ThunderC4S

I just purchased from my recent USA visit some Bilstein HD's and H&R Reds.

What initial height/thread setting should I set the spring hangers on the Bilstein HD's ?

As for the alignment - Shoud I go factory ROW Turbo 3.6, RS spec or something else ?

Rgds,

ThunderC4S (John)

Metal Guru

I did RS height in the rear and a 10 mm lower than RS in the front, reason being that I still had bump steer at the RS height and lower looks better
As for settings I went with factory values for toe (-25' in front, -15' rear each side) camber - 50' front and -1deg, 10' rear, which is an aggressive street set-up.

cobalt

Hate to argue with anyone but you can't achieve RS height with Bilstein HD's and reds.

ghhally

Sorry Cobalt,

prove is sitting in my garage. Bilstein with red H&R at RS spec ride height.

cobalt

I have the same suspension in my car and it's at it's lowest setting and I am far from RS spec. Maybe we need to clarify what RS spec is. Unless you cut the springs the Reds will only drop the car 1.4 " front and 1.3" rear from US spec. The bilstein's with the reds will not lower the car more than the PSS9's which are the same as the H&R coil over kits and they will lower the car a max of 1.7" f/r. So the most you can drop a Turbo from US spec is 1.7" front and rear using this setup. This does not allow for corner balance adjustments. To achieve RS spec ride height you would need to drop the front by 1.96" and the rear by 2.44". US spec turbo is measured at 175mm front and 280mm rear RS spec height is measured at 125mm front and 218mm rear. Not sure how you can achieve what others cannot without major modifications.

http://hrsprings.com/scripts/appguide.php?Mode=Application+Guide&SubMode=Find2&Year=1994&ModelID=382& q=1994%20|%20Porsche%20|%20911/964%20Turbo

I will caution you that if you use wheel arch measurements and compare narrow body measurements to widebody they will not correspond. I have both my C2 and turbo set to the same spec and the measurements to the wheel well of the turbo measures about 1" lower than that of my c2 due to fender flair design. BTW The H&R's are universal so they would not lower the car more for ROW cars than they do US spec cars. Less change in overall settings would be achieved since ROW 94 turbos are set to 155mm front and 260mm rear Min setting on either US or ROW cars should be 132mm front and 237mm rear max not RS spec which would be 125mm F and 218mm rear

I am adding a pic of a rennlisters 1992 turbo S which uses the same settings as the RS. These cars like the RS used special short dampers and springs along with some other components to achieve this lowered stance. I believe if you look at the picture even your avatar shot does not look as low as this car does.

ghhally

Back from the garage, and i have in the front at both sides 126mm measured at
the bolt near the inner wheel as per Porsche service manual.
Unless Roock motorsport has mounted an other type of RED H&R (which I repainted black during the winter unfortunatly without retieving the partnumber first), I would say you still can achieve RS height ( same as Metal Guru). I must confess that the lower spring is pretty low.

cobalt

Your car looks to sit about the same height as mine and IMO from the pictures your rear is no where near the 218mm rear RS spec or close to the turbo S pic i posted which is RS spec height.

Here is a pic of my car with the greens in it before I switched to the reds. As you can see mine are adjusted as low as they go and I was barely able to achieve 137mm in the front. It would appear the coating on your springs had degraded and if the spring began to rust they might have sagged a bit. With the reds in my car I am at the same lowest settings and again I am just about at 137mm in the front and no where near the 218mm in the rear. My car sits about 240mm rear since it was last adjusted and I can assure you with new shocks and springs this is as low as a 964 turbo can go using Bilstein HD's and H&R reds.

cobalt

Here is one move comparison for you. here is my C2 with same Bilstein HD's and H&R reds set to lowest setting. vs a picture of an actual RS. You can see the difference in stance is quite noticeable. The gray car in the foreground is set about the same as my car and is sitting on 18" speedlines the white car is an RS on 17" cups. As you can see the difference is considerable.

ghhally

Thx for the comparison pictures! Will remeasure the back end over the week end and will take some side view pictures.

Metal Guru can you elaborate how you achieved sub RS height in the front?

Metal Guru

I have H&R springs and shocks.
When I purchased my car it was 116 in the front (measured at the front crossmember bolt head) and 226 at the rear(measured at the casting boss on the rear trailing arm). In Adrian's book he lists RS height at 125 in the front and 218 in the rear. He shows the same values for the Turbo S but I believe that the S was possibly 15 mm lower in the front.
Even at 116 in the front there was two inches of thread to go so I could have dropped down to "S" height with no problem.
Here's a picture of the car before I raised the front:

ghhally

Quite similar to the stands on my car.

stu.p

Best in my opinion with this set up (bilstein hd's h and r springs)
Go as low as you can with the front(even out on both sides) then set up rear after that so that the car has a few degrees downrake(nose slightly pointing down)
Then set camber/toe etc to suit your driving style/needs!
I personally went for 3.3 "s" settings for camber etc,less understeer,better turn in with some lift off oversteer for good measure or feeling brave power on oversteer
Good compromise for street with occasional track use!

__________________
Porsche inspector for Peter Morgan UK
http://www.petermorgan.org.uk/inspection.htm
"92" 964 turbo,recently rebuilt using all ARP hardware.Modified heads,SC cams 1 bar boost,headers,wastegate/ tial 0.8 spring to acheive 1 bar,cat bypass,own adj wur,rpm switch,powerflow air intake..bilstein hd with h&r springs,front carbon strut brace

Metal Guru

Two problems with that statement:
(1) Very little suspension travel at the lowest setting, making for a bone-jarring ride
(2) Really bad bump steer

stu.p

If you look at the pictures of the 2 examples above you will see that like mine the front settings in both cobalts and ghallys cars have nearly no thread if at all any showing which is the same as mine and it feels absolutely fine to me and is not a bone jarring ride in my car!

Excessive bump steer NOT an issue for me like this either!!..i test numerous of these cars and i find it perfect...so no problems here!
Shame you dont live over here in the uk because you would be more than happy to test for yourself!
__________________
Porsche inspector for Peter Morgan UK
http://www.petermorgan.org.uk/inspection.htm
"92" 964 turbo,recently rebuilt using all ARP hardware.Modified heads,SC cams 1 bar boost,headers,wastegate/ tial 0.8 spring to acheive 1 bar,cat bypass,own adj wur,rpm switch,powerflow air intake..bilstein hd with h&r springs,front carbon strut brace

Boeing 717

Hey thunder that looks like sweet sweet pieces of candy!!!