Camber Plates: Vorshlag vs GC

[z31maniac]

Better customer service, in my experience.

I've had great customer service from both.

I spent along time on the phone with Jay and Frankie coming up with rates for my swap car and they were nothing but helpful. I've only had one transaction with Vorshalg, but it was good and my parts arrived FAST.

[Brew]

Better customer service, in my experience.

[lifeiskaos]

Hate to bump old threads, but I don't feel like making a new one.

So often I hear that Vorshlag is "better" but I don't know why. From what I understand, the new Ground Control camber plates offer more camber and caster adjustment, they have a shorter stack height, and they are significantly cheaper. Am I missing something? What's better about Vorshlag's?

[hfmjic]

I hear yea...



Well I admit to not having slept in a Holiday Inn Express lately but that's just what we've measured. :) We shortened a pair of stock strut housings ourselves (not bent), and we do run the car pretty low, so that's giving us more camber than others may see at taller heights. Our Hyperco slightly "beehive" shaped OBD series springs are allowing more spring travel than older spring designs - several spring manufacturers have adopted this same strategy.





Just took those pictures moments ago (it finally quit flooding here in Texas and the sun is out). Not arguing that the GC plates do not have more inboard camber travel - they look like they do. We just chose a different path for an E30 plate design. Its all good. :)

OK, I'm getting back to work...

Is it poor form to point out that using a smart camber gauge there is no way you got a legit zero for that measurement on that surface? I've used that gauge for years and learned the hard way that it's usefully for differential measurements only on anything but properly leveled scale pads. Even then, its accuracy is good but it's precision is only so-so. It's a great track-side tool when a pyrometer gives you good data though.

[Hellabad]

^ horrible news!! I suspected that by looking at the peach/spring so I called up GC and asked. He said it would work just fine. Figures.

Well everybody at GC knows the correct answer, that you can't use the old perch, so whomever it was must have misunderstood the question.

So I need my car up and running by monday. I dont want to put back on the GC plates since the bearings are all fucked. Where can I pick up these perches?

Call someone at GC, you can probably just service the camber plates and everything will be fine. Anybody there can walk you through it, but ask for Mark, Frankie, Jay or John.

530 677 8600 open at 9 pst

[Schniddy]

^ horrible news!! I suspected that by looking at the peach/spring so I called up GC and asked. He said it would work just fine. Figures.

So I need my car up and running by monday. I dont want to put back on the GC plates since the bearings are all fucked. Where can I pick up these perches?

[Hellabad]

a little off topic, but:

I shouldn't have any problems switching over to oem mounts/perches from having GC plates w/ coilovers, correct?

Actually you are more on topic than most. You will need the specific upper perch designed for a coilover mated to an oem bmw upper mount, The camber/caster plate perch won't work.



Jay

[Schniddy]

a little off topic, but:

I shouldn't have any problems switching over to oem mounts/perches from having GC plates w/ coilovers, correct?

[Fair!]

yeah, sucks actually, I really have a full plate besides this.

I hear yea...

You cannot move the strut 0.920 over from the center of the strut tower, on an e30 with unbent struts, and get 4.3.

Well I admit to not having slept in a Holiday Inn Express lately but that's just what we've measured. :) We shortened a pair of stock strut housings ourselves (not bent), and we do run the car pretty low, so that's giving us more camber than others may see at taller heights. Our Hyperco slightly "beehive" shaped OBD series springs are allowing more spring travel than older spring designs - several spring manufacturers have adopted this same strategy.





Just took those pictures moments ago (it finally quit flooding here in Texas and the sun is out). Not arguing that the GC plates do not have more inboard camber travel - they look like they do. We just chose a different path for an E30 plate design. Its all good. :)

OK, I'm getting back to work...

[Hellabad]

For those of you who don't want to go measure, or those of you who do:

The length from the center of the lower ball joint to the camber plate pivot is 23.0 inches (on an e30 with 12" CL to fender). This is essentially how long the front strut is. Lets make this the hypotenuse of a right triangle. The short side of the triangle is 0.730 from center of hole to max inboard, on the camber plate referenced above.


Here is the link to an online calculator:

http://www.easycalculation.com/trigonometry/triangle-angles.php

Therefore, an e30 with 4.3 degrees at max negative, will be
Use the numbers I have provided, or measure your own.

Long side, hypotenuse, the length of the strut, is 23 on my 1987 325is. The movement of the camber plate is 0.730, which is the "short side". The online calculator makes your HP35 obsolete as it figures out the sine for you.

My answer is 1.8199 degrees (rounded to 1.8-degrees). This is how many degrees of camber, a 23 inch long strut will gain (or lose) when moved 0.730 inches. You can try your own measurements.

Therefore, when sliding the strut back toward positive to the center of the hole, what should the camber be?

-4.3, sliding to the center +1.8 degrees means that in the center of the strut tower the camber will be -2.5.

Lots of guys here have their e30 lowered to 12 inches from the center of the Roundel to the fender lip, but dont have camber plates. Are they all running around with -2.5 degrees negative on their daily commute? I don't think so. Otherwise there would be a clamor for camber plates that TOOK AWAY all that negative camber.

Photos soon....

[Hellabad]

that plate wont flex with nothing holding it down on one side?

There is plenty of strength and planty of bolts, I just want to make them work for it, so I'm not going to post complete pictures.

right now my GC plates limit the caster movement because of the camber bolts

That is always the way it has been , because I first designed that plate in 1992 or 3, and the IT rules allowed coilovers but Street Prepared didnt.

So the camber plates have always necessitated cutting as allowed by the rules to get max adjustment. As mentioned, there is a height penalty, but new advances in high-tensile wire and barrel spring design allow shorter springs while retaining adequate suspension travel. So now we can make a slightly thiscker plate, without worrying as much about coilbind.

Jay

[Hellabad]

Hey, its Jay from GC joining the thread. Welcome.

yeah, sucks actually, I really have a full plate besides this.

So with these coilovers we are seeing a maximum -4.3° of camber and +9° caster using our plates.



Cheers,

You cannot move the strut 0.920 *edit*(-0.920 is the range of travel, 0.730 is distance to the center) over from the center of the strut tower, on an e30 with unbent struts, and get 4.3.

Notwithstanding, lots of people run more than 4.3 with great success, especially road racing, but also some parking lot stuff too.

Mathematical proof in the next post.


Jay Morris from GC slept at a Holiday Inn

[Fair!]

Hey, its Jay from GC joining the thread. Welcome.

Just wanted to post a picture of our shop E30 at last weekend's SCCA Divisional event at Texas Motor Speedway. We played with camber settings to clear up some understeer on Day 1 we were experiencing. Went from -3.8° to -4.3° (which was the max for this car) up front and the both drivers dropped 1 second on a 60 second course. This alignment was achieved using our off-the-shelf Vorshlag E30 plates and AST 4100 front struts with 60mm springs. This picture is with the car fully loaded in a corner data logging 1.15g lateral on shaved 140 treadwear 205mm Bridgestone RE01Rs (this class is limited to 140 treadwear or higher, with 225mm max width).



In our experience the springs are the biggest limiting factor for camber - if you have OEM springs they will contact the strut tower long before the top of the strut shaft runs into the strut tower opening up top. With coilovers using 2.5" or 60mm springs, this isn't a concern, so the more travel you can get up top the better. Lower ride heights also get more negative camber at all settings. Our car is fairly low, 12.3" from center of wheel to fender lip, using 1" shortened strut housings and a 6" long coilover spring. So with these coilovers we are seeing a maximum -4.3° of camber and +9° caster using our plates.

Can another plate design possibly get more than that? Sure, its possible. Do you need more than that much camber? I don't know, it's debatable, but our testing shows the best cornering power between -3 to -4° in most BMWs. One more thnig, with our shorter single-row sealed radial bearing perches you get 5mm less stack-up height than with our standard double row bearings. This works for race set-ups that are using coilovers (like our car has), but is not made for OEM perches (which themselves are pretty tall).

Cheers,

[Eric]

Ground Control already makes these plates. And they are still shorter than 'the other ones'.

uh oh....somebody finally told GC about this thread.

You can adjust the caster and camber to extremes also. Been around a while, but seems to get lost in all the BS.

Jay Morris

that plate wont flex with nothing holding it down on one side?

It'd be nice to make a plate that the camber bolts are sunk down into the main plate.

I want to set my camber, then slide the plate forward or aft to adjust my caster. I won't be doing the "dump the camber for the track" deal. once the car is alighned, the plates wont be touched until the next alighnmnet.

right now my GC plates limit the caster movement because of the camber bolts

[Hellabad]

I guess that would be at the expense of the stack height? I think I'd rather be a bit higher and have the extra room to move around...

Ground Control already makes these plates. And they are still shorter than 'the other ones'.

You can adjust the caster and camber to extremes also. Been around a while, but seems to get lost in all the BS.

Jay Morris