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

[Chris28]

Went ahead and shipped my knuckles to PSM for the pro knuckle mod, in the mean time I'll be modifying my LCAs. Right now my tire rubs the frame rail in the back side of the wheel well at full lock, and all I have are rack spacers. While I box my LCAs in I also plan on extending them a bit, possibly only 10-15mm. Has anyone had experience with how far I should extend them? I'm going to measure everything to see how far out I have to go in order to not rub, but if someone has found a sweet spot I'll just go for that.

[mikerbike]

I extended mine 1.5".





I extended them to get the wheel away from the TC rod and swaybar. Getting the tire away from the frame rail was a bonus.

[Chris28]

What tie rods are you using? I'm running Megan inners, 11.5" end to end. Not sure if those will be long enough to deal with the knuckle and an extended lca, and I don't want to run into issues when putting everything back together. Since I'm running s14 inners I can probably extend to the length of stock s14 lcas and be fine, I'm just wondering how much further I can go.

[mikerbike]

I'm using the tie rods in the second picture, also extended 1.5".

[DC Dan MAX USA]

how far to extend the LCA maybe depends on the amount of negative camber you want to add

[TheRealSy90]

100mm, I want all the negative Camber.

[mikerbike]

I pushed the camber plates all the way to the outside. Although I still gained a bit of camber, I didn't want to add camber so much as I wanted my wheel to stop hitting my TC rod and sway bar. And I didn't want to add spacers (scrub too) because then the wheel hits front and back in the wheel well.

[Chris28]

Originally Posted by mikerbike

I pushed the camber plates all the way to the outside. Although I still gained a bit of camber, I didn't want to add camber so much as I wanted my wheel to stop hitting my TC rod and sway bar. And I didn't want to add spacers (scrub too) because then the wheel hits front and back in the wheel well.

This is exactly why I want to extend my lcas as well. I'll try to be keeping my camber around -3 up front, I just want to get the wheel away from my tension rod, sway bar, and frame rail.

[Hashiriya415]

What's the length of stock s13 arm? From center pivot of ball-joint to center bushing at cross-member.

[!Zar!]

Originally Posted by motoxris

Sorry but your data chart doesn't look real or accurate. And more is not always better but moving your rack 1" rather than 6mm is better because you have better control of your steering in next to lock position. You dont have as much twitchy movement in your steering because of the angle of your steering arm on the knuckle in relation to the tie-rod. It's not all about preventing over centering but having better control of your vehicle. Just saying.

So if a potential buyer doesn't think 6mm forward is enough, couldn't they just buy the offset tierod spacers which moves the tierods 35mm forward? So I would imagine that is the same as moving a rack an inch forward, no?

[TheRealSy90]

I just wouldn't run those myself after seeing bent and broken steering racks from using those kind of spacers.

[PoorMans180SX]

Originally Posted by TheRealSy90

I just wouldn't run those myself after seeing bent and broken steering racks from using those kind of spacers.

I still don't understand that. There are drift teams running them without issue. It's not like they can afford to replace their rack mid-event all the time.

[az_240]

Drift teams also use modified crossmembers to fit oil pans(can't move the rack because you now have an oil pan there). Using the offset spacers is a way around this... and while bent racks have happened I doubt they happen easily.

[Jonnie Fraz]

Originally Posted by Hashiriya415

What's the length of stock s13 arm? From center pivot of ball-joint to center bushing at cross-member.

Approx 370mm for S13. Anyone have the S14 length?

[Chris28]

Everything I've read says they're 10mm longer than s13 arms, so around 380mm.

Turns out there's not enough thread engagement on the Megan tie rods for me to feel safe extending my lcas, so until I get SPL outers or Ikeya inners I won't be extending the control arms.

On the topic of lengths, anyone know the length of Ikeya inner tie rods? The length of Megan tie rods is 11.5", I'll measure the length of stock s14 inners this weekend.

Think cutting a stock tie rod end where the threaded portion starts and welding a longer female standoff to it to account for the length difference would work? I'm assuming the tie rod ends are cast, would welding an attachment to it be safe since it sees so much stress?

[Croustibat]

I switched S13 FCA to S14 FCAs (and now adjustable FCAs). I was told the difference was 8mm for each arm... if i find my previous OEM LCAs i can measure that. Drop me a PM sunday evening so i remember to do that. Will take pics with measurements.

[az_240]

Originally Posted by Jonnie Fraz

Approx 370mm for S13. Anyone have the S14 length?

You must be measuring the entire arm... I got 416mm for the entire S14 FLCA and 362mm from center of ball joint to center of bushing.

Tein S14 inners are 262mm and Ikeya inners are 286mm (Ikeyas are double adjusted.... this was with 25mm of thread engaged) not including the threads that screw into the rack.

Tein S14 outers are 102mm measuring to center of ball joint... used to have the length for SPL outers but lost that somehow

[Chris28]

I got 330mm from center of ball joint to center of bushing for the s13.

Megan inners are 266mm from end to end, not including rack threads.

SPL outers: turnbuckle is 82mm, rod end is 70mm from center of heim to end of the threads.

[motoxris]

I dont think they move 35mm forward. I thought it was 25mm. But yes its an easy way to move it forward more, I don't agree with them because there more feasible to damaging the rack, but you still shouldn't be hitting curbs anyways.

Originally Posted by !Zar!

So if a potential buyer doesn't think 6mm forward is enough, couldn't they just buy the offset tierod spacers which moves the tierods 35mm forward? So I would imagine that is the same as moving a rack an inch forward, no?

[Hashiriya415]

Maybe this will help you guys understand how to measure correctly, from center of bushing on left, to center of pivoting point of ball joint, the center of the ball.

[az_240]

That's where I measured.

[Jonnie Fraz]

Az you are right...I am using an inch tape and converting it. I am between 13.375-13.50 which converts to 339-343mm. I had burned an inch and forgot to subtract it.

[Def]

Originally Posted by mikerbike

I extended mine 1.5".


Pics removed


I extended them to get the wheel away from the TC rod and swaybar. Getting the tire away from the frame rail was a bonus.

Why in the world did you keep the stock bushing? That's the 2nd worst bushing on the whole car for performance (1st being the tension rod). Put a rod end there.

[az_240]

^He was trying to distance the wheel from the tension rod/sway bar. Rod end would mean more chopping/welding/money

[PoorMans180SX]

The Era1 website is up in case anyone wants their drop knuckles. They're certainly not a deal though. Basically the same price as driftworks. I thought knockoffs were supposed to be cheaper? Hahahah.

PSM has pretty much got the deal of the century in comparison.

www.era-one.com

[DJPimpFlex]

Yea I didn't expect a large 4 diget price tag on those. Glws.

Also poly bushings = fail. What are these for? Street cars?

[GripTerror]

unimpressed...

i just wish pbm would bloody release spindles with non poly/rubber bushings...

[DJPimpFlex]

Look what I got

[Om1kron]

baller

[az_240]

Originally Posted by GripTerror

unimpressed...

i just wish pbm would bloody release spindles with non poly/rubber bushings...

Uhh see above pic.

For a track car running hydro these rear knuckles should be an easy choice. Pretty shocked when I saw $400 price tag.