This is the roll center, suspension pickup, and steering angle modification thread.

[SicBastard]

What part numbers/suppliers did you guys use in the front LCA?

[95KA-Turbo]

Kill240 - you didn't weld that housing on with the sphericals in place did you? I'm not sure why you would be having issues with them moving if they're brand new.


Def has a little write up on NRR about making some cheap LCAs.

Here's the link - after searching for it I realized I have hours of reading I need to catch up on at NRR, but part of me doesn't want to read it because I don't want to rip my suspension apart again (right now).

HOW TO: Ultimate budget front LCAs - Nissan Road Racing Forums

[killer240]

Originally Posted by 95KA-Turbo

Kill240 - you didn't weld that housing on with the sphericals in place did you? I'm not sure why you would be having issues with them moving if they're brand new.

i didnt weld it, i had a shop welded it. but he only welded the housing on the arms. then i had another shop pressed the sphericals in.
yes, they are brand new. thats why i dont get why it turned out like this.

i might have to get new spherical bearings and housing because i dont think i can still save these ones i got. ill just have to grind off the welds and start again. ugh

[singlecamslam]

I was going to do the same thing in that write up, but i swear i got the crappiest GS arm, it was so oblong and crappy i just threw it away. I did though cut off the heim joint part and welded it on my stock arm, and also welded in a housing like the above picture, so the stock arms is as adjustable as any aftermarket arm, will have a crappy cell pic later.

[killer240]

hmmm maybe i can just press the sphericals out again and wire brush the inside of the housing. that write up def did is really nice but i dont think i wana start all over again. maybe i will try that one later or just go with PBM

[SoSideways]

You need to get yourself a caliper and find out what the I.D. of the housing is, and then find out what the O.D. of the spherical bearing is.

The welding process could have warped the housing a little bit to where it is out of round, which would cause the bearing to be tight.

My suggestion is for you to take the bearings out (you can use the socket + hammer method of "pressing" the bearings back out, if they aren't in too tight), then measure everything first, and make sure the bearing cups are still round.

I would say to make sure the clearance is about .002", that should give you a nice easy press fit, to where it still requires a little bit of force to press the bearing into the cup, but it won't take a press; a light'ish hit with a hammer on a socket will drop that bearing into the cup.

With a light press fit, the bearing should stay in place, while being able to rotate freely without the housing holding it in place, which is what's happening to your's.

Oh, and use some grease to help with the "fit". I used wheel bearing grease.

[GripTerror]

so any updates from pbm, any updates from def on his potential design, any updates from driftworks?

[SoSideways]

Def said he probably won't do the knuckles anymore, but may go ahead with designing a FLCA solution.

[SicBastard]

Thanks for the link to Def's NRRF article! Do you have to machine your own bearing cup, or is there an available solution? Def used the original bearing cup that was already installed in a Godspeed LCA, but I'd like to just modify my stock arms.

[SicBastard]

After a bit more searching I found these cups

Off Road Warehouse - Racing Parts FK Bearings Rod End & Uniball Kits COMH24T Kit - 1.5" ID Uniball Kit

but the kit is $150 per corner! Looks like the bearing is an FK, but the cup part number looks to be made by "H&M". Anybody have any idea who H&M is?

[SicBastard]

UNI-BALL WELD CUP, 1-7/16" ROD END INSERT - C73-443 at The Chassis Shop

$37 per corner!

[singlecamslam]

The UB machine ones are the cheapest, 13.50 per corner.

[PoorMans180SX]

Originally Posted by GripTerror

so any updates from pbm, any updates from def on his potential design, any updates from driftworks?

Parts Shop MAX arms are at the factory being tooled.

Driftworks G2's look nicer than the old ones:

Driftworks | Christmas has come early. GeoMaster2 now in stock.

This is a good shot that hasn't been posted yet:



Pretty much zero ackerman from what I can see.

[GripTerror]

ya thats way too much angle for my 295s up front... the tires would shred to bits n pieces lol... if for whatever reason I were to steer more and not realize it...

[PoorMans180SX]

Big steering stops are your friends.

[SicBastard]

I've got a basic roll center question. Ideally the roll center would as close to the CG as possible, and move as little as possible in compression. Lets say we really go extreme with roll center correction and we actually get the resting height of the roll center ABOVE the CG, and then in compression it moves to BELOW the CG. This set-up would of course minimize roll couple at all times, but would it lead to an unstable feeling? Is the IDEAL set-up really to have the resting roll center at (or below) the CG and then let it only move away (lower) with compression?

My thinking is that the force vectors of the roll couple would be changing 180 degrees as the roll couple goes from positive to negative with a path above-to-below the CG. And this would cause an unpredictable feeling. Am I off base?

[PoorMans180SX]

You're totally right. Having your roll center right at or above CG would definitely be weird feeling as your car rolls.

You ideally want the RC a little below the CG.

It's one of the first questions I asked in this thread, and Def said the same thing.

[SoSideways]

Originally Posted by SicBastard

UNI-BALL WELD CUP, 1-7/16" ROD END INSERT - C73-443 at The Chassis Shop

$37 per corner!

That cup is not big enough.

The O.D. of the AIB12T bearing that Def and I used for our modded GS arms is 1.5000", and the YPB12T bearing that I wanted to use has an O.D. of 1.5625", and I honestly have not found any readily found bearing cups on the market that will accommodate the 1.5625" O.D. bearings, so no go there...

[killer240]

Originally Posted by SoSideways

You need to get yourself a caliper and find out what the I.D. of the housing is, and then find out what the O.D. of the spherical bearing is.

The welding process could have warped the housing a little bit to where it is out of round, which would cause the bearing to be tight.

My suggestion is for you to take the bearings out (you can use the socket + hammer method of "pressing" the bearings back out, if they aren't in too tight), then measure everything first, and make sure the bearing cups are still round.

I would say to make sure the clearance is about .002", that should give you a nice easy press fit, to where it still requires a little bit of force to press the bearing into the cup, but it won't take a press; a light'ish hit with a hammer on a socket will drop that bearing into the cup.

With a light press fit, the bearing should stay in place, while being able to rotate freely without the housing holding it in place, which is what's happening to your's.

Oh, and use some grease to help with the "fit". I used wheel bearing grease.

im thinking your right, the cup probably got out of shape from welding it on the arm.

anyways i remember the shop that pressed the bearing in said he used 10,000 pounds. so i have to go back there and have it out again.

[GripTerror]

Originally Posted by PoorMans180SX

Big steering stops are your friends.

Who is this friend and where can I meet this friend lol

[az_240]

I'm currently in the same boat trying to find a cheap solution to adjustable roll center.
Any additional info on the Godspeed setup on low cars would be great. Specifically about the outer spherical possibly binding.

[GripTerror]

Check this find out manual rack in the works and there will be a column mounted EPS option too that will be like an s2000 (turns off at higher speed -- also a programmable version):



Interest Check: Performance true manual rack for s13 and s14 : 240sx General Discussion - Page 5

Been taking a while but I suppose some of you guys could put some feedback in there although this is still in prototype stages.

RX7 guys loved theirs.

[PoorMans180SX]

Originally Posted by GripTerror

Who is this friend and where can I meet this friend lol

his last name is welder, and he can be found in lots of peoples garages.

Why would you want a manual rack?

[GripTerror]

be more specific lol.

Why would you want an ancient slush pump rack lol.

[Pandapants]

wont the wheel hit the tension rod on those DW knuckles?

[PoorMans180SX]

Originally Posted by GripTerror

be more specific lol.

Why would you want an ancient slush pump rack lol.

I'm saying weld some big-boy tie rod stops onto your LCA's. Excessive lock problem solved.

Because I like to be able to turn in parking lots. And I don't want my thumbs broken off when I let the wheel autosteer and go to catch it while drifting.

Originally Posted by Pandapants

wont the wheel hit the tension rod on those DW knuckles?

Maybe. That's what spacers are for.

And if it does? Smooth tension rod meets smooth wheel or tire. Can't really do much damage.

PSM lower arms have the tension rods moved in farther btw, so that would help.

[nieko]

This is for whoever asked, i think 95ka-turbo or whatver!

Outter LCA point



Inner LCA point




Tension rod.

[GripTerror]

Originally Posted by PoorMans180SX

I'm saying weld some big-boy tie rod stops onto your LCA's. Excessive lock problem solved.

Because I like to be able to turn in parking lots. And I don't want my thumbs broken off when I let the wheel autosteer and go to catch it while drifting.



Maybe. That's what spacers are for.

And if it does? Smooth tension rod meets smooth wheel or tire. Can't really do much damage.

lol build some forearms man... plus a car is meant to be driven not parked

[PoorMans180SX]

Haha, have you ever tried to catch an autosteering wheel without power steering?

It will definitely wreck whatever's in it's path.

Plus I don't like to have to struggle through high-speed sweepers. You should be focusing on how the car is reacting, now how hard you have to push/pull the steering wheel.

[Def]

Originally Posted by SicBastard

I've got a basic roll center question. Ideally the roll center would as close to the CG as possible, and move as little as possible in compression. Lets say we really go extreme with roll center correction and we actually get the resting height of the roll center ABOVE the CG, and then in compression it moves to BELOW the CG. This set-up would of course minimize roll couple at all times, but would it lead to an unstable feeling? Is the IDEAL set-up really to have the resting roll center at (or below) the CG and then let it only move away (lower) with compression?

My thinking is that the force vectors of the roll couple would be changing 180 degrees as the roll couple goes from positive to negative with a path above-to-below the CG. And this would cause an unpredictable feeling. Am I off base?

You don't want roll center right at CG and definitely not above it. It will move(vertically and laterally) when you corner. You don't want a huge percentage change in roll couple as the car goes into a corner. It'll give it an odd feeling as your total roll moment shoots way up as the car rolls(and makes it want to roll more etc.).

A larger static roll couple gives you less percentage increase as the roll center migrates. But you don't want to get a huge roll couple all the time. As with most things with suspension, there's a compromise on setting the car up.