Aftermarket ball joints that change the roll center?

[drivemusicnow]

I think the solution to this problem is to create a production aftermarket control arm. First off, replacing the subframe is out due to the costs involved. (at least for me) Then the next step is to get a few of the committed guys together with those parameters and figure out the best course of action.

I have been tossing a couple ideas around including machining some aluminum lower control arms. I could fairly easily design these to be cheap (ish) to CNC and allow for either a standard racing ball joint (take a standard off the shelf part or a race part) or a spherical bearing receiver like pagosa was mentioning.

The advantage of doing machined arms would be two fold. 1) in the long term it would be cheaper because the largest costs are single time costs: A) designing them which I would donate and B)creating the toolpaths to machine them. (which I could do depending on who's going to be machining them) Once these two things are done, creating another arm is as simple as buying a chunk of 6061 billet and throwing it on a cnc machine. 2) Small changes like ball joint height or style of ball joint would be a fairly simple change to implement.

I also like aluminum arms due to their strength and not having to worry about quality of welds which have been a problem in the past with cro-mo tubular arms. This is compared to tubular arms where each set is a completely new project and requires just as much time as the last set.

I think (based upon other applications I've seen) that we could do these for 1300-1500$ a set. but this is assuming at least 5 people are interesting. I'm one, I think that Chris, you would be another.

What are your thoughts?

[WatchItExplode]

I have a hunch that the majority of racers serious enough to replace the control arms on a 1g can make their own or have a friend/sponsor help them. I guess my point is, its going to be hard to find buyers at $1300 a set. In my case for example, I'll be using the resources available at my school's machine shop to make some (that is, if I'm at that stage in my project before graduation )

[drivemusicnow]

Originally Posted by WatchItExplode

I have a hunch that the majority of racers serious enough to replace the control arms on a 1g can make their own or have a friend/sponsor help them. I guess my point is, its going to be hard to find buyers at $1300 a set. In my case for example, I'll be using the resources available at my school's machine shop to make some (that is, if I'm at that stage in my project before graduation )

Exactly. Here's the issue with that mentality. If you're making your own tubular arms need to know how to weld, material properties, and take a guess on the design as to what is strong enough, on top of you needing to know how to take the proper measurements to correct the roll center based upon ride height. This limits the number of people that can make GOOD race quality arms for the dsm to a handful of fabricators and a few engineers who race them, and a very few do-it-your-selfers.

Polk made tubular arms before he passed away, and he was a very experienced fabricator. They were not suitable for road course use and broke. LCA's are a critical part that you can't skimp on.

I really was in a very similar place a few years ago, and I probably thought the same way, but unless you REALLY know what you're doing, you shouldn't attempt this.

I could spend a lot less time and the same amount of money and just spec some tubular arms to a fabricator... But I thought I might see if anyone is interested in a better, equivalently priced option.

[underradar92]

The spindle/ball joint height is the easiest/cheapest way to adjust roll center, if needed. The control arm is irrelevant.

No need to overthink this.

[Ludachris]

Originally Posted by drivemusicnow

I think the solution to this problem is to create a production aftermarket control arm. First off, replacing the subframe is out due to the costs involved. (at least for me) Then the next step is to get a few of the committed guys together with those parameters and figure out the best course of action.

I have been tossing a couple ideas around including machining some aluminum lower control arms. I could fairly easily design these to be cheap (ish) to CNC and allow for either a standard racing ball joint (take a standard off the shelf part or a race part) or a spherical bearing receiver like pagosa was mentioning.

The advantage of doing machined arms would be two fold. 1) in the long term it would be cheaper because the largest costs are single time costs: A) designing them which I would donate and B)creating the toolpaths to machine them. (which I could do depending on who's going to be machining them) Once these two things are done, creating another arm is as simple as buying a chunk of 6061 billet and throwing it on a cnc machine. 2) Small changes like ball joint height or style of ball joint would be a fairly simple change to implement.

I also like aluminum arms due to their strength and not having to worry about quality of welds which have been a problem in the past with cro-mo tubular arms. This is compared to tubular arms where each set is a completely new project and requires just as much time as the last set.

I think (based upon other applications I've seen) that we could do these for 1300-1500$ a set. but this is assuming at least 5 people are interesting. I'm one, I think that Chris, you would be another.

What are your thoughts?

Although I think that CNC'd control arms would open up a lot of possibilities for handling and even space for brake ducting, I just don't see more than a few people paying $1300-1500 for them. I don't know that I could come up with the cash for that.

This platform is aging more and more and the pool of owners with enough cash for these types of projects is dwindling. I think we could make a bigger impact by finding solutions that involve a combination of swaps from newer cars (like the Evo) and minimal fab work compared to creating a brand new part from scratch.

One example is the possibility of the Evo spindle being swapped out on the 1G to allow for Evo ball joints and the modification of the 1G control arm to accept those ball joints. If we do this, we can then use the Whiteline roll center adjustment kits. If we can use stock pieces from other cars that require minimal fab work, we can keep the costs down and publish these solutions for everyone to use. I'm all for having the perfect part made, but realistically, I think we have to use our creativity in finding cost effective solutions that will work just as good. High cost parts and DSMs are becoming less and less synonymous.

I love the creativity, innovation, and the genuine desire I see from you guys in wanting to help the DSM racing community. It goes to show that we have a lot of good people wanting to help others here on DSMtuners. Let's see if we can redirect this creative effort a little bit in a way where we can make a bigger impact. I want to see stuff like this be successful on a bigger scale. If we can't make it somewhat affordable I'm worried that we won't be able to get more people out there racing these cars.

[aaronmatusz]

drivemusicnow:
I've thought along the same lines before and really felt I was on to something, and it just didn't work.
If you make a fancy new control arm that has adjustable vertical balljoint position, it doesn't change the geometry, it just looks like it. As for using different ball joints, a little carefull grinding & welding and you've got it.
Matching an appropriate ball joint to the spindle, THAT'S the problem.

[pagosa dsm]

I was in a shop today.I was checking out a 2001 talon,it looks like the lower control arm and the spindle will fit a 1st gen.The 2001 lower ball joint is the same as the evo.It looks the same ,but I might be wrong.It is something to look at.

[drivemusicnow]

I think you mean 2001 eclipse, but maybe you're talking about a different car?

Aaron, changing the angle of the LCA will change the bump/camber curve, which will in turn provide a increase in camber under compression (to a point) this is beneficial in keeping the outer tire flatter to the pavement.

The roll center a much more complicated concept that I think most people don't fully understand.

I don't have time to try and explain it so I've attached two PDFs of two people who did, and fairly well at that.

[aaronmatusz]

OK, I got it.
Next time I'll just read the entire post & save everybody a lot of trouble...sorry about all that.

Hey, if you want to machine something, maybe a weld-in socket (for the stock LCA) to accept a spherical bearing of spiffy ball joint?

[underradar92]

Originally Posted by aaronmatusz

Hey, if you want to machine something, maybe a weld-in socket (for the stock LCA) to accept a spherical bearing of spiffy ball joint?

This seems a more realistic/affordable option, if we can find a balljoint with a compatible taper, or if need be, like was mentioned previously, ream the knuckle. I believe tapered reams for this sort of thing are readily available through circle track suppliers.

So now we need a sample ball joint. I can find a lathe if needed.

[pagosa dsm]

Originally Posted by pagosa dsm

I was in a shop today.I was checking out a 2001 talon,it looks like the lower control arm and the spindle will fit a 1st gen.The 2001 lower ball joint is the same as the evo.It looks the same ,but I might be wrong.It is something to look at.

I made a mistake,the car I check out was a 2001 Eclipse.I think it is a bolt in to a 1st gen

[Ludachris]

Originally Posted by underradar92

This seems a more realistic/affordable option, if we can find a balljoint with a compatible taper, or if need be, like was mentioned previously, ream the knuckle. I believe tapered reams for this sort of thing are readily available through circle track suppliers.

So now we need a sample ball joint. I can find a lathe if needed.

I'm still interested in seeing if we can find out whether or not the Evo spindle would bolt right up. That would take care of the reaming issue and would allow us to use the roll center kit from Whiteline. I'll start looking for one.

[underradar92]

Originally Posted by Ludachris

I'm still interested in seeing if we can find out whether or not the Evo spindle would bolt right up. That would take care of the reaming issue and would allow us to use the roll center kit from Whiteline. I'll start looking for one.

That seems even better. It would also give us (hopefully) better wheel bearings, less flex/pad knockback, seemingly infinite brake options, and on, and on.

Hopefully the driveshaft splines are compatible too.

[Zmann42087]

Originally Posted by underradar92

The spindle/ball joint height is the easiest/cheapest way to adjust roll center, if needed. The control arm is irrelevant.

No need to overthink this.

Exactly. I'd look into getting something like this roll center kit Megan Racing makes for the 240sx. All you have to do is replace the ball joint. Simple and effective.

[Ludachris]

Hell, if the 240sx ball joint taper is the same size as the 1G, that might be the easiest and cheapest option yet.

I'm still going to look into the Evo spindle for all of the reasons Jim mentioned above.

[cioc]

Looking closely at the Megan 240 kit you can see that a machined collar was added to the assembly with the retaining clip sitting on top of that collar. That being said, the only dimension that would need to be exact would be the taper. If the OD of the ball joint is slightly larger, the 1g arms could be opened up just a tad with a dremel. If the OD is a tad small, another collar(washer) could be made for the bottom. This is starting to interest me, however the Evo spindle would be the best option.

[Ludachris]

I am going to call a local shop here where the owners have 240's. I'll see if they have some old ball joints or know where I could find some cheap. I'm trying to do the same for Evo spindles, but the first place I checked with wants $125 each. I just need to see one and take some measurements... maybe have a 1g spindle on hand to hold up next to it.

[cioc]

Any progress on finding out if the 240's will work? Here are a couple of other companies doing similar lengthened joints. When doing these to the front, is there anything that has to be done to the rear or can that geometry just be lowered with no adverse effects.

MFactory Front Roll Center Adjusters

Roll Center correcting ball joints - Club RSX Message Board

Z-1 Performance Automotive Services Inc. - Moonface Racing Roll Center Adjuster 350Z

Also, what kind of extension are we looking for here for optimal performance?....an inch...two? No pun intended.