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

This kit allows you to drop the 944 X-member for engine to hood clearance and correct the steering geometry without having to install custom ball joints or bother with the tie rods. You are effectively raising the car by the same amount you drop the X-member....CNC machined billet steel and aluminum. You will need to purchase the Xmember and rear control arm longer bolts ($12-15) at a local hardware.
3 week lead time. All Hardware included. 1/4 to 1" custom made to order... PM me for details....
If you want to build yourself, I will post dimensions to the strut spacers.

That looks great. I just wished you would of had this done before I installed the Camaro front springs in my car. Yes I said Camaro. They fit with just the pig tial cut off.

Did that raise or drop the car?
Whatever works is a good idea......You know my motto.....POPP

I just leveled the car out. When I first put them on the car was about 2" nose high. after a few cuts I got it down to a respectable level.

Before I was so rudely interupted and lost all my stuff on this project. I went back this weekend and recalculated the custom rod needed for an inexpensive and super strong Tie rod drop down swap (bump steer).....

I am assuming that the late 944 tie rod is 1.1" longer than the early 944 tie rod as noted from a ****list discussion.


You have to drill your spindle tie rod inserts to the beefy 5/8" shaft diameter

****************EDIT****************
The fat lady started singing......... Final design is done.....
For this bolt design, the 5/8 Heim-joint automatically sets the tie-rod down 3/8"
Just machine some spacers out to size and drop the tie-rod down up to a full 1.00"

The Part #es2279R is actually a Mcquay Norris part# on the box from Autozone...
These Toyota inner tie rods all have the rubber boot catch machined at the exact location as the stock 944 inner tie rods!

You mention the amount of spacing is variable and up to the user. How do you best determine the necessary spacing? Do you have to mock up the engine in the car to check for clearance?

No, the spacing down at the spindle bolt is determined by the thickness of your X-member spacers and rear control arm spacers.

I think I'm confused. I thought the spacing of the subframe mounts was variable according to the user's spec's. Is this not the case? Does the LSx require different spacing than the LT1?

Are you talking about spacing for the tie rod ends and spring hats?

there are 2 different ways to go about it. The very first pic is a complete simple bolt on solution (top hats)to make up for the droppped X-member.
The 2nd route is more extensive, you need a tie rod drop, a ball-joint drop, along with the X-member drop and rear control arm drop all dropped the same distance. Most people get away with 1/2" but some have hood clearance issues unless 3/4" drop is done. ( I see Scott from Renegade just mentioned this on PHB).....I have a 1" X-member drop (which technically raises car 1") because It will help when I stick on 18's. Hope this is clear....Rob

If anyone knows him from the other GESTAPOville. Could you tell him I've cracked the code here, Thanks

Hi Guys,
Made the trip over. If anyone is unclear on bump steer and the ramifications, there is an excellent article in the April edition of Race Tech magazine.

Welcome Al!

I don't have that mag...here's the best info I could get on bump steer.

From HPBooks “How to Make Your Car Handle”
by Fred Puhn

Adjusting bump steer is an advanced suspension tuning technique, and often makes the difference between average and outstanding handling. Many elusive twitches and wiggles can be blamed on bump steer, and often it is the cause of high-speed stability problems. Bump steer is the change in toe setting as the wheels move through full travel. It can happen at front or rear. Ideally, you want zero bump steer-the toe setting should remain constant no matter where the suspension moves.

How to diagnose and adjust bump steer:

First you will need a tool to check bump steer. You could use a toe gauge, but a bump steer gauge is easy to construct, and often a lot easier to use. Below is a diagram of a home-built bump steer gauge.



You can build this handy bump steer gauge out of two pieces of plywood, a piano hinge, two bolts and four nuts. The gauge is positioned on the floor, held by a heavy item such as a battery. The gauge can have several hole patterns for various size wheels. Adjust the bolts so they contact the wheel rim. If more accuracy is required, substitute a dial indicator for one of the bolts. This gauge measures changes in toe, not the actual toe setting.

Diagnosing bump steer

To check bump steer, remove the springs so the suspension may be moved through its full range of travel. With the tires resting on the garage floor, the car chassis is moved through its full range of travel with a jack under the frame. On some cars, it may be necessary to place blocks under the tires, so the frame can be lowered to its full bump position with the jack. Do not attempt to go beyond the normal range of suspension travel.

Start with the car at full bump position. Make sure the bump steer gauge has both bolts against the wheel rim. Raise the jack ½” and look at the bump steer gauge. If both bolts are still touching the wheel rim, there has been no change in toe. A change will show as a gap between one bolt and the wheel. If the gap is on the front bolt, the wheel has increased toe-in. A gap at the rear bolt indicates increased toe-out. Record the gap and the ride height.

Move the jack again, and take another reading. Record the toe change if any. Continue this process until you have measured the toe change throughout the full range of suspension travel, from bumpstop to full droop. Record the results.

If you are using a dial indicator, the gap shows up as a reading on the dial indicator. Start with the dial set to zero, so the reading is the change from the initial setting. This method is more accurate than measuring the gap between the bolt and the wheel rim.

Adjusting bump steer

If there is a significant toe change, an adjustment will be necessary. This will vary with the design of the car, and is different on the front and rear suspensions.

On the front suspension, the bump steer can be adjusted by changing the height of one end of the tie rod, assuming your car has a conventional steering system using equal-length tie rods. This type of steering system is almost universal with independent front suspension of the A-arm or MacPherson strut type. Other types of front suspension such as sliding pillar, trailing arm, or swing axle generally cannot be bump steered.

On rack and pinion steering suspensions, the rack may be lowered on its mounts. Installing shims under the rack brackets, or machining the bottom of the brackets will work for the adjustments. On cars with a steering box, the usual method of adjustment is to modify the steering arm. To avoid steering arm modifications, the steering system can be converted to spherical rod ends, in place of tie rod ends. This allows shims to be used between the steering arm and the rod end (for small bump steer adjustments). Large changes cannot be made this way, although it is a good way of making extremely precise adjustments.

The ideal adjustment translates to zero bump steer at the front. A car with bump steer in the front suspension will be unpredictable in a turn and unstable during braking. The car will also be very sensitive to toe-in changes. With bump steer, toe changes can happen with every dip in the road, or when the brakes are applied. Both toe-in and toe-out errors give terrible handling, and should be avoided in the front suspension.

Rear Suspension bump steer

Cars with independent rear suspension may also have bump steer at the rear. The adjustment is usually difficult or impossible. Stiffening the rear suspension is usually the only acceptable alternative. Many cars with semi-trailing arm rear suspension fall into this category. Race cars with fully adjustable rear suspensions have the advantage of being adjustable for bump steer. This is accomplished by changing the caster of the rear suspension upright (i.e. strut or coilover). This is also a trial and error procedure. Zero toe change is ideal, but if this is not possible, adjust for toe-in that increases as the wheel rises. Avoid rear toe-out adjustments completely.

How do I get me one of the bump steer and xmember drop downs?

I hacked up my crossmember already but have a spare...

Thanks for the information!

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.