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

[godrifttoday]

i get 80 degree of lock

[Johannes]

Soooo... a question here.
Thinking about doing the monoball housing/bearings on my front S14 LCA. (S13 Car)

And from my research, people who lengthen their ball joint to correct roll center, gives them toe in because the ball joint stud would angle inwards.

I already have heim outer tie rods, al. hex tubing for my outer tie rods, and S14 inners, and toe adjustment is max. Toe in max that is, for both sides (of course, toe measurement is at 0*).

My question is;
If I lengthen my ball joint (What 95KA-Turbo did), would I need to weld on a tube insert with adjustable heim joint on the other side to compensate for the toe in problem that this will give? Or should I be fine with stock LCA crossmember point, and extended monoball balljoint?

Or.... I can always cut some threads off of my inner tie rod and I could have more toe adjustment? Will it be enough though? Hmm.

Also, another question..
People have been having problems with the LCA rubbing on the rotors, are there any other solutions to this except for grinding some off of the LCA? Or is it actually enough for it not to rub?
I'm guessing this is all depending on how much roll center correction you've done? More spacers = more closer it sits to the rotor?

[Taylor008]

Originally Posted by Johannes

snip

I'm confused to what you're asking. If you use RC correction on the (knuckle) ball joint, I don't see how you're going to be changing toe. Are you sure you're not confusing toe with Ackerman?

For your second question I'm not sure. But I wanna ask another question now, on RC corrected KNUCKLES like MAX, do you guys still run into this lca+rotor problem?

[PoorMans180SX]

Originally Posted by Taylor008

I'm confused to what you're asking. If you use RC correction on the (knuckle) ball joint, I don't see how you're going to be changing toe. Are you sure you're not confusing toe with Ackerman?

For your second question I'm not sure. But I wanna ask another question now, on RC corrected KNUCKLES like MAX, do you guys still run into this lca+rotor problem?

No, the roll center correction is made by dropping the lca hole straight down, so clearance stays the same in that regard.

[Ash pants]

Must say i have been looking at this thread for a long time and its all crazy!! (in a good way)

Re problems with knuckle rotor clearence, i have the old style psm kit that i had an engineering place fit up and do the roll center correction and with 32gtr brakes its tight but more so the problem is with alot of caster 7plus rotor can touch on lock without silly amounts of camber (running around 4) so im running around 6 and that seems good.

Have been running them for a few years now and on two cars but havent done a heap of track time due to time, money, lack of a car that holds together. And im really only starting to get a feel for them. I think fast steering is great but unsure if all the rest helps me at all (well not spin as much maybe)

Anyways just wanted to say Hi as i have been lurking waaay too long.

So a big hello from oz

[swiftmini]

I use driftworks knuckles and even though they can only do 55degree lock I can't imagine ever needing or wanting more. My lock is retarded in my opinion. And now that the roll centres and weight distribution and front/rear grip ratio are set perfect for my style, the car is literally impossible to spin and does backwards stuff without ever trying.

this whole lock quest thing is stupid imo. Infact I'm gonna start reducing my lock now until it effects my driving or driving style.

Imo if you gonna get knuckles they should be of a conventional style like gktech, part shop max pro mod or forged and also the geomaster.

No need for anymore imo!!

[PoorMans180SX]

The red and white coupe in this video has TDP's lock kit on it, and it shows it off pretty well IMO.

Epizod 10 - RAGE Team przedstawia - Ostatnia runda.... - YouTube

[PoorMans180SX]

Originally Posted by swiftmini

the car is literally impossible to spin and does backwards stuff without ever trying.

Videos of backwards stuff or lies.

[Johannes]

Originally Posted by PoorMans180SX

No, the roll center correction is made by dropping the lca hole straight down, so clearance stays the same in that regard.

I don't know if this has been answered before but can't I angle the bearing cup on the LCA closer to 180* to compensate for the longer shank/increased in ackerman?
And make a bracket on the most outside underneath part of the LCA to hold the cup on there good.

edit;
I might just do what SoSideways did.. to run a 3/4" high misalignment bearing cup, and weld and angle the housing towards the rotor.

[PoorMans180SX]

You can't really do that unless you cut and weld the mount in the knuckle, as that shank has to stay at the same angle to tighten in the knuckle.

SoSideways setup didn't end up working out so great if I remember correctly.

[CaptainVlad]

Does anyone know if PBM will be releasing some rear knuckles along with their front forged knuckles? And if so, how much? Cheaper than GKTech possibly?

[Motary]

Originally Posted by swiftmini

I use driftworks knuckles and even though they can only do 55degree lock I can't imagine ever needing or wanting more. My lock is retarded in my opinion. And now that the roll centres and weight distribution and front/rear grip ratio are set perfect for my style, the car is literally impossible to spin and does backwards stuff without ever trying.

this whole lock quest thing is stupid imo. Infact I'm gonna start reducing my lock now until it effects my driving or driving style.

Imo if you gonna get knuckles they should be of a conventional style like gktech, part shop max pro mod or forged and also the geomaster.

No need for anymore imo!!

There is much more to front suspension than those 3, there is kinematic camber, bumpsteer, body jacking, scrub radius, ackermann geometry, self steer forces etc. The problem with pro-ackermann is that it drags one of the wheels and when you are at the absolute limit, you will spin because the inside wheel is slowing the car down and forcing it to rotate around it.

This is why Wisefab and Trackday performance have whole front suspension kits, not everyone can make parts from different makes work together, some just want to drive. I mean look at the contact patch of their kits, you can use much narrower wheels and still have same front grip and dont need the front to understeer to save you from a spin, just steer it!





You also don't need much static camber.
Tires following the road = speed
Tire barely in contact with road and sliding (inner front) = loss of speed
But I see you are a loyal fan for Driftworks, so you try it your own way

[PoorMans180SX]

So I was reading this review on the GKtech knuckles:

Testing the GKtech Billet Knuckles - My thoughts - Simon Michelmore Drift

And this guys is saying that when using zero ackerman, he's had to use 20-30mm toe out to get the car to steer in. That seems obscenely excessive to me. Any guys here running zero ackerman knuckles that want to chime in?

[IThaJokaI]

Whoops nevermind.

[nieko]

Originally Posted by PoorMans180SX

So I was reading this review on the GKtech knuckles:

Testing the GKtech Billet Knuckles - My thoughts - Simon Michelmore Drift

And this guys is saying that when using zero ackerman, he's had to use 20-30mm toe out to get the car to steer in. That seems obscenely excessive to me. Any guys here running zero ackerman knuckles that want to chime in?

"I never got the chance to do a proper wheel alignment, only a tape measure and string line job so I cannot tell you how much castor I had and toe was approx 20mm out, possibly a tad less."

I just have a feeling this guy doesn't know how to measure or something. There is no way he is running 20mm toe out.

I run zero ackerman, I have zero issues with turn in. There is something horribly wrong with something, imo.

-Nieko

[mikerbike]

Originally Posted by PoorMans180SX

Any guys here running zero ackerman knuckles that want to chime in?

I feel like my knuckles have zero ackerman. I run zero toe, but I measure with strings in my garage. I feel like I've got incredible turn-in, even with all-season tires. (see below)


And I figured out how to do reverse entries. I wouldn't say I can do it without trying. But, I do feel like I actually have to TRY to make the car spin. It's at the end of the video.


Relevant specs, in case anyone is interested..
FRONT:
215/45/17 Continental ProContact on a 7.5" +8 @35psi (all-season half dead from the tire store dead pile.)
Knuckles pictured above, ~3.875" TR-LBJ and estimated zero ackerman
Tension rod heim spacer modified to move it inward all the way
Factory replacement control arms with steering stopper removed
Megan Track series coilovers with Tanabe spring. Probably 8k. I'm not completely sure. They came from GD Sustec pro coilovers.
Max camber from camber plates. I didn't measure but it looks like 3* or less.
no sway bar

REAR:
0 toe
+1 camber
8.7" traction rod
Megan Track series coilovers with Tanabe spring from the same GD Sustec Pros. No idea what rate, but they're SOFT.
17x 8.5 or 9" wheel with ~+25 offset and anywhere from a 205/50 to 235/45 whatever tire. I don't remember what I had on for that run. @40psi

ENGINE:
Stock SR with an S15 turbo at 10psi, no tuning at all. Just a 3" turbo-back straight pipe. I estimate 230whp, but I really don't know.

[DJPimpFlex]

All I can see is dashboard....

[derass]

In regards to DIY alignments, how are people doing them when using adjustable or extended LCAs? i would previously use the string method by measuring off the hubs but with a different length LCA, the front track width is altered. the track width is not increased by the same amount as the LCA is lengthened, rather a trigometric function of camber angle, extension length and vertical distance beween ball joint and hub. i was thinking of just using toe plates, but then would not be able to dial in thrust angle. maybe someone whos got this modeled in CAD can help me out?

also what size front wheel tire combo are people using? im using 17x9 +20 235/40, considering 17x9 +0 215/40, but not sure if i can fit that under stock fenders with 40mm S13 extended LCAs

[mikerbike]

Originally Posted by DJPimpFlex

All I can see is dashboard....

Yeah, but that dash cover is sexy as hell. haha

Originally Posted by derass

In regards to DIY alignments, how are people doing them when using adjustable or extended LCAs? i would previously use the string method by measuring off the hubs but with a different length LCA, the front track width is altered. the track width is not increased by the same amount as the LCA is lengthened, rather a trigometric function of camber angle, extension length and vertical distance beween ball joint and hub. i was thinking of just using toe plates, but then would not be able to dial in thrust angle. maybe someone whos got this modeled in CAD can help me out?

also what size front wheel tire combo are people using? im using 17x9 +20 235/40, considering 17x9 +0 215/40, but not sure if i can fit that under stock fenders with 40mm S13 extended LCAs

When I used extended FCAs, I still used strings to dial out the crab walk (I assume that's what you mean by thrust angle) and then toe plates (more like a toe 2x4) to get back to zero toe.

Are you decreasing offset to gain inner clearance? Do you need to be stancy stretched? I ran into that same problem with my 37mm extended FCAs, so I got skinny wheels. They don't pick up many bitches or cute scene boys, but they have a lot more clearance and they fit under stock fenders. Just a thought.

[PoorMans180SX]

Nice vid! Thanks for the input on the ackerman subject.

(5,000th post in here guys!)

[mikerbike]

You don't have to lie to me. I know the video sucked. haha

I installed those knuckles in June. Before that I had some with pretty much stock ackerman. I don't think I have any more leading wheel angle now, just more trailing wheel angle.

Here's a good example of an older attempt to get to 90*. Don't watch the rest of the video please.
G1!!!!! March 10th! - YouTube

So yeah, I am down with reducing ackerman 100%.

[IThaJokaI]

Has anyone actually measured to know 100% that they have 0 ackerman? Or are you just judging by eye?

[derass]

Originally Posted by mikerbike

When I used extended FCAs, I still used strings to dial out the crab walk

i dont see how this would work. when you measure off the hubs you are creating lines parallel to the car centerline. an unknown increase in front track would make those line not parallel and thus toe measurements inaccurate. i will also be using toe 2x10s, is measuring toe at ground level vs hub any different due to camber angle?

Originally Posted by mikerbike

Are you decreasing offset to gain inner clearance? Do you need to be stancy stretched?

yes. extended lca to clear framerail. then less offset to clear tension rod / sway bar. perhaps the lcas will be enough to clear those. i can fit 17x9 +20 235/40 with lcas or 215/40 with 0 offset but not sure with lcas.

[mikerbike]

Correct. When I used the strings, all 4 wheels were toed out, because I had more front track than rear track. But also, all 4 wheels were pointed the same direction. So when i went back to zero toe on the front, I made the same adjustment to the left and right side evenly until it was at 0 with the blocks. And same on the rear.

And I guess I should have rephrased the offset/wheel width question. Is there any reason you need a 9" wheel on the front, other than stancing? A skinnier front wheel will give you more inner and outer clearance. Stretched tires are incredibly useful for picking up scene boys from the mall, but if you're trying to get more clearance, it's probably worth the loss of a few style points to get an 8" front wheel.

My car is ugly though, so don't listen to me.

[DJPimpFlex]

Originally Posted by mikerbike

And I guess I should have rephrased the offset/wheel width question. Is there any reason you need a 9" wheel on the front, other than stancing? A skinnier front wheel will give you more inner and outer clearance. Stretched tires are incredibly useful for picking up scene boys from the mall, but if you're trying to get more clearance, it's probably worth the loss of a few style points to get an 8" front wheel.

My car is ugly though, so don't listen to me.

I've been wondering this as well. I run a 17x9 0 offset effectively with spacers in the front. I run a 225/45/17 RT-615 and have no front grip issues. I think it would be rad to get crazy angle with a 8" wide wheel and tons of inner clearance. What are the downsides?

Edit: ugly car<massive angle

[derass]

i chose a square setup to prevent understeer. 9 inch wide to fit the widest wheel with most tire under stock bodied s13. this was before i started researching steering angle mods. i looked into getting 17x8 in the front but for the price of a pair and spacers i got a set of another 4 17x9s, lots of spares for the rear now.

only down side i can see would be the understeer of an 8 / 9 stagger

[DJPimpFlex]

Originally Posted by derass

i chose a square setup to prevent understeer. 9 inch wide to fit the widest wheel with most tire under stock bodied s13. this was before i started researching steering angle mods. i looked into getting 17x8 in the front but for the price of a pair and spacers i got a set of another 4 17x9s, lots of spares for the rear now.

only down side i can see would be the understeer of an 8 / 9 stagger

For drifting you can run a ton of camber to help with that and sticky tires

[mikerbike]

Originally Posted by DJPimpFlex

Edit: ugly car<massive angle

Aww.. That's the nicest thing you've said to me all afternoon.

But for rillio. I run a 17x7.5" front wheel with 205-215/45 street car take-off tires. Maybe it's placebo, but I felt like I understeered a lot more with those same sizes on the 17x9s I ran before.

I agree with Pimpflex, try more camber and/or a more grippy tire.

[DJPimpFlex]

Originally Posted by mikerbike

Aww.. That's the nicest thing you've said to me all afternoon.

But for rillio. I run a 17x7.5" front wheel with 205-215/45 street car take-off tires. Maybe it's placebo, but I felt like I understeered a lot more with those same sizes on the 17x9s I ran before.

I agree with Pimpflex, try more camber and/or a more grippy tire.

Ya my friends all make fun of my monster truck car but fuck it id rather no rub.

[mikerbike]

Originally Posted by IThaJokaI

Has anyone actually measured to know 100% that they have 0 ackerman? Or are you just judging by eye?

Oh hey, didn't see this. I just judged by eye. Not by looking at how the wheels turn, but looking at the placement of the ball joint and tie rod pivots. That's why I say stuff like, "I feel like I have 0 ackerman." haha