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

I hate to burst anyones bubble but all of this bump steer info is flawed.

With what is being proposed here, you will be increasing bump steer significantly.

The method used to determine the correct geometry for the steering suspension is this:

You need to find the instant center. This is a point determined by drawing a line through the ball joint pivot and the inner pivot. Then you draw a line 90 degrees to the strut from the upper strut pivot point. Where these lines meet is the instant center. To eliminate bump steer you need to draw a line from the instant center to the outer tie rod pivot. Then draw a line fron the upper strut pivot to the lower ball joint and then from the upper pivot to the inner a-arm pivot.

The steering arm needs to be at the angle of the line from the instant center to the outer tie rod pivot and the inner and outer tie rod pivots need to intersect the lines drawn from the top strut pivot to the ball joint and top strut pivot to the a-arm inner pivot. in this condition you will not have any bump steer. All of these measurements are taken with the car at the normal ride height. (I.E. without the suspension compressed or extended)

If you move the rack down no matter what you do you will increase bump steer. You will be moving the inner tie rod pivot farther from the line between the strut top pivot and the inner a-arm pivot and away from the instant center.

misinterpretation....
I got all the info from you originally form Gestapoville.
To get the LS engine in nicely without jacking with the hood and having good oilpan clearance, 1" X-member to frame spacers are used and to get the geometry of the steering back SIMPLY is to use strut hat spacers (VERSION 1) which technically raises car 1" (great for 18" wheel swap)
(Version 2) is to drop X-member by 1" spacers, NO strut top hat spacers, drop the control arm ball joint down from spindle by 1", and drop the outter tie-rod by 1" (using the tie-rod drop kit)
(Version 2) does not affect ride height

So which is the better setup? Lesser of two evils per se?

Well I found my suspension design book and verified. If you don't use the instant center for setting the steering you will have bump steer. If you lower the rack without lowering the inner pivot of the a-arm you will have bump steer. When the inner and outer tie rod end are in line with the inner pivot and ball joint on the a-arm you will have the optimum set-up You can move the rack up and the outer tie rod end up and keep this. But you cannot just lower the rack.

I originally lowered the rack and the center of the crossmsmember on my car but changed it because of this. Lowering the rack like you suggest could give you so much bump steer that the car would be difficult to drive and the handling would be horrible. Back on "Gestapoville" I was going by memory because I couldn't find the book.

I have so many books and never really organized them after we moved so most are in boxes or piled around book shelves.

If you look at the big picture, Version 1 is only raising the body 1" on the stock steering geometry.
I have studied the $^%^# out of this X-member and it can be easily modded where the front control arm bolt goes to an upper location on the X-member (1" is perfect), add 1" spacers effectively dropping the rack and X-member for engine clearance meanwhile keeping the stock steering geometry. You'ld just need to add the tie-rod drop that Version 2 provides. Anybody ever seen drop spindles for these cars?

wait.. thats what we did right?

the terminology is a bit confused (we obviously were making it up as we went...lol) using what your book seems to have defined:

the inner pivots of the a arm and tie rod are lowered simultaneously with spacers... so you get the lack of travel of the outer pivot, this is corrected by flattening the A arm with respect to the ground... IE adding the longer pins.. but that throws the alignment of the tie rod outer pivots, thats corrected by lowering the tie rod outer pivots with the tie rod pins.

I'm curious can just the cross member drop be used or would that run into problems. I just lowered my car about an inch all around and wouldn't want to put the spacer for the struts on because that would negate the fact that I lowered my car.

Tha's the other problem with lowering the car with shorter springs. The ball joint binding again comes into play. Ball joint extension pins are needed.

OK gents, finally got a weekend to install the bump steer kit. ITS AMAZING. that is... standing still... car is still a long way off but everything bolted up like a dream (I know all the tricks now to tearing a car down to spindles and putting it all back.. did it like 4 times)

you'll have to excuse the cellphone pictures but I promised some photos:

passenger's side:


driver's side:


and check it out! I rolled the car out of the garage! give her some air. my alignment is FUBAR... Ill have to go to a shop for that (thatll be fun.. english and metric?)


My only concerns are that the tie rod is beginning to rust, i may have to tear it all apart again to paint or powder coat (theyll fit in a toaster right?) the rods. what was that thing with acid xschop? think I can get that done without killing myself? I feel like powder coating will wear on the wrench links and in the spot where the locking bolts hit the rod.

oh yeah, here is the image of the car rolled out of the garage:

youll have to excuse the sun reflecting off the body, some of the dust pollen and metal shavings patina came off when I rolled the car out.

Can you show a pic of the 1-piece bolt bottom to inner rim clearance?
Oh yes, 20% Phosphoric acid. There is a rattle can called "Rust-Converter at Wally World that has the correct formula. The trick is to let your parts get nice and rusty all over first, then spray them with the converter. It turns the rust to an Iron Phosphate primer that is permanent. I just did the battery tray this weekend, brushed the heavy rust off, shot it with HPO4 rust converter, let it turn to black primer, then polyurethaned it with a caulk gun, easy-cheesy.
Did you also get the protective boots I sent?

ic ic, ill check that stuff out in a month or so.
Its dark out right now, i can snap a photo tomorrow, it doesnt stick out much further than the rotor though. the boots are also installed! its good stuff.

oh with your battery tray, i dunno how bad it is but mine was rusted all the way into the frame (theres a square section that goes back to the passenger's side) I had to paint rust bullet alllll the way inside there

here you go, plenty of room under 18s

very sweet. looks like with the 18's you could do another 1-1.25" drop if you went radical with the steering rack location. Somethin' to keep in mind for a future Manual rack transplant from another manufacturer.

yeah its nice, any future impants for me at least would have to be an electric assist rack, I have to flex my EE nerd muscles somehow
I just cant wait to see the look on the alignment shop guys' face. Hopefully in the near future ill be able to actually measure the bump steer and adjust the spacers properly.

Hmmm... this thread has me thinking "what if there is an easier way?" Or maybe not easier, but one that keep the stock suspension geometry intact.

No, I'm not planning to start building parts- I just want to toss this one out there for the folks that have the appropriate machine tools (mill, for example) and see if someone wants to give this a shot.

Problem 1: We need to drop the front crossmember for engine clearance.

Problem 2: If we drop the front crossmember, we're also dropping the mounting points for the suspension.

My proposed solution:

Instead of simple spacer blocks to drop the crossmember, why not make a slightly more complex spacer block- one that integrates the suspension mounting point into the spacer? Essentially duplicate the end of the crossmember as part of the spacer block, and cut the end off the stock crossmember flush with the outside of the subframe rails. This leaves the steering geometry stock and doesn't raise the car. The 944 is purported to be the best handling car ever built by Porsche... why not try to keep the suspension the way it was designed?

Someone mentioned the idea of building a tubular crossmember one one of the threads... Ok, not a bad plan, but I think this is an easier solution.

Additional thoughts: I notice the mention of 3 piece crossmembers on one of the threads, to allow the center of the crossmember to be dropped out to remove the oil pan. Well, since we're already hacking up a crossmember, why not do that at the same time? HOWEVER, the modified crossmembers I have seen use bolts in tension to retain the center section. That is much weaker than using bolts in shear. Hmmmm... what to do? (here's one for you true do-it-yourself types.) Additionally, I personally prefer the strength of a solid crossmember... so this is just another "what if?"

With the crossmember out of the car (you didn't think we were going to do this while it was installed did you?) we need to make 4 steel plates (2 for each side) to "sandwich" the crossmember. They use 8 bolts to retain them, and are "offset" from each other so that only 4 of the bolts pass through both plates. The upper plate sits further to the outside, the lower plate sits further to the inside, offset enough to clear one set of bolts on each end. Spacers will be needed that match the depth of the "webbing" of the crossmember at the location of all the bolts that pass through the lower plate.

Clamp in place, drill through, and bolt. Repeat for the other end. Now remove the plates and cut the crossmember between the center set of bolt holes for each end. Reassemble and install in the car.

To remove the center section of the crossmember, simply remove the 4 "center" bolts from each end.

Ok folks... comments? Thoughts? Do you have a solution that might improve upon these?

xschop, you're evidently "the man" on this kind of stuff... what do you think? Would you like to give it a try?

Brad

Take the Moroso 20140 pan and cut it laterally in half, weld on attachment mating plates to front and back halves (there's room aft of the X-member for the new bolt flanges to protrude down in that location), make a homemade gasket for the new area and call it a day. Then get on the phone to Vegas and tell Renegade not to steal your idea LOL....

xschop wrote:Take the Moroso 20140 pan and cut it laterally in half, weld on attachment mating plates to front and back halves (there's room aft of the X-member for the new bolt flanges to protrude down in that location), make a homemade gasket for the new area and call it a day. Then get on the phone to Vegas and tell Renegade not to steal your idea LOL....

Hmmm... what do you think of the other part?

p.s. what does "PORH" mean? (I get that the last 2 letters are "Renegade Hybrids" but can someone 'splain the first part?)

I've talked about it before that the X-member can be set on a mill and LINE-BORED 1 to 1.5" upwards where the control arms bolt-thru and the exact spacers can be put between X-member and frame. This would work but only lower the rack in comparison to the control arms. However there is a remedy for this....offset tie rod to rack adapters would have to be conjured (SIC) which wouldn't be difficult to make, but a different rubber rack bellow would need to be located.

As far as what you say, I think it could be worked out....so knock yourself out. There's more than 1 way to skin a cat.
Alot of the original ideas were censored and deleted over on "Gestapoville", now known as "Cricketville" (PHB) because the establishment that took over (RH) doesn't like free thinkers. I'm over that last year already. So this will be the last time I state it and will make it clear for everyone.....PORH



(needle bearings are for neophytes)....

(POST EDITED PER 944hybrids FORUM RULES

"You agree not to post any abusive, obscene, vulgar, slanderous, hateful, threatening, sexually-oriented, or any other material that may violate any laws"

IMAGE REMOVED>>>That's pushing it, dude...This isn't PHB or RH, but we do have a few rules.
Edited by gt1scca 10.23.09 @ 1:43 P.M. EST)

xschop wrote:(needle bearings are for neophytes)....

^this

For the 944 Manual Rack, I will offer these custom threaded rods instead of the longer Rods for the PS RACK. Just PM me
****NOTE***** This female threaded rod and the Moog Tie-rod are designed for the EARLY Manual Rack and LATE offset.
Also The MOOG tie rod has shorter female threads at the rack end than the BECK/ARNLEY Part # 1013475. The Moog tie-rod will have the manual rack lock nut set outwards by 1/2" and this is not a problem and can be cut down 1.00" at the outter tie rod end If you wanted to put the bump steer kit on an EARLY manual rack and EARLY offset.

Drawing as promised for the DIY crew.....

Forgot I had this pic in my email (Thanks Gene)

The pic (upper) shows the Rabbit inner tie rod and 5/8" Heim adapter. Notice it is 1.25" longer (+29mm for Late 944 offset) as this setup was installed on a Late 944.

The bottom pic is the factory Early offset manual rack tie-rod assembly

NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

xschop wrote: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.

Hello xschop, admin wont let me PM you. Do you happen to have any of these parts in stock at this time and how much for say 1/2"
Thanks, Mike at IFC Racing

xschop wrote:Forgot I had this pic in my email (Thanks Gene)

The pic (upper) shows the Rabbit inner tie rod and 5/8" Heim adapter. Notice it is 1.25" longer (+29mm for Late 944 offset) as this setup was installed on a Late 944.

The bottom pic is the factory Early offset manual rack tie-rod assembly

NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

Rob, when you mention the shortening to get to the early offset, is that done entirely off of the adapter piece? It's hard to tell by the wording if you mean to take off 1" from the MOOG inner tie rod or 1" from the adapter (MOOG tie rod side).

robstah wrote:

xschop wrote:Forgot I had this pic in my email (Thanks Gene)

The pic (upper) shows the Rabbit inner tie rod and 5/8" Heim adapter. Notice it is 1.25" longer (+29mm for Late 944 offset) as this setup was installed on a Late 944.

The bottom pic is the factory Early offset manual rack tie-rod assembly

NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

Rob, when you mention the shortening to get to the early offset, is that done entirely off of the adapter piece? It's hard to tell by the wording if you mean to take off 1" from the MOOG inner tie rod or 1" from the adapter (MOOG tie rod side).

robstah: Your question is just a joke right? You are just kidding right??? Or did something not go your way like the last episode and you're out to blame someone for something?!!

I read the wording as:
NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

Maybe I need to ask Rob if the top pic is the top pic or is it really the bottom pic the bottom pic? I'm not sure of the wording either. I'm so confussed.

Tehone wrote:

robstah wrote:

xschop wrote:Forgot I had this pic in my email (Thanks Gene)

The pic (upper) shows the Rabbit inner tie rod and 5/8" Heim adapter. Notice it is 1.25" longer (+29mm for Late 944 offset) as this setup was installed on a Late 944.

The bottom pic is the factory Early offset manual rack tie-rod assembly

NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

Rob, when you mention the shortening to get to the early offset, is that done entirely off of the adapter piece? It's hard to tell by the wording if you mean to take off 1" from the MOOG inner tie rod or 1" from the adapter (MOOG tie rod side).

robstah: Your question is just a joke right? You are just kidding right??? Or did something not go your way like the last episode and you're out to blame someone for something?!!

I read the wording as:
NOTE**** For Early offset and Manual Steering rack, simply cut off 1.00" from the end of the VW Rabbit tie-rod and 0.5" from the adapter at the tie-rod end for adjustability*****

Maybe I need to ask Rob if the top pic is the top pic or is it really the bottom pic the bottom pic? I'm not sure of the wording either. I'm so confussed.

This is cute. Everyone is out to get me now. How quaint.

I was just confirming with what he said. I do not have the inner tie rod with me and from the picture, I see that the threading on the inner tie rod looks maxed out for the late offset and cutting an inch off of the threading will still max out at the same spot, which would not be a reduction of an inch, no?

No problem Rob,
For an EARLY offset, Reduce the ADAPTER by 1/2" on the M14 x 1.5 side. If you need more than that, just chop 1/2" off the TIE-ROD and use a M14 x 1.5 die on the tie-rod itself.