AST Suspension

[motomoron]

Second autocross on the 4100s today. AI at FedEx Field. Wet and crappy in the morning turned sunny and breezy for a dry and comparitively grippy course in the afternoon for the afternoon sesions. STU was in the last session of the day.

I reset ride height, and wound the fronts up to 13", and had the rears at 12.4". I ran full hard front, 2 clicks off rear. full hard front bar, soft rear. 38 psi front-36 rear, and bled down between runs.

The car felt really planted. Turn in was nice, but I was having a little trouble getting power down, and in a slalom section the rear felt a little like it wanted to come around to surprise me. The car is clearly better than me now, and there's much room for improvement on my behalf. That said, the car goes where it's pointed, and it does feel planted.

The linearity of the damping vs. where the knob is, is very, very good. As I get some miles on these, they feel better and better. Driving home from the event with the tires at 34/32 and dampers on full soft, the car felt better than it did 2 weeks ago on 67k old stock shocks.

The AST4100s are some pretty awesome dampers.

[Gleb]

Just a "for what its worth" post -- springs are not expensive. Not sure what Terry and Brian would charge for individual springs, but there is "another vendor" who runs a website to sell H&R springs for something like $44/ea. So if you guys ever want to change spring rates or height, it's not that expensive.

I would still contact vorshlag first though

Oh, I agree 100%, springs can be changed for relatively little money. And I will probably do that eventually, this is just a starting point, since I am not sure how the car will behave with all of the changes we are doing to it.
Just wanted to get some general advice/suggestions.

[Alan Coles]

...I was having a little trouble getting power down, and in a slalom section the rear felt a little like it wanted to come around to surprise me...

Are you still running 0.1"/per side, Toe-in for rear toe (0.2" Total Rear Toe-in)? If so, you may want to try a bit more rear toe-in. I had the same problem at roughly the same rear toe/camber settings and after setting it to 0.14" (per side) Toe-in for the rear toe, (0.28" Total Rear Toe-in) the problem was solved.

Regards, Alan

[M52 POWER!]

Are you still running 0.1"/per side, Toe-in for rear toe (0.2" Total Rear Toe-in)? If so, you may want to try a bit more rear toe-in. I had the same problem at roughly the same rear toe/camber settings and after setting it to 0.14" (per side) Toe-in for the rear toe, (0.28" Total Rear Toe-in) the problem was solved.

Regards, Alan

I may have to try that to since I'm running .1 per side. I'm putting new tires on and re-aligning it this weekend anyways! Susp. should be mostly settled by now.

[fsmtnbiker]

Edit: Reading comprehension > me, apparently.

I agree - You can either add rear toe-in, or go a little softer in rear spring rate. You could also back off a little bit on front rebound damping, which should add corner-exit grip in the rear.

[Danny318]

[ChosenGSR]

Hey guys, looking at the list and realoem picture that motomoron posted on page 10, what is the difference between FIT BOLT and CAMBER CORRECTION BOLT both reflect #5 on the diagram. Is one shorter than the other? Which is better for the coilover setup.

Thanks.

[epj3]

Hey guys, looking at the list and realoem picture that motomoron posted on page 10, what is the difference between FIT BOLT and CAMBER CORRECTION BOLT both reflect #5 on the diagram. Is one shorter than the other? Which is better for the coilover setup.

Thanks.

Don't get the camber correction bolt if you're getting camber plates.

[Alan Coles]

...what is the difference between FIT BOLT and CAMBER CORRECTION BOLT both reflect #5 on the diagram. Is one shorter than the other? Which is better for the coilover setup...

Alex, the correction bolt (also commonly know as "crash bolts") is designed to fix a camber problem typically caused by an accident where there is a slight issue with not being able to get camber setting within factory settings after frame straightening, etc. I don't know the specific differences with the BMW part, but typically the "Crash Bolts" have an eccentric (cam lobe) on their shaft to move the two parts a few degrees in or out, relative to one another and thereby alter your available camber adjustment.

They've also been used in "stock" Solo II classes to get more camber than is possible otherwise within the rules.

As Epj3, suggested, there should be no need to use these if you have camber plates.

Motomoron, could you explain why you state that these bolts "must" be replaced? To the best of my knowledge, they are not stretch-to-yield bolts, just a normal M12x20mm bolt (don't recall the hardness grade). Perhaps I missed something.

Regards, Alan

[epj3]

Alex, the correction bolt (also commonly know as "crash bolts") is designed to fix a camber problem typically caused by an accident where there is a slight issue with not being able to get camber setting within factory settings after frame straightening, etc. I don't know the specific differences with the BMW part, but typically the "Crash Bolts" have an eccentric (cam lobe) on their shaft to move the two parts a few degrees in or out, relative to one another and thereby alter your available camber adjustment.

They've also been used in "stock" Solo II classes to get more camber than is possible otherwise within the rules.

As Epj3, suggested, there should be no need to use these if you have camber plates.

Motomoron, could you explain why you state that these bolts "must" be replaced? To the best of my knowledge, they are not stretch-to-yield bolts, just a normal M12x20mm bolt (don't recall the hardness grade). Perhaps I missed something.

Regards, Alan

The lower two strut bolts are an encapsulated. Really if you clean off the bolt and use loctite, I'm sure you would be fine.

[murph1379]

Does anyone know if the crash bolts are available for E46 330's?

[DSP74]

Are 4100's and 4200's available JUST for the rear of an E30 application?

[B.Watts]

Does anyone know if the crash bolts are available for E46 330's?

E46 uses a different style mount between the strut tube and the hub than the E36.

[motomoron]

The lower strut to spindle bolts are 12x1.75 grade 10.9 bolts w/ a pre-applied threadlocking compound. The torque value is like 84ft/lbs or such, so they're obviously not a stretch fastener.

BMW's recommendation in the service literature is that they be replaced after removal.

My ~opinion~ in that in the grand scheme of preparing to install struts-shocks-camber adjusting plates-sway bars-adjustable end links-Euro rotors-turned rear rotors-SS brakelines-upper tower brace-X brace-fresh RE01Rs on K1s-full service w/ Redline lubes-Guibo/center bearing, all of which cost like 5-1/2 grand...

4 bolts at $2 ea. is not an issue. Fresh, clean hardware is nice on fresh, clean suspension.

[epj3]

The lower strut to spindle bolts are 12x1.75 grade 10.9 bolts w/ a pre-applied threadlocking compound. The torque value is like 84ft/lbs or such, so they're obviously not a stretch fastener.

BMW's recommendation in the service literature is that they be replaced after removal.

My ~opinion~ in that in the grand scheme of preparing to install struts-shocks-camber adjusting plates-sway bars-adjustable end links-Euro rotors-turned rear rotors-SS brakelines-upper tower brace-X brace-fresh RE01Rs on K1s-full service w/ Redline lubes-Guibo/center bearing, all of which cost like 5-1/2 grand...

4 bolts at $2 ea. is not an issue. Fresh, clean hardware is nice on fresh, clean suspension.

Exactly. In fact, ever since replacing my clutch last summer, I made the decision to buy new fasteners from now on.

Not only does it make everything go back together nicely (since you won't worry about losing bolts) but it makes getting it apart in the future MUCH easier. ie the outer lower control arm eccentric bolts. It used to be a pain in the butt to order every little fastener at the dealership -- now I use mileoneparts.com

[Alan Coles]

Regarding the "stretch fastener", torque-to-yield aspect, I understand that an M12x1.75, 10.9 bolt torqued to 78 ft-lb won't be stretched and, under normal circumstances, won't be a disposable item. That's the only reason I was asking if I was missing something when I'd read that they "must" be replaced.

I take what BMW says with a grain of salt. They also want you to never change your tranny or diff fluids, etc., etc., and we all know they're completely wrong there and on many other points.

The Bentley manual states:

Use new steering arm mounting bolts, or clean bolts and use Locktite® 270 or equivalent thread-locking compound.

For me it's not about cost, but more about throwing away perfectly good parts. Trying to get more socially conscious you know.

If something is in good shape, has tons of useful life left in it and just needs a little cleaning up and a bit of Locktite to do as good a job as a new piece will than, for me, I'm good-to-go.

Regards, Alan

[mmdb]

hi, I'm new to this forum, and came across AST suspension a few months ago when I was searching for new suspension for my car. I don't have a BMW, but a Nissan 240sx. My desire to purchase new suspension came from an incident at a local race track. No matter what I did to my suspension dampening changes were not apparent. The coilovers I had before were built in Japan and carried a lot of respect, but regardless I wasn't happy with them. So here I am I use my car for daily driving, road racing, and autocrossing. In the future, my car will be made strictly as a race car. The car has suspension modifications and go fast parts (see picture below). The car is unique in that it has an Ls1 motor which is fully stock and fully lethal But enough about the car, what about the suspension?

To begin I'd like to thank Brian over at Vorshalg for going through the troubles of getting this set together. He had to, according to my specs, talk to AST in Holland, which then talked to AST's distributor in Japan, to information on which spring rates for me to run. It only gets harder because I have a one-off car. So again, thanks Brian for the effort.

As far as comments, I can only on the build quality and the knob adjustments. So far, I give them both high praise. The welds look great, the material looks top notch, and they feel very sturdy and beefy. The knob adjustments have a very precise and determined "click". Adjustments, unlike other manufacturers, have limits - one can only turn the knob a certain amount of times one way (I noticed these in lower end brand coilovers). This is very important to me to fine tune a car and produce consistent results.

Unfortunately I don't have opinions about the ride quality because my car is currently in the shop (got rear ended). I'll later follow up with their handling later on. I'll let the pictures speak for themselves.


Packaging...


Front and rear coilovers... and hat...


Front coilovers (inverted monotube... very nice)...


Rear coilovers (not so exciting as the fronts)...


Front knob adjustment...


Another shot of the reservoir...


High pressure warning on external reservoir...


High and Low speed Adjustments on reservoir...


And finally the car they're going on...

[Faerus]

That is exactly the way my car would look if I had done a 240sx LS1 swap, beautiful car man! Good choice on the coilovers as well . Do post some pictures of it on the track once you get it back and running.

[ChosenGSR]

That's one clean looking car.

[mmdb]

Hey thanks for the complements guys. The car's been through a lot and I've asked a lot from it, and it still keeps rollin'. Here's a picture of when I took it to Fontana Raceway.

[epj3]

Wow very nice!

[M52 POWER!]

I'm having a issue with my rear ride height adjusters. During medium speed up-hill turns I hear a clunk/clink in the back telling me the spring/seat is shifting.

Yesterday I was mounting new tires and inspected the new suspension in between. It seems the rear driver side adjuster is binding up and tore the "slip rings".

Is there any solution to this?

Cell phone pics:





Passenger side is perfectly fine:

[Danny318]

what do you mean slip rings? the threads that the adjuster screws on?

[Danny318]

I like the adjuster on the bottom, it fits good over the little nub on the lower control arm with no spring pad, then spring pad on the top.

[M52 POWER!]

what do you mean slip rings? the threads that the adjuster screws on?

By "slip rings" I mean the 2 rings that let the spring "slip" or rotate as the suspension compresses.

So nobody else has clunk/clinking issues as they turn, back out of a driveway with a dip etc??