X-Member Drop Down & BOLT-ON BUMP STEER KIT

IM HERE! sorry, too many forums to little of a lunch break.

this looks very nice, im pretty pissed that ive already bought new spindles thinking "PH tanked, fukit im running with bump steer until a future date"

the reason this bump steer pin is so vital is that with the drop of the xmember and the lowering springs you run the risk of your A arms cracking at the ball joints, to avoid this I put in a set of lowering pins (about an inch or so longer shaft on the ball itself). that put the steering way out of whack, the tie rods and the A arms no longer move the same way as they travel through the movement of the shocks, so the tie rod connection to the spindle needs to be lowered to match.
Kits exist but they are not for the 944, and are like 350 bucks, not to mention one failed on a guy cause he installed some parts wrong, they are a 3 peice setup with a tapered spacer, a cone spacer and a 1/2" bolt (not sure about that size but its smaller than the taper of the spindle and way smaller than 5/8"), the threads of the bolt in the wrong orientation caused a stress fracture to propogate and rust and eventually POP..... the 911 spun around and ground to a halt on gravel, nobody was hurt.
Xschop's design elimanates all the components (and potential failure points) by making it one peice.

crap, im actually out of time, I have to stop posting and pull up the site so I can read it after the lockdown lol.

Ok I am confused here I see the kit comes with spacers for the top of the struts(which would raise the engine compartment area) that makes sense to me.
What doesnt make sense are the other parts , what are they used for and where do they go? Couldn't you just stick with the spacers ontop of the struts if you had any clearance issues?

ffmedic wrote:Ok I am confused here I see the kit comes with spacers for the top of the struts(which would raise the engine compartment area) that makes sense to me.
What doesnt make sense are the other parts , what are they used for and where do they go? Couldn't you just stick with the spacers ontop of the struts if you had any clearance issues?

You need to raise the complete body, rear A arm mounts, crossmember mounts, sway bar mounts, strut mounts.

xschop I updated that old bmp I made that was stuck on the work computer:

I'm machining 1/8" holes on the bottom threading for Castle nuts as well. This will be The sweet set-up for the tie-rod drop solution. You should have your spindles drilled AND REAMED to 0.625" (5/8") exactly for a tight "slip fit". Once you have done this and have the bolt installed, it is inexpensive replaceable parts from there on.

the newer porsches actually replace that castle nut with a nylon locknut, might be good to just use lock nuts instead, the pins on the castle nuts would rust and then fall out.

I'm using stainless pins. But a 5/8-18 Ny-Lock nut can still be used if you'ld like

I actually already have a bunch of this hardware, I guess whichever is cheaper. The lock nuts mean you dont have to back them out to get the pin through... so it might mean everything stays snug, with the caveat that every time they are removed you need a new set. (man I have to get bins for all this stuff...)

Hey, so how is the Heim Joint protected from say water, dirt, dust, debris? Anything go over it or is it safe as is? Its now a very critical part of the steering system and if fails.....

Would recommend this protective boot???

http://ydoraa.bay.livefilestore.com/y1pCnbCVbPlEYOt0ubyndzdlChvc9qaOlWQ3QsrIF5ykYskv92OQTlUgc7LdTInbG_i7kKU75XFqule_7pFVIHe4hIrQQE56Yne/DSC05671

yeah, good call, it would be a good idea, its not exactly in a clean place, there are a bunch of boots and they arent expensive.

Bling Bling....
Modified my original cone design to get even more overkill strength in the 5/8" bump steer bolt....
I am drilling out my spindle's tapered steering knuckles starting with a 9/16" cobalt drill bit....
Then I will precision ream it to 0.625" (5/8") for a nice tight slip fit with the drop bolts. They are automatically set up for 3/8" drop, but can be spaced down to a full 1" drop......
I will put it all together this weekend and do a pictorial.....
PORH
POPP

Where do you get those boots?
They sell the ones that slip over just the front and backs, but I like those.

Well Friends, this journey is also over..... Fat lady sings another tune.....

From the drawings I posted, I only cross drilled the custom drop bolt at 90* for another cotter pin location for more adjustment/tightening.....Used only the best for the drop-bolt....4130 chromoly steel (95,000 lb/in stress)....


After setting spindles in vice and positioning the mating face perfectly flat....



I Drilled the spindle attachment CONCENTRIC 1st with a 39/64 drill bit......


Then I Reamed that drill hole with a new 0.625" (5/8") Reamer for an exact tight slip fit of the 5/8" drop-down bolt


PLENTY of spindle meat left with the beefier 5/8" shaft that replaces the 944 tie rod 12mm-13.5mm taper....


Everything bolts up beautifully and most importantly TIGHT....




Where's the beef!?.....Puts the stock 944 tie-rod shank to shame....


Side by side comparison of the upgrade. The Toyota inner tie rod fits the 944 Steering rack M14 x 1.5 threads and has the exact pivot offset.....


And the icing on the cake (besides $38 for the Toyota pair shipped).....Is the Inner rubber boot catch is machined exactly where the stock 944 boot catch is located!....


Almost forgot after this long post..........yeah you guessed it......P.O.R.H.

Damn that looks great! What year Toyota model etc was that again??? Very strong looking!

Think I can get the same results with just a 18 volt drill?

Heres the boots.

http://www.bakerprecision.com/rodacc.htm

About 5.00-9.00 bucks. Scroll to the bottom of the page.

Yes, I ordered a few sets from Dabay.
As a side note....There are Heim joints now that are Nylon-lined and Teflon-lined which are a cut above the plain hardened, zinc plated ones. They are nice and stiff in the spherical joint with no play at all. I have the Teflon ones pictured here. ($25 per set).....POPP

Good. The greaseable ones seem to have an affinity for dirt and start to seize. I was reading (offroad jeep stuff) that after a single winter, the non-teflon heims seized.

Dupont is making a semi-liquid teflon that you could add to the inside of the boots to help it out. Not sure if its needed, but for 25 bucks a set.....

ah! you folks beat me to it, I shall continue to drool over this hardware.
well done xschop! POPP.... and lock!

cant wait to install this, just gotta find a way to get the holes drilled around here.

oh and word from a trusted ME buddy of mine:

the reamer sold it for me
thats when you know he knows how to machine

Wow, I haven't checked in for a few days. That is a VERY impressive setup. My RX7 uses modified tie rods for bump steer correction but they are not as stout as those.

Well done.

Here is a little gif explaining why the bump steer kit is nescessary, forgot to add lowering springs to that but the second image (upper right) basically shows the effects of both the xmember drop and lowering springs.

What you really need to know on your car Tet, is the original relationship of the top hat mounting surface to the upper spindle mounting bolt hole on the spindle BEFORE the lowering spring was installed. After the spring install, take new measurement and subtract from the original....that is your drop.
I know what the 944 EARLY STOCK measurement is but not sure about LATE 944 measurement because I have the EARLY rebuildable Struts on hand.

good point, I dont have the spring compressors anymore but I bought the weltmeister 250LB springs that were suggested over in cricketville. does anybody know offhand?

So theoretically, if I put a 2" drop spring on this EARLY strut, the 20" measurement would now be 18"
To clarify, 20" measurement in the pic is exactly from the strut top mating face to the Center of the top spindle hole.

but the spring height is separate from what the bump steer kit would correct, the drop pin and bump steer kit simply brings the A arm and tie rod back into alignment after the drop, the drop distance should only affect the travel right?

If you drop the springs 1.25" you need to drop the control arm at the ball-joint 1.25" and the tie rod at the steering knuckle 1.25" as well.