TheOtherEric

So if the static height was the same, yet they lower the car an inch or whatever, then that means that they have a lower spring rate than stock US M030. So pairing Eibachs with HD shocks would seem less than ideal, since HDs are meant for stiffer springs. Unless I'm missing something there.

smddanny

Othereric:

I dunno what ride height I would have had if I installed the eibachs with the oem shocks. As you pointed out earlier this wouldn't have been a grand idea. I was quick to throw the oem shocks away.. that act gave me great pleasure. The hds had an adjsutable perch height as you know and I am unsure of the relative perch height difference between the oem and the hds now. I am 2/3 of the way to rs ride height front and rear. This was dictated by the rear perches which are most of the way to full up... I do think the spring rate of the eibachs is higher than what than the oem M030 I just can't quantify.

Danny
96 993 tt

Greg Fishman

Unbelievable that rennlist could put two fraternity brothers in contact again. Amazing!

Butzi

Phi phi! To the Garnet & Gold!
Gamma Delta Chapter-now dead-(UofAZ).

Jukelemon

Phi Phi back my friend. Kappa chapter.

I'll buzz you Greg. Take it easy.

ChrisA

I bought the ROW springs from 2 of 2 and added HD's. Completed the instal last week but just got the car on the road today as I also completed the SAI port clean. Suspension instal was easy and based on the limited driving till system settles in and required alignment, wow... What a difference, the car is back on rails, the old shocks were gone but the transformation is amazing. Car is now lowered aprox. 1.5 inches and there does not appear to be a problem with curbs or major bumps. Have not pushed it much till the alignment is complete, but would highly recommend.

tj90

I currently have the M030 shocks, sways and eibach springs. Ride height is very low - maybe a little too low for most tastes - but I like it. I think the data sheet says that the car height drops 1.3 to 1.5 in using the eibachs over stock springs. As far as ride goes, Im happy with the suspension, but after driving a bilstein equipped car, I realize that I have no dampening - so I conclude that my shocks are shot.. Driving N into the San Fernando valley from LA on the 405 and the car handling stinks in the fast lane where the pavement is bad. I would assume better dampening would improve this..

Im thinking of upgrading to HDs since 90% of my driving is on the street. Does anyone know if ride height is going to change? I believe that others report that HDs will raise the car height.

Jukelemon

I just don't follow how the shocks will create a height difference unless they are not identical in mounting specs and this can only be for the front. Springs set the ride height of the vehicle and the shocks set the dampening i.e. a shock does not have the ability to "hold" the vehicle at a certain level. Its job is to manage the spring rate in/out of compression.

Am I off on this guys or ??

allill

the bilstein hd's they are talking about have threaded bodies (coilover).

InTheAir

You are correct. I haven't reread this thread to see who might have been supporting a position contrary to what you just said, but suffice it to say that you are correct.

That being said, the shocks themselves can be used to set the ride height because the shock bodies carry the lower spring perch upon which the springs rest. The stock shocks were essentially nonadjustable from a ride height perspective (....yes, the fronts had some minor adjustability in perch height, thus permitting minor ride height adjustment). The aftermarket shocks, namely Bilstein, have the threaded bodies that permit the lower spring perches to be set at an desired height, thus permitting the ride height to be set.

So, the shock mechanism does not set the ride height, but the threaded body of the shock does permit setting of ride heights.

tj90

Jeff - thanks for the clarification. I have heard and read on old posts and pcar.com that the old Bilstein shocks may not have had enough thread up front to adjust the spring perch, but that problem has gone away on newer Bilstein shocks. I did not realize that it was the perch, I was unsure that the piston itself was raising the car.

With that said, it seems that Danny is saying that the Eibach/HD combo works. I read on the Eibach pro kit information that the springs 7209 and 7208 for the 993 are designed to have progressive spring rates and designed to carry the same maximum load as the stock suspension. Since they achieve same max load with the same unloaded -static - stack heightv as M030 but yet lower the car, Ive got to think that either the spring is slightly softer than stock in the initial compression (car weight only) and they get progressively stiffer faster than stock as the springs reach higher compression. The eibachs are designed to achieve same max load as stock springs. I guess the primary advantage to eibachs over stock is the overall lower CG of the car. Not sure how the well the eibach progressive spring rate matches the bilstein shocks compared to OEM springs..

Also, eibachs are heat treated and guaranteed to never sag for a million miles. If anyone has sagging issues over the life of the car, send them back.[/QUOTE]

Jukelemon

Exactly.

That is what I was getting at i.e. it always the geometry of the spring which takes into consideration the mounting structures-regardless of whether they are on a strut or the chassis.

InTheAir

With the original HDs, there was not enough thread to lower the front of our cars to RS ride height when using the ROW MO30 springs. Therefore, we would lower the fronts as low as they could go with the short-threaded HDs and then set the rears to get the correct suspension profile.

Gert at Carnewal approached Bilstein Germany to manufacture special HDs for him to include more threads on the front, thereby permitting more lowering with the MO30 combination. That's why everyone pretty much went to him to get the HDs.

However, Bilstein US liked the idea and because they are pretty much autonomous to Bilstein German, started selling all of their HDs with the extended threads in the US by default. Therefore, about 2 years ago, the HDs in the US started showing up with the extra threads. This was all realized when I organized the suspension group buy.

So, now, the HDs with the extra threads are more accessible and provide the necessary lowering for the MO30 springs.

Nickels

Phi, Phi back at ya a 3rd time...Eta-Beta Chapter, Seton Hall

Slow Guy

Koni makes a very good sport shock for the 968 but Bilstein doesn't make a shock for it. Maybe they got together and divided up the models (just kidding).