IXLR8

I wonder what their spring lengths are compared to stock.

The reason for asking is a local has M030 springs on his Bilstein HDs and with the adjuster fully "up", his springs are loose within the shocks to the tune of 20+ mm when the car is lifted. He had a shop install them so he was unaware of that till he lifted the car.

bcameron59

Alex, mine do the same thing (Koni FSD with ROW M030), ie loose top to bottom when jacked up. I wrapped a couple of turns of duck tape around the bottom of the shock so the spring fits snugly at the bottom and won't tend to rotate while jacked up. That way (hopefully) when I put it back on the ground the top of the springs will reliably re-seat in the top mount, which is contoured to receive the spring in a very specific orientation.

IXLR8

Thanks Brian,

The latter that I bolded is his concern.

He already found the shock spring out of position with respect to the top mount, in fact even cocked over a bit.

I'm thinking a couple of spacers turned on my lathe to take up the slack. Something we can try.

As it stands at the moment, his car is sitting at 120 mm and that is with the collars at the end of their threaded range on the Bilsteins. That means he can only adjust his car lower and he is already quite low. He'd prefer the collar to be more in the middle of the range for adjustability.

I will be out there to verify. He had the rears installed last year by a shop. I never looked at them since all I did was install his front Bilstein HDs the other week. BTW, talk about an easy install. He'd like to sort this out before he takes it in for a full alignment.

Hoping for more feedback.

Ed Hughes

Yes, and some people's skill levels are such that the car shouldn't go faster than 45mph.

IXLR8

How true! All one would have to do is look at their driving record.

willus

To clarify, the front ride-height of the car is at 120mm with Bilstein HD's at the top of their adjustment range (HD version with only 10-15mm of thread) and RoW M030 springs?

I ask because I have the same Bilstein HD's with H&R springs (purple model, 29953 VA) and 120mm is as high as I can get the front. I was thinking of changing over to M030's, but if they have similar ride height...

IXLR8

No, the Bilstein HDs and M030 springs that he has issues with are the rear units.

He has the collars all the way up to the end of their range on the shocks and the max he can get in ride height (measured at the appropriate points) is 120 mm. I'll be going over to check out his set-up next week to make sure it isn't an operator/installer problem.

His main concern is the locating of the springs in the upper mounts. With the car off the ground, his springs are loose by the tune of 20+ mm. Brian (bcameron59) a few posts up noticed the same issue with his Koni FSDs and M030 springs.

Which is why it would be nice to know each spring's free length and also spring rate characteristic (linear or progressive). I had the opportunity to measure them in my last place of work, but early retirement sounded too good.

JB 911

That is low for the front, lower than RS which is 124/107. ROW M030 is listed as 144front 127 rear per of of Bill Verburg's charts. I realize you said you had the H&R's, but I wonder if other HDs have more thread? It seems if for example you bought M030's and HD's you ought to be able to get the spec'd ride height 144/127 out of them? Even if you chose to adjust them lower?

willus

Apologies for diverting the thread, but...

Yes, the front ride height on my setup is too low and I am trying to figure out which way to fix it. The previous owner installed Bilstein HD's (PN F4-VE3-4692-H0 and F4-VE3-4693-H0). The current generation of the Bilstein HD's has a much longer threaded section, as do those sold by Gert with the extra thread option. Either would certainly allow the front to be set at RS+10 or maybe higher with the H&R springs. I contacted Bilstein about getting mine rebuilt with more thread, but they would not do it.

I am confused how I ended up in this situation. 993 US front ride height = 174mm, H&R springs are spec'd to lower the front by 35mm, I should be sitting at 139mm; not 120mm. I wish I had measured the Bilstein HD + US stock springs when it had that setup, but I didn't. Once I started searching on the Bilstein HD + H&R setup, I found several old posts where people commented this combination was very low in front. My best guess is that my version of the Bilstein HD's were designed to lower the front of the car about 20mm versus stock struts, but that's just a guess.

gtroth

Wait. What?
To be that loose when jacked up kind of bugs me. It's making me rethink my whole plan (FSD+ROW MO30). Am I worrying too much?

Am I right in assuming US MO30 would better in that respect?

bcameron59

As far as I can remember, my old standard USA height springs did the same thing, ie were shorter than the space between the top and bottom mounts when jacked up.

The original springs were held in place on the bottom perch by a plastic insert (part number 11, drawing 502-00 in the parts catalog / PET). I surmise this kept the orientation of the spring so it would fit back into the contoured space in the top mount when the jack was lowered to put the car back on the ground.

However the new M030 spring / FSD shock combo didn't leave enough space ie was too tight to fit the insert, yet without the insert the spring was free to rotate at will and lose its position vs the top mount. A couple of wraps of duck tape filled the space between the shock and the spring, performing the same function as the old insert. See pic below.

bcameron59

This pic shows the contouring on the top mount. The end of the spring fits into the groove at about one o'clock on the outer rubber ring. Hope this clarifies a bit.

Ed Hughes

IMO you are worrying too much. It's really a non-issue.

bcameron59

Ed's right. Non-issue, unless you're planning to be airborne quite a bit...

CeeTwoS

Not wanting to highjack this but after reading this I want to know for a 993 2S are you recommending that replacement of the stock shocks and springs should be:

A. Koni FSD with RoW M030
B. Koni FSD with RoW M033

for someone wanting to get to the ROW ride height but not the really low look?

I use my car as a daily driver and I am on the CA freeways. I don't track the car but want to take some of the space out of the wheel well to make the car look more sporty.

Thanks for the help. I will doing all this replacement in June 2014, so thanks for the recommendations!

By the way, you guys are really giving great info with this thread!