the NonM may have too large of a diameter of the actual rubber. You want as little rubber here as possible, so whichever oem mount is the smallest (95M?) may be best. There are gussets on the M mounts, that may interfere and I'd be hesitant grinding those off...if you're an engineer too you know they are there for a reason.

[NoLastName]

'95 strut mounts (guide supports) will decrease positive caster compared to later parts. The bore for the shock shaft is slightly farther forward than later M mounts. Non-M strut mounts will decrease positive caster significantly. If I recall correctly, the shock bore is dead center on those.

From what you described of your situation, I would first check to see if someone shimmed the spindles at the bottom bolts. You might be able to remove shims there to reduce negative camber some.

Otherwise, for street use I'd probably swap strut mounts back to the correct side and invest in some aftermarket (fixed or adjustable) camber plates. I think it would be difficult to make anything with decently usability and safety from stock guide supports. They're pretty thin.

My experience is that around 2 degrees negative camber is fun for the street without getting excessive tire wear. On the other hand, 2 degrees isn't nearly enough for track use.

Oh and I'm sure you're probably already aware, but whatever you do remember to get aligned afterwards. Changing camber changes toe at the same time.

[pbonsalb]

Maybe the machinest could make some fixed camber plates. Dinan fixed plates added just 1/4 or 3/8 inch stack height. Unless they were slightly contoured to the bottom of the strut tower, and I cannot recall but think they might have been, they would be very easy to make th. Essentially, you punched the studs out of the stock bushing plate. The Dinan plate bolted to it through those wedge head socket bolts that were flush mounted into the Dinan plate and bolted to the underside of the stock plate through the original stud holes. The Dinan plate then had upward facing bolts or studs that relocated the strut mounting into the tower to give maybe 1 degree more camber. Try to find a picture of fixed e36 camber plates and you will understand.

[tsmith25]

Thanks for the thoughts guys. I know all of the normal tricks. The reason I was considering this is with the intent of having the fine tuning ability that adjustable camber plates give you rather than a "you get what you get" type setup. Also, I can do this nearly for free vs 300-400 for "real" plates. Plus I like making things myself.

After staring at pictures of the different options for oem strut mounts I think I the best option is to use the 96 plus. They look like I can fit the longest slots between their gussets. I'm anticipating between .25-.5" of adjustment range. That will be either with them going from normal to an extra degree if you have them on the correct side or max to about a degree less than max if you put them on swapped sides.

So that should give me around -1.5 to -2.5 with the. Mounted on the correct side of the car and -4 to -3 with them swapped.

I'm hopefully getting a used set in the near future for experimenting. I would be happy to share a dxf of whatever I come up with for the bolt carrier plate. The mounts themselves will probably have to be slotted with a mill or by hand though.

[TostitoBandito]

I applaud the willingness and ability to fabricate, but echoing what others have said I think it's more practical just to get a set of camber plates. They aren't THAT expensive, and they'll let you dial in camber/caster perfectly.

Also, you can probably pickup a set of stock M3 struts, in good shape, for cheap. Lots of people run aftermarket struts and more or less give them away if they don't stash them.

[tsmith25]

I decided on a plan of action so I thought that I would update you guys.

I am going to use 96+ M3 hats, and instead of slotting the holes horizontally after pressing the studs out, I am going to slot them so the hat rotates about an axis that is centered in the hole pattern. This should let me use either hat on either side, and give me the entire camber adjustment allowable by the hole in the chassis (I have koni SA inserts protruding), while keeping the caster as high as it can be for a given camber setting.

I will provide a drawing or dxf for whoever wants it. I don't know if I will host is somewhere or send it via email or PM. I'll figure that out later.

[Moron95M3]

Sub'd! Good luck!

[tsmith25]

I think you know what that combo means.
camber from coffee.JPG

[JEC928]

I decided on a plan of action so I thought that I would update you guys.

I am going to use 96+ M3 hats, and instead of slotting the holes horizontally after pressing the studs out, I am going to slot them so the hat rotates about an axis that is centered in the hole pattern. This should let me use either hat on either side, and give me the entire camber adjustment allowable by the hole in the chassis (I have koni SA inserts protruding), while keeping the caster as high as it can be for a given camber setting.

I will provide a drawing or dxf for whoever wants it. I don't know if I will host is somewhere or send it via email or PM. I'll figure that out later.

Are you going to adjust this setup via DIY string or take it to a place with an alignment rack?

[tsmith25]

It's going to a shop. Unfortunately, I don't have time to learn to do or actually perform a string alignment for this next alignment. I was thinking about making my own toe plates, but that is a ways down the road.

progress update: I managed to make a stand-in model of the mount in Solidworks to verify clearances. I will probably be able to draw the bole carrier plate tomorrow. I anticipating trimming the tips of gussets back to the welds, since any material past the welds is not contributing to the strength that they add. That should increase the area of bolt carrier plate that will be compressing the mount against the strut tower.

[doktor b]

subscribed

[tsmith25]

I have both good and terrible news.

first the good.
IMG_4459.jpg IMG_4460.jpg

I found these on my desk when I got to work this morning. While generally grumpy, our machinist here does like to help with strange projects. Those pics are top and bottom of the same hat.

The terrible news:

I was in a hit and run accident on Friday night. The high quality people that blew a right turn into my lane then proceeded to re-grip after I had steered into the opposite lane to avoid them, to make sure to hit me, broke my strut, bent my control arm, and scraped every panel on the right side of the car. I was hopeful that it was just body panels, but I got the fender off last night and found this.

IMG_4450.jpg

I am now looking for a chassis shop that know E36's some where near Tampa FL. There will be a new thread asking that question with more pics. I intend to fix it, but I now have reached the "how much" stage. I hope it is not going to be too much...

I will keep updating you guys about the camber plate mods.

[tsmith25]

I bet you guys thought I forgot about this.

If you didn't see my thread, I managed to get through the insurance hassle, and replace the black 98 5 spd 4dr with a 99 estoril 5spd coupe. I have been busy addressing a couple minor issues with that one and work and toddler, but I managed to get the bolt carrier plates cut. They interfere a little in a couple of spots, but I think that the raw shape is good and a little grinder chamfering will clean up the clearance issue. They have most of their range of adjustment without any modification, but I want the full range of adjustment.

OOOH PICTURES!!!

IMG_4960.jpgIMG_4962.jpgIMG_4961.jpg

[Moron95M3]

very cool!!! Post a couple installed vids/pics when you can

Do you have the dxf file for the sliders? (or would you be willing to share?)

[tsmith25]

I am happy to share it. I don't see this being a lucrative money making opportunity, I only did it to because I can, and to get camber adjustability for just the price of new strut mounts. I will probably just send files to those who ask.

I want to get it mounted and verify that it works like I expect before I start telling people that they should do it to their car too. I can't see any reason for a problem, but I don't want to unwittingly pass problems along to people. I probably won't be able to get them installed till sometime in September, and maybe even October, since I have some birthdays here and a wedding that I'm flying up to CT for coming up in August and the beginning of September.

Funny story... I realized that when I was laying the bolt carrier over the strut mount for those pictures, I had it backwards. That's right, I was test fitting the part that I designed, and had it positioned incorrectly. With it in the correct orientation, it fits perfectly, without any interference. If anything, I could add a little thickness to the thinnest section.

[tsmith25]

Well, I was pretty good with my timing prediction. They are not in yet, but I will likely install them this weekend. I got some help from one of our welders. He welded the heads of the bolts to the carrier plates for me. Before I install, I need to paint them for a little corrosion protection, and I decided to grind a little bit off of the gussets on the mounts to get the full range of adjustment. With the bolt heads, they bind between two the gussets and the cylinder that the rubber and bearing are in. It only reduces the travel by about .0625", but I might as well have access to the full slots.

Pictures!!

IMG_5224 by Taylor Smith, on Flickr

IMG_5223 by Taylor Smith, on Flickr

IMG_5222 by Taylor Smith, on Flickr

IMG_5221 by Taylor Smith, on Flickr

IMG_5220 by Taylor Smith, on Flickr

[tsmith25]

Apparently when I said this weekend, I meant late next month. I finally got them in. They work well. They don't like to slide easily, but I managed to get them adjusted pretty accurately to the same position on each side(not quite to the alignment stage). I like that they don't want to slide easily, that should make them hold their adjustment well because of it.

video of movement(have to click on it) I don't have a youtube account at this pointso its just on flickr
404EE701-B19C-4D71-8246-6BF5AA7D8C68 by Taylor Smith, on Flickr

maxed camber
3AFE02A9-79E3-4392-B7D5-A804400621DA by Taylor Smith, on Flickr

about stock
D6E577BA-9DF2-4C27-A5A5-1806B8FB9C77 by Taylor Smith, on Flickr

stock
E294D853-6BE0-4D93-A64A-2C4431B27D67 by Taylor Smith, on Flickr

about maxed
E4FFAB0E-E7FD-42E9-93B9-B9CD532CAB18 by Taylor Smith, on Flickr

[NeilM]

They don't like to slide easily, but I managed to get them adjusted pretty accurately to the same position on each side(not quite to the alignment stage). I like that they don't want to slide easily, that should make them hold their adjustment well because of it.

Drill the hat and weld on a bolt with its hex head on the top. Then you can use a socket and ratchet handle from above to turn for adjustment.

Clever project!

Neil

[Moron95M3]

Nice!!

[tsmith25]

I didn't mention in my post above, I decided not to grind the gussets at all. So the only modification to the mounts is pressing the studs out then cutting the slots.

Drill the hat and weld on a bolt with its hex head on the top. Then you can use a socket and ratchet handle from above to turn for adjustment.

Clever project!

Neil

Thanks. That is an interesting idea. I would be concerned about the heat from welding affecting the rubber in the mount though. I may drill two holes and make a fork like adjustment tool to accomplish what you were suggesting without damaging the integrity of the rubber.

Nice!!

Thanks. Send me a pm with your email, and I will send you a .dxf of the carrier part.

[RRSperry]

Man, that is a lot of camber...

[tsmith25]

It is about the same range as any other camber plate. I set them at about half way through their range. Stock is about -0.8 deg, and they are at about -2 deg, so they should max out around -3.2 deg.

[TostitoBandito]

My GC plates max out at around -3.6-3.7 degrees (measured) before the center strut post hits the edge/lip of the tower. The highest I ever need to go is around -3.5.