need to find a steering rack

i'm messing with my grand prix. currently it has a rear steer rack mounted kinda right in front of the firewall about mid oil pan level. my plan is to swap the knuckles side for side as all is symmetrical except the tie rod hookup and find a proper width front steer rack so i'm not turning the wheel left to go right.

is there a book out there with dimensions like that a rebuilder might be able to acquire or is this one deal where i need to go to the boneyard with a tape measure and start checking out similar width cars? how about where the tie rod ends go into the knuckle - is everyone's taper and size different?

the new engine has some spinny parts that occupy the space currently taken up by the steering rack

or how about this - does anyone make a small gear box to reverse the steering input? i know they make little gear boxes to quicken the ratio.

Why not install a Mustang rack? The SN95 rack could be a good option.

pjesus said: the new engine has some spinny parts that occupy the space currently taken up by the steering rack

Stoopid engines going the wrong way.

i will check that out for sure. unfortunately my fiancee's mom donated her SN95 to charity because she did not think i was serious about volunteering to take it off her hands.

the mustang II rack is narrow - i'm guessing i could get other length tie rods though if necessary

Swapping the knuckles side to side will totally ruin any ackerman angles in the front end. The car my actually be un-drivable afterwards.

Any chance you can flip the tie rods to the bottom of the arms with a re-drill and just lower the rack enough to get it out of the way?

What year GP?

Would a Fox body mustang rack work?

AFAIK, it's tape measure time. I haven't seen a length listing. Ideally, you want the distance between the inner tie rod pivot centers to be the same as the distance between the inner lower control arm pivot bolt centers.

In most cases, rear steer racks will have the pinion above the rack, front steer will have it below the rack. A Fox body rack is a front steer and it is pretty easily available.

oldopelguy's right about Ackerman changes, you can minimize that by mounting the rack far enough back that the tie rods angle forward when the steering is centered, and when the wheel is turned all the way either direction there is a straight line between all 4 tie rod pivots: the two inners and the two outers. Best of all would be to have the tie rods still angle forward about 1/4" with the steering all the way to lock, that means mounting the rack a bit further back.

You also want the tie rods to follow the angle of the lower control arms, i.e. if you drew a straight line through the center of the lower control arm pivot bolt and the center of the ball joint, the tie rod would be parallel to this line as viewed from the front.

If you need to redrill the tie rod holes, they need to be tapered. Several of the hotrod houses sell a 7 degree tapered reamer just for that.

well, this brings up a question I have been wondering.

I am going with a rack instead of a box on my 124 spider. Like the GP, it is rear stear. As I am going to be running wider and stickier tyres than it came with (probably 215s vs 165s) I was considering a power steering rack. If I got a rack from a UK spec BMW Z3.. can it be flipped over and run rear stear instead of front?

Miata could also be an answer but you would need custom adapters between the inner and outer tie rod ends for length.

As light as a Spider is, I'm not seeing a need for power steering. There's several rear steer racks out there, the Omni/Horizon piece is popular for that type of swap. There's a company called Unisteer http://www.unisteer.com/mm5/merchant.mvc that makes new racks in the Pinto front steer and Omni rear steer versions. They also have power versions if you want. They actually are pretty reasonably priced.

Try e-bay for Sweet , woodward, Appleton, southwest, coleman racing racks. With out without powere steering. I've found 3 rachs for short $$ lately.

This is going to take awhile to write so print it out and take it to the car and look at stuff.

1) Measure the distance between the two inner ball joints (hiems) lets say for example its 22 inches

2) Look in catalogs that have rack dimensions for a rack with inner tie rods at 22 inches. You'd like to get as close as possible.

3) make sure the rack you pick you can get the steering shaft to with out going through the motor. Tried to help several racers fit racks that just didn't work.

4) Rack height. This depends on a few measurements so take you time and get it right! 4a) Measure from the outer ball joints center of swivel to ground. Be careful if you use real ball joint like me it can be deceiving as to where the center of rotation is. Cut and old one to make sure. lets say its 8.0 4b) Measure from outer tie rod center of rotation to ground. Lets say its 8.5 4c) so you have a outer tie rod that 1/2 inch higher then the ball joint this means you rack need to be 1/2 inch hirer then the inner ball joints. This will set the angles of the tie rods the same as the lower control arms thus minimize bump steer.

5) I race pavement and have found some Ackerman to be a good thing. Most big car set the racks 1.5 to 2 inches off the center line of the outer tie rods In DWARFS 1/2 to 3/4 works good. 5a) Point both wheels straight now tie a string around the outer tie rode bolts measure to a cross member in-line with the inner ball joints let say its 12 inches. So if you have front steer spindles (most dwarfs do) you should set the racks center line at 11.5 to 11.25 from the cross member.

Keeping a rack in the right place is hard!! An easy way to help is this. Measure the rack diameter and find some tubing that will snuggly fit over the racks ends now weld on some thin sheet metal to the tubing this can be clamped to the 1x2 frame that comes out to hold the bumper.

So to sum it up you want the tie rod angles to match the lower control arm angles when viewed from the front and you want the rack set back toward the motor .5 to .75 from the outer tie rod ends.

Best of luck 44dwarf

the beauty of Fiat's steering box set up.. it was more or less already set up for a rack. Instead of using unequal length tierods from the box, it ran a centre draglink to a dampner on the other side of the firewall. In essence, they are "mirrored" which makes it very easy to modify a spider from left to right hand drive (even know fiat never did this)

so really, all I have to do is figure out the length of the rack. I was thinking P/S as when i was running 195s on my old spider, parking could be a real bear.. and I happened to like how "transparent" BMW's P/S system is

924s & 944s are front steer.

Infact the 924 uses a flipped euro rabbit rack, but it isn't powered.

The 924S and the 944 use a Porsche designed rack, that uses regular ATF for it's fluid.

fiat22turbo wrote: 924s & 944s are front steer. Infact the 924 uses a flipped euro rabbit rack, but it isn't powered. The 924S and the 944 use a Porsche designed rack, that uses regular ATF for it's fluid.

+1

I have a complete 944 power rack set up (including pump, reservoir, line cooler ) sitting in a box in my garage, needs new tie rod ends, and pump pulley is a little bent, but that would probably need to be changed anyhow...

I can take any measurements you need to see if that set up works for you, i was just looking at it yesterday and can still get to it... (the garage hasnt eaten it yet! )