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

[GripTerror]

Originally Posted by DC Dan MAX USA

FLCA prototype

As you can see the connection point for the tension rod is as far towards the inside as we could get it so that if your car has super crazy knuckles your wheel wont be hitting.

That is sweet.

[PoorMans180SX]

And now PSM makes every suspension arm for the s-chassis. So cool.

[SoSideways]

The rod ends on the outside still scare me though...

Would be much more comfortable if it was a spherical bearing inside a bearing cup mount.

Also, have you guys tested those out yet? I'm curious to see what the effects are with zero steering axis inclination on those arms.



BTW, slight update from me: last night, I was taking my passenger side front coilover's spring off so I can work on that side, and while mounting the coilover back up, I decided to mount it so the slot in the camber plate is diagonally pointed, so I can mess with caster a little bit there.

Haven't really gotten anywhere with that yet, as the passenger side spacers and shims need to be dremelled down a little bit first, since I'm binding a little bit approaching full lock, so once that's done, I should have a little more info about how that setup would be like.

So far, it looks like I might have lost some camber, but the upside is, the caster looked less severe, even over stock, so the wheels shouldn't get huge camber changes while in the full lock positions, so no need to run ridiculous amount of camber.

Downside is, my wheels might not fit under the fender anymore due to the lack of camber lol D'OH!!!

[conrad_s13.5]

cant wait till some of all their prototypes are available!

[PoorMans180SX]

Originally Posted by SoSideways

The rod ends on the outside still scare me though...

Would be much more comfortable if it was a spherical bearing inside a bearing cup mount.

Also, have you guys tested those out yet? I'm curious to see what the effects are with zero steering axis inclination on those arms.

I'm sure it will go through plenty of testing.

And, the arm doesn't really have an effect on steering axis, the rod end/shank will be angled when put in the ball joint hole.

[SoSideways]

Originally Posted by PoorMans180SX

I'm sure it will go through plenty of testing.

And, the arm doesn't really have an effect on steering axis, the rod end/shank will be angled when put in the ball joint hole.

Well then I hope there's enough room for the pin to move around on those rod ends and not bind up.

That's how my setup is getting me into trouble, the bearing itself is on the edge of almost not having enough range of motion.

[95KA-Turbo]

Originally Posted by SoSideways

The rod ends on the outside still scare me though...

Would be much more comfortable if it was a spherical bearing inside a bearing cup mount.

Also, have you guys tested those out yet? I'm curious to see what the effects are with zero steering axis inclination on those arms.



BTW, slight update from me: last night, I was taking my passenger side front coilover's spring off so I can work on that side, and while mounting the coilover back up, I decided to mount it so the slot in the camber plate is diagonally pointed, so I can mess with caster a little bit there.

Haven't really gotten anywhere with that yet, as the passenger side spacers and shims need to be dremelled down a little bit first, since I'm binding a little bit approaching full lock, so once that's done, I should have a little more info about how that setup would be like.

So far, it looks like I might have lost some camber, but the upside is, the caster looked less severe, even over stock, so the wheels shouldn't get huge camber changes while in the full lock positions, so no need to run ridiculous amount of camber.

Downside is, my wheels might not fit under the fender anymore due to the lack of camber lol D'OH!!!

Haha, that's a clever idea! You can always wallow out the top bolt hole for some camber if you need to - assuming you have enough space between your wheel and coilover.

I may have to mock that up once everything is bolted together on my front suspension.

[SoSideways]

As you can see, it sits like a good inch more forward, but you're losing a lot of camber from that.

Then again, I just realized, I can reposition it so that it's diagonal the other way, so that I'd still have a bit of camber, but also less caster.

Guess I was a bit more tired yesterday when I started to do this than I thought... I knew something wasn't quite right lol good thing I decided to post this on here hahaha

[S14DB]

Slot the upper bolt hole in the upright.

[DC Dan MAX USA]

~ Some fitting on the car revealed the proper angle of the rod end (not the stock angle).
~ Pillowball is near its max while the car is on the lift and it is well within its range while the car is on the road.
~ You can see that the tension rod is just inside the front sway bar so if you were to do some knuckle mod with zero ackerman you have the freedom here.
~ We repositioned the SAK like Tommy Roberts proto knuckle and also did the same Roll Center adjustment.
~ As you can see there is massive angle achieved here with additional reduction in ackerman and the tie rod is NOT overcentered and the rack has not been moved.
~ Dont let the camera fool you there is still some ackerman otherwise we would be touching the sway bar with the wheel.
~ Knuckle RC mod puts the LCA end joint really close to the brake rotor which is the reason for the double LCA adjusters.
~ This LCA needs to be really long (and the tie rods too) so before the REIB police come after me, let me test this at the track first and then we may put a non adjustable end on the LCA but unfortunately that may require two different lengths of LCA one for RC modded knuckled and one for normal knuckles.
~ We did not change the KPI angle much here but it will need to be more vertical if additional RC change is done through the use of a longer taper rod. However I dont think the car will need more RC change in the front since most automotive engineers would agree that the the roll axis inclination needs to be lower in front. I'll let the track testing be the judge.

[Jonnie Fraz]

Good God Almighty! That is amazing! I can't wait for some cool testing videos. Please keep up the great work Dan.

[Om1kron]

you just changed my fucking life right now Dan, I have no use for any of these parts but I would totally buy them if I was into drifting.

[GripTerror]

i know that all looks epic for drifting but what about us lil guys the grip guys lol that looks insane though lol

[DC Dan MAX USA]

best compliments ever! thanks guys.

Drift or grip, its just different settings.

Grip guys need to do all of the mods except the steering angle and you are good.

[95KA-Turbo]

Very, VERY cool Dan. I can't wait to see how your track testing goes!

I hope mine prove to work as well as I hope they do.

[recklessrob]

msglength ftw

[GripTerror]

Ya I just don't want all that crazy angle not sure how you dial it out, as I thought this was a fixed package deal

[PoorMans180SX]

Originally Posted by GripTerror

Ya I just don't want all that crazy angle not sure how you dial it out, as I thought this was a fixed package deal

Ummm, don't turn that far? They can make them so that they barely change your ackerman at all. All it will be like is having a Hicas rack.

Originally Posted by DC Dan MAX USA

~ We did not change the KPI angle much here but it will need to be more vertical if additional RC change is done through the use of a longer taper rod. However I dont think the car will need more RC change in the front since most automotive engineers would agree that the the roll axis inclination needs to be lower in front. I'll let the track testing be the judge.

I'm pretty sure this is the craziest angle I've ever seen. Looks like you had to kink the arms up after all eh? Cool stuff.

Don't forget however, that the front roll center also drops faster than the rear. I'm sure you'll be able to figure everything out during testing.

[GripTerror]

Yea well, that's dumb "don't turn that far", that's not a smart answer or solution.

[thefro526]

Originally Posted by GripTerror

Ya I just don't want all that crazy angle not sure how you dial it out, as I thought this was a fixed package deal

Pretty sure you could get adjustable stops put on so the wheel would stop before it gets crazy angle.

Or you could just have crazy angle and never use it unless you absolutely need it. (Better to have something and not need it than to need something and not have it.)

[GripTerror]

I rather not have it, anything could happen and suddenly i could accidentally turn that much in a race situation i rather not.. i know it sounds stupid but its just as stupid as saying well dont turn that far... seriously Ah well I'm sure PBM will have a solution for us grip guys

[PoorMans180SX]

You are making no sense.

Use the steering wheel like you normally would. It's not hard.

Of course you will have to get used to the quicker steering, but that's not hard either.

I'm sure if you're really worried about it, PSM will weld an adjustable bumpstop on the LCA for you.

[SoSideways]

Originally Posted by DC Dan MAX USA

~ Some fitting on the car revealed the proper angle of the rod end (not the stock angle).
~ Pillowball is near its max while the car is on the lift and it is well within its range while the car is on the road.
~ You can see that the tension rod is just inside the front sway bar so if you were to do some knuckle mod with zero ackerman you have the freedom here.
~ We repositioned the SAK like Tommy Roberts proto knuckle and also did the same Roll Center adjustment.
~ As you can see there is massive angle achieved here with additional reduction in ackerman and the tie rod is NOT overcentered and the rack has not been moved.
~ Dont let the camera fool you there is still some ackerman otherwise we would be touching the sway bar with the wheel.
~ Knuckle RC mod puts the LCA end joint really close to the brake rotor which is the reason for the double LCA adjusters.
~ This LCA needs to be really long (and the tie rods too) so before the REIB police come after me, let me test this at the track first and then we may put a non adjustable end on the LCA but unfortunately that may require two different lengths of LCA one for RC modded knuckled and one for normal knuckles.
~ We did not change the KPI angle much here but it will need to be more vertical if additional RC change is done through the use of a longer taper rod. However I dont think the car will need more RC change in the front since most automotive engineers would agree that the the roll axis inclination needs to be lower in front. I'll let the track testing be the judge.

A lot of those points I have already covered with my reports, so I guess it's true even for arms of different design.

Take note people.

So far, I've noticed 3 definite things that is true between all the different types of FLCA designs:

1) if you are low, the FLCAs have to be quite long to place the ball joint/spherical bearing/rod ends in their optimal range.

2) if you are low, the tie rods themselves have to be pretty long. Tein S-chassis tie rods I know for a fact should be long enough for the job, if you pair them up with the SPL tie rod ends. I think the Ikeya Formula tie rods will be long enough too, from the measurements that Dan gave me awhile back.

3) if you space the FLCAs too much, there will come a point where the arm itself (if it uses a spherical bearing) or the rod end will come into contact with the brake rotor.

4) if you have too much angle, you will hit the tension rods

5) if you have too much angle, you will hit the tie rods, and/or hit the brake caliper bracket in the wheel well and the lip on the frame.

Originally Posted by GripTerror

I rather not have it, anything could happen and suddenly i could accidentally turn that much in a race situation i rather not.. i know it sounds stupid but its just as stupid as saying well dont turn that far... seriously Ah well I'm sure PBM will have a solution for us grip guys

Instead of spinning out on track, you could be a hero and save it with that much angle.

You do sound stupid as hell.

[conrad_s13.5]

mother of god

[PoorMans180SX]

BTW, PSM makes tie rods (inner and outer) now as well. Inners are long like S14.

[slow_sr20]

Originally Posted by SoSideways

BTW, slight update from me: last night, I was taking my passenger side front coilover's spring off so I can work on that side, and while mounting the coilover back up, I decided to mount it so the slot in the camber plate is diagonally pointed, so I can mess with caster a little bit there.

i remember back in the enjuku racing, matt back vasssssss days they used to setup their front like this. saw the cars in chicago for formula d a few years ago. said it helped out with caster adjustmet. haven't notice anyone else in formula d running it like that since then. not sure if i have any pics from that long ago or not.....

[GripTerror]

DAMN those tie rods look more beefy than my tein z33 tie rods with spl outers holyyy

And dude, i like quicker steering BUT don't want the angle that is all and I hope they have a solution to adjust that or whatever with different length 'locks' or something to differentiate or whatever.

[SoSideways]

Then when you get their SAK, tell them to grind that plate down so that instead of it angling outward for more angle, to angle it inward like stock, and use the hole towards the front and not the hole in the back (that's what she said).

Jebus, this isn't rocket science.

After 49 pages of this shit, I figured people would have a little more understanding on how this stuff works by now.

FUCK.

Anyway, slow_sr20, after going out to the garage and messing with different ways of mounting the camber plate up top, I decided to leave it the "stock" way, where it just goes straight in and out (that's what she said) to adjust only camber, as when I flipped it the other way, there were BARELY any noticeable difference in caster... like, maybe half an inch more forward (due to the camber plate design though, other camber plates might result in something different), but I lose a lot more camber doing this, thus it was actually like taking a step forward, then 2 steps back.

[nieko]

Yeah bro... there is 2 tie rod mounting holes on the PSM knuckles to choose from...

mount in on the farther back hole, slower steering, less angle.

lol so simple.

and you make no sense... usually the grip guys dont want the super fast steering, its not the angle that bothers them.....

[SoSideways]

Nah, grip guys want the faster steering.

That's why the Evos tend to have a "sharper handling characteristic" over the Imprezas, because Evos came with a pretty damn quick steering rack. The Imprezas were stuck with a relatively slow rack.

I just put in a HICAS rack, at least I hope it's a HICAS rack... it only takes like a turn an a half to hit full lock from center. From what I can remember, that's a bit quicker than the stock non-HICAS racks.