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

[ballinnmiami240sx]

someone need to post a stock s13/s14 ride height and lest look at how nissan originally had it.

[Otto347]

Originally Posted by 95KA-Turbo

So having it flat in the front and nearly flat in the back is ideal?

Basiclly, you're trying to find a happy medium between squat and anti squat. Then depending on how the weight transfers to the rear tune it for what works for your application.

[VIPDRFT]

Originally Posted by 95KA-Turbo

What kind of car is that?

You can do this for your lower arms (you'll have to weld in some flat metal on the one with a hole in it):

It looks like there's another arm on top of the spindle? You would need to correct that as well.

Changing the strut length will just raise the car up higher, which would correct the geometry - but defeat the purpose.

It's a JZX90/100 Toyota Chaser/Cresta/Mark II

I see. Good idea. I hadn't thought of that. That arm on top is the RUCA. I'm still have no idea on how to correct that, besides raising the subframe.

Yeah, I don't want my car having 4x4 status. :P

Originally Posted by Def

That's similar to an E36/E46 rear suspension(BMW) - most of those guys just raise up the subframe as much as possible and call it good in the rear.

In our cars, the roll center doesn't drop as quickly in the rear as the front, so a huge amount of correction is not needed back there like the front.

That doesn't surprise me becuase I've heard the JZX-chassis was built to compete with the BMW sedans. Would I just use subframe spacers like Parts Shop Max makes for th S-chassis?

Good to know. Thanks.

[white92_s13]

ok so this thread inspired me! I had a spare set of knuckles and lower control arms. I took some 1/8th" plate i had and cut it out cleaned it up and boxed the lower control arm. need to weld one more plate on to add some more strength. Then i did some research on Knuckle modification

P/s knuckle TOP and NON p/s knuckle Bottom



These are the "D1 SUPER ANGLE" modified shortened stock p/s knuckles! SHORT!!!!


Anyways I have a friend with a good welder and a oxy acetylene torch and we can heat them up and weld it up nice! Im going to post more pictures of them modified tomorrow!

[Sonic Motor]

great thread. All newbie drifts looking to setup their suspension for drifting, look here first!
Me thinks this should be sticky in Motorsport forum or something.

thanks for posting this!

[lflkajfj12123]

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

[SoSideways]

Originally Posted by s0apgun

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

See...

You're a cool dude, but honestly, everytime someone tries to talk technical stuffs, you spew that crap out...

Fixing the roll center will allow the car to corner flatter, especially the front, so instead of running like 15k springs up front and a 50mm sway bar, you can run 8k springs and stock sway bars and have the car stay mostly flat. How does that require more skills to notice?

Even BH noticed his car rolls a bit much during drifts, and it shows on the banner pic on his blog.

He has said that he doesn't care about it, so that's cool, it's up to him how he wants to setup his car (although he has said he wanted to buy Tanabe sways to remedy that situation), but he doesn't come onto any of the roll center and other technical discussion threads and tell how everyone sucks at driving and they shouldn't care.

Geez dude.

BTW thanks for uploading Video Option Vol 81 on youtube. That's the one with the Stinger team. Appreciate it!

[Steve Lloyd]

Originally Posted by Steve Lloyd

Couldn't you just alter the mounting point on the struts (custom housings) to raise the spindle. There's already a guy that makes custom housings, but I was thinking you could alter the mounting location to put the spindle wherever you wanted it, and use more minor adjustments on the LCA.

Just a thought...........

Am I way off base here?? I'm getting ready to make my own coilover setup and would like some feedback.............

[SoSideways]

^ For which application?

Oh hey I just realized it you man, how's it going?

[mmdb]

Originally Posted by s0apgun

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

You might not feel the difference. That's probably cause you're too busy struggling to shove your elbow into the door sill to prop yourself to see over the dash as you car is riding on two wheels through any corner.

J/k J/k. Anyway, all kidding aside. I'd put modifying roll center up there with adding a sway bar or stiffer springs. It's makes a huge difference.

[PoorMans180SX]

Originally Posted by 95KA-Turbo

So having it flat in the front and nearly flat in the back is ideal?

Basically you want it just under your center of gravity. I think what Def is saying is that the rear arms don't need to be corrected as much because they don't go to such extreme angles like the front ones do.

I'm pretty sure having both front and rear angled slightly up is ideal. The center of gravity on these cars is pretty low, but not low enough to warrant flat arms.

Anyone can feel free to correct me if I'm wrong. I'll edit this post afterward. The reason I edit my posts is because I don't want to have any misinformation in this thead. Sometimes people don't read through things all the way and get the wrong ideas, and I don't want that happening here.

Originally Posted by s0apgun

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

SoSideways said it already, but we know this. I think what carparthookup was saying was that the newbies should check this stuff out first, because bottom line, your car will function better with these kind of suspension setups.

It doesn't take any more skill to use a better-functioning suspension.

I can see what you're saying about the angle mods, because they DO take more skill to use.

[GripTerror]

Keep the stupid comments to the minimum gentlemen So far this thread kicks ass I wish driftworks would respond i contacted them with questions but no response yet

[PoorMans180SX]

Originally Posted by Steve Lloyd

Am I way off base here?? I'm getting ready to make my own coilover setup and would like some feedback.............

Yeah bro. All you're doing by making custom damper housings is using a longer shock. There is no way to correct your roll center/suspension movement using coilovers, besides riding like a 4x4.

[mmdb]

I'm currently communicating with Ben from Driftworks concerning his rear knuckles. So far this is what I know.
1. they won't modify their design to work with the z32 rear fork type
2. custom roll center adjustment is a NO and will remain fixed at the height listed.

I got a few more questions asked and I'll post 'em up as I get answers.

[PoorMans180SX]

Originally Posted by white92_s13

ok so this thread inspired me! I had a spare set of knuckles and lower control arms. I took some 1/8th" plate i had and cut it out cleaned it up and boxed the lower control arm. need to weld one more plate on to add some more strength. Then i did some research on Knuckle modification

Anyways I have a friend with a good welder and a oxy acetylene torch and we can heat them up and weld it up nice! Im going to post more pictures of them modified tomorrow!

This is for an AE86 yes?

[PoorMans180SX]

Originally Posted by mmdb

I'm currently communicating with Ben from Driftworks concerning his rear knuckles. So far this is what I know.
1. they won't modify their design to work with the z32 rear fork type
2. custom roll center adjustment is a NO and will remain fixed at the height listed.

I got a few more questions asked and I'll post 'em up as I get answers.

On number two, you can't really go a whole lot farther otherwise you interfere with the axle boot. This is the what Dan from Parts Shop MAX has to say about it:

Originally Posted by Parts Shop MAX Dan

The limiting factor of how much we can raise the spindle to drop the car seems to be the interaction between the RUCA arm and the axle boot.
Our current RUCA arm is upswept already especially designed for lowered cars so if you even try to do a drop spindle on someone elses RUCA your pretty much f@cked.



we disconnected the coilover and jacked up the wheel all the way to take a look at the most extreme clearance situation:





And then we put it back to a normal suspension compression and measured again





It seems like 3/4" drop spindle is the happy medium because it looks like half an inch is totally safe and 1 inch is the max.
with the half inch subframe risers its already a big difference so this should be a great mod for suspension performance on extra low cars.

If we wanted to take it farther we would have to sweep the arm up on the RUCA more or get a custom slim boot for the axle, but I'm betting as is its going to make a huge difference without going any farther.

[GripTerror]

Originally Posted by mmdb

I'm currently communicating with Ben from Driftworks concerning his rear knuckles. So far this is what I know.
1. they won't modify their design to work with the z32 rear fork type
2. custom roll center adjustment is a NO and will remain fixed at the height listed.

I got a few more questions asked and I'll post 'em up as I get answers.

shit that means ill have to mod my shocks to be stock s13 bushing type not z32 fork type........

what about spherical bearings as opposed to polyurethane ones...

[CrimsonRockett]

Don't fuck up another thread by making useless posts.

Fair warning to everybody.

[mmdb]

Originally Posted by GripTerror

shit that means ill have to mod my shocks to be stock s13 bushing type not z32 fork type........

what about spherical bearings as opposed to polyurethane ones...

I'm not sure... I asked them if OEM ones had the same diameter of the stock ones. In that case you should be able to use Def's spherical bearings. I'll talk to my local fab shop to modify the knuckles if I get them. I asked a few details about their knuckle's geometry in the rear... that's most important.

[GripTerror]

ya i already got def's sphericals in the rear... i dun think i can just press them out lol... and reuse them.. they'll be fubared by the time i take them out hahaha... it would just be less of a pain in the ass if they had an option with them already... seriously... but oh well.

[ManoNegra]

Originally Posted by mmdb

I'm not sure... I asked them if OEM ones had the same diameter of the stock ones. In that case you should be able to use Def's spherical bearings. I'll talk to my local fab shop to modify the knuckles if I get them. I asked a few details about their knuckle's geometry in the rear... that's most important.

I'm curious about that aswell

Originally Posted by GripTerror

ya i already got def's sphericals in the rear... i dun think i can just press them out lol... and reuse them.. they'll be fubared by the time i take them out hahaha... it would just be less of a pain in the ass if they had an option with them already... seriously... but oh well.

that is likely to be the case, it's what happened to the ones we took out while making adjustments.

[Teknolust72]

If you are using a modified drop spindle in the rear, would there even be an extra benefit to using Z32 rear fork?

My first thought is that it wouldnt matter at all, but if someone knows, please enlighten me.....

[ManoNegra]

Originally Posted by Teknolust72

If you are using a modified drop spindle in the rear, would there even be an extra benefit to using Z32 rear fork?

My first thought is that it wouldnt matter at all, but if someone knows, please enlighten me.....

There wouldn't from a user point of view.
There would from a manufacturing one though, it's easier by far make to make an upright that utilizes a fork style mount IMO.

[mmdb]

Originally Posted by Teknolust72

If you are using a modified drop spindle in the rear, would there even be an extra benefit to using Z32 rear fork?

My first thought is that it wouldnt matter at all, but if someone knows, please enlighten me.....

There is no real benefit using one type or another, but the reason why some of us have the fork type is because we're using the z32 rear aluminum spindles to save UNSPRUNG weight.

[GripTerror]

8lbs per corner if I'm not mistaken. It's significantly lighter just by feel... its a no brainer.

Edit: Aluminum vs iron no brainer

[Teknolust72]

Originally Posted by mmdb

There is no real benefit using one type or another, but the reason why some of us have the fork type is because we're using the z32 rear aluminum spindles to save UNSPRUNG weight.

Oh ok, thats what I thought. I know Kawabata's GP Sports 180SX uses BNR34 rear spindles for weight savings too, but I thought there was some other "black magic" going on under there....lol

Anyway, I wanted to share with you guys this scan from Doriten of the modified rear spindles that Team Evolution uses on their cars:



I noticed the toe arm position being moved; does the Driftworks one do that too?

If someone wants the hi-res/4mb file, I can email it.

[GripTerror]

we need engrish translat0rz

[PoorMans180SX]

Originally Posted by Teknolust72

Oh ok, thats what I thought. I know Kawabata's GP Sports 180SX uses BNR34 rear spindles for weight savings too, but I thought there was some other "black magic" going on under there....lol

Anyway, I wanted to share with you guys this scan from Doriten of the modified rear spindles that Team Evolution uses on their cars:



I noticed the toe arm position being moved; does the Driftworks one do that too?

If someone wants the hi-res/4mb file, I can email it.

What they're doing there is the same thing the JIC team (and that S15 that KA-turbo posted) does. They're cutting off the toe and coilover mount and re-welding them lower. This makes the toe arm parallel with the lower control arm and corrects your toe curve when really low.

I think they move the coilover mount just so they don't have to max out the lowness on the coilover.

The lower control arm ball joint might be a little lower there too. This would correct roll center a hair.

Just a side note, but that lower control arm that they "made" looks janky.

[PoorMans180SX]

Also, if someone actually made aluminum drop knuckles, it would probably be the coolest thing ever.

They would also probably cost a ridiculous amount of money.

So much so that I would probably just buy steel. I'm guessing the driftworks ones are a little lighter than stock anyway.

[GripTerror]

Well they should offer an aluminum and spherical option... especially when some of us are interseted in extracting maximum performance. I mean correcting geometry is a bigger pro/gain than anything else for the most part... but going back to something that potentially heavier and binding (polyurethane) is not cool. As mmdb said though we COULD make/buy alternatively sphericals as he and I already have... but why not have a product already with that err..

And why should it be automatically 'expensive', that sounds stupid. If Nissan could bring both on a factory car, an aftermarket one should be available with little to no difference equally.

At the end of the day all we're getting is the effort of someone else who figured out how to move these points and then cast/forge/put together magically with their choice of metal/material. A. Because alot of us dont have the knowledge B. Don't have the connections.

That being said, just because its aluminum doesnt mean that it should cost automatically more on the price. Think about it... The s13 and z32 spindles are not that different just different material and fork vs bushing type. They are overall the same shit.