RED.86.951

Here’s the deal, I am going to be installing my Bilstein coil overs on my 86 951 in the next few weeks. I see many users doing different things with their cars. Some remove the torsion bars completely, while others keep them and swap them out for different diameters.

Car use will be sunny day back road cruises, and SCCA autocrosses. I am not trying to be super competitive in the car just a fun hobby.

Your recommendations and comments are greatly appreciated.

xsboost90

i tried reindexing the torsion and using coilovers on my old 951 which made the car bounce around under braking when it would lift off the coil springs. Best thing i ever did was remove them and install racer's edge lower mounts.

RED.86.951

Good to know! thanks!

RED.86.951

$150.00 doesnt break the bank either. What is benefit with using these rather than just bolting them up to stock hardware.

MAGK944

FYI The racers edge mounts are designed for spherical bearings. I think your bilsteins have rubber so are designed for the stock mounts.

I used rears with torsion bars in the past and they really just act as helper springs. If I recall I couldn't go much above 100# on the coilover without reindexing and after that they got bouncy as mentioned. Went to full coilover and was happier.

If you are using this as a weekend cruiser, keep the rubber mounts and try it as a helper with a low spring rate. You don't say what valving you have so I presume you have the lower street valving.

The spherical solid mounts do transmit a lot of noise and you might find that annoying on a leisurely drive. Saying that I don't think you can retrofit sphericals to the bilsteins anyway, it's been a while since I used them and things might have changed.

944meister

I'm pretty sure you can send the rears coilovers to bilstein and have spherical bearings fitted, it would be well worth calling them to find out at the very least.

Darwantae951

The spherical mounts would be overkill on a street car. MAGK is correct. If it has a stock style lower mount, then it is designed to use the factory bolt. RE recommends increasing the torque value applied to the bolt for anti-shear reasons.

RED.86.951

So what it sounds like is...... remove the t-bars and run straight coil overs. my spring rates are beefy enough to handle it.

Dawgz83948

I just went from 150# rear springs to 300# with the coilovers. When I called and spoke to the guys at Groundcontrol they told me the rear spring rates are a little tricky to calculate. Basically it's 80% of 1/2 the rate. So basically a 300# spring = 300/2=150*.8=120# effective rate. Why? Well if I understand it correctly it's all about the angles. The shock bolts up at roughly the halfway point on the trailing arm, and since every 1" of shock movement = 2" of wheel movement (because of leverage) and then you must factor the angle of the shock because it's not straight up and down either. A Mechanical Engineer friend of mine looked at the angles and figured 80% because of the shock angles. If anyone wants 150# Eibach 2.5"x8" 150lb coilover springs let me know.

MAGK944

My daily driver has coilovers all around and handles smoothly yet firmly. I'm using:

200F (188 effective rate)
450R (189 effective rate)
30mm F 19mm R sways

The multiplication factor I used for the spring rates, (without torsion bars), using motion ratios is 0.94F 0.42R

Hope that helps.

xsboost90

i was running 450 front and 525 rears - alittle too stiff for street - perfect for the track.

Dawgz83948

HEHE I have 500# fronts and 300# rear in addition to the rear torsion bar. I'm very happy with it.

Darwantae951

I run 300 front and 500 rear on a street oriented t-bar delete set-up.

Opeth

Im running :
Billstien Shocks w/ Eibach springs: 550lb front 450lb rear
Ground Control Camber Plates
Racers Edge rear suspension bushings
M030 swaybars and castor blocks
no torsion bars

Its a firm ride but its also with 18's and she likes to hold the ruts.

944meister

What lower mounting bolts are you using for the rears? Stock? Just curious as I am considering bilstein coilovers in the near future.