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

[Z33dori]

Originally Posted by Z33dori

sorry sit.

but once its all bolted up its pushing out on the endlinks. Then i took the bushing off the other day to drop my oil pan, and now i can get the bar back in right..... It seems like its forced in there. But last time i checked the hicas and non-hicas were the same length.

anyone? i really wanna put it back on w/o breaking shit

[SoSideways]

I didn't have any problems with my HICAS bar installation back when I put it on my car (S13).

Friend put a HICAS bar on his S14 without problems either.

Just loosen the D bushing brackets until you have the end links sorted out, then you can tighten the D bushing brackets.

Other than that, you might have bent end links or something.

[95KA-Turbo]

Just thought I'd post this up. You can see the angle my front control arms still have. I am going to work on getting them a little flatter.



I can definitely feel that the rear has more grip then my front. I am going to try and go up a tire size up front too (at least get a brand that runs wider and a grippier tire).

[SoSideways]

Looks like your upper strut mounting point and the LCA mounting points are right around 90 degrees there, which if your LCAs don't point any higher than that, you should be ok in terms of still having neg camber gain when the suspension compresses up front.

Doesn't matter how high the arm looks like it's pointing, the only things that matter are the imaginary lines made by the inner and outter mounting points of the LCA as well as the upper strut mounting point.

[95KA-Turbo]

I'm pretty sure my outer pick up points are ~4" higher then my inner pick up points for the front LCAs

[29psiHybrid]

Originally Posted by DC Dan MAX USA

The one on the right no one would do, it would add more Ackerman. The one on the left would maintain Ackerman (while quickening the steering and adding angle). And if the point was moved towards the brake rotor it would reduce Ackerman.

Thanks!

[SoSideways]

Originally Posted by 95KA-Turbo

I'm pretty sure my outer pick up points are ~4" higher then my inner pick up points for the front LCAs

If your's is that bad, then mine is definitely worse.

I'm running 215/40/17s up front and the tire is pretty much level with with the fender arch.

But then again, I'm running a 2" spacer between the knuckles and the lower arm.

[ballinnmiami240sx]

my modded knuckles and thats it. LCA's are pointing to the sky!!!! Sways bar is unhooked. Car felt awesome!!! We had to raise the car up because it would not handle for anything at the superslammed ride hieght we had it. Im over superslammed cars NOW!!!

[thefro526]

Kind of a shot in the dark here, but:

Does anyone know if you can run Angled Toe Arms and Ruca's (PBM or SPL style) with the DriftWorks Hubs? It looks like the Ruca would be close to touching the axle from the pictures I've seen but I think there might be enough room.

I want to figure out before I bite the bullet and order a set of rear hubs from DW now that I got the shipping sorted out and it won't cost $400.

[VIPDRFT]

Originally Posted by ballinnmiami240sx

my modded knuckles and thats it. LCA's are pointing to the sky!!!! Sways bar is unhooked. Car felt awesome!!! We had to raise the car up because it would not handle for anything at the superslammed ride hieght we had it. Im over superslammed cars NOW!!!

Is that with a stock KA? I don't see an intercooler.

[NYS13SLIDER]

can anyone please send me a picture of stock rear lower control arms that have been reinforced(boxed)? ive been searching and i know ive seen them on the sight,and maybe even in this thread but cant seem to find them now that my control arms are off the car and i have my welder in my hand and ready to start...ofcource! Thanks in advance for the help!!!

[ballinnmiami240sx]

Originally Posted by VIPDRFT

Is that with a stock KA? I don't see an intercooler.

YES...

Here a link to the car.......it goes hard
Sumospeed » Blog Archive » Sumospeed’s Charity car build

can anyone please send me a picture of stock rear lower control arms that have been reinforced(boxed)? ive been searching and i know ive seen them on the sight,and maybe even in this thread but cant seem to find them now that my control arms are off the car and i have my welder in my hand and ready to start...ofcource! Thanks in advance for the help!!!

This is how we did ours. dont copy the notch because it will cause your knuckles to be overcenter

[VIPDRFT]

Originally Posted by ballinnmiami240sx

YES...

Is it hard to maintan that angle with the low power?

[ballinnmiami240sx]

nope..its actually fun throwing the car around. This winter we are gonna pull the KA and 1jz the car for 2011 competition.

here is a pick of Matt P. s14. I say we are there angle wise!!!

[Tearlessj]

Heres a picture of my car. I don't have any roll center mods at all, just some PBM knuckles. Car felt pretty twitchy at the last event. The alignment shop read my front caster at 9.2. I don't know if it was read right or not. The tire nearly hits the firewall as is, I don't see how I can adjust it anymore. How can I get more tire on the ground?

Toe:-.01
Caster: 9.2
Camber: -2.5

[ballinnmiami240sx]

Your caster is way up there.

Our set up is:

Camber: F: -2.5 R: 0
Toe: F: Little out R: 0
Caster: 8.0


We play a lot with camber depending on how the car is switching back and forth. A reason for your twitchyness could be your extreme caster setting. I dont know anyone running anything pass 8.5. I think the stock setting is something like 6.5

[codyace]

Originally Posted by NYS13SLIDER

can anyone please send me a picture of stock rear lower control arms that have been reinforced(boxed)? ive been searching and i know ive seen them on the sight,and maybe even in this thread but cant seem to find them now that my control arms are off the car and i have my welder in my hand and ready to start...ofcource! Thanks in advance for the help!!!

[SoSideways]

Yeah I would decease caster back to around stock if I were you, as the less caster there is, the less positive camber gain the leading tire (in a drift) will get, and the less neg camber the trailing wheel (in a drift) will get, resulting in more tire on the road on both front wheels.

Unless you can't do any less caster than that, then your only option is to run a little more static camber (more than -2.5, like -4 or more) to counteract the caster.

[95KA-Turbo]

Yeah, its because you have your caster adjusted in an improper way. You need caster plates to run that much caster and not have your wheel look like its about the fly off. Most people just crank their tension rods down and pull the LCA forward, but that makes the shock go from I to \, the only way to fix that is to move the top of the shock forward too with caster plates.

What size tire are you running? I am hitting my firewall, but as you can see from my picture I am barely running any caster. I unfortunately need to add some, I would like to make some caster plates though.

[SoSideways]

Dude, go check out the GC plates.

All they did, was slot the holes where the 3 bolts go into the camber plate, so when you mount the camber plate onto the shock tower, you can literally move the camber plate forward or backward. It didn't look like a whole lot of adjustment, but there seem to be about at least a couple of degrees you can mess with.

So what I'm trying to say is, don't worry about no caster plate, just slot those holes on your current camber plates.

[thefro526]

Originally Posted by SoSideways

So what I'm trying to say is, don't worry about no caster plate, just slot those holes on your current camber plates.

If you did this would you just knock the studs out of the top hat and use a nut and bolt? I'm thinking of doing this to my coils as a temporary solution.

[95KA-Turbo]

You can't just slot holes though, you have to have a two piece set up to properly adjust camber and caster:

[Z33dori]

i need tension rods bad, D 6.2 P 7.2 ......

[SoSideways]

Why do you NEED that other plate?

You're not messing with camber when you slide the whole plate forward or backwards.











Pics courtesy of Ahmed from NRR.

[ballinnmiami240sx]

that looks like it would work, but 240 coilvers dont bolt in that like.



you would have to find a manufacturer that makes their top mounting plates wider, so you can mod them. In the picture is a Fortune Auto coilover to show the standard plates.

[SoSideways]

Ok, makes sense.

But my point was just that you don't ABSOLUTELY NEED a second bottom plate for them to be caster adjustable as well.

[PoorMans180SX]

Originally Posted by 95KA-Turbo

Yeah, its because you have your caster adjusted in an improper way. You need caster plates to run that much caster and not have your wheel look like its about the fly off. Most people just crank their tension rods down and pull the LCA forward, but that makes the shock go from I to \, the only way to fix that is to move the top of the shock forward too with caster plates.

What size tire are you running? I am hitting my firewall, but as you can see from my picture I am barely running any caster. I unfortunately need to add some, I would like to make some caster plates though.

You realize that the angle of the shock IS caster, right? The farther you move the LCA forward the MORE caster you will have. What he's saying is his caster is really high, but he's still hitting the firewall.

You are right in the fact that he needs caster plates, but he needs them to reduce caster after he pulls his LCA forward to keep from hitting the firewall.

Originally Posted by Tearlessj

Heres a picture of my car. I don't have any roll center mods at all, just some PBM knuckles. Car felt pretty twitchy at the last event. The alignment shop read my front caster at 9.2. I don't know if it was read right or not. The tire nearly hits the firewall as is, I don't see how I can adjust it anymore. How can I get more tire on the ground?

Toe:-.01
Caster: 9.2
Camber: -2.5

Slot your lower brackets on your coilovers. This is the only way to get more leading tire on the ground besides running less caster. The first choice would be running less caster. Use your tension rod to pull your tire farther from the firewall and use caster plates to decrease your caster. It might even out. You can always slot the strut tower (I know, lots of people are against this).

Are you running stock tension rods? If so, there's your problem. Those bushings are gone and causing the whole front suspension to move back with the bushing flex in those and the LCA.

BTW, your front roll center is at somewhere around the core of the earth.

Originally Posted by SoSideways

Yeah I would decease caster back to around stock if I were you, as the less caster there is, the less positive camber gain the leading tire (in a drift) will get, and the less neg camber the trailing wheel (in a drift) will get, resulting in more tire on the road on both front wheels.

Unless you can't do any less caster than that, then your only option is to run a little more static camber (more than -2.5, like -4 or more) to counteract the caster.

You're right, but to specify again, using a camber plate won't do. You have to think of how the shock turns when your wheels does. Camber plates don't affect the steering axis really, only slotting your lower coilover bracket will do that.

[Waylayer]

U can also take the main bolt out for the lca and put in a camber bolt to adjust ur caster. I had to do this after hitting a curb and ovaling out the hole for the main bolt.

[PoorMans180SX]

Originally Posted by Waylayer

U can also take the main bolt out for the lca and put in a camber bolt to adjust ur caster. I had to do this after hitting a curb and ovaling out the hole for the main bolt.

That will do nothing to adjust caster, only camber, and "camber bolts" aren't a good way to fix anything. They are really weak, and have no place in motorsports.

[SoSideways]

Originally Posted by PoorMans180SX

You're right, but to specify again, using a camber plate won't do. You have to think of how the shock turns when your wheels does. Camber plates don't affect the steering axis really, only slotting your lower coilover bracket will do that.

I don't know about that.

I have personally adjusted my front suspension to extreme positive caster, probably in the 8 degrees + range, and have seen my wheels lean over, and when I adjusted it back to close to stock, the leaning was much less severe, all without touching the camber, which was done via the top camber plate.

Apply your own thinking a little bit, about how the shock turns when the wheels do.

The wheels pretty much HAVE TO rotate pretty close to the angle of the struts, as the knuckles are bolted to the struts. Even with spherical bearings on the inboard pick up points of the FLCAs, the wheels will rotate around the axis created by the struts' top mounting points and lower mounting points (where it goes into the LCAs, either via ball joints or some type of spherical bearings and pins or bolts). There will be slight movement from the lower control arms as the knuckles pull/push them, and if there is no bind from the inboard pick up points of the LCAs, but they shouldn't affect the angle too much.

In any case, give it a try, see it first hand.