Solid Steering Rack Bushings (Press Fit)

[Carolina Dyno]

We will be making a variety of solid bushings for our new shop car but we decided to start with the ones most directly connected to the steering feel.

We designed a solid aluminum bushing with much tighter bolt holes, and a true press fit. These can be easily installed by putting them in the freezer for 20 minutes at which point they virtually slide in.

We also took out as much material as possible bringing them from 143 grams stock to 54 grams. It doesn't sound like much but we strive to make every part as light as possible.

[CSG Mike]

Interesting. Please excuse my ignorance; what is the benefit of a lighter bushing in this location? What is the implication on durability for track applications? Am I correct in assuming that there is no downside, since the material is taken out from a non-stress point?

[Carolina Dyno]

Originally Posted by CSG Mike

Interesting. Please excuse my ignorance; what is the benefit of a lighter bushing in this location? What is the implication on durability for track applications? Am I correct in assuming that there is no downside, since the material is taken out from a non-stress point?

Well the stock bushing is rubber so the main advantage is the rack isn't moving without driver input. Any movement in the rubber bushings is effectively unwanted steering input.

As far as the bushing being lighter, there is no particular advantage in that location vs anywhere else on the car it's just reducing overall weight. A few grams isn't much but notice its almost 1/3rd the original weight. It might seem like such a small weight savings that it's irrelevant but if you pay attention to the weight of every detail you possibly can you can shave hundreds of pounds 1 ounce at a time.

For track durability this would be a one time purchase, you are never going to wear out a pressed in solid bushing.

[Calum]

How many racks have you measured to get your baseline for the inside diameter? What have you found the factory tolerance to be?

[Carolina Dyno]

Originally Posted by Calum

How many racks have you measured to get your baseline for the inside diameter? What have you found the factory tolerance to be?

We've only measured two so far but we do have a couple cars coming in this week for verification. The two I measured were within 1 thou on both holes. I find this to be extremely strange considering the OEM bushing is fairly loose fitting rubber, but the odds of that being a coincidence are virtually nonexistent.

That said if anyone ever has a rack that is way off what we measured we can easily make a set to fit.

[continuecrushing]

hmm, nice. Any idea on price point?

[RacerDrews]

Originally Posted by Shutter

hmm, nice. Any idea on price point?

Has anything progressed with this set up yet? Would be interesting to see how much this actually is going to affect the feel of steering play if the stock bushings are as loose and poor tolerance as they claim.

[smbstyle]

Nice!

Off topic, but I recognize your shop's name from my days in North Carolina (Went to NC State), and I believe you guys are big on the HorsepowerJunkies forum with some serious builds, including that bad ass F40 build you all did.... I was drooling over the welding work you did.

[wu_dot_com]

what is being done to prevent corrosion? especially the dissimilar metal galvanic kind at the interface between bolt to bushing and bushing to rack?

my experience working with aircraft landing gear components made out of alum tells me that your product cannot and will not last for the life of the car as you clam due to operating environment. even with extreme protective measure, unlike rubber, or polyurethane, alum will corrode over time.

once it corrode, what is your plan to remove those bushings w/o making the hole ID oversize? putting it in is easy, removing and replaceing those bushing with basic hand tool is hard.

[cmcauley]

I may be incorrect on this, but I thought with aluminum parts the corrosion to aluminum oxide essentially protects the underlying aluminum. So the part itself will be okay, but this may be saying very little about it seizing against other parts that corrode.

[wu_dot_com]

Originally Posted by cmcauley

I may be incorrect on this, but I thought with aluminum parts the corrosion to aluminum oxide essentially protects the underlying aluminum. So the part itself will be okay, but this may be saying very little about it seizing against other parts that corrode.

not really, the alum corrosion in this case propagate when it comes in contact with another dissimilar metals. so, it would continue to corrode at an increase rate even with standard anodizing protection. also aluminum oxide (anodizing) protects the wear life of the substraight aluminum by being harder, it does not do much against corrosion. also Anodizing is a special processes, its different than your natural corrosion

[Carolina Dyno]

Originally Posted by Shutter

hmm, nice. Any idea on price point?

We're hoping around $40 shipped in the continental US

Originally Posted by RacerDrew

Has anything progressed with this set up yet? Would be interesting to see how much this actually is going to affect the feel of steering play if the stock bushings are as loose and poor tolerance as they claim.

We have them installed on our shop car however we have a lot of things apart right now while we design a few other parts and work on our turbo setup. Even though this is a very simple part and there shouldn't be any issue with the design we wont sell something without testing it on track first. We're hoping to have it back on the road by mid December.

To be perfectly honest you're not going to see a huge night and day difference from this part alone (though it will help), like everything else chassis/suspension related it's the whole package that makes the difference.

Originally Posted by smbstyle

Nice!

Off topic, but I recognize your shop's name from my days in North Carolina (Went to NC State), and I believe you guys are big on the HorsepowerJunkies forum with some serious builds, including that bad ass F40 build you all did.... I was drooling over the welding work you did.

Thanks! That's us, here's a link to the thread for anyone interested... I know we never get sick of looking at it, definitely the most amazing street car I've had the pleasure of working on.

http://www.horsepowerjunkies.com/for...=138096&page=3

Originally Posted by wu_dot_com

what is being done to prevent corrosion? especially the dissimilar metal galvanic kind at the interface between bolt to bushing and bushing to rack?

They will be available anodized for an additional fee however it's really unnecessary unless you drive you car in some really harsh conditions.

my experience working with aircraft landing gear components made out of alum tells me that your product cannot and will not last for the life of the car as you clam due to operating environment. even with extreme protective measure, unlike rubber, or polyurethane, alum will corrode over time.

once it corrode, what is your plan to remove those bushings w/o making the hole ID oversize? putting it in is easy, removing and replaceing those bushing with basic hand tool is hard.

Aircraft are subject to VERY different environments, take a look in your engine bay, there are literally hundreds of bare aluminum parts connected by bolts, sleeves, bushings, etc with a variety of materials. This part is no different than those.

As for replacing it, although there is almost no chance of that being necessary in a worst case scenario any decent shop should be able to handle the job easily.

Originally Posted by cmcauley

I may be incorrect on this, but I thought with aluminum parts the corrosion to aluminum oxide essentially protects the underlying aluminum. So the part itself will be okay, but this may be saying very little about it seizing against other parts that corrode.

Originally Posted by wu_dot_com

not really, the alum corrosion in this case propagate when it comes in contact with another dissimilar metals. so, it would continue to corrode at an increase rate even with standard anodizing protection. also aluminum oxide (anodizing) protects the wear life of the substraight aluminum by being harder, it does not do much against corrosion. also Anodizing is a special processes, its different than your natural corrosion

Anodizing is actually an extremely effective method of corrosion protection, however like you said purposefully anodizing a part is much different than natural oxidation.

Years ago I worked for a historic racing shop that serviced cars from road cars to race cars from the 50's and 60's. I could count on 1 hand the number of times we had issues with pressed in aluminum parts even 40+ years old.



Thanks for the interest, we will be sure to update this thread as soon as our car is back on the road.

Happy Thanksgiving!

[DriftEightSix]

Wow impresssive stuff on the F40!!

You looking at doing a kit for the 86?

[Carolina Dyno]

Originally Posted by DriftEightSix

Wow impresssive stuff on the F40!!

You looking at doing a kit for the 86?

We just finished up our exhaust manifold flanges, and opened up a box of 321 stainless tubing. We will be creating another thread for that!