Raising Spindles?

[Ferrino]

Something I am undecided on in the suspension part of my project, is whether to have the spindles on my Bilstein struts raised to compensate for the lowered car and larger-than-original wheel/tire diameter.

I am installing 21/27 torsion bars, with Carrera 22/21 swaybars. Wheels are 17" diameter, with tire size to be decided, but probably putting me at a total tire diameter of 25-25.5". I am going to guess that ride height will be around that region or slightly lower?

Question is: will I benefit significantly from raised spindles at this ride-height and tire combination? Car will be mainly street use for the next few years, with the occasional trackday. Is it actually even more important to have that extra suspension travel on the street, given the wild nature of our roads? It's around a $600 commitment to get it done (when you factor in the new rod-ends), so I'm thinking carefully about it.

One option is to just "suck it and see" with the stock spindle height - just fit some steering rack shims to dial out some bump steer for the time being and see how it behaves.

Has anyone experienced the same setup with and without raised spindles? I'd be interested to hear your thoughts.

Thanks!

[jpnovak]

I would do it. It helps stabilize the steering at lowered ride heights by putting a more correct matching angle between the a-arm and the steering rack. This way they both articulate at the same arc. An added bonus is the improved travel which is less of a benefit as you go up in spring rate (torsion bar size).

The lowered, relative a-arm position also helps with camber gain during cornering due to body roll.

Lots of benefits. The only downside is cost. Also if you raise too much you may limit wheel size choices in the future.

[moneymanager]

It's a nice improvement but you will never notice the difference on the street. Save your money.

[Flieger]

Unless you are running low with soft torsion bars. I have 22/31 on a car that weighs about 2000 pounds empty and it bottoms out the A-arms on the chassis if I hit a bump wrong. Car isn't even that low.

Raised spindles would help in my case.

[Craig_D]

I would, and did do it. Elephant Racing raised mine 30 mm and I'm running 21/28 hollow torsion bars with later Carrera sways on my 2400 lb SC. The travel is fantastic and I haven't bottomed yet.

The real test was driving near 70mph on a highway that was undergoing construction, when I drove into a 10 foot long patch, that fell away like a speed dip. I was waiting for a huge impact that never happened. Car soaked it up like a champ and never missed a beat. I was a true believer at that point.

Here's my build: '78 SC Elephant Racing Suspension Upgrade

[will hung]

I had rebuilt my suspension and lowered it without raising the spindles. The previous owner had installed bumpsteer spacers before I bought it. The front end was worthless. The camber curves were ruined, it would under steer everywhere and bumpsteer was horrific.

I bought a set of Bilstein struts and had Chuck raise the spindles 30mm and add the double shear bumpsteer bracket. I also bought and installed an adjustable bumpsteer kit from Chuck. Before installing the struts, I raised my front ride height back to stock. It is now lowered 30mm up front, but it now rides like a stock car, and the front end grip is excellent. I definitely recommend it if you plan to lower your car.

I looked at it this way, to correct for the ruined camber curves by being over lowered, I would have to add a ton of static negative camber. So then I'd be regularly ruining front tires. So very quickly I can justify the cost of properly setting up my front suspension.

[Cairo94507]

Raising spindles is the best way to maintain as close to original geometry in the steering and suspension so the suspension works as designed. I am raising the spindles on my project to the extent I am able, about 16-17mm, as I am running the deep six Fuchs wheels. The wheel is the limiting factor on the amount I am able to raise the spindle so we don't end up making contact with the barrel of the rim.

[Scheebs]

As most have said, raising the spindles is really very important to the overall handling and longevity of the shocks.
But if you keep your car long enough, as I have (40 years), you will tire of this setup on the road and want to go back to a more comfortable ride.
I would suggest sourcing a set of struts with this mod already completed, thereby saving your originals for that day in the future when sanity prevails.

[Ferrino]

Thanks for all the feedback. I definitely appreciate that it's the right thing to do. Something I am unclear on is how people calculate how much to raise the spindles. I see there are some basic guidelines based on wheel diameter, but surely it depends on tire diameter and ride-height too. I am not certain which tires and height I will be running until everything is down on the floor. It might make more sense to wait until then?

[OffCamber00]

Waiting is fine. Most of the bump steer kits are adjustable - they use different thickness washers/shims so you can dial things in once the car is at the desired height.

[will hung]

Originally Posted by Ferrino

Thanks for all the feedback. I definitely appreciate that it's the right thing to do. Something I am unclear on is how people calculate how much to raise the spindles. I see there are some basic guidelines based on wheel diameter, but surely it depends on tire diameter and ride-height too. I am not certain which tires and height I will be running until everything is down on the floor. It might make more sense to wait until then?

Raise the spindles the maximum your wheels will allow. The wheel sizes limit how much you can raise the spindles and that limitation will prevent you from going too far.

For 15" Fuchs, it is 19mm; for 16" Fuchs, it's 30mm, and for 17" wheels, 40mm is the rule of thumb. I raised mine 30mm because I have 16" Fuchs, but to be honest, I had to have my inner wheel weights repositioned further to the inside of the wheel because the ball joint retainer would rub against them. So waiting to be able to measure the gap from the bottom of your ball joint to the inner rim is a good idea.

Or if you want to be safe, since you plan to run 17" wheels, you can raise them 30mm. That is a lot of drop, will guarantee clearance, and if you ever want to run 16" wheels you still can.