Bob P. - What's Wrong with this Picture?

[patrickt]

OK, after more than a decade, maybe it's time to replace my steering rack mounting bushings. I ordered Energy Suspension #15.10.199.39, which I think is the right part, but they don't give you pictures on the Energy Suspension parts web site, so you kinda have to shoot in the dark. I'll know when they come. Do you guys put any grease on these bushings? Or do you install them dry? Am I going to need to drop the rack, or am I going to be able to squeeze them in after just taking off the brackets? And, yes, I see those funky little spacers in there under the bracket -- I'll try not to lose them, but no guaranties.

[strictlypersonl]

Interesting...
The "Subaru style" was a long time ago, but we ended up having the bushing custom-molded by Energy Suspension because we couldn't get the original ones anywhere. If the ones you receive aren't correct, we've still got a bunch here.
The only lube I would use is some silicone spray. It helps preserve the rubber and makes installation easier.

[patrickt]

That appears to be a Flaming River rack #FR1502 3X3 that you all modified to remove the little circular mounts by grinding them off flush. Remember, this was back in early 2006.

[strictlypersonl]

Originally Posted by patrickt

That appears to be a Flaming River rack #FR1502 3X3 that you all modified to remove the little circular mounts by grinding them off flush. Remember, this was back in early 2006.

You are correct. We machined the housing to duplicate the previously-used Subaru rack. We wanted to avoid changing the chassis brackets. For a while, there were companies that could supply rebuilt Subaru units, but they eventually dried up, so we changed the basic setup.

[patrickt]

Originally Posted by strictlypersonl

You are correct. We machined the housing to duplicate the previously-used Subaru rack. We wanted to avoid changing the chassis brackets. For a while, there were companies that could supply rebuilt Subaru units, but they eventually dried up, so we changed the basic setup.

OK, will you pop two of the rubber insulators that fit there in the mail to me? I'm still at the same address. Include an invoice should you feel the need. I'm pretty sure the Energy Suspension part that I ordered is not the right one. I really should have known better, since it was only four dollars. Thanks.

[strictlypersonl]

Pat,

Will do.

[patrickt]

Originally Posted by strictlypersonl

Pat,

Will do.

Muchas gracias. You know, in an effort to do a "Morris-Level R&R" on this job which, let's face it, is basically the benchmark for going as far as you can go on these cars (whether warranted or not), I think I'll put my magnetic dial indicator on the frame and steering rack to see what the lateral play is with the bushings I have now versus the new ones when turned with full weight on the wheels. I don't know if there's a spec for steering rack float, but I would suspect zero is the target.

[Morris]

I agree......

[patrickt]

Here's a video of the steering rack float with a dial indicator on it -- now remember, it still has the bad bushing on there. All comments welcome. If it doesn't embed right, please click here to view it: https://youtu.be/gjhUpHmH_cI

[ACHiPo]

Can't read the dial indicator--is that ~+0.050" ?

[patrickt]

Originally Posted by ACHiPo

Can't read the dial indicator--is that ~+0.050" ?

Yes, it's the same as most dial indicators. Each little mark is .001" and all the way around once is .1" -- if you go around ten full times you've moved one inch.

[DanEC]

OK This is just the bad bushing "baseline" test - correct? And you're planning to repeat with the new bushings and hoping to see a significant difference /reduction in play. Have I got this right?

[patrickt]

Originally Posted by DanEC

OK This is just the bad bushing "baseline" test - correct? And you're planning to repeat with the new bushings and hoping to see a significant difference /reduction in play. Have I got this right?

Yes, you have that right. I'm patiently awaiting the new bushings from Bob. But, if any of the "real" Cobra mechanics out there have an opinion on steering rack float specs, I'm all ears.

[FWB]

and i came to this thread hoping to see the latest in Patrick's manicure, but alas I am riddled with disappointment. i guess it's better than riddled with bullets.

[Morris]

You think there’s a reason why all race cars bolt their steering rack to the chassis???.....

When you are racing.....we concentrated on being right on the apex of the turn....not 3” away.....so you can’t have any movement in the steering rack.

If you are off the apex ....you will scrub speed and not get around the corner at speed.....so turn-in is a major part when negotiating a corner.....

No movement is allowed on the rack.

[patrickt]

Assuming the new bushings (which Bob says are on the way) don't reduce float to near zero with my little "back and forth" test, then fabbing up a brace from the middle part of the rack to the two adjacent frame rails (where the bushings mount) would not be difficult. That would eliminate lateral float. That's a nice winter time project.

[strictlypersonl]

With rubber, there will always be a bit of compliance - but that shouldn't translate into any noticeable play on the street. The rubber is there to absorb high-frequency vibrations transmitted from the suspension.

[DanEC]

Good old NHV measures. The street is one thing and the race track another.

[patrickt]

Well I don't know how I managed to shred that one particular bushing, but I did. Over on the Jaguar forums they're complaining of their racks moving one full inch laterally. Yes, that's one full inch.

[patrickt]

Originally Posted by DanEC

Good old NHV measures. The street is one thing and the race track another.

NHV is nice to avoid.... But, when I take her out for a run, I'm mostly trying to avoid a DNF.