This is the roll center, suspension pickup, and steering angle modification thread. - Page 18 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

PoorMans180SX · 02-26-2010, 11:34 AM

Quote:

Originally Posted by articdragon192

Sounds good. Can't wait to see the modded versions, as it means it'll be able to work on my car

Front roll center adjustment through hubs is almost non existent for my car. But hopefully some modded LCAs along with the remodels DW rear spindles would do wonders for my car. I wonder how different roll center adjustment is between your guys' MacPhearson strut design, and my multi-link rear.

Wait, you mean our MacPherson strut suspension and your front multi-link? You essentially have a double wishbone front setup, therefore your front roll center should drop a little slower than our MacPherson strut front.

You really need to figure out where your roll centers and front and rear centers of gravity are to modify your roll center/roll axis properly.

I'd imagine without some sort of drop-knuckle front, you'll need to modify your upper control arm pivot points if you intend on using the driftworks knuckles in the rear. Just a guess though.

SicBastard · 02-28-2010, 05:32 AM

Is the ideal roll couple zero?

PoorMans180SX · 03-01-2010, 08:08 AM

No sir, you want your roll center under your center of gravity. Your car will handle weird if your roll center is even with or above your center of gravity.

nieko · 03-01-2010, 12:59 PM

I dont know if these have been mentioned at all.

I am pretty against megan products but they sell these.

Megan Racing MR-6465 Rear Roll Center Adjuster Nissan 240SX S13 89-94

for the front and the rear.

i really like the DW spindles but right now they are a little out of my budget...

would these be effective?

mmdb · 03-01-2010, 01:11 PM

^ it was discussed on nissan road racing, but I believe the conclusion is no. The improvement is only limited to being visual, because the pivot point in the roll center adjuster is moved upward, yet the mount where the spindle meets taper does not change.

nieko · 03-01-2010, 01:17 PM

Rad, thank you. lol

Guess i'm going to save up for DW shit.

hopefully something a little cheaper, or maybe made over here will come out.

mmdb · 03-01-2010, 05:52 PM

Before you do, it was noted by DEF that the rear multilink design doesn't require much RC adjustment due to the RC vs CG distance during cornering to be much less radical compared to the front macpherson strut design. So you could probably put the money elsewhere for better results (take a look at nissan road racing forum and read up on threads concerning roll center adjustment for the front).

Although I'm doing it because: 1. I'm curious - You'll never know till you try it, 2. I can afford it for now, and 3. If it does work to my benefit I can be that much more faster on the track. So for me it was a gamble worth taking. Good luck!

SicBastard · 03-02-2010, 05:40 AM

mmdb,

Have you considered modeling the 240sx's suspension? If you have the time and money... You'd need a good set of corner scales to determine you actual front and rear CG, and then some decent software. But you might find it more helpful then adding random parts.

PoorMans180SX · 03-02-2010, 12:36 PM

Yeah, from my basic calculations, the DW knuckles put the roll centers at about ideal locations. You have to take into account the slope of the Roll axis versus the mass axis, as this determines some of your basic handling characteristics.

So it really all depends on how much you're lowering, but the rear roll center is not raised as much as you would think when you take into account the instant centers and where the CG is in the back.

Take a look at 95KA's rear lower arm;

With something like that angle, the roll center is way down in the ground. It needs the kind of adjustment the DW knuckles provide.

Quote:

Originally Posted by SicBastard

mmdb,

Have you considered modeling the 240sx's suspension? If you have the time and money... You'd need a good set of corner scales to determine you actual front and rear CG, and then some decent software. But you might find it more helpful then adding random parts.

This would be awesome.

mmdb · 03-02-2010, 01:47 PM

Quote:

Originally Posted by SicBastard

mmdb,

Have you considered modeling the 240sx's suspension? If you have the time and money... You'd need a good set of corner scales to determine you actual front and rear CG, and then some decent software. But you might find it more helpful then adding random parts.

Yeah that's a really, really good way to approach the problem. I would have... but in all honesty I'm just... sorta lazy... so... I'm basing my judgement to use the DW rear spindles on the most important sensor. It's what BMW M-engineers refer to as the "po-po meter" (my butt).

SicBastard · 03-02-2010, 08:45 PM

fair enough!

articdragon192 · 03-03-2010, 12:16 AM

Well, I might just end up modifying some LCAs and maybe that by itself will help? Might have the upper link that connects to the upper control arm up front shortened so that the front upper control arm sits flatter. I figure if the arms don't need much roll center adjusting, it may be as simple as welding in sleeves, pressing in ball joints, and running new longer shanks, similar to what Otto did on some arms he worked on, to make a significant improvement at my height.

PoorMans180SX · 03-03-2010, 09:33 AM

Quote:

Originally Posted by articdragon192

Well, I might just end up modifying some LCAs and maybe that by itself will help? Might have the upper link that connects to the upper control arm up front shortened so that the front upper control arm sits flatter. I figure if the arms don't need much roll center adjusting, it may be as simple as welding in sleeves, pressing in ball joints, and running new longer shanks, similar to what Otto did on some arms he worked on, to make a significant improvement at my height.

That will definitely work. Longer shanks combined with the shorter upright section should do wonders.

*DALAZ_68* · 03-03-2010, 09:50 AM

ok...so they other day...(whilst slightly intoxicated and beyond tired) i was over hearing a conversation dealing with modifying the location of the steering rack to allow less wheel lock... im pretty sure i fucked something up in that sentence...but can someone explain to me...how moving the steering rack, say 1 1/2'' foward would actually help this?

or should i just sit down and shut up with the dunce cap on...lol

SoSideways · 03-03-2010, 10:31 AM

^ Go back one page, PoorMans180sx already explained why.

mmdb · 03-03-2010, 09:02 PM

Picks of Skullworks' progress... Ebrake cable looks like a go!

longfellow · 03-03-2010, 09:42 PM

That looks like a pretty big notch, what are you going to do about giving that corner back its structural integrity?

Otto347 · 03-03-2010, 09:57 PM

I went ahead and fitted the fronts with the same cups as the rears. I was going to make full tubular FLCA but I just figured this will be a lot faster lol

mmdb · 03-03-2010, 10:18 PM

Quote:

Originally Posted by longfellow

That looks like a pretty big notch, what are you going to do about giving that corner back its structural integrity?

Skullworks are going to using a half cut tube and weld it around the e-brake cable. I assume if that's not enough further structural pieces will need to be added to reinforce it.

longfellow · 03-04-2010, 08:20 AM

Quote:

Originally Posted by Otto347

I went ahead and fitted the fronts with the same cups as the rears. I was going to make full tubular FLCA but I just figured this will be a lot faster lol

Where do you get the cups? I've been wanting to make something similar.

Quote:

Originally Posted by mmdb

Skullworks are going to using a half cut tube and weld it around the e-brake cable. I assume if that's not enough further structural pieces will need to be added to reinforce it.

That works. Just wondering because that was a huge chunk taken out.

*ManoNegra* · 03-04-2010, 10:11 AM

Quote:

Originally Posted by SicBastard

Have you considered modeling the 240sx's suspension? If you have the time and money... You'd need a good set of corner scales to determine you actual front and rear CG, and then some decent software. But you might find it more helpful then adding random parts.

We have scales here at the shop (we're just too lazy to used them...)
what software are you talking about?
I'd love to get my hands on a copy of Wingeo.

Quote:

Originally Posted by mmdb

Skullworks are going to using a half cut tube and weld it around the e-brake cable. I assume if that's not enough further structural pieces will need to be added to reinforce it.

Quote:

Originally Posted by longfellow

That works. Just wondering because that was a huge chunk taken out.

That's the plan
take them to one of the fabricators we know and reinforce them

95KA-Turbo · 03-04-2010, 10:03 PM

Quote:

Originally Posted by longfellow

Where do you get the cups? I've been wanting to make something similar.

That works. Just wondering because that was a huge chunk taken out.

There is a parts list I used on the first page.

I actually just ordered some new 3/4 to 5/8ths reducers that will work way better.

I am trying to figure out my tie rod situation up front right now. I am using a custom M16 aurora heim joint tie rod right now but the stud part has me stumped as I cannot find a high misalignment spacer that doesn't reduce it to a M12. I think I might have to drill out my spacers to accept a M14......or bite the bullet and get some 5/8ths heim joints and redo the whole set up and just run the same shank I have in my LCAs - then drill out the spindle again.

I am going to order some spacers and attempt to calculate my instant and roll centers and adjust the LCAs properly....or I might just space the front out more then the rear and hope it feels good, HAHA!

SicBastard · 03-05-2010, 07:45 AM

Here's a interesting discussion on some software.

Automotive suspension engineering - Software for Suspension Design

They can get CRAZY$$$$, but I know there's a simpler/more affordable one I saw somewhere. It's going to be a while till my LSx swap is done, so I'm not too concerned about it till then. But it is interesting.

SoSideways · 03-05-2010, 10:33 AM

95KAturbo - dude, you should have told me like, last week, before I ordered the raw materials.

I am making a turnbuckle for M14x1.5 to 5/8-18 to use on Tein S-chassis tie rods, using 5/8" bolts for the tie rod ends.

I'm using the 2 piece QA1 rod ends that allows for 64 degrees of misalignment too, so that should be plenty.

Only thing is, I'm still on stock knuckles, so I will be making the turnbuckle as short as possible so that I won't have an issue of having massive toe in due to the overall length of the tie rods + tie rod ends being too long.

I'm going to have a machine shop do this for me, so if you're interested, let me know, I already know where to get everything and will have the plans drawn out with the machine shop, so it's just a matter of if you want this done, I can get it done for you in no time for not a whole lot of dough either.

PM me for more details if you are interested.

*DALAZ_68* · 03-05-2010, 12:50 PM

Quote:

Originally Posted by SoSideways

^ Go back one page, PoorMans180sx already explained why.

why thank you sir...

PoorMans180SX · 03-05-2010, 02:40 PM

Why are you guys not using SPL tie rod ends? You making them cheaper or something?

Just thought I'd share this speedhunters article on the Garage Ito R34. Coolest suspension design that I have seen pictures of:

CAR FEATURE>> GARAGE ITO WITH PROSTOCK GT-R - Speedhunters

*DALAZ_68* · 03-05-2010, 02:47 PM

i think im just gonna go home tonight and read this thead begining to fucking end...

atutt · 03-05-2010, 04:53 PM

Quote:

Originally Posted by DALAZ_68

i think im just gonna go home tonight and read this thead begining to fucking end...

I've done it.. It sucked, lol
Now I have to do it again because I retained zero information from my first reading...

*ManoNegra* · 03-05-2010, 05:53 PM

Quote:

Originally Posted by PoorMans180SX

Just thought I'd share this speedhunters article on the Garage Ito R34. Coolest suspension design that I have seen pictures of:

CAR FEATURE>> GARAGE ITO WITH PROSTOCK GT-R - Speedhunters

Super baller, custom work from well known companies = $$$$$$$$$$$$

We were given an early Porsche tiptronic transmission and told to
take it apart and replace whatever we could with titanium
about 15 parts and a barrel of money later we were able to shave about 11lbs off
tranny was disposed of

I can't imagine ever having that much money

az_240 · 03-06-2010, 12:11 AM

Any opinions on this? I've only seen the washer type spacers like what SPL sells. Apparently you only use 1 of these on the passenger side.

Do you guys that use modded knuckles use steering spacers as well?

02-28-2010, 05:32 AM	#512
SicBastard Zilvia Addict Join Date: Mar 2006 Location: New York, NY Posts: 803 Trader Rating: (0) Feedback Score: 0 reviews	Is the ideal roll couple zero? __________________ BURN OUT IN YOUR FACE! 1998 S14 LS7/T56 swap in progress, build thread: http://zilvia.net/f/tech-talk/147301...d-gto-pan.html

03-01-2010, 08:08 AM	#513
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 36 Posts: 5,574 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	No sir, you want your roll center under your center of gravity. Your car will handle weird if your roll center is even with or above your center of gravity. __________________ Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs.

03-01-2010, 01:11 PM	#515
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	^ it was discussed on nissan road racing, but I believe the conclusion is no. The improvement is only limited to being visual, because the pivot point in the roll center adjuster is moved upward, yet the mount where the spindle meets taper does not change. __________________ .25 till 3

03-01-2010, 05:52 PM	#517
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	Before you do, it was noted by DEF that the rear multilink design doesn't require much RC adjustment due to the RC vs CG distance during cornering to be much less radical compared to the front macpherson strut design. So you could probably put the money elsewhere for better results (take a look at nissan road racing forum and read up on threads concerning roll center adjustment for the front). Although I'm doing it because: 1. I'm curious - You'll never know till you try it, 2. I can afford it for now, and 3. If it does work to my benefit I can be that much more faster on the track. So for me it was a gamble worth taking. Good luck! __________________ .25 till 3

03-02-2010, 05:40 AM	#518
SicBastard Zilvia Addict Join Date: Mar 2006 Location: New York, NY Posts: 803 Trader Rating: (0) Feedback Score: 0 reviews	mmdb, Have you considered modeling the 240sx's suspension? If you have the time and money... You'd need a good set of corner scales to determine you actual front and rear CG, and then some decent software. But you might find it more helpful then adding random parts. __________________ BURN OUT IN YOUR FACE! 1998 S14 LS7/T56 swap in progress, build thread: http://zilvia.net/f/tech-talk/147301...d-gto-pan.html

03-01-2010, 12:59 PM	#514
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 33 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	I dont know if these have been mentioned at all. I am pretty against megan products but they sell these. Megan Racing MR-6465 Rear Roll Center Adjuster Nissan 240SX S13 89-94 for the front and the rear. i really like the DW spindles but right now they are a little out of my budget... would these be effective?

03-01-2010, 01:17 PM	#516
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 33 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	Rad, thank you. lol Guess i'm going to save up for DW shit. hopefully something a little cheaper, or maybe made over here will come out.

03-02-2010, 08:45 PM	#521
SicBastard Zilvia Addict Join Date: Mar 2006 Location: New York, NY Posts: 803 Trader Rating: (0) Feedback Score: 0 reviews	fair enough! __________________ BURN OUT IN YOUR FACE! 1998 S14 LS7/T56 swap in progress, build thread: http://zilvia.net/f/tech-talk/147301...d-gto-pan.html

03-03-2010, 12:16 AM	#522
articdragon192 Post Whore! Join Date: Jan 2005 Location: West covina Age: 38 Posts: 6,792 Trader Rating: (9) Feedback Score: 9 reviews	Well, I might just end up modifying some LCAs and maybe that by itself will help? Might have the upper link that connects to the upper control arm up front shortened so that the front upper control arm sits flatter. I figure if the arms don't need much roll center adjusting, it may be as simple as welding in sleeves, pressing in ball joints, and running new longer shanks, similar to what Otto did on some arms he worked on, to make a significant improvement at my height. __________________ Need help? Click here Still stumped? Try this Can't find what you're looking for? Here you go.

03-03-2010, 09:50 AM	#524
DALAZ_68 not giving a fuck Join Date: Apr 2007 Location: Los angeles Age: 38 Posts: 15,077 Trader Rating: (104) Feedback Score: 104 reviews	ok...so they other day...(whilst slightly intoxicated and beyond tired) i was over hearing a conversation dealing with modifying the location of the steering rack to allow less wheel lock... im pretty sure i fucked something up in that sentence...but can someone explain to me...how moving the steering rack, say 1 1/2'' foward would actually help this? or should i just sit down and shut up with the dunce cap on...lol __________________ LOL 240... whats better than 1? 5 1's ...lol PSN & XBL GT : Wh0pp3r68 CLUB LEXUS : Wh0pp3r

03-03-2010, 10:31 AM	#525
SoSideways Post Whore! Join Date: Apr 2003 Location: 你老母 Posts: 4,371 Trader Rating: (4) Feedback Score: 4 reviews	^ Go back one page, PoorMans180sx already explained why. __________________ SoSideway's iTrader Rating!! *SoSideways' Review Thread!!* http://sosideways.wordpress.com/

03-03-2010, 09:02 PM	#526
mmdb Zilvia FREAK! Join Date: Apr 2003 Location: 240sx Posts: 1,558 Trader Rating: (20) Feedback Score: 20 reviews	Picks of Skullworks' progress... Ebrake cable looks like a go! __________________ .25 till 3

03-03-2010, 09:42 PM	#527
longfellow Zilvia Addict Join Date: Apr 2006 Location: Tampa Area Posts: 606 Trader Rating: (2) Feedback Score: 2 reviews	That looks like a pretty big notch, what are you going to do about giving that corner back its structural integrity? __________________ http://timeattackdan.blogspot.com/

03-05-2010, 07:45 AM	#533
SicBastard Zilvia Addict Join Date: Mar 2006 Location: New York, NY Posts: 803 Trader Rating: (0) Feedback Score: 0 reviews	Here's a interesting discussion on some software. Automotive suspension engineering - Software for Suspension Design They can get CRAZY$$$$, but I know there's a simpler/more affordable one I saw somewhere. It's going to be a while till my LSx swap is done, so I'm not too concerned about it till then. But it is interesting. __________________ BURN OUT IN YOUR FACE! 1998 S14 LS7/T56 swap in progress, build thread: http://zilvia.net/f/tech-talk/147301...d-gto-pan.html

03-05-2010, 10:33 AM	#534
SoSideways Post Whore! Join Date: Apr 2003 Location: 你老母 Posts: 4,371 Trader Rating: (4) Feedback Score: 4 reviews	95KAturbo - dude, you should have told me like, last week, before I ordered the raw materials. I am making a turnbuckle for M14x1.5 to 5/8-18 to use on Tein S-chassis tie rods, using 5/8" bolts for the tie rod ends. I'm using the 2 piece QA1 rod ends that allows for 64 degrees of misalignment too, so that should be plenty. Only thing is, I'm still on stock knuckles, so I will be making the turnbuckle as short as possible so that I won't have an issue of having massive toe in due to the overall length of the tie rods + tie rod ends being too long. I'm going to have a machine shop do this for me, so if you're interested, let me know, I already know where to get everything and will have the plans drawn out with the machine shop, so it's just a matter of if you want this done, I can get it done for you in no time for not a whole lot of dough either. PM me for more details if you are interested. __________________ SoSideway's iTrader Rating!! *SoSideways' Review Thread!!* http://sosideways.wordpress.com/

03-05-2010, 02:40 PM	#536
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 36 Posts: 5,574 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	Why are you guys not using SPL tie rod ends? You making them cheaper or something? Just thought I'd share this speedhunters article on the Garage Ito R34. Coolest suspension design that I have seen pictures of: CAR FEATURE>> GARAGE ITO WITH PROSTOCK GT-R - Speedhunters __________________ Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs.

03-05-2010, 02:47 PM	#537
DALAZ_68 not giving a fuck Join Date: Apr 2007 Location: Los angeles Age: 38 Posts: 15,077 Trader Rating: (104) Feedback Score: 104 reviews	i think im just gonna go home tonight and read this thead begining to fucking end... __________________ LOL 240... whats better than 1? 5 1's ...lol PSN & XBL GT : Wh0pp3r68 CLUB LEXUS : Wh0pp3r

03-06-2010, 12:11 AM	#540
az_240 Post Whore! Join Date: Jan 2006 Location: Phx Posts: 3,097 Trader Rating: (41) Feedback Score: 41 reviews	Any opinions on this? I've only seen the washer type spacers like what SPL sells. Apparently you only use 1 of these on the passenger side. Do you guys that use modded knuckles use steering spacers as well?