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

[thefro526]

Originally Posted by joshchewuhh

I was thinking about purchasing two of the "big angle spacer" people sell for the steering rack to space the inners further out. Any thoughts or better ideas? Thanks

I'd stay away from running multiple spacers at the rack since you're going to be pushing the tie rod pivot 'out' (closer to the knuckle) a bunch - not to mention adding additional stress to the rack.

Originally Posted by joshchewuhh

Just ordered PSM inner tie rods thinking they would be long enough with my 15mm extended S14 LCA, PSM forged knuckles and moog outer tie rod ends and they aren't. (S13)

Originally Posted by MidwestMyriad

So, if I understand this correctly, PBM recommended you purchase their tie-rods, then they didn't fit? This is disconcerting info considering my recent acquisition of tie-rods from them.

This is actually really weird. If I remember correctly, S14 LCA's are only 7-8mm longer than S13 (Overall Track width is ~15mm different) - so your LCA's are basically extended ~22 - 23mm Over Stock S13.

I can measure my car when I have a chance, but I'm pretty damn sure that I extended both LCA's ~25-30mm over stock (PBM Adjustable LCA) and have their Pro Knuckle Mod / Inner Tie Rod / MOOG S14 Outers.

Maybe your outers are weird? Or your inners were cut short?

[living4surf]

did you order them cut to stock length? they should of been long enough

[PoorMans180SX]

Originally Posted by thefro526

I'd stay away from running multiple spacers at the rack since you're going to be pushing the tie rod pivot 'out' (closer to the knuckle) a bunch - not to mention adding additional stress to the rack.

They don't really put stress on the rack, since the tie rod pivots. Offset spacers put stress on the rack because they put a bending load on the rack when steering, straight spacers shouldn't put any additional load on the rack.

To all:
There is a list on the first page of this thread with tie rod lengths (including what PSM's were/are). Measure and report back please Josh.

[joshchewuhh]

I just measured the inners and outers heres the lengths. They seem to be the right length.



Here is the inners on the rack. Now where the locking nuts are, are where my outers thread on to make the wheel straight (im eyeballing this but even if the toe isnt 0 it should def have more threads than that to work with)

driver side



passenger side




Now I was thinking that the rack could possibly be off center but I already checked the turns on the steering wheel. From center its a little over 1.5 turns to full lock (right and left).

Im confused as to why these aren't long enough. When I had my SPL outers they had plenty of room but I sold them to get the MOOG inners since the design of the knuckles were made to run these. I also sold them because I didn't want to cut the bolt that holds the bump-steer washers as it was hitting the LCA before it hit the bump-stops.

[derass]

You should have kept those SPL outers. My DMAX adjustable outers are 3/4" longer than OE when extended. The SPL's are likely even longer, seeing as its instructed to use the shorter Z32 inners on a stock knuckle S-chassis. Even though the PSM knuckles have bump steer correction, you could have used the adjustable outers with no spacers (least correction). On my MA motorsport knuckle setup, the outers don't even touch the LCA at full lock. I was going to suggest offset rack spacers as they add 40mm per side, but I can see that you are using eccentric rack bushings for over center prevention. 1 or 2 bolt on spacers should work in your case.

[thefro526]

Originally Posted by PoorMans180SX

They don't really put stress on the rack, since the tie rod pivots. Offset spacers put stress on the rack because they put a bending load on the rack when steering, straight spacers shouldn't put any additional load on the rack.

To all:
There is a list on the first page of this thread with tie rod lengths (including what PSM's were/are). Measure and report back please Josh.

You're right, I guess I should have been a bit more clear in my post. Doubling up on straight spacers is no where near as bad as offset spacers, I just look at it as moving the pivot further away from the rack end is going to mean that more of the rack is 'unsupported' when compared to a setup with the pivot closer. More often than not, the tie rod pivots reducing the load, but I can think of scenarios where the the rack would technically be in 'bending' - although all of these instances are on the fringe of a 'standard operating range'.

Also, those tie rods seem to measure correctly.... weird.

Random, but what do your tension rods look like? Kind of a shot in the dark, but if your wheel is pulled way forward, then that might not be helping the situation.

[joshchewuhh]

Ya I wish I kept the outers also. But everyone I talked to said to run stock style outers. So I sold them.

The tension rods are SPL and they are set to 7 degrees caster.

[kewilso3]

Just go to a parts store and bring your PSM inners. Compare to i30/q45/j30 OEM inners and choose accordingly. Lifetime warranty, swap them out if they bend or go bad

[mikerbike]

Originally Posted by DC Dan MAX USA

Everyone should buy the knuckle still & resist the urge to cheap out on the bottom bracket because while you are saving money you are killing the KPI and Scrub Radius. Thats the compromise you have to consider & thats why its still worth your money for a complete knuckle.

These don't move the lower ball joint. So only scrub radius is affected. Or am I missing something?

Originally Posted by GKTECH

[joshchewuhh]

well im just going to have my friend extend my outers 2'' problem solved.

A company should start selling stock outers that have longer ends on them that way they can use any inner they want and cut it to size.

[Black240Ct]

Originally Posted by kewilso3

Just go to a parts store and bring your PSM inners. Compare to i30/q45/j30 OEM inners and choose accordingly. Lifetime warranty, swap them out if they bend or go bad

the q45 outer tie rods, are an inch longer then moog s14. off rockauto a pair was around 32 shipped... but the taper is not the same as a 240sx

the taper of the 96 q45 outer tie rod is slightly thicker then a s14. I dont like the contact of the taper and scrapping this idea for 1990 maxima outers.
i did a little more research. on the Moog site the taper dimentions match on the 90 maxima and 240, Small Taper: .511 large taper: 6.10. the maxima has a length of 5 inches and a rod thread of m14-1.5 R... the moog 240sx length is 3.7 inches.





i shopped around to find some locally to test fit but there were none so i just ordered, will be going on my psm knuckles this week

[derass]

Originally Posted by joshchewuhh

A company should start selling stock outers that have longer ends on them that way they can use any inner they want and cut it to size.

GKTech has got those coming.

High misalignment (64 degrees) tie rod ends (12mm/14mm) - PRE BUY PRICE - ETA LATE November

[DC Dan MAX USA]

Originally Posted by mikerbike

These don't move the lower ball joint. So only scrub radius is affected. Or am I missing something?

you are correct, the steering axis angle has not changed but your offset in relation to where the axis hits the ground to the tire's center line has changed to be farther away from whats ideal. A full knuckle does not do that.

[InsTanCeZ]

Found some crazy stuff on Minkara lol

Does anyone know what the advantages are of modifying the traction rod position like this?



I don't even know what's going on here, but this car is slammed!





It's also running 20kg Swift springs in the front, and 10kg Silk Roads in the rear. What a crazy setup!



Shorter RUCAs for more camber too. :P



And 40mm extended FLCAs (2 20mm wide metal blocks, weld together, done! lol) Looks like some possible roll center correction is happening here as well maybe? (Ball joints are welded higher)









I love crazy builds like this where zero fux are given haha

[GKTECH]

so you guys want tie rod ends like these?

- Uses QA1 5/8" high misalignment rose joints
- 3 different length rods (standard length, +15mm and +35mm's) included
- Available in both 12mm and 14mm (specify at the time of ordering)
- Dust boots included

$99 intro price ($90 excluding tax) in Australian dollars so around $81.34 USD + shipping based on todays exchange rate

[TheRealSy90]

IIRC Welding the flca offset like that does NOT affect roll centre.

@GKTech, YES!

[Motary]

Originally Posted by InsTanCeZ

Found some crazy stuff on Minkara lol

Does anyone know what the advantages are of modifying the traction rod position like this?

15% increase in anti squat, still no anti squat at that ride height.

Slight reduction of camber gain and bump steer, nothing relevant at that ride height either.

Originally Posted by DC Dan MAX USA

you are correct, the steering axis angle has not changed but your offset in relation to where the axis hits the ground to the tire's center line has changed to be farther away from whats ideal. A full knuckle does not do that.

You can counter that by moving the top of the strut towards inside the chassis. For the money it is heaps better than a home welded knuckle or anything of similar value.

[Def]

Those welds on that subframe and RUCA are kinda scary. Way too cold, and the proudness of the weld indicates the joints were not properly prepped with at least a slight bevel.

[PoorMans180SX]

Originally Posted by TheRealSy90

IIRC Welding the flca offset like that does NOT affect roll centre.

You are correct.

Strange that he took the time to modify all that stuff when he's just sitting on the subframe.

I guess if you like slowly sliding around a course and using a lot of tires you're probably not the most "conventional" thinker. Whatever floats your boat I guess.

[Def]

The the hell S chassis guys insist on running that horribly soft stock FLCA bushing is beyond me. Or maybe they run a urethane bushing which in a lot of ways is even worse.

Then again, the average S chassis guy likes to cut his FLCA and weld it back together in a zigzag shape and think it's doing something besides looking stupid...

[dudermagee]

Originally Posted by Def

The the hell S chassis guys insist on running that horribly soft stock FLCA bushing is beyond me. Or maybe they run a urethane bushing which in a lot of ways is even worse.

Then again, the average S chassis guy likes to cut his FLCA and weld it back together in a zigzag shape and think it's doing something besides looking stupid...

How do yo feel about the delrin style bushings?

[PoorMans180SX]

Originally Posted by dudermagee

How do yo feel about the delrin style bushings?

The FLCA bushing has to move up/down and side-to-side, you can't/shouldn't really use anything there but a rubber bushing (if you like stock parts) or a heim joint.

[Def]

Originally Posted by PoorMans180SX

The FLCA bushing has to move up/down and side-to-side, you can't/shouldn't really use anything there but a rubber bushing (if you like stock parts) or a heim joint.

This. FLCA doesn't move straight up and down around a single pivot plane like the RLCA. Delrin bushings work great in the inner RLCA pivots.

[Black240Ct]

This pic below u can see the larger taper on the q45 tie rod that isn't in the knuckle


Need to set caster toe and make bump stops. Waiting on proper outer tie rods. Seems fun tho

[jaysgottaredtop]

Originally Posted by Black240Ct

the q45 outer tie rods, are an inch longer then moog s14. off rockauto a pair was around 32 shipped... but the taper is not the same as a 240sx

the taper of the 96 q45 outer tie rod is slightly thicker then a s14. I dont like the contact of the taper and scrapping this idea for 1990 maxima outers.
i did a little more research. on the Moog site the taper dimentions match on the 90 maxima and 240, Small Taper: .511 large taper: 6.10. the maxima has a length of 5 inches and a rod thread of m14-1.5 R... the moog 240sx length is 3.7 inches.

{img}

{img}

i shopped around to find some locally to test fit but there were none so i just ordered, will be going on my psm knuckles this week

just so we're all clear here:

90-96 q45 outers are longer than s14 outers BUT have the wrong taper.
89-94 maxima outers are longer than s14 outers AND have the correct taper.

is this correct?

[Black240Ct]

Originally Posted by jaysgottaredtop

just so we're all clear here:

90-96 q45 outers are longer than s14 outers BUT have the wrong taper.
89-94 maxima outers are longer than s14 outers AND have the correct taper.

is this correct?

Yup. Q45 is too large, I wasted money on them. Moog site says maxima is the same. I'll have photo proof in a day or two

[codyace]

Originally Posted by GKTECH

so you guys want tie rod ends like these?

That's a slick setup

Originally Posted by Def

Then again, the average S chassis guy likes to cut his FLCA and weld it back together in a zigzag shape and think it's doing something besides looking stupid...

LOL!!!

[Therealdapnyc]

Tryna do this to my s13 wanna redo. Front and rear suspension any help or ideas ?


Sent from my iPhone using Tapatalk

[Therealdapnyc]

Starting with the front ?


Sent from my iPhone using Tapatalk

[joshchewuhh]

Well got my outer Moog S14 tie rod ends extended 1.6'' by Matt @streetfaction. Threads on perfect with plenty of adjustment. Problem solved.