Unforeseen issue with raised spindles...

Fly911 · Fly911's Garage

The first thing I did when I got my '87 Carrera 5 years ago, was to replace the torsion bar suspension and brakes. I went with Bilstein coil overs with Eibach springs, and a full 930 Turbo brake set up. The front struts were modified (Rebel Racing) with 1"+ raised spindles and reinforced steering arms with bump steer elimination. I also got a set of Rota Fox wheels, 7.5"x17"ET36 and 9"x17"ET16. So far so good...

Here the other day I was working on another front suspension mod (lengthening the control arms 20mm), when I realized that raising the spindles has moved the control arms down accordingly, they barely clear the inside of the 17" rims.

My motivation for the 930 brakes was to use 15" wheels for the track, but now I need to stick with the 17" wheels, there is no way I can get 15" (or 16") wheels to clear the control arms.

Are there other ways of lowering the suspension, and still get the correct steering geometry, without raising the spindles?

Sebscst · 12-12-2016, 01:19 PM

I have pretty much the same setup my spindles are only raised 19mm and i can fit my 15" fuchs. Theyre tight but fit. Your 17" should fit easily.

Cory M · 07:23 AM

my spindles are raised 29mm and decambered 2 degrees, 16" fuchs fit, barely

DanielDudley · 12-12-2016, 04:31 PM

Sounds like a 16 will fit, but a 15 won't.

tirwin · tirwin's Garage

Quote:

Originally Posted by Sebscst

I have pretty much the same setup my spindles are only raised 19mm and i can fit my 15" fuchs. Theyre tight but fit. Your 17" should fit easily.

I think his problem is the 15s don't fit with that setup.

When I raised my spindles I had 16s and hadn't gone to 17s yet but I was planning on it. We discussed 30mm might be tight with the 16s so we only raised it 25mm. I can see where that could be an issue with 15s.

Would a spacer possibly help with the 15s? (assuming you have room?)

stownsen914 · 12-13-2016, 03:47 AM

It does look pretty close with the car jacked as in the picture above. How is the clearance when the car is at its normal stance? The clearance will be less when jacked due to the angle of the A arm. If that's the case, one option might be to put some droop limiters. Not common on street cars, but it might work.

As for other ways besides raising spindles to keep suspension geometry closer to normal, smaller diameter wheels/tires are the only other option I can think of.

Scott

jpnovak · 12-13-2016, 03:53 AM

15" Fuchs wheels will only allow you to raise the spindle about 17mm. If you trim the outer seam and radius the ball joint castle nut you might be able to get 20 or 21 depending on your individual wheel and how thick the barrel is. However, this is reducing the clearance where it might rub under extreme load. Too close for me.

KTL · 12-13-2016, 11:09 AM

Sorry in advance for the off-topic question. But I have to ask, is that sway bar drop link U-bracket attached to the A-arm by drilling thru it and bolting it in place? Doesn't seem like a good idea to drill a hole in the suspension arm like that.

Regarding the raised spindles, I measured the front of my '86 911 with Boge struts and 16x7 wheels. I came up with around 25mm of clearance allowed, leaving a little bit of clearance for, well, some clearance and not cutting it too close. With that said i'm not trying to indirectly say Cory's numbers are wrong. I'm sure I could get another 4mm if I wanted to make it reaaaaaaaaaaaly tight.

Cory M · 12-13-2016, 11:42 AM

Mine are Bilsteins, and it is extremely tight but it fits, maybe it's different for the Boges? I've seen guys grind the edges of the control arm around the balljoint to gain more clearance.

Elombard · 12-13-2016, 12:52 PM

I think you can send the struts back to clint and he can move the spindles back down to where they would clear 15"s. it might be easier to sell those and get a new set of struts to start with.

piggdekk · 02-12-2017, 04:39 AM

I've always wondered, wouldn't it be possible to machine a bit the spindle and weld a threaded pipe on the strut to make the spindle adjustable in height? it doesn't look imposible to me, but I have no idea of how much one would need to machine from the spindle itself to make it slide over the threaded section. Alternatively one could remove a section of the strut and weld a threaded pipe, but that looks more involved.
Has anyone ever tried it?
luca

mreid · 02-12-2017, 04:46 AM

I believe the factory approach was to raise them 19mm on the RSR. That's what I did with my coil over set up from Clint. They cleared 9"x15" Braid RSR wheels, but I later went with 17". Not only better handling, but better tire choice.

KTL · 02-13-2017, 07:41 AM

Smart Racing Products used to offer a front strut assembly from Fox which had an adjustable spindle height. You can see in the picture it was a clamp bolt in the rear to allow the adjustment.

RichardNew · RichardNew's Garage

Am I looking at Rebel Racing front torsion bar bushing?

It looks as if you had to create the same washer stack that I did.

Richard Newton
An Endless 911 Project

piggdekk · 02-13-2017, 09:27 PM

Quote:

Originally Posted by KTL

Smart Racing Products used to offer a front strut assembly from Fox which had an adjustable spindle height. You can see in the picture it was a clamp bolt in the rear to allow the adjustment.

I think the clam bolt is a bit too crude, would You trust it?

I was looking at Werks911 web site and they produce some sleeves for coilover conversión:
Coilover Parts-911 Sleeve Kit For Bilstein Front (Springs Not Included) Pair 1965-89 | Werks911 Porsche Parts

Maybe similar threaded sleeves could be used to change the spindle height? Reason why I'm asking is that I have front Koni struts with alloy calipers and I would like to have 2 options: one for rally (lowered spindles, 50 mm?) and one for track (raised spindle 19 mm). Those struts are really hard to get by, so I don't want to look for another pair!
However now You got me thinking. Maybe a much simpler alternative is modify the spindle with a couple of clamping bolts and then machine a couple of clamps to be bolted on the strut to keep the strut from moving axially?
luca

piggdekk · 02-13-2017, 10:57 PM

thinking more...
I don't like the clamping bolts because I'm afraid they could break and/or damage the struts. However, to better spread the load, one could weld a clamp on the strut at the highest spindle position (+19 mm), this would work as a stopper to keep the spindle from moving further up without having to load too much the clamping bolts. Then when going -50 mm one could machine a pipe with ID same as the strut OD and 69 mm length and slide it between the spindle and the welded clamp for the "rally" position.
does it make any sense?
luca

KTL · 02-14-2017, 08:35 AM

Well Smart Racing provided top quality parts and the owner was directly involved with Porsche pro racing for a long time. So he knew what was required in providing well designed parts. If Smart Racing felt that the clamped spindle was OK, i'd tend to agree with them.

I suspect Smart Racing partnered with Fox and had Fox build them a strut to their specs. Fox has been building top quality suspension parts for a number of years. So I don't think they'd put their name on something that wouldn't perform properly? https://www.ridefox.com/

Yes I follow what you're saying with the upper collar at the max. height to set your raised position. Then when you lower the spindle to rally position, your inserted spacing pipe can provide that same safety support you're looking for.