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

[GripTerror]

i just hope its safe and durable... would hate to drive that on any local roads (which are shit btw)... we shall see I guess that's all we can say.

[GripTerror]

atutt no... raising the subframe introduces anti-squat... which we dont want... reason s13s are good for drifting is cause they have alot of anti squat... s14 on the other hand has more squat than the s13... thus more rear traction and more of a 'real car' feel so to speak... raising it up to the sky will fuck up things even more... if you want to ice skate I suppose its okay...

Raising the subframe 'corrects' roll center. Imagine how the arms shoot up as you lower the car by the shock... the arms shoot up but on the subframe they remain lower (get it? picture it in ur head)... now if you lower by shock AND they shoot up.. BUT you raise the subframe those points suddenly move up and voila the arms straighten up.... you get lower... with arms parallel/roll center 'corrected'.. however now the car has massive anti squat and traction go bye bye

[!Zar!]

None of these parts are made to be used on the street, and most are only expected to last a year or so.

So if a part breaks because someone is running links and joints for X-years longer than they were supposed to be, and never maintaining the part, things will break.

[Def]

I really have to wonder how much "engineering" is going into these uprights that are flooding the market. All the info I've generated seems to say they're headed down the wrong path, but maybe they know something I don't.

[atutt]

Originally Posted by GripTerror

i just hope its safe and durable... would hate to drive that on any local roads (which are shit btw)... we shall see I guess that's all we can say.

I'm honeslty not to impressed with the PSM prototypes... Could be a lot better.

Originally Posted by GripTerror

atutt no... raising the subframe introduces anti-squat... which we dont want... reason s13s are good for drifting is cause they have alot of anti squat... s14 on the other hand has more squat than the s13... thus more rear traction and more of a 'real car' feel so to speak... raising it up to the sky will fuck up things even more... if you want to ice skate I suppose its okay...

Raising the subframe 'corrects' roll center. Imagine how the arms shoot up as you lower the car by the shock... the arms shoot up but on the subframe they remain lower (get it? picture it in ur head)... now if you lower by shock AND they shoot up.. BUT you raise the subframe those points suddenly move up and voila the arms straighten up.... you get lower... with arms parallel/roll center 'corrected'.. however now the car has massive anti squat and traction go bye bye

Now I fully understand. So the best thing would be to MAYBE slightly raise the subframe (less than 1/2'') to somewhat help correct roll centre. But, use drop spindles to correct it fully(ish). This should still retain the traction, yet keep the arms parallel. Correct?

But, why do so many people switch to the S14 and 15 subframes? I thought they did this to increase traction? I think that's what is confusing me the most.

Originally Posted by Def

I really have to wonder how much "engineering" is going into these uprights that are flooding the market. All the info I've generated seems to say they're headed down the wrong path, but maybe they know something I don't.

That's why we have this awesome sauce thread! lol

[GripTerror]

Well you understood the raising subframe thing correclty... however when you do that you affect anti-squat.. you dont want anti-squat... s13 subframe has more of it, s14/s15 (same -- s15 just has extra bracing) dont.

The less of anti-squat = better traction hence reason why people go for the subframe swap.

Now with the pbm/spl subframe bushings.. you can offset the subframe up and down... thus when you raise the subframe up... you correct roll center slightly... and introduce some anti-squat so its a give and take thing. Do you get it now?

Correct roll center = good
Anti-squat = bad

lol

[atutt]

Originally Posted by GripTerror

Well you understood the raising subframe thing correclty... however when you do that you affect anti-squat.. you dont want anti-squat... s13 subframe has more of it, s14/s15 (same -- s15 just has extra bracing) dont.

The less of anti-squat = better traction hence reason why people go for the subframe swap.

Now with the pbm/spl subframe bushings.. you can offset the subframe up and down... thus when you raise the subframe up... you correct roll center slightly... and introduce some anti-squat so its a give and take thing. Do you get it now?

Correct roll center = good
Anti-squat = bad

lol

Yeah I get it now. I think it was the amount of misinformation going around about the whole anti-squat thing. And swapping subframes.

Makes sense now.

[PoorMans180SX]

They went a full inch. That's 25.4mm.



I don't see how these are any worse than the driftworks atutt. At least these come with spherical bearings and they actually did the research.

[Propaganda]

Do you think this correct the rear without raising the subframe or does it need help from the risers?

[Pandapants]

With the risers, that would be about 1.5" / 38mm of correction. From what everyone says about the rears not needing "that much" attention, I think it really depends on your ride height.

[mmdb]

I figure the "research" the driftworks knuckles are based on are from sp tec who labored over them. Take a look at the scorch's s15. if he posted the fastest s15 lap time EVER with those knuckles, and if that doesn't hold up in court then Dayam I dunno what to say really, other than I'll pass your ass in the corner and have you eat my dust in the straight suckas!

anyway, after Fontanas event with these on I only hav positive things to say bout em. if someone competent could develop something with some sound engineering this could be the next best thing.

[mmdb]

double post my bad. damn iPhone. go lakers!

[xpertsnowcarver]

^^Don't get me so excited about this.

I want to see how well your car performs when you weigh at least 2650lbs with you in it.

[PoorMans180SX]

mmdb, could you measure from the top hub bolt to the camber arm bolt on your stock knuckles and your driftworks ones. Also from the bottom of the hub to the bottom of the lca pickup on both. I believe that will solve the "real drop" mystery.

[mmdb]

Originally Posted by xpertsnowcarver

^^Don't get me so excited about this.

I want to see how well your car performs when you weigh at least 2650lbs with you in it.

That'd be awesome of I can get it to that weight. I've been thinking about it last night and the more I realize what I have to do the I realize that I don't want to do it.

Holy triple post! Sure when I got the time. I recon it might be a while though.

Sorry bout the poor grammer in my previous posts. It's hard eating and typing on the iphone.

[nieko]

ooooooooohhh any idea on price for the psm knuckles yet?

and did you say they ARE going to make some for the front too?

or are they just sticking with the ones they have which dont fix like any roll centre.. LOL

[PoorMans180SX]

Sorry about that, I fixed it. Stupid phone.

I haven't heard anything about a front knuckle from PSM.

[Pandapants]

I thought it would be more feasible to make a front lower control arm... since they already have a front knuckle.

[atutt]

Originally Posted by PoorMans180SX

They went a full inch. That's 25.4mm.



I don't see how these are any worse than the driftworks atutt. At least these come with spherical bearings and they actually did the research.

Those little tab things (bracing if you will) they have welded across the bearing housing isn't impressive...
If everything is coped properly and fits properly there is no need for that. Period.
But that's just my opinion.

[Slidin' Sam]

added re-enforcement for a more solid mount?...similar to welding up a subframe maybe?

[atutt]

Proper fitment and proper welding techniques and it won't need any reinforcement.
At that point you're just adding unnecessary material and weld. There are also less half-assed looking ways to reinforce that if that's in fact what they were going for.
Also, there is only one spot on those knuckles that should be reinforced, but isn't.
The tube coming off the shock mount (toe arm right?) should be reinforced to the knuckle plate. Even though the cast stock versions don't have that. Cast if very different from steel plates and tubes welded together.....
This is why it comes off as half assed to me...

Please, no one chew my head off for saying that... lol

But, these are JUST prototypes so whose to say they won't change it?

[GripTerror]

bahaha my car is 2500lbs with me in it and im 190lbs

[nieko]

Yeah the prototype looks funny. but if you woulda read what was going on.

they are going to be fully machined uprights. so i highly doubt they will look like that.

[atutt]

Originally Posted by nieko

Yeah the prototype looks funny. but if you woulda read what was going on.

they are going to be fully machined uprights. so i highly doubt they will look like that.

I did read and they said full machined FRONT aluminum knuckles are something they are working on.

[Def]

Originally Posted by atutt

I did read and they said full machined FRONT aluminum knuckles are something they are working on.

Someone might have been talking about the ones I'm making(aluminum front uprights).

Unless PSM is also making aluminum machined uprights.

[GripTerror]

well they better be safe and drop the car 2-3" with not just drift crowd in mind but grip crowd as well. I wana rape more expensive cars with my s chassis track car haha

[Def]

They're not really made with drift cars in mind, but I don't see why they wouldn't work for both.

They won't "drop" the car at all - they are going to correct the geometry to be optimal and adjustable for each user's setup. Any "drop" spindle in the front that only moves the hub location in relation to otherwise almost stock upright locations does "bad" things to all sorts of the geometry.

[GripTerror]

I still want to drop my car 2-3" I hope your uprights will allow that with correct geometry

[atutt]

Originally Posted by GripTerror

I still want to drop my car 2-3" I hope your uprights will allow that with correct geometry

Whenever I get around to making mine I'm shooting for a minimum 2'' drop...
They won't be nearly as baller as Def's though, by the sounds of it, lol

[PoorMans180SX]

PSM is making machined REAR uprights. Not fronts.