AST Suspension

[ChosenGSR]

Does this look right to you guys? Not sure how perfectly perpendicular the sway bar has to be to the ground.

[fsmtnbiker]

That looks fine to me.

[epj3]

Yup looks about where my sway bracket is.

[ChosenGSR]

I also put some electric tape on the sway bar link adjuster to check for rubbing and it looks like I am good to go. I tried both minimum camber and my track setting. I guess 235/40 is probably as wide as you can go before you need a spacer, at least with the Kosei K1s.

[Don Nguyen]

How did you guys install your Vorshlag RSMs? Did you have the studs facing upwards or downwards? What would the difference be, mounting them either way?

[B.Watts]

How did you guys install your Vorshlag RSMs? Did you have the studs facing upwards or downwards? What would the difference be, mounting them either way?

The shock mount mounts "under" the car. Is that what you're asking?

[clopez95m3]

How did you guys install your Vorshlag RSMs? Did you have the studs facing upwards or downwards? What would the difference be, mounting them either way?

New design or are they the orange ASTs with the spherical bearing? As Bryan pointed out the shock mounts go under the shock tower and the studs point up.

Good luck,
Carlos.

[Don Nguyen]

New design or are they the orange ASTs with the spherical bearing? As Bryan pointed out the shock mounts go under the shock tower and the studs point up.

Good luck,
Carlos.

They are the orange ones.

I think I had another brain fart. I am just used to using the GC ones, and mine had a separate mounting plate/bracket that went from inside the car to the outside/fender area.

[epj3]

They are the orange ones.

I think I had another brain fart. I am just used to using the GC ones, and mine had a separate mounting plate/bracket that went from inside the car to the outside/fender area.

Yea some shock mounts were made to allow you to remove the shock from outside the car (ie to adjust rear koni rebound)

[Don Nguyen]

What adjustment settings do you guys have your AST 4100s set at, for those running a staggered wheel/tire set up, if that matters.

[Don Nguyen]

Is anyone else running this shock in the rear?

If you can see in the picture, at the bottom of the shock, there are two aluminum pieces. One is larger than the other. I am trying to figure out if the larger or smaller piece faces outwards and towards the wheel, or inwards and towards the car.

[Danny318]

depends on your spring rate but im finding with +8 or so in the rear and +5 or 6 in the front is pretty good, but I still have no idea and would like to know what other people run with these same springs.

[Don Nguyen]

I am running 600 fronts and 700lb rears. I'll give Vorshlag a call tomorrow when they are open. They are a couple of hours ahead of me, so by the time I get home, they are usually already closed.

[epj3]

For street driving +4 front +3 rear. Haven't had a huge chance to mess with it though.

[John in Houston]

Is anyone else running this shock in the rear?

If you can see in the picture, at the bottom of the shock, there are two aluminum pieces. One is larger than the other. I am trying to figure out if the larger or smaller piece faces outwards and towards the wheel, or inwards and towards the car.

The larger spacer goes towards the rear spindle... spacing the shock body away from the spindle. Smaller piece goes on the outside (towards the center of the car).

[Fair]

Is anyone else running this shock in the rear?

If you can see in the picture, at the bottom of the shock, there are two aluminum pieces. One is larger than the other. I am trying to figure out if the larger or smaller piece faces outwards and towards the wheel, or inwards and towards the car.

As you noticed we answered your e-mail request before we saw your post here, but here goes:



As it shows in the AST installaiton instruction gallery, and as John pointed out, the longer bushing goes outboard.

Cheers,

[John in Houston]

..and as John pointed out, the longer bushing goes outboard.

Lots of practice installing / uninstalling suspension parts

[Don Nguyen]

I didn't even realize there was a instruction gallery at first.

I was just going to this before http://www.vorshlag.com/instructions.php

Also, the sway bar mounting tab on the front shock is suppose to be pointing towards the front of the car, correct? I no longer have my stock/old suspension, and I don't remember it exactly off the top of my head. With the sway bar mounting tab pointing fowards, it causes the sway bar end links to sit at a weird angle. I'll have to double check once I get home later.

[John in Houston]

The tab faces towards the rear of the car. You can see it in one of the photos above. The endlink should be straight up and down (for the most part) with zero pre-load.

The easiest way to get zero preload? Set the car on jackstands... but place the front jackstands on the actual control arms (after the struts are securely installed). This mimics the car being loaded on it's suspension. Then adjust the AST endlink tab up / down until the end of the endlink easily fits into the tab. That should be just about zero preload.

[Don Nguyen]

Here's the way to align a dual-use BMW E36 or E46 with Vorshlag camber+caster plates and coilover shocks (for track+street or autox+street):

• Go to the alignment shop with the ride heights set and at MINIMUM front camber adjustment (for the street). Camber should correspond to the farthest outboard camber mark on the plates - the minimum setting.
• Set your caster at the maximum positive setting. Luckily, we always ship the plates this way - on an E46 or E36 you have to unbolt the main plates from the bearing holders if you want to change caster (almost nobody ever does).
• Ask the race car friendly alignment shop to check the total toe-in at the front. It should be around zero or even 1/8" toe in (more on that in a second - no need to set this yet)
• Align the rear to your tastes. We usually set it at around -2 to -2.5°, but we are still experimenting with more because at full cornering load the rear seems to still go positive (see pics below).
• Set the rear toe out to -1/8" or even -1.4" total toe in. We have tested with favorably with 1/4" total toe in out back and its faster on track and in autocross conditions. Power application on corner exit is better.
• After they have your street settings checked have them raise the front end, loosen the camber plates, and slide it all the way in. Tighten and re-check.
• That is your max camber setting. Its usually around -4 to -4.5° camber at lowered ride heights with coilovers. This may be perfect for your car, especially for lower speed autocross type events. Or you may want a bit less - most users seem happiest on track with -3 to -3.5° camber. The more grip you make the more camber you lose cornering, and the more static negative camber you need. (with 275mm R compound Hoosiers we run -5° for autocross and -4° on track; less grip means less static camber needed)
• Once you have picked your camber setting (again, -3.5° is a good bet) have the shop set it to that and mark the pointer and associated engraved mark on the plates with a sharpie, or count the marks and make a note of it in your log book (you DO keep a log book for your various settings and event results, right?)
• The toe change over this camber swing is usually about 1/4", when going from min to max camber. KEEP THIS IN MIND BECAUSE TOE IS WHAT WEARS TIRES THE MOST. For autocross we tend to run 1/4" toe out at max camber settings for the best turn in and grip. This tends to swing the toe to about zero for street use. For road course using 1/4" toe out is "a bit darty" for most folks and will impact tire wear. 1/8" to 3/16" total toe out is more reasonable and still has knife edge turn-in.
• Have the shop now set the toe at your max camber setting to suit your needs (autocross or track; see above) and lock it down. Then have them slide the camber back to you minimum street camber setting and note the toe. It should be around zero toe for the street, or as much as 1/8" toe in.
• Having some toe-in for your street setting is fine, and in fact makes the car more stable and tramline less over ripples and crowns in the road. Zero toe is optimal for wear but as much as 1/8" toe in or toe out has minimal affect on tire wear. Drive around with more than 1/8" on the street and you will notice more tire wear. All that hubbub about offsetting the crown in the road with different camber from side to side is an old wives's tale.
• If the shop refers to toe in degrees ask them to switch the settings on their machine to total toe in inches - this is what racers refer to because most of us buy our own toe measuring palates ($50, Longacre) and check it periodically.
• To optimize your camber for track or autocross buy a probe type pyrometer (no, infrared doesn't work - you need to probe under the surface of the tread) and use it during testing. Skidpad the car (150 to 200' diameter) for autocross use and hot lap testing for road course. That deserves its own thread, and in fact has been discussed in the track forum at length I'm sure.

That's all you need to know. Easy as pie. Setting the camber track side takes about 45 seconds per side - raise the front corner of the car (yes, RAISE THE CAR; I've seen goofballs adjust to max camber with the car on the ground and it SLAMS the strut into the strut tower opening and damages it), loosen the three strut top nuts with a 13mm deep socket, slide the wheel in or out to your camber mark, tighten the nuts back to 16 ft lbs (just a hair over hand tight), and lower. While you have the car in the air you can also check shock settings, change tires, inspect the pads, check the front swaybar setting, etc.

If you know the toe at both the min and max setting there's little reason to check it, but many racers do have a set of toe plates and still verify it periodically. A once-a-year shop alignment is still smart money, as things can shift or slide in the rear, especially if you tend to run into curbs.


Note the front and rear camber under load. Rear could use more static negative camber, and that was with -2° out back and only RE01R "street" tires on asphalt


Left: The front has -4.2° static camber. Right: Same car same day under max cornering load (1.2g). Note the nearly zero front camber and positive rear camber under load. This is on Yokohama AD07 street tires and concrete.

My experience is very much the same as what Terry has relayed.

TC535i, I don't think the rear sways will help once you're out much over 200-210 RWHP. The problem comes from power application moving the rear wheels to toe-out. The rear sway bar will definitely help with rear camber, as will stiffer rear springs. People need to remember though to just go as stiff as needed on spring rates, anything more and you also lose traction.

Neil, I'd suggest 1/8" rear toe-in (total) as a starting point for any from stock to 220 RWHP. If you've got much more than stock and are finding the back-end too tail-happy on corner exit, but fine everywhere else, than try moving closer to 1/4" rear toe-in (total). If your over 230 RWHP than 3/8" might even be good. I like it anyway.

Although I'm not able to get as much negative camber as I'd like (Terry, I've been extremely busy but we'll need to talk and "put our heads together" to see if there's something further that can be done). Like Danny318, I'm not getting all the front camber I'm after. Only getting -3.5° front camber all the way in. That's OK, but I'd really prefer about -4.0° with my 265/35/18s (BFGoodrich g-Force R1), although the pyrometer is so far saying we're close to where we should be, there is more to be had.

I approached things only slightly different in that my initial alignment settings were my track setup (then my street setup - if I'm going to compromise the street is where I'll do it):

First - I do my alignment setting with me in the driver's seat as the E36/E46 suspension geometry is such that you loose camber on compression and me being at 200 lbs, even with 550lb front springs, the car looses approximately 0.2° front left camber when I'm there versus when the car is empty. To compensate for this and not have to run different positions left to right, I shim my left front strut (at the hub mounting - only a little if using OE length bolts) to match the right with me in the car and the plates set to the same position. No need to get overly fussy, just close, as all these setting change slightly once you drive/run the car.

• Track
  
  • Camber
    
    • Front: -3.5° (this is with the camber plates moved in to max travel. At the moment, my car gives slightly less camber than the -4.0° I'm looking for)
      
    • Rear: - 2.5°
    
    
  
  
  
  
  • Toe
    
    • Front: 0" (will be switching to 1/8" out)
    • Rear: 3/8" toe-in
    
    
  
  
  
  
  • Caster: maximum. Don't recall the figure but think it's around 6.5° (had to reduce it slightly to maximize front camber)
  
  

---------------------------------------------------------------

• Street
  
  • Camber
    
    • Front: -1.95° (second mark in on driver's camber plate for my car. We then set the passenger's side to match and scribed & sharpied it)
    • Rear: - 2.5° (untouched from track setup)
    
    
  
  
  
  • Toe
    
    • Front: 1/4" toe-in (the switch to 1/8" toe-out for my track setting will adjust this to a tire friendlier 1/8" toe-in)
    • Rear: 3/8" toe in (untouched from track setup)
    
    
  
  

This setup woks well for me running RD sways full stiff front and 3/4 soft rear, springs 550lbs-F and 650lbs-R, bushings, etc., etc.

I run the 3/8" toe-in on the rear to keep the tail-end planted on corner exit. Currently have a problem with my piston rings not seating so we've not been able to tune the engine, but even with that, I expect we're around 240RWHP so that's why the 3/8". The 265's are still breaking loose around 4,000 rpm in second gear in a straight line on most courses, so I figure we're in that range. (New pistons and rings during our 3 week break in July will fix the ring seating and tuning will bring more power)

BTW Terry, we are now 3 for 3 in class wins (B/SP) with 2 FTDs for 2008. Running the AST 4100, Mason Bar, Vorshlag motor mounts, etc.

Just did a Regional on Sunday. Number 3 of the three, and missed FTD to a full race C-Mod Porsche 914-6 on a choppy course that was nice but lacked flow and had several very constricted sections that allowed a C/SP Miata to get within 0.174 seconds and a C/SS Miata to get within 0.860 seconds of our time. We've got a real problem locally with people, mistakingly thinking they can build the PAX factor into the course design Doesn't work as it misrepresents not only run times but destroys car classification.
That's my rant on Go-Kart course design.

Regards, Alan

How are your tire wears, with those rear settings, using ~2.5 degrees of camber and 1/8th or 3/8th total rear toe inwards?

[epj3]

I know we were talking about lower spring perches. Just saw this on their site yesterday?
Wish the price would've been a little lower ($60), but I'll still be picking up a set.

http://www.vorshlag.com/product_info...roducts_id=229

[hancheyb]

I know we were talking about lower spring perches. Just saw this on their site yesterday?
Wish the price would've been a little lower ($60), but I'll still be picking up a set.

http://www.vorshlag.com/product_info...roducts_id=229

I blame it on petroleum.

[GotCone?]

I have a set of those off-white perches and they are very nice! A nice addition to an already superior product from Vorshlag. Keep up the good work VM.

[epj3]

I blame it on petroleum.

I think it's safe to blame just about everything on petroleum now-a-days

[ChosenGSR]

Wish the price would've been a little lower ($60), but I'll still be picking up a set.

Should be a discount for current kit owners