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

[Ichiban4]

Yea I am definitely interested in well

[Motary]

Prototype model ^

3 people have shown interest in buying them, which means 7 pairs are still available for booking!

first ten pairs are priced at 150 USD plus shipping.

60 degrees of trailing wheel angle

[burgessn]

Hey dan from PBM,
i was looking at the setup you guys have on your s15 and i just had some questions regarding the alighnment you guys have.
I have a s13 with
PBM bent lower control arm tension arm combo
Driftworks knuckles
PMB comp coilovers
wheels are 18x9.5 and tires are 225x40s
My questions are I dont have my lower control arms extended nearly as much as you guys do i only extended them 10 full turns and i have the camber adjustment on the coilover top hats as positive as they will go and i still have stupid amounts of negative camber i havnt put a gage on it but im guessing its prob around 10 degrees or so. how did you guys get only 4 dergress. if im thinking correctly the farther i extend them it will increas how much camber i have.
my other question is i notice that you have the tensions rods extended pretty far out. I have mine set at there shortest seting(turned all the way in) if i lenghten them very far my wheels rub the rear wheel well pretty bad and i have beat it in pretty far with a big hammer. lol. If you guys could shed some light on what i need to do to get my alignment right it would be greaT
i can post pictures if you would like.

[mikerbike]

Install ANGLE FINDER app on your phone. It will give you a much better idea of your 'probably around 10 degrees or so" front camber.

[DC Dan MAX USA]

Measure it. If we are talking just about how it looks, 4-5 degrees of camber looks pretty extreme especially if you (you should) have zero in the rear, and you sight line down the side of the car, the difference is big. 10 is like demon oni camber where the tire contact patch is barely touching the ground. Our coilover lower mount has built in negative camber. My tension rod is long because it has to be to compliment the track width. I have a widebody kit.

[InsTanCeZ]

Hey guys is it bad to only use roll center corrected knuckles in the front? I've heard from many people that it's better to have a higher roll center in the rear than in the front, so if you have roll center knuckles in the front wouldn't that raise the front roll center higher than the rear causing some odd handling characteristics such as massive oversteer when cornering hard? I suppose this isn't much of a problem for drifting though, since you would have more grip in the front.

[Def]

Our front roll center drops way quicker when lowering an S chassis than the rear. They don't drop at anywhere near the same rate.

[godrifttoday]

Originally Posted by Motary

Prototype model ^

3 people have shown interest in buying them, which means 7 pairs are still available for booking!

first ten pairs are priced at 150 USD plus shipping.

60 degrees of trailing wheel angle

how heavy? and what material will they be made of?

[Motary]

It will be made of high grade steel, 4 times stronger than necessary.
Total weight per tension rod is roughly 300 grams, 0,66lbs for you american guys

[mechanicalmoron]

Originally Posted by Motary

Prototype model ^

3 people have shown interest in buying them, which means 7 pairs are still available for booking!

first ten pairs are priced at 150 USD plus shipping.

60 degrees of trailing wheel angle

Any change the price would go down on the next batch?

If so, I might be interested.

Also wondering about those GKTech balljoint spacers.... did they happen?

[PoorMans180SX]

Originally Posted by mechanicalmoron

Any change the price would go down on the next batch?

If so, I might be interested.

Also wondering about those GKTech balljoint spacers.... did they happen?

Really? $150USD is a DEAL for a tension rod with that much clearance. A standard PSM or SPL part is over $200.

GKTech knuckle adapters are still in the works.

[powahh]

Originally Posted by Motary

Prototype model ^

3 people have shown interest in buying them, which means 7 pairs are still available for booking!

first ten pairs are priced at 150 USD plus shipping.

60 degrees of trailing wheel angle

i want!!! now

It will be caster adjustable right?

[MidwestMyriad]

Next time anyone from GKTech is on here, if they would care to comment on how much the hub is extended out with the bolt-on adapters, that would be appreciated. (to compensate for extended lca's)

[Motary]

Originally Posted by powahh

i want!!! now

It will be caster adjustable right?

Yes, but it will be single adjuster so you need to take out the bolt from tension rod and turn the rod end out. I can make double adjuster ones too but that adds about 15 dollars to the price

[G@briel]

I have a vision here but I'm not sure if what I've thought up will work. Perhaps you guys can point me in the right direction.

I'm building a car with a tube frame front and I want to use S-chassis suspension because of the availability of parts. However,
I also really want a double wishbone set up in front, so here is what I've come up with:

I'll use an s-chassis subframe, rack, and LCAs, and then machine a metal puck which will be welded into a short cut off part of
the strut, holding a ball joint and attaching to the upper control arm which I'll fabricate. Sort of like the image below:



However, I'm thinking that since the s-chassis strut and lower ball joint are not in line, the strut and knuckle must rotate in an
odd arc shape, which will be lost when I convert to double wishbone. What will be the effect of this on the steering geometry?

I'd appreciate any help, thanks!

[IThaJokaI]

Why not just use Z or R chassis knuckles?

[Motary]

Or MX-5, they are pretty cheap and popular track cars, double wishbone straight from factory too

[G@briel]

MX-5 has limited parts availability and lousy angle from the factory, I'm still considering the Z or R chassis parts but it seems to me the community has the s-chassis steering geometry pretty much figured out, which has me favoring that solution.

I want to achieve what Matt Fields is doing with his S14 in the parts shop max video:

Parts Shop MAX + Matt Field MANitiations, a smashing good time in FD VEGAS video 1 of 2 - YouTube

[PoorMans180SX]

This isn't much related to the current debate, besides you might be able to use the knuckle. I just wanted to show this to everyone.

TDP R-body suspension in photo-booth glory. Even if you don't like the overall design, you've gotta admit that super-high articulation spherical at the bottom of the knuckle is way cool, haha.

[IThaJokaI]

Garage7 offers a bolt on angle option for R chassis, similar to GKtechs new bolt on mod for Schassis.

Gktech is also releasing a Z/R setup similar to their full billet schassis knuckle as well as TDP, so the options for the Z/R are coming out fast.

[xoxide]

Originally Posted by Motary

Prototype model ^

3 people have shown interest in buying them, which means 7 pairs are still available for booking!

first ten pairs are priced at 150 USD plus shipping.

60 degrees of trailing wheel angle

Id like to see some actually cut and mounted on the car before committing to buying these, but id be very interested in picking a set up.

[[email protected]]

Originally Posted by PoorMans180SX

This isn't much related to the current debate, besides you might be able to use the knuckle. I just wanted to show this to everyone.

TDP R-body suspension in photo-booth glory. Even if you don't like the overall design, you've gotta admit that super-high articulation spherical at the bottom of the knuckle is way cool, haha.

Thanks for posting PoorMans180sx.

Until proven incorrect our R-body kit is the only Kit that has full camber adjustment at the knuckle. This really helps with the contact patch at bigger angles.

( Its not a photo booth its a bit of white card.

[Black R]

Is fullrace still the only solution if you want double wishbone front on an s-chassis?

[PoorMans180SX]

Originally Posted by Black R

Is fullrace still the only solution if you want double wishbone front on an s-chassis?

You could make your own. The factory Skyline and Z32 stuff doesn't actually have that great of geometry...

[Black R]

Originally Posted by PoorMans180SX

You could make your own. The factory Skyline and Z32 stuff doesn't actually have that great of geometry...

I was thinking more along the lines of fd3s or s2000 front suspension...

[PoorMans180SX]

Originally Posted by Black R

I was thinking more along the lines of fd3s or s2000 front suspension...

No sense going through all that fab work just to put some other cars stock parts on your car. Start from the ground up and optimize it for whatever you're trying to do with the car.

[Black R]

^ I see what you're saying, but this is the thread for such a conversation...

With the amount of drop knuckles and bowed out tension rods, steering angle modifiers, etc, we are fast approaching the cost of an entirely revised front suspension.

At that point, why not at least consider double wishbone?

[PoorMans180SX]

Originally Posted by Black R

^ I see what you're saying, but this is the thread for such a conversation...

With the amount of drop knuckles and bowed out tension rods, steering angle modifiers, etc, we are fast approaching the cost of an entirely revised front suspension.

At that point, why not at least consider double wishbone?

I think this is definitely something some people should look into, BUT there are two major issues that I think hold people back:

1. You no longer fit into ANY racing class besides absolute top level stuff.
2. A lot of people don't have either the skills or resources to fabricate something.

[InsTanCeZ]

Okay, I've got a question. There's something very interesting I've noticed lately in Drift Tengoku, and various other Japanese websites and blogs about drifting. I've been seeing people take regular S-chassis coilovers with normal spring rates of 8k/6k or similar, and switching out the springs for crazy rates, like 20k/10k without even re-valving the dampers. When they do that the front coilovers are severely underdamped, and the rears probably underdamped a little bit. And I know the reason they are doing this is because they are crazy low, and are trying to avoid rubbing tires, etc. But alot of them are actually saying they like it alot and it handles better during drifting and stuff like that. So I thought about it and with the front suspension being so underdamped, maybe it gives more grip in the front since the suspension is so bouncy or something? I'm sure this would be awful for any type of conventional racing though. IDK I don't really understand. Does anyone have any ideas? I kind of want to try this, as stupid as it sounds lol.

[jaysgottaredtop]

Originally Posted by InsTanCeZ

Okay, I've got a question. There's something very interesting I've noticed lately in Drift Tengoku, and various other Japanese websites and blogs about drifting. I've been seeing people take regular S-chassis coilovers with normal spring rates of 8k/6k or similar, and switching out the springs for crazy rates, like 20k/10k without even re-valving the dampers. When they do that the front coilovers are severely underdamped, and the rears probably underdamped a little bit. And I know the reason they are doing this is because they are crazy low, and are trying to avoid rubbing tires, etc. But alot of them are actually saying they like it alot and it handles better during drifting and stuff like that. So I thought about it and with the front suspension being so underdamped, maybe it gives more grip in the front since the suspension is so bouncy or something? I'm sure this would be awful for any type of conventional racing though. IDK I don't really understand. Does anyone have any ideas? I kind of want to try this, as stupid as it sounds lol.

poor damping is poor damping. idk how having a bouncy ride could possibly be good in any form of driving.

as for stiffer rates... stiffer rear springs will help to keep the back end from squatting, and thus forcing the car's weight from loading up the rear tires. this keeps grip away from the rear (see: FWD drag cars). in the case of drifting, this might be somewhat helpful if you're low on power and want keep your tires spinning more easily... but you won't be able to "bite" as well under throttle and accelerate through/out the corner like you could with softer rear rates.

...in a nutshell. i'm sure some of these other guys can fill in the specifics.