On the research I've done, the 97+ DSMs have more positive Passenger (Right) caster than the Driver (Left) side of the car. I mainly use my car for the streets and AutoX and would like to even the caster up a bit (currently pulls to the left slightly).

Question is:

There's a bushing on the front lower compression arm that can be pressed-out & flipped to change the caster ever so slightly. So which one do I need to flip? The Driver side or the passenger side? Or does it really not matter that much in the long run as far as handling & performance is concerned?

-Tsunari

The bushing to flip is on the inboard end of the driver's side compression arm. This will add caster to this side. If you flip the passenger side, you will also get the casters closer together, but at the lower value. And (up to a point) more caster is better.

- Jtoby

ps. this mod adds around a degree of caster ... not a small amount by any means

sweet . . . thanks for the quick reply JToby

As a follow-up, let me explain the pros and cons of more caster.

On the good side, more positive caster means a larger gain in negative camber for the outside front when you steer. Think of it as free camber when and only when you need it, allowing you to run less static camber, which keeps the tread flat for launching. Put another way: although very few BMWs use the fronts for power, M3s have something like 6 degrees of caster. That would be a good target for us, too, but even with the flipped bushing, you only have about 4 to 4.5 degrees.

On the bad side, more caster means that the relative heights of the front wheels are mis-adjusted more when you steer. In particular, it pushes the inside down while pulling the outside up (assuming that you have some negative camber to start with - a safe assumption, I believe), which accentuates the effects of body roll. In the extreme - as in when you have a very stiff chassis - this affects all four corners as the car is effectively made to have poorly set-up corner weights for the turn that you are making. But this isn't really an issue on our cars, since we all have the torsional stiffness of over-cooked pasta. One popular car that it does affect is the Impreza (incl the WRX), since those cars have an amazingly stiff chassis. I've heard the same of Evo8s, but never had a chance to jack one up and play with it.

One other side-effect of caster is self-centering steering. The more caster you have, the more the fronts want to self-center. This can be seen as good or bad. I don't really like it, but I'd still take 6 degrees of caster if I could get it.

- Jtoby

Since I've found some ambiguity on the subject, I assume you mean the "compression" arm to be the curved arm that points toward the rear of the car, and the "lateral" arm is the straight "dogbone" shaped piece that is replaced for the ball joint recall?

And I assume the inboard bushing is the one to the rear of the compression arm, that has the chunk of metal in the middle with two bolt holes for connecting to the bottom of the chassis?

Ryan

TurboGarageTech said:

Since I've found some ambiguity on the subject, I assume you mean the "compression" arm to be the curved arm that points toward the rear of the car,

Click to expand...

Correct

and the "lateral" arm is the straight "dogbone" shaped piece that is replaced for the ball joint recall?

Click to expand...

Correct

And I assume the inboard bushing is the one to the rear of the compression arm, that has the chunk of metal in the middle with two bolt holes for connecting to the bottom of the chassis?

Click to expand...

Correct


When I get around to doing it, I'll get some pictures in this thread for reference . . .

Digging through threads, and talking with a few of you on here (you know who you are . . .) it has come to my attention that the 97-99 front suspension has a bit more passenger-side caster (5*-7*) while the driver side has a bit less (3*-5*). The reason being is sometime in 95-96, Mitsubishi aparently had enought complaints about the car drifting on crowned roads that they decided to remove some caster out of the driver side. They accomplished this by flipping the bushing on the driver-side lower compression arm.

Now for those of us who live on an autoX course, we would LOVE to even this back out seeing as how there are just as many left turns as there are right turns on a course. Here's my question:

The ball joint on my compression arms need to be replaced- hence I need to goto satan and get new compression arms. If I get a VIN # off of a 95-96 eclipse, will the bushings I've referred to be as I want them? (i.e.- I will not have to press that mutha out and flip it . . .)
If so . . . are the dimensions of the arm identical to the 97-99 compression arms?

Hoping someone out there has some 1st hand experience with this!

Nope, you will get a 'flipped bushing' arm, same as everyone else. The 95 arm in its original form is NLA.

You'll have to flip the bushing yourself.

Charles

ACM said:

Nope, you will get a 'flipped bushing' arm, same as everyone else. The 95 arm in its original form is NLA.

You'll have to flip the bushing yourself.

Charles

Click to expand...

That's kind of what I was thinking . . . The arms for the RS/GS/GST/GSX should all be the same though -ya? Don't think I've ever come across anything mentioning that part of the chasis being different. Mainly just brakes, sway bars, and the rear-end in the case of the GSX . . .

Note, also, that since you have a 97, you cannot do the bushing-flip trick in Stock. It's a gray area in STX, since you could try to argue that it was part of your home-made "camber kit," but that sounds tortured to me. You're fine in ESP and above.

- Jtoby

jtmcinder said:

Note, also, that since you have a 97, you cannot do the bushing-flip trick in Stock. It's a gray area in STX, since you could try to argue that it was part of your home-made "camber kit," but that sounds tortured to me. You're fine in ESP and above.

- Jtoby

Click to expand...

AH! That hadn't even ever crossed my mind. . . Maybe this next question deserves a different thread, or discussion off-line, but I wanted to get rid of my rear camber kit from Ingalls for 2 reasons:

1) The monkeys @ the alignment shop NEVER adjust the 2 cam bolts the same- for some reason they think one of the bolts is for adjusting camber and the other is for toe

2) I *THINK* the cam is slipping over time (IE- not retaining its settings) - perhaps the bolts just aren't being tightened down enough?

Anyways . . . I wanted to switch over to the homemade washer kit, but I do believe this is illegal in anything below SM for Solo2 because the upper A-Arm would no longer be using the stock mounting point? Does that sound right?

Relax. Shims are legal in SP (15.1.F). Shims are a form of "camber kits" and are, therefore, also legal in ST (14.8.G).

- Jtoby

jtmcinder said:

Relax. Shims are legal in SP (15.1.F). Shims are a form of "camber kits" and are, therefore, also legal in ST (14.8.G).

- Jtoby

Click to expand...

sweeeeeet- I must have definitely missed that part (although I have no idea how with as many times as I've read through the book).

Thanks yet again Jtoby!

ACM said:

Nope, you will get a 'flipped bushing' arm, same as everyone else. The 95 arm in its original form is NLA.

You'll have to flip the bushing yourself.

Charles

Click to expand...

Just got off the phone w/ Satan . . . here are the part #'s for the lower compression arms:

95 GST:

MR162583 - left
MR162584 - Right

97 GST:
MR296292 - left
MR296291 - Right

So you thinkin if I order the 95 ones, they'll just send me the ones for the 97+ ?

I don't know if this was a typing error on your part or you were dealing with typical Mitsu people, but MR296291 is the left, not the right, and MR296292 is the right, not the left.

Also MR162583 is NLA and is now MR296287 while MR162584 is now MR296288. In this case the sides are correct, but those parts are for a non-turbo, not a GST.

You can check these yourself at: https://www.mitsubishiparts.com/oe_parts_catalog.html

- Jtoby

Those were straight from the mouth of Mitsu ppl . . . Thanks for clearing it up for me JToby. Guess I'll go ahead and order the ones for my car and just flip the bushing. 10-ton press you say? hmmm . . . wonder where I could source one of those . . .

Alright, to follow up on this thread for any who are following it . . . I have FINALLY gotten the lower control arm bushing on the driver's side flipped!! Ordered some new ones from the dealership since the ball-joints on mine were pretty much worn out and I REALLY didn't want to go through the hastle of flipping the bushing on something that should be replaced anyways.

For those of you looking to do this yourself, a 1 5/8" deep impact socket fits around the bushing quite nicely. I've attached a picture of the final results - big thanks to all who've helped out in this venture to get my car to handle that much better . . .

Okay . . . Okay . . . yeah- I suck Almost completely forgot about this thread, but I actually got the bushing flipped in June of '05 and here are a couple of pix for reference.

If you look at the holes, you will notice they are slightly off-center of the metal bar. In the picture with both compression arms, you'll notice they are on the same side of the center-line. . . this is after the driver-side bushing was flipped.

Hope this helps someone!

This is interesting.

Referring to the the last photo.....that is how my bushings already were oriented when I removed my original Compression arms. Bolt holes offset away from the ball joint. (I got my car completely stock.)

And when orderd my new arms the bushings were oriented the same to how yours were when you ordered them. Passenger bolt holes were offset away....but the driver was offset towards the ball joint.

I flipped mine around just as you did, but no because of the caster(I did not know of any caster difference between sides)...I just wanted the bushing to be identical to what originally came off my car.

So with that said.....I think Mitsubishi has been doing the caster correction on there own now, witch would explain why the driver side arm comes with the bushing bolt holes offset towards the ball joint......and by flipping that new one....we just just did the opposite of what we were trying to achieve.

Anyone understand?

My thread here: http://www.dsmtuners.com/forums/handling-tech/319825-what-deal-2g-compression-arms-bushings.html

What is Jtoby refering to when he said "97's cannot do the bushing flip-flop in stock"?

"Stock" is a racing class. Under the class rules, people with 97's can't perform this "modification".

Im so confused....

OK With some more carfull reading I have come to a new conclusion.

When mitsubishi decided to flip the Bushing it must have been after my build date of 8/23/96.....BECAUSE my original driver side compression arm bushing was oriented the correct way that would keep the caster equal on both sides.

That explains why both me and Tsunari got the driver arm with the bushing flipped 180* when compared to the passenger arm.....as it was mistubishi "FIX" to the "drifting on crowned roads" complaints.

This might make sense.

The top pic above shows a drivers side arm, typical of what you get when ordering new mitsubishi replacement parts. The bushing in this configuration lessens the caster on that side, theoretically optimizing handling on the right side of a crowned road. For equal (and generally better) cornering, the drivers side bushing is flipped 180°. The bottom pic shows a flipped bushing so that it matches the right side arm, allowing more and similar caster on both sides.

Right! I got it now. Thanks Wret.