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

[xilovelsdx]

Originally Posted by SupaDoopa

To those with the PBM knuckles on S13's:

What tie rod setup are most of you running? I was talking to them over the phone and they suggest the PBM S14 inners with Moog outers. I'm PLANNING on going with their tension/FLCA combo up there as well.

Any help would be dope.

I have tein inners and spl outters. I did have to take out all the spacers except for the cone one because they dropped the joint to low and it was almost going under the control arm.

[swiftmini]

the DG-5 coilovers will be reducing the included angle in the knuckle. Which also helps with reducing camber gain throughout steering angle

[PoorMans180SX]

Hmmmm, Maybe he doesn't run as much static as I thought.

[thefro526]

Originally Posted by SupaDoopa

To those with the PBM knuckles on S13's:

What tie rod setup are most of you running? I was talking to them over the phone and they suggest the PBM S14 inners with Moog outers. I'm PLANNING on going with their tension/FLCA combo up there as well.

Any help would be dope.

I have PBM cut and weld pro knuckles (basically the same as forged) with their original release FLCA and Tension rod set.

Right now, the car has PBM Inners (the spherical jawns) and Moog S14 outers. The geometry is essentially optimal as far as I can tell, but I haven't driven the car yet.

As far has I have been able to tell, the PBM inners are WAY longer than standard S14 units, which allows S13 owners theoretically infinite (within reason) adjustment of track width and all that other fun stuff. When I get home and under my car again, I can measure and or photo whatever you need. On some real talk though, I think the tie rod setup cost me like 130 bucks total, and will probably never break. Any other setup is probably $100 more and doesn't have OEM (will last longer) spec outers.

With that being said, PBM is PBM so if they have some part that you want, buy it when you can because it'll probably never be in stock again ever... Not kidding.

[Bink Industries]

Originally Posted by swiftmini

the DG-5 coilovers will be reducing the included angle in the knuckle. Which also helps with reducing camber gain throughout steering angle

camber gain through steering has nothing to do with the angle on the lower coil over perch. NOTHING. steering axis inclination and caster has everything to do with it.

[Motary]

Originally Posted by PoorMans180SX

Hmmmm, Maybe he doesn't run as much static as I thought.

[IMG]image

My mad photoshop skills tell me it is 6 degrees of negative camber and he's right ^, also the the DG-5 coilovers increase negative camber

I made some new uprights and this poorly edited image to show previous ones:

[Bink Industries]

6 degrees is too much for any set up. cool for the VIP guys but no performance gain with that much. 3 to 5 is ok depending on set up of KPI and caster.

when your setting up your contact patch for your front tires you don't want to set up for full lock because in drift you are rarely sitting at full lock. You are more in the 0 to 30 degree range (both ways) when sideways. I would be more concered about what the tires are doing in that range then anything else.

its like setting up a pikes peak car SPECIFICLY for dirt ONLY when most of the track is paved. you would set up for mostly for pavement and make it controllable in the dirt. I don't know if that analogy makes sense but I tried haha.

[tobroketobuildarealcar]

What setup works for one may not work for another it is all about driving style and driver prefetence

[xoxide]

Originally Posted by tobroketobuildarealcar

What setup works for one may not work for another it is all about driving style and driver prefetence

Hey guys.... Have you met my friend Captain Obvious?



Motary- Any more pics of your spindles... Very unique looking haha.

[Bink Industries]

Originally Posted by tobroketobuildarealcar

What setup works for one may not work for another it is all about driving style and driver preference

I agree to an very small extent, if your just sliding around for fun yes that totally applies, but if your competing you have to make the car competitive and that may require the driver to adapt to the car instead of adapting the car to the driver. the driver may drive very well on a certain set up BUT that setup may not be competitive in pro drift. at least this is my personal experience. I hope this makes sense.

[Bink Industries]

Originally Posted by Motary

My mad photoshop skills tell me it is 6 degrees of negative camber and he's right ^, also the the DG-5 coilovers increase negative camber

I made some new uprights and this poorly edited image to show previous ones:

gald you went double shear on the pick up points for the knuckle and FLCA. im guessing you have to have a custom FLCA to run that knuckle right?

[tobroketobuildarealcar]

Originally Posted by N8 of S-Empire

I agree to an very small extent, if your just sliding around for fun yes that totally applies, but if your competing you have to make the car competitive and that may require the driver to adapt to the car instead of adapting the car to the driver. the driver may drive very well on a certain set up BUT that setup may not be competitive in pro drift. at least this is my personal experience. I hope this makes sense.

I understand what you are saying but if you were right there would be 1 right way to set a car up and we all know that is not how it is. We all like our car to feel and respond differently that is whi there is so many different part manufactures out there.

[thefro526]

Originally Posted by N8 of S-Empire

camber gain through steering has nothing to do with the angle on the lower coil over perch. NOTHING. steering axis inclination and caster has everything to do with it.

Truth.

But with that being said, even though negative camber gained at the lower mount doesn't have much/any effect on dynamic changes, camber is camber.

Technically, when camber is gained or lost at the mount, it may as well be 'built' into the knuckle. Either way, if you're going to gain or lose 5deg of camber through the travel range, the static camber at the mount will come into play here... I guess basically what I'm saying is that if you're at X degrees without messing with the mount and at Y after playing with it, you'll still have Z camber change during motion assuming all other things are equal.

[Bink Industries]

Originally Posted by tobroketobuildarealcar

I understand what you are saying but if you were right there would be 1 right way to set a car up and we all know that is not how it is. We all like our car to feel and respond differently that is whi there is so many different part manufactures out there.

there is a very small VERY small difference between ALL s chassis in FD ( that are competitive top tear chassis, not just any 240 in FD) so there is a "formula" for the perfect setup so I can not agree with you on that. I can not release any setup info as it is proprietary to how I set up FD cars. but I will tell you that as you stray away from this "ideal" set up that all the other competitive drivers are using the car becomes non competitive.

there are so many part manufactures not because of driver preference but because everyone's brain comes up with different ways to skin a cat. some choose quality some choose china, some choose to fabricate some choose to cnc. all parts will work just different approaches.

drifting is interesting because all the books and schooling, personal experiences I've gone through drifting seems to break a lot of the rules, it is also a constant developing sport (it hasn't really be around that long compared to a lot of other motorsports) so what works this season in FD might not be competitive in the following year as the team find new and innovative ways to set up the cars, and those people that do not develop the chassis in the off season will find themselves behind in the following season (as compared to road race or any other very developed sport).

[Bink Industries]

Originally Posted by thefro526

Truth.

But with that being said, even though negative camber gained at the lower mount doesn't have much/any effect on dynamic changes, camber is camber.

Technically, when camber is gained or lost at the mount, it may as well be 'built' into the knuckle. Either way, if you're going to gain or lose 5deg of camber through the travel range, the static camber at the mount will come into play here... I guess basically what I'm saying is that if you're at X degrees without messing with the mount and at Y after playing with it, you'll still have Z camber change during motion assuming all other things are equal.

that post was extremely confusing

I think I grasped the concept though

if you have 1 degree of camber change per inch of travel in the front (playing scenarios here) and you have a standard coil over with a static camber of 3 degrees every inch of travel will yield 1 degree of camber change. unbolt that coil over and put in a coil over with more built in camber say 5 degrees, you will still see the same 1 degree of camber change per inch of travel.

unless you move the upper spring perch (effecting SAI/KPI) or lengthen your FLCA (again effecting SAI/KPI) or change your caster settings (adjusting tension rod or rotating camber plate) then you will effect the dynamic camber change per inch of travel. but a lower coil over mount on its own will NOT change the dynamic camber change of the suspension as it is not a pivot point.

[swiftmini]

Originally Posted by N8 of S-Empire

camber gain through steering has nothing to do with the angle on the lower coil over perch. NOTHING. steering axis inclination and caster has everything to do with it.

Of course it does lol. Thats suspension 101 level stuff!!

Kingpin inclination and included angle go hand in hand. Changing the bottom bracket angle IS altering the included angle.

If you reduce included angle by 2* you will have a 2* increase in negative camber. The kingpin inclination remains the same.

If you reset the camber to the original figure then you will have altered the kingpin inclination.

You do know what included angle is....right??



Just an aside but....
In 2009 and i made my own drop knuckles. they were a copy of the old psm weld ons with an additional weld on for roll centre correction. I removed as much included angle out of the knuckle as possible until i ran into scrub radius problems and clearance problems. At -5* camber i was running a much reduced KPI. I also ran almost very low caster around 5*. The wheel would stay very upright and not gain much camber all the way through the lock. It also had great steering feel but very little self steer. (could be fixed by running more caster trail, i didnt know that then)

My setup is completely the opposite now. I have no front end grip on lock too be honest and i think its amazeballs. I have to really drive the car with the rear end and if you dont do uber aggro transitions itll understeer and straighten. Basically ive made my car have a tonne of rear grip and traction and as a consequence i need to be way more aggressive.

Its down to personal preference and everyone is different

[swiftmini]

Originally Posted by PoorMans180SX

Thanks man. Ironic I know. I plan on buying the wisefab rear kit too, but well after I get the car on the road. I just don't like buying things twice with what little money I have.

I still have a LOT of adjusting to do...

R32 and S14 look good, that picture of the S14 hurts my eyes though, haha.

That wisefab rear end looks fully amazing. Im tempted to get it but i have geomasters on both my cars and im more than happy with how they perform in most respects. Im seriously not happy that they arent designed for low cars though. Both my cars ruin cv boots on the camber and traction arms and i actually would like to go about an inch lower on both cars.

[swiftmini]

Oh i thought i should add this info to the thread. im keeping it seperated from my babbling so it doesnt go un-noticed.

I just fitted geomasters and adjustable arms to my s14.

I measured the camber and traction rods before i setup the new adjustable arms.

The traction rod WAS/IS 67% of the length of the camber arm. I had to lengthen my camber arm by 10mm to get 0.5mm camber at the ride height iam at, so i added 7mm too the traction rod.

It has almost no bump steer. I will be using the smart strings in the week to set up the toe and i will measure bumpsteer whilst iam at it.

[az_240]

^When I switched from the DW knuckles to the PSM knuckles I found I was able to go a little lower due to more space between the RUCAs/traction rods and the axles.. also less stress on the axles due to the hub not sitting as high.

My issue now is lack of camber gain = wheels going into the fenders. I hate to do it but might have to get overs

What are the overall lengths (center hole to center hole) of your trac/ruca? I know the stock lengths are 12" and 8.25". After reading the bumpsteer thread on NRR a while back it seems adjusting the trac/ruca in equal lengths is the way to go for minimal bumpsteer and to adjust camber at the eccentric to fine tune. In the same thread Geoff@fullrace suggested running the toe eccentric so the toe arm is at it's shortest length possible and to adjust toe at the arm lengths which I thought was interesting.

[Motary]

PSM rear uprights don't eliminate camber gain, it's impossible to do that with moving upper arms pivot points down only 25mm, you'd need to move them down 57mm if my measurements of the upright are correct.

[PoorMans180SX]

Originally Posted by Motary

My mad photoshop skills tell me it is 6 degrees of negative camber and he's right ^, also the the DG-5 coilovers increase negative camber

I made some new uprights and this poorly edited image to show previous ones:

Dude, your latest upright looks really awesome. Lots of RC correction, double shear joints, and a big increase in caster trail. Please post fitment pics and some results with videos!

Originally Posted by N8 of S-Empire

when your setting up your contact patch for your front tires you don't want to set up for full lock because in drift you are rarely sitting at full lock. You are more in the 0 to 30 degree range (both ways) when sideways. I would be more concered about what the tires are doing in that range then anything else.

Originally Posted by N8 of S-Empire

there is a very small VERY small difference between ALL s chassis in FD ( that are competitive top tear chassis, not just any 240 in FD) so there is a "formula" for the perfect setup so I can not agree with you on that.

This is assuming that we need or want to set our cars up like lame FD cars. I personally would rather have a car I can drive at big angles because I think it looks so much cooler than the "fast" approach that FD uses. Also, Most European drifting has a bigger focus on angle, they can do backwards entries in competition and generally hold more angle. I feel like Chelsea Denofa and Mike Essa are slowing bringing this to FD, everyone knows their drifting is exciting to watch. I hope it becomes a trend.

Originally Posted by swiftmini

Of course it does lol. Thats suspension 101 level stuff!!

Kingpin inclination and included angle go hand in hand. Changing the bottom bracket angle IS altering the included angle.

If you reduce included angle by 2* you will have a 2* increase in negative camber. The kingpin inclination remains the same.

If you reset the camber to the original figure then you will have altered the kingpin inclination.

You do know what included angle is....right??



Just an aside but....

My setup is completely the opposite now. I have no front end grip on lock too be honest and i think its amazeballs. I have to really drive the car with the rear end and if you dont do uber aggro transitions itll understeer and straighten. Basically ive made my car have a tonne of rear grip and traction and as a consequence i need to be way more aggressive.

Its down to personal preference and everyone is different

Remind us what you're running in the front and how it's aligned? I know you've been over it a hundred times but for the ease of people reading these last pages it'd help to not have to read back through 10 pages.

Originally Posted by swiftmini

That wisefab rear end looks fully amazing. Im tempted to get it but i have geomasters on both my cars and im more than happy with how they perform in most respects. Im seriously not happy that they arent designed for low cars though. Both my cars ruin cv boots on the camber and traction arms and i actually would like to go about an inch lower on both cars.

Originally Posted by az_240

^When I switched from the DW knuckles to the PSM knuckles I found I was able to go a little lower due to more space between the RUCAs/traction rods and the axles.. also less stress on the axles due to the hub not sitting as high.

My issue now is lack of camber gain = wheels going into the fenders. I hate to do it but might have to get overs.

You guy need smaller axle boots like S13's have. Ah, lack of camber gain, a blessing and a curse, hahaha.

[az_240]

Originally Posted by Motary

PSM rear uprights don't eliminate camber gain, it's impossible to do that with moving upper arms pivot points down only 25mm, you'd need to move them down 57mm if my measurements of the upright are correct.

"~ Eliminates camber gain on compression to maintain traction and even tire wear"

^taken from PSMs website regarding their rear drop knuckles.

I know others have experienced a decrease in camber gain after installing these as well.

Originally Posted by PoorMans180SX

You guy need smaller axle boots like S13's have. Ah, lack of camber gain, a blessing and a curse, hahaha.

I actually had some s13 axles laying around and it did help with the boots going into the trac/ruca but still puts the axles at a bad angle when slammed because the hub is so high.

Edit: rough idea of what I'm talking about.... don't mind the upside down RUCA... they wouldn't fit right side up. With the axles like this it felt way rougher than it should have when spinning the hub. The RUCA was close but not quite hitting the axle yet in this pic.

[Motary]

Originally Posted by az_240

"~ Eliminates camber gain on compression to maintain traction and even tire wear"

^taken from PSMs website regarding their rear drop knuckles.

I know others have experienced a decrease in camber gain after installing these as well.

I'm sure you have heard of marketing.
This is how camber gain works:



1. Negative camber gain
2. 0 camber gain
3. Positive camber gain

For 0 camber gain the arms need to be parallel, which gives infinite IC length. 0 cambergain would hamper performance too. Independent suspension has a disadvantage of wheels rolling together with the body which is why camber gain was introduced. The rear roll center would be too low too. Please give it some thought instead of eating whatever salespeople give you.

Originally Posted by PoorMans180SX

Dude, your latest upright looks really awesome. Lots of RC correction, double shear joints, and a big increase in caster trail. Please post fitment pics and some results with videos!

Fitment without relocation bracket, which I haven't finished designing







I have about same retarded camber as your car

[az_240]

I never said 0 camber gain... only a decrease. It made enough of a difference that I'll probably need overs or run more neg camber than I'd like for how low I want to go. I know these knuckles alone will not completely eliminate camber gain.

[PoorMans180SX]

Originally Posted by Motary

Fitment without relocation bracket, which I haven't finished designing

Very cool. How much RC correction is in them?

To everyone:

TDP is going to be making a prototype R-body kit soon:

[Motary]

You did however quote PSM which said camber gain has been eliminated. I'm glad this misunderstanding is now sorted

Just out of curiosity for PSM rear uprights design, how are they holding up? The design doesn't look too stiff.

I am currently in the process of engineering a new double wishbone design for S13, current version of the upright looks like this:



It has reduced camber gain, anti-squat curve is half as steep and bumpsteer in the range of 70 bump and 50mm of droop is less than 0.4mm

Originally Posted by PoorMans180SX

Very cool. How much RC correction is in them?

55mm

I wonder why TDP use so many bolts in their design, overstock in ireland?

[Bink Industries]

Originally Posted by swiftmini

Of course it does lol. Thats suspension 101 level stuff!!

Kingpin inclination and included angle go hand in hand. Changing the bottom bracket angle IS altering the included angle.

If you reduce included angle by 2* you will have a 2* increase in negative camber. The kingpin inclination remains the same.

If you reset the camber to the original figure then you will have altered the kingpin inclination.

You do know what included angle is....right??

im very familiar with ALL suspension geo. that's my job.

you have brought in INCLUDED ANGLE which is not what we were even talking about. we were talking about camber gain through suspension travel. the answer to that is still the same, altering the included angle in the knuckle or coilover WILL NOT change camber gain during suspension travel. that is simply not how it works. however moving the location of the lower ball joint will change that.

I will clarify how KPI is measured so there is not confusion and hopefully educate those that are not familiar.

find the pivot point at the top of your coil over mount. now find the center of the pivot of the ball joint on the lower control arm. snap an imaginary line through those points and measure the angle at 90 degrees from the chassis. that is your KPI angle.


so u can see that it doesn't matter what you do in between because the pivot points are what matter as the suspension is pivoting from those locations NOT from some fixed point in the middle. included angle just changes your static camber not your dynamic camber change

this is why I prefer to set camber with camber bolts rather than at the coil over "camber plates" because when you mover that point up top you change your KPI angle AND mildly change your roll centers.

I hope this helps clarify a few things as I want you guys to have good sound solid info so you guys can set your cars up right and go have fun and kick some ass

[Bink Industries]

one more picture to help visuals

[PoorMans180SX]

Originally Posted by Motary

You did however quote PSM which said camber gain has been eliminated. I'm glad this misunderstanding is now sorted

Just out of curiosity for PSM rear uprights design, how are they holding up? The design doesn't look too stiff.

I am currently in the process of engineering a new double wishbone design for S13, current version of the upright looks like this:

__________________________________________________ _________

I wonder why TDP use so many bolts in their design, overstock in ireland?

What's the difference between your front and rear stuff and Wisefabs? It seems your knuckle has more caster trail in the front, what about the rear stuff? It looks extremely similar to the uninformed eye.

Haha yeah, TDP does use a lot of bolts. On the lower arm it's important because the back block pivots so that the lower can move and be used to change caster if desired.

Originally Posted by N8 of S-Empire

you have brought in INCLUDED ANGLE which is not what we were even talking about. we were talking about camber gain through suspension travel. the answer to that is still the same, altering the included angle in the knuckle or coilover WILL NOT change camber gain during suspension travel. that is simply not how it works. however moving the location of the lower ball joint will change that.

EDIT: What we're all trying to say here is that you can alter the tires relationship with the steering axis by using the knuckle/lower bracket. This changes how the wheel sits at lock. This doesn't alter the camber change. It alters the angles through which the camber changes. Does this make better sense now?

Example:

Take a tire that is parallel to the KPI, turn it to 60 degrees. There will be a certain amount of camber change.

Take the same tire, and use the knuckle to add 2* more camber. The camber change is still the same, but now the tire sits differently in the arch at 60 degrees of lock because of angle at the knuckle.

[swiftmini]

Originally Posted by PoorMans180SX

Quote:
Originally Posted by N8 of S-Empire View Post
you have brought in INCLUDED ANGLE which is not what we were even talking about. we were talking about camber gain through suspension travel. the answer to that is still the same, altering the included angle in the knuckle or coilover WILL NOT change camber gain during suspension travel. that is simply not how it works. however moving the location of the lower ball joint will change that.

EDIT: What we're all trying to say here is that you can alter the tires relationship with the steering axis by using the knuckle/lower bracket. This changes how the wheel sits at lock. This doesn't alter the camber change. It alters the angles through which the camber changes. Does this make better sense now?

Example:

Take a tire that is parallel to the KPI, turn it to 60 degrees. There will be a certain amount of camber change.

Take the same tire, and use the knuckle to add 2* more camber. The camber change is still the same, but now the tire sits differently in the arch at 60 degrees of lock because of angle at the knuckle.

Yes thats what i was trying to say But the point i was trying to make was that once you have dialled out the extra 2* camber, the camber gain will have changed due to moving the kpi