Ball joint extenders
 

All you suspensions nerds, have you ever seen these? Comments? They're mad-tite JDM, so they must be good, right? I'm not gonna buy them - I just came across them and thought they were interesting.

http://www.edoperformance.com/ForumI.../Diagram01.jpg

Dang, those could be very interesting. The problem remains though that if you go past vertical, now you go positive that much faster...

We ned Mr. suspension geometry to chime in.

Austin!!!

http://forums.nasioc.com/forums/show....php?t=1055510

They're a good idea if you account for bumpsteer, which the 6gun ones do, but these zero-sports ones do not.

Also, they're expensive!

6gun's look very interesting. Not sure where they fall form a solo rules perspective. They are after the suspension pick up points, so they do not fall under the same issue as the ALKs. hmmmm

They're legal in SM.

/end of Scott's concern

If anybody ever questions why we gripe about body roll and camber so much, post 51 of that thread says it all. Also explains why the monster front sway bar in AS does not induce massive understeer because it reduces roll and thus the positive camber change.

hhttp://forums.nasioc.com/forums/sho...4&postcount=51

Huh?

Dean, I think your page settings on NASIOC aren't the same as mine. How about citing the post by number, or linking directly to it?

Post #51 I think, is what Dean is referring to. That's what comes up when I click the link.

This?

http://forums.nasioc.com/forums/show...4&postcount=51

That's it, sorry. -Fixed

They are having problems with their Tie rod extenders though, so we will see how that turns out.

Their JDM-explanation is pretty funny, but yes, these would have a positive effect on suspension geometry for lowered cars. How much of an effect just depends on how much the pivot center is moved in relation to the OE ball joint center. There are similar extended ball joints for the Mustangs; as I recall they moved the pivot maybe 0.5" lower. There's always a limit to how much you can lower that outer pivot; you're constrained by packaging/control arm clearance to the wheel, and also the longer that shaft on the ball joint is, the higher its operating stress.

So, basically it depends on how much you've lowered the car. If the new pivot is 0.75" lower and the car is lowered 0.75", then your geometry is roughly back to stock. If the car is lowered 2", then your geometry is still off by a lot.

But they're generally better than nothing. :)

And yes, bumpsteer is definitely something you need to take into account when making front-end geometry changes like this. When you relocate control arm pivots the bumpsteer will probably get very large. Hell even with a stock-geometry car, you could pick up some time on the track by tweaking the bumpsteer. OE cars usually have noticeable roll understeer behavior designed into them that you can mostly tune out with adjustable tie rods.

Austin, take a look at the linked alternative to the ball joints in the 1st post. They're not just replacement joints, they're actually extenders, so if you wear out the BJ you only need to buy an OEM one for ~$40.

But as Dean mentioned, it sounds like the tie-rock extensions are failing from the lateral load... so I too am going to hold of on a fix for that before getting into something like this.

Austin, tell us about adjustable tie rods? Are you talking about just alternate ends, or replacement arms?

I was wondering why they were trying to extend the stock end rather than just using a spherical rod end and machining a beefier riser. Rod ends are relatively cheap, and a riser is probably as easy if not easier to machine than the extension they were building. No internal work, just external, and no set screws.

Something like http://www.ikeya-f.co.jp/images/prod...orks/ntend.jpg

So it looks like their widget clamps on to the ball joint boss and provides a new mounting point lower down for an OE ball joint? Sounds good, although I couldn't judge how strong or reliable the new assembly would be without looking at one on a spindle up close.

Something like this:

http://www.maximummotorsports.com/st...TR-2%20Web.jpg

So basically you take off the OE outer tie rod and install a kit like that in its place. The tapered part of the stud fits into the spindle, and you can adjust the vertical height of the rod end by changing the order of the spacers on the lower section of the stud.

This picture shows one installed.

The ball joint extenders are reported to kick ass:

...but the tie-rod extenders fail. :mad:

Here's the kit from 6gun:

http://www.6gunracing.com/misc_pics/install1.jpg

Same deal pretty much, but designed to plug-n-play w/ the OEM bits.

Well, buy it and get an adjustable tie rod kit to use instead of their dookie "tie-rod extender". With a car like yours you want the bumpsteer to be adjustable anyway.

They're not selling 'em until the tie-rod fix is in.. :(

Rumor has it Whiteline has their own version of this kit coming out too. Considering how satisfied I've been in the past with everything Whiteline, I'll probably just go that route.

But speaking of adjustable bump steer, I don't think I've ever paid close enough attention to bump steer to know how to adjust for it... really, I just put the car on the line it needs to apex properly, and react as necessary to keep the car where I want it... I don't think I've ever consciously experienced bump steer to the point where a voice in my head said "woah, I which that bump steer didn't happen", so the idea of tuning it seems near impossible. I guess that's just a result of only driving on sort of car at the track. I really need some seat time in cars that are really set up to handle, like a Miata or Elise or something. :devil:

Exactly what I was describing. Why try and extend the stock unit when there are other ways to do it relatively inexpensively.

Actually, they are selling the kit w/o the tie rod extender. $320.

http://www.6gunracing.com/products.asp

Cool! I didn't see that in the WRX/STi specific areas of the TiC website and the old link to 'em was invalid, so I figured they weren't for sale any longer.

Those plus some appropriate adjustable tie-rod ends may be just the ticket.

Well, that's just kinda the wrong way to think about it. It's really not bump-steer, it's roll-steer that you're tuning. It's wheel steering behavior in response to suspension movement - which happens every time you turn the car in to a corner. Consequently the roll steer has a significant effect on handling. This applies to both axles, btw - not just the front end.

At MM I ran through lots of iterations of different bumpsteer spacer arrangements on the racecar's IRS, and plotted the behavior out for them all; then when we tested the car at the track we were able to improve the IRS handling from stock quite a bit with that adjustment alone, and shave noticeable lap time.

http://forums.nasioc.com/forums/show....php?t=1155654

It looks like whiteline has made something like this for Evos, and will be doing subarus soon.

I also noticed from reading that thread that the 6gun versions had some bad failures, which they are still sorting out.

I'm so all over those. sweet.

Nothing better than a extended ball joint.