User 41221

Is there any reason to not take this a step further? Instead of reusing 951 spindles and control arms, why not find something strong/better and swap the whoile thing in, and just redo the mounting points? Street rodders do this sort of thing all the time and aside from having to play with aignment geometry, its all pretty basic stuff.

Regards,

vt951

Thanks for posting those dimensions. Must be nice to be able to use a cmm for stuff like this!

I would say most cars are lowered 1.5 - 2 inches. My car has the 250# weltmeisters and it is supposedly 1.25" drop. Most cars I've seen with coilovers look a little lower than mine.

EDIT: I just looked at the Paragon info on my springs, and it says 1.25" drop, not 1.5".

xschop

I'm going to do the spindle shafts from 4140 in the 87-up shaft dims. I'm still considering the Early strut mounting dims though...more positives there.

Olli Snellman

What model year RX7 arms are those?

sillbeer

Those are "early" dubbed Series 4 (1986-1988) control arms. Just like the 944, the "later" dubbed series 5 (-1998-1991) rx7s have built in ball joints. Both series have aluminum arms, its just that the S4 arms have replaceable ball joints like the early 944s. No change in suspension geometry between series.

xschop

I've done 3 sets already. The vulcanized factory rear poly-u has to be milled off because there is a hidden inner compression ring. Try hack-sawing by hand and you are within mm's of the inner arm alloy....



RX7 to 944 Ball-joint positioning programmed, using 1/2" thick 4130 (this is thicker than the stock RX7 B-J arms even)




The difficult task was getting the Porsche frame rear control arm area to mate to the Beefier RX7 polyurethane isolators while maintaining pivot length congruence...had to brake out the billet block on the CNC

vt951

How will you adjust caster?

Nice job on the cnc'd blocks. Pretty.

xschop

They are at 0 (as if caster tab is straight down)
I'm building this one as a daily driver, If I were to track it, I would build some camber/caster plates up top with monoballs and thrusts.
Have you ever taken a good look at a 944/951/958 spindle M030 spindle as well?
Porsche designed this car with the spindle shafts already behind the B-joint points at a specified distance so the caster bolt is fine tuning for people with OCD.

xschop

Does anybody know where to find the info on the M030 spindle difference. I asked about this in another M030 thread. I had a set of M030 spindles a few months back, but not the hubs. I thought I had read somewhere that there was a 3mm difference in the shaft or the hub offset between the 87-up spindles (I know about the 130mm radial caliper mount difference)....FYI, it wouldn't be difficult to make a bracket that converted 87-up spindles to the m030 radial mounts... The spindle drop design I'm working on hopefully will allow Turbo and M030 caliper ear brackets to bolt right on and interchange between the two....The 3mm or so difference can be made up in the radial mounted adapter....someone here knows this info....

sillbeer

I am VERY interested in this, being as I am an RX7 enthusiast and a P car enthusiast. I have my early 944, and an 87 FC with a 6.2L V8 . RX7 control arms are a dime a dozen and dirt cheap. Usually selling for less than $40 set used, and the S4 arms (as these are) have replaceable ball joints. Are you going to be selling this as a kit? if so, any idea on the ballpark price?

I would be very interested to have adjustable for late or early offset arms and have the ability to run Porsche spindles in either turbo or m030 trim. This would really open the door for the na and turbo guys alike.

xschop

I do have an extra set of adapters if you want to build your own set. Just get the RX7 arms. Like I said, you'd need to take the arms to a machine shop and mill off that inner compression ring. As for the spindles, you can contact me when I have them done, I always make copies of everything I do. I can't quote prices here either, but they will be less expensive to build than buying a set of M030 spindles by a long shot... I promise they will be stronger than the factory ones too where it counts at the spindle shaft. Looks like my drawings are coming up with Turbo and M030 caliper swap brackets on the same spindle....getting stoked

Olli Snellman

I am not sure did i get it right. I suppose all axial caliper spindles, 1988 951S and 1989-1991 951 ones are the same. Also 1987-1988 non M030 radial caliper ones are identical. Adapters which accept axial caliper for 1987/88 cars have been made for years. It's the different story if you would like to install late model Monoblock radial mount calipers to radial caliper spindles of 1988 951 S and 1989-91 951. If someone can produce such a adapter it will be a instant hit seller.
These pictures have been here too many times

Late model 6-pot GT2 monoblocks installed into 1987/88 axial mount spindle

xschop

What are the large rings with the square step for?

After doing the Lexus caliper/Boxster S rotor conversions, I discovered that the expensive M030 spindles can be sidestepped. The Lexus RADIAL mounted monoblock bolt throughs are also 130mm spreadwiths and they have large locating dowels that make them stronger than the Porsche stuff. What I ran into was the bracket design for the Lexus caliper is easier/better design for the 87-spindles with the 76mm caliper ears. I made a set for the 86T (94mm spreadwidth) and to get the offset correct, the Turbo ear tabs on the spindle hadto be trimmed on the outsides to accept the adapter bracket....
So IMO, an 87-up NA or S spindle with 76mm caliper ears is THE spindle to have on these cars and can be had inexpensively.

I just found the M030 info I was hunting down. The M030 hub has an extra 3mm on the hub face. So a stock 87 NA spindle AND HUB and an adapter braket with another -3mm Radial offset and you have M030 on the cheap.

964-C2

Do you mean the inner joints or the outer pin-joint (or both)?

xschop

VT's talking about the inner front and rear sphericals. The spindle ball-joint or pin joints both make hard contact so they are negligible as far a road noise is concerned.

Hey OLLI, what did you do for a master cylinder when going to the 6-pots up front..... or are the 6-pot piston surfaces equal to the 4-pots and you kept the stock Turbo MC?