Traction Bars?

[DSMinn0vati0ns]

i was wondering if they made traction bars for the 2gen eclipse gst

 

[jtmcinder]

Crawl under your car, just behind a front wheel, and take a look at the great, wonking arm that goes back from the bottom of the knuckle. Then ask yourself what a traction bar is supposed to do that this "compression arm" doesn't.

It's a koan. No reply is needed.

- Jtoby

 

[my98GST]

LSD, motor mounts, good suspenion mounts, good clutch/fly combo, and slicks is prety much our only hope

 

[DSMinn0vati0ns]

i see i see... thanks!

 

[Mikael SS]

Crawl under your car, just behind a front wheel, and take a look at the great, wonking arm that goes back from the bottom of the knuckle. Then ask yourself what a traction bar is supposed to do that this "compression arm" doesn't.

It's a koan. No reply is needed.

- Jtoby

I don't think a compression arm will keep his leaf springs from twisting. So if he wants to prevent his leaf springs from twisting, he should go ahead and get them.

 

[topstreet]

I have some on my car...

 

[jtmcinder]

Pictures, please. And what are they supposed to be doing?

- Jtoby

 

[topstreet]

I will see what I can do about pics as soon as I get around to it.

The idea/theory is addition support. (Simply Put) I have seen cases (mainly in SRT4's) where they are using a two bolt flange as an upper spindle mount, and it is bending.

Now this design is identical to the 1G dsm front shock mount. The reason that I became concerned is because of the limited amount of reenforcement and the added amount of leverage that this system has. I will explain. If you look at a A-arm (like the 2G) it offers roughly 8-9" of support from one bushing to the other. The ball joint then sits slightly farther forward then the center of the two bushings. This means that there is roughly 5-6" (from the ball joint) of bracing. If you looked at it like a right angle. The 1G's design uses that in the lower control arm but not in the upper spindle mount. Because Of this, the fear of suspension/drive train "whip" began to concern me. Basically the amount of give from an unloaded (not weight but torque) to a loaded position. After the suspension bushings and arms give all of the slack that they have, it will stop. It is how hard it stops that concerned my. Many times this is what will cause wheel hop, because the movement and power transfer has to go somewhere.

So... To prevent this movement, I added 2 huge 3/4" chromoly heim joints with grade 8 bolts and aluminum hex tubes. These mount to the lower control arm (closer to the ball joint) and then connect to a 2" stainless steel "cross bow". This cross bow now also serves as a reenforcement for the sub frame that the lower control arms attach to, and the rear engine mount, and attaches to the frame where the stock front cross member would have. The torque links attach to this and the front engine mount does as well. (5/8" rod ends and swedge tube.)

Because the cross bow attaches to the sub-frame, and the sub-frame holds the lower control arms, and the lower control arms attach to the torque links, and the torque links attach to the cross bow, and the cross bow attaches back to the frame. Every thing is tied together significantly more than the original design ever would have allowed.

The reason for all of this was to attempt to provide a solid, triangulated suspension link... And a flexible, but solid engine mount.

Please tell me if I have been unclear or if there is anything else and I will try and explain it better. I have not taken my meds today so I may have forgotten something... Just kidding....

Jake H

 

[WatchItExplode]

yeah, I definately need to see some pictures of this...having trouble getting a mental picture.

 

[topstreet]

I will try and get some pics soon.

Simply put:

I re-made the factory front cross member pieces. They are now made of tubular. I have torque bars connecting this tubular bar to the lower control arms. The hope is that it will reduce any chance of wheel hop and stabilize the suspension.

Sorry about that... I was trying to give more detail to explain better and just made it more confusing.

Jake

 

[topstreet]

You must be logged in to view this image or video.

 

[jtmcinder]

What is it about the compression arm that makes you think you need this as well? If we had a true lower A-arm, then I can see the value of the added bracing (either forward or aft), but given where the compression arm mounts to the car, I can't see how your trailing link will help.

If it's the squishiness of the compression arm's bushing that is causing it to be ineffective, then replace the bushing.

Even worse, you have now created an impossible situation. The arc of the compression arm pulls back on the knuckle in bump and rebound. Your traction bar's arc will pull forward on the knuckle in bump and rebound. But the knuckle can't move in both directions at once, so the entire unit will bind.

The binding probably won't be a serious issue, because the compression arm has a large and squishy bushing, but that brings me back to the above: fix the compression arm; don't add another one on the opposite side of the knuckle.

- Jtoby

 

[topstreet]

What is it about the compression arm that makes you think you need this as well? If we had a true lower A-arm, then I can see the value of the added bracing

This is more of a reason to have it. These 2 arms that the 2Gs have are going to allow more flex and distortion than the 1Gs will.

I am happy with the results. Many owners of different types of cars are happy about them. We can talk in theory all you would like, but this is what is working for me.

 

[topstreet]

This is a product made for the hondas by Full-Race.com Also look at where the inner end of the link connects (topic starter) and you will see that it is going to the through bolt for the shock fork. This is a really nice refference if you wanted to make your own set. I am not 100% but, I do not believe that a company is making these for a 2G.. Or a DSM for that matter.

You must be logged in to view this image or video.

The Hondas are lacking the rear arm that you are reffering to on the 2G. Otherwise, the front suspension is very similar.

Personally, I would have to say that a heim joint rod end forward link is going to be more durable and benificial then the 2G cast, hooked, bracket that uses ball joints and rubber bushings. There is more leverage with the traction bars (to keep it straight) and more strength.

Considering that the 2Gs usually will make more power and are by far heavier cars... I would say, all the help they can get is going to help.

Jake

 

[underradar92]

If it's the squishiness of the compression arm's bushing that is causing it to be ineffective, then replace the bushing.

Even worse, you have now created an impossible situation. The arc of the compression arm pulls back on the knuckle in bump and rebound. Your traction bar's arc will pull forward on the knuckle in bump and rebound. But the knuckle can't move in both directions at once, so the entire unit will bind.



- Jtoby

There have been fabricators (Polk Racing for one) who have made 1g a-arms with solid bushings and heim joint attachments to address bushing flex and save a little weight to boot.

I've seen Jake's system and his torque arms are anchored approximately inline and at the same height as the theoretical pivot axis, so the binding isn't really a concern. Jake, the main (only?) real drawback to your system is the fact that the links add a bit of weight to our already nose biased pigs.

Not a super biggie to those with FWD, I suppose.

 

[jtmcinder]

Holy thread-jacking, Batman! I didn't notice until now that you have a 1G. The OP was asking about 2Gs and I was talking about 2Gs. 1Gs have struts with a real lower A-arm, so it doesn't surprise me that you like having a traction bar.

- Jtoby

 

[underradar92]

I noticed that, but I had a$$umed that since you were playing along, that 2g's had a similar issue, even though their suspension is a lot different.

 

[jtmcinder]

It's funny. When I saw the first post, I double checked that it really was about a 2G. But, after that, I stopped paying attention. When you look at how far back the compression arm mounts to the chassis, you'll see why I don't see much if any value -- and a lot of problems -- putting a traction bar on a 2G. Living with an offset twin-ball-joint pseudo lower A-arm is interesting at best. Trying to make a working computer model of the front end of a 2G was a trip, especially in turbo pascal.

- Jtoby

 

[topstreet]

There is absolutely no reason that this would not help a 2G. You could throw that heavy cast arm in the garbage at that point. That thing will never add the type of stable and positive driving charateristics that a forward mounted torque link setup will. If you would like to disagree with me, thats fine. I have nothing to prove, that I dont every time I drive the car.

I would rather help the thread starter (being a 1G owner or not, considering that I have and do own many 2Gs as well) then tell him that it is a bad idea. If you ran the setup in question for multiple seasons of racing and street use, and THEN had a problem with it, please jump in and tell us why we are all wrong and you are right. Theory and actual use are two very different things that get confused somethings. Im just trying to help.

 

[jtmcinder]

Cool. A Wiseman squabble.

There is absolutely no reason that this would not help a 2G.

No reason? The 2G's compression arm mounts to the car more than two feet from the inboard end of the lateral arm. That's a heck of big triangle, especially when compared to the triangles on 1Gs and Hondas.

To return the favor: why do you believe that arms which go forward are better than arms that go back? If anything, having the piece that keeps the knuckle from moving be under tension would seem better than having it be under compression. My => guess <= is that these aftermarket arms go forward because there's something to attach them to in front.

- Jtoby

 

[topstreet]

Cool. A Wiseman squabble.

"Ahhh... The game is a foot Trebek!"

Sorry if the implication was there, but I am not saying a forward mount would be better than rear. Just saying that the rod end system is better.

Personally, I would much rather put my faith in more than a cast bracket and ball joints. With an avid off-roading backround as well, I can positively tell you that rod ends (single or double shear) are very much stronger than ball joints. And the ball joints we break are much stronger and larger than the little Mitsu ones.

When the 2G application presents itself... Seriously ask yourself: If the factory were looking at the type of performance we DSMers demand... And they were soley looking at this, do you think that silly little cast arm is what they would have chosen? In my opinion... No...

The bend in the bracket is the other concern. Its the whole stand on a soda can thing... It works untill there is a crease in the aluminum.

You must be logged in to view this image or video.

Your move...

Jake

 

[jtmcinder]

If you can break a 2G's compression arm then I don't know what to say. I must be the girly man that I'm rumored to be. In other words: you can point at the curve all you want, but the thing is solid.

Now, if you want to argue that a straight arm could be made a lot lighter while being just as strong, I won't argue one bit, but that's a very different issue.

Likewise, if you go back up through the thread, you see that I've already raised the question of bushing squish. If your problem with th 2G compession arm is this, then, again, I won't argue, but that has nothing to do with whether you need to add forward-going braces, as well. Just replace the bushings.

The key points that I've been trying to make are these: First, there is no need to add another arm to a 2G, since it has one that provides an incredible triangle (because of the curve); if you have issues with the implementation of the 2G compression arm, then fix it; don't toss it out. Second, you cannot add a second arm to a screwy, psuedo lower A-arm where the two inboard pick-ups aren't coaxial. As the suspension moves up and down, the knuckle moves forward and back. (Long time fans of this forum will recognoze this as the issue that kills front shocks if you use those nasty little black bushings that come with a GC upper plate.) If you tried to add another arm on the front, the entire system would bind.

1Gs have a small triangle and a true lower A-arm (i.e., coaxial pick-ups). The first means that a T-bar would be helpful; the second means that it can be added.

2Gs have a huge triangle and non-coaxial pick-ups. The first means it doesn't really need a T-bar; the second means you can't add one, anyway.

There's not a whole lot more I can add to this. It's time to sleep, anyway.

- Jtoby

ps. you have force going in the wrong direction in your diagrams; at least, I assumed that we were talking about accelerating, not braking

 

[topstreet]

It's time to sleep, anyway.

- Jtoby

ps. you have force going in the wrong direction in your diagrams; at least, I assumed that we were talking about accelerating, not braking

I as well, am getting sleepy. Soo... sorry about that.

I was going to start drawing several different "force" arrows and then got sleepy as well and figured we could leave it as one. As far as the "failure point" I am not JUST saying breakage. I am also going to say bending or twisting. As an example of this: High HP 2Gs on the dyno will show the flex quite well. You can see the entire wheel move in or out with load. On my car, this went away after the links where added.

I am willing to say, that was a good debate. If your on for tomorrow... Just let me know!

Jake

 

[Zex4g63]

This is more of a reason to have it. These 2 arms that the 2Gs have are going to allow more flex and distortion than the 1Gs will.

I am happy with the results. Many owners of different types of cars are happy about them. We can talk in theory all you would like, but this is what is working for me.

After watching tons of video and seeing it in person, the 1G's are much worse than a 2G. Traction bars have been debated quite a bit lately. I was going to make poly bushing for the compression arm, but I'm worried it may make the suppension bind too much and become difficult to turn. Most likely I will be making a link setup like yours using the compression arms rear mount and the lower shock mount.

 

[jtmcinder]

The problem is the curve to the 2G compession arm. You can't do something like swap in a spherical bearing, as the arm will swing around and drag on the ground. But you also can't just install a bearing with just one degree of freedom, because the arm pulls in and pushes out when you steer, as well as goes up and down when you hit bumps. So, you're darned close to SOL when it comes to reducing the bushing compliance to zero.

- Jtoby