Modifying Bilstein Shocks

[Hyper4mance2k]

Originally Posted by Kostamojen

Well... Attempting to modify the bumpstops is one of the worst mistakes ive ever made...

I'm stuck now with no car to drive until I can get a replacement shock...

Removing the nut was easy, but the shock WOULD NOT move. I tapped on it a bit and nothing so i gave up, but the threads were ruined so the nut wouldn't go back on. I tried to re-thread the shaft but my rethreader wont fit in that recessed area. So i tried a larger thread nut that i could just force on there so something would be there, but it decided to rotate the whole shaft and move it finally but by then the threads are so ruined that nut just spins. Now I'm stuck with the shaft partially pushed through and no way to get it to go all the way through or back out, its stuck

The good news is i discovered that the springs were just BARELY compressed, which means i need some "non-lowering" camber plates to help with the ride height.

Yup, there's your problem.
For future users, no amount of tapping, striking, hammering, or bumping will move the insert out of the housing. The strut insert screws in and out of the housing. You do not need a pass through socket for this. Since the insert is threaded into the housing, the nut will come right off, and the insert will not move. Then, you need to heat the insert and the housing until it is so hot you can't touch the housing without gloves. You have to literally (note: proper use of this word) melt the Loctite. I use a heat gun and let it sit on high about 4" from the strut for at least 5 minutes. I set them up and walk away. Once the strut is damn good and hot, you can insert an Allen wrench and the insert will screw right out of the housing.
Also, the Allen hole in the insert is very fragile, and super easy to strip. Take the proper sized Allen key and wrap a blue shop rag or paper towel and tap it into the Allen key hole. That will help with the clearances and allow you to put a bit more torque on the insert without stripping it. However, these should be installed with very little torque. Again, it is held in with Loctite, so you NEED heat to melt the Loctite in order to screw out the strut insert from the housing. If you have to put force on it, it's not hot enough. The Loctite will melt and it will screw right out. Loctite aside, they are screwed in just beyond hand tight.

[Kostamojen]

FWIW I just found out the bumpstops for the B14's are about 1.5" but are EXTREMELY hard. I'm having the shocks worked on now to repair my damage, and got the info.

Also, I'm going to be running Ground Control camber plates and trying out a little trick I figured out to increase the front suspension travel so stay tuned, might have to start a separate thread about it

[Rameus]

Originally Posted by Shankenstein

I was really confused about how to disassemble an inverted shock, and seeing the Mini Cooper setup helps demystify it.

I'm still not 100% clear on the process of de-pressurizing and re-pressurizing the gas behind the separator piston. It looks like the system is designed not to need pressurization. Once the separator piston makes the seal, the gas behind it gets compressed 10-15x (150 - 220 psi). This is the right range for shocks anyways... so it may not need to be "filled" in the traditional sense. Obviously, nitrogen (or atleast dry shop air) would be used.

Did you ever figure this out, @Shankenstein?

This would seem to be the last piece of the puzzle to pulling off a DIY revalve on a set of Bilsteins for our car.

It would not be easy to compress the gas chamber while assembling the strut. One would have to somehow hold the separator piston deep inside the strut tube (maintaining the probably ~200psi*~1.5in^2 = ~300 lbs [rough estimate assuming 200psi gas pressure and 36mm piston diameter, no idea if true] of force on the separator piston), then simultaneously insert the valve piston + rod, fill with oil, and somehow install the strut tube rod guide/seal and bleed the oil at the same time. That sounds nearly impossible. Perhaps there's a way to inject the oil into the oil chamber under pressure after everything has been assembled, thereby forcing the separator piston down and compressing the gas chamber?

While looking for an answer I also found these alternate options (ctrl+f "strut" and you'll see the pic, read the blurb above it too): http://farnorthracing.com/autocross_secrets18.html

I don't like the inset schraeder valve option that much, especially if one wants to cut their bumpstops. Gun drilling the stud to install a valve would require a large stud, and thus also custom top mounts or at least new top mount bearings.

Last thing: I seem to remember Shaikh from FatCat mentioning a special tool used to assemble struts, but I can't find that video anymore. Maybe there is some sort of injection tool or something?

[Kostamojen]

Got my Bilsteins back from repair courtesy FRSport. They were revalved and bumpstops shortedned. Plus you can see my new camber plates. I'm going to try something unique with the camber plates too. Won't be installing these for a week or two though.

The valving should work even for stiffer springs if I choose to go with those later.

Photo of the shock dyno:



Pics:

[Ro_Ja]

Sweeeeet. I think I missed it earlier - what rates did you select? And you left the rears alone?

[JoeHK]

Damn they look beastly!


Sent from my iPhone using Tapatalk

[Rameus]

Originally Posted by Kostamojen

Photo of the shock dyno:

Would I be correct to assume each gridline along the x-axis is 1 in/s?

They sure look nice.

[Kostamojen]

Originally Posted by Ro_Ja

Sweeeeet. I think I missed it earlier - what rates did you select? And you left the rears alone?

I went with 225 fronts. Rears I havent done anything with yet. I might go linear 325 rears eventually if I dont like it how it is.

Originally Posted by Rameus

Would I be correct to assume each gridline along the x-axis is 1 in/s?

I have no idea whats going on with that chart actually LOL

[Ro_Ja]

Originally Posted by Kostamojen

I went with 225 fronts. Rears I havent done anything with yet. I might go linear 325 rears eventually if I dont like it how it is.

Well, when you get them on and have some miles on them, let us know what you think. I spoke to our shock tech at my work and he came back with a range of about 250-275 front and 300-325 rear, so it sounds like we're basically on the same page.

What's your wheel/tire setup? Stock sways?

[Kostamojen]

Originally Posted by Ro_Ja

Well, when you get them on and have some miles on them, let us know what you think. I spoke to our shock tech at my work and he came back with a range of about 250-275 front and 300-325 rear, so it sounds like we're basically on the same page.

What's your wheel/tire setup? Stock sways?

17x9"s with 245/45/17 RE71R's
Strano front sway with Whiteline endlinks
Stock rear sway with Kartboy endlinks

A stiffer front spring at 6" with helper springs would probably work best for most people.

[AJ124]

Originally Posted by Racecomp Engineering

If you guys are able to wait just a couple of weeks, we may have something interesting for you.

- Andrew

Any updates on your new offering RCE?

[Markiv]

Originally Posted by AJ124

Any updates on your new offering RCE?

If you didn't see it earlier here you go:

Originally Posted by Racecomp Engineering

I'll spill the beans a little bit. We will be releasing a custom valved Bilstein non-ajustable coilover soon with 400 lbs/in springs (linear) soon. Price is more than B14s but remember these are custom valved with custom linear springs. From our testing...AWESOME ride quality and performance that's great too. Good simple fun set up.

- Andrew

[Shankenstein]

For those keeping an eye on Bilstein upgradeable coilovers, the current catalog has all of the piston shafts/rods listed.

Non-adjustable: $35
Single-Adjustable: $285
Double-Adjustable: $421

By offering a non-adjustable setup, RCE is saving the customer $1200 on a set (in parts with no markup). I'm sure they (or GTWorx) could make a tricked-out setup if you'd like.

Personally, a square spring setup won't dance (oversteer) eagerly enough for my needs (400/400 is 2.5 Hz front, 2.1 Hz rear)... but it will be forgiving and confidence-inspiring for those who enjoy spirited driving and autocross (STX). Power oversteer will still be a thing, but you can stay on the jagged edge with confidence (just like the Tarmac 2 coilovers won over Randy Pobst).

[AJ124]

Originally Posted by Markiv

If you didn't see it earlier here you go:

I did, was hoping if they had any news beyond that .