Real Fiero Tech

The passenger side mount is stock '88 Fiero.

It's possible for my driver's side mount to be off. Maybe there are some reference points I can measure from to see if the rack is still parallel to the crossmember.

FYI...

I ran across these a while back, but forgot where they were listed.
I'd been thinking for a long time about how to get rid of those silly rubber steering rack mounts.

http://www.flamingriver.com/index.php/p ... 0013/s0012

BMW is shameless about hard mounting steering racks and suspension pivots...

Cool. It would be easy to hard-mount a stock '88 rack (and the passenger side of the 'vette) with something like that.

On the Corvette rack, the driver's side mount is a cylindrical bushing perpendicular to the rack. Fabricating a solid insert would be trivial with a lathe. It just looks like a suspension bushing.

Do a bump steer measurement...
Yes, it's a PITA.
However, just like degreeing cams, you don't really know what you have until you take the measurement.

Oh yeah, another thing I found with the ridiculously fast steering is that I can actually catch the back end stepping out before it turns into a spin. It's not the fastest way through a corner, but on more than one of my autocross runs I saved it when there's no way I could have with the old slow stock steering.

*THAT* is the only reason to go to power steering, in my opinion... To have reasonable effort when making the steering fast enough to catch a spin.

I've been looking into ways to increase the steering effort and get some feeling back in my steering.

I just got off the phone with Jeff at Turn One Steering. This guy knows his stuff. I learned a lot in just a brief phone call.

1) The torsion bar presses into the pinion, so the valve assembly includes the spool valve. This means that an assembled spool valve is tied to a rack ratio, since the pinion can't be changed out.

2) Turn One might be able to rework a spool valve to have a stiffer torsion bar, but it's not easy. Possible, but very difficult. They do have the means to do it, but I should look into other possibilities first.

3) Turn One has some parts for the slower-ratio Corvette racks. My rack is two turns lock to lock, but Jeff explained that the number of turns is not a good way to check the rack ratio, because of external and internal travel limiters. If my rack is a fast-ratio rack, then the Turn One does have different spool valves that will fit.

4) The rack rebuilder (I have a rebuilt rack) may have made a mistake during the rebuild, that increased the assist of the spool valve. By checking the operating pressure of the rack we can see if this is what's happening.

I now have some action items:
1) Verify the steering rack ratio by turning the pinion 360 degrees and measuring the linear motion of the rack.
2) Measure the power steering pressure on the high side during a static steering maneuver to see if the spool valve is operating properly.

Also if my rack is indeed the fast-ratio rack, Jeff doesn't think it's from a '94 (which is what I thought I got). Definitely got some investigatin' to do!

There's some magic which can be worked via changes to design parameters of steering gear, but to most shops they're black boxes and to most rebuilders magic recipes.

I had a customer who ordered a rebuilt 282 from a big supplier and received a gearbox with the right bellhousing, VSS and clutch mechanism to go into his car, but the international market Q4 minivan gearing...

I was wondering about trying an electric assist at the pinion with about a 1.5:1 steering quickener in place the steering shaft, if it can be made to fit. With optimized offset and steering geometry, that should work reasonably well.