This is the roll center, suspension pickup, and steering angle modification thread. - Page 43 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

PoorMans180SX · 07-14-2010, 05:29 PM

Quote:

Originally Posted by 95KA-Turbo

Would I be correct in saying that 'more ackerman' with toe in will give you more angle? That's what I am getting from that article.

So if 240s have less then 100% ackerman from the factory, then changing it to 100% ackerman will give you more angle?

I hope I am understanding that article correctly, it seems fairly cut and dry to me but I could be incorrectly interpreting it.

Also, I should be able to find my round about ackerman by having the car up in the air and using something straight (maybe string would work?) to make a line from my tie rod end heim joints to the rear center of the car?

I just found this program, it looks simple to use and extremely handy:

Auto-Ware (Autoware Inc) Software applications

No, it won't give you more angle to have 100% ackerman, it will just lessen your angle on one side.

Toe out with give more angle on the outside (leading tire in drift), less on the inside tire. Toe in the opposite.

Ackerman doesn't really have to do with the angle you can achieve, just with the relationship between the inside wheel's angle vs the outside one's.

Yes, you could measure it roughly like that.

Def · 07-14-2010, 05:30 PM

For drifting you probably want zero or very close to zero ackerman(aka parallel steer). Ackerman gives you more steering angle on your inner wheel so that it follows a tighter arc than the outer wheel. This is good when you're cruising in a parking lot or at lower speeds on the street/autocrossing etc.

When you're drifting, you've got extreme amounts of steering angle put in, and so the ackerman effect is really huge, especially if you add more angle to the car. You end up having a really loaded "inner" tire in the drift that dictates the car's direction, then the "outer" wheel(the trailing front wheel in a drift) has quite a bit less steering angle on it. You essentially drag that outer front wheel along to some extent.

That's why some people find it's easier to drift with a ton of preload on their coilovers which kills droop travel and picks up the outer front wheel in a drift. The car would be fastest if it had all four wheels on the ground and the front wheels pointing the same direction, but it's better to just pick that dragging outer front up and let the inner one do all the work with stock ackerman.

So parallel steer or something close to it is probably the best way to go for drifting.

Slidin' Sam · 07-14-2010, 05:32 PM

Ok, so with the max knuckles parts kit, how would you want to set up the knuckles so that you can get minimal to 0 ackerman?...I am currently installing my knuckles...

PoorMans180SX · 07-14-2010, 05:35 PM

Quote:

Originally Posted by Slidin' Sam

Ok, so with the max knuckles parts kit, how would you want to set up the knuckles so that you can get minimal to 0 ackerman?...I am currently installing my knuckles...

Line the tie rod holes up straight behind the ball joint holes. Look at the pictures in the article, it's the same on a real car.

Good explanation Def.

Slidin' Sam · 07-14-2010, 05:38 PM

Quote:

Originally Posted by PoorMans180SX

Line the tie rod holes up straight behind the ball joint holes. Look at the pictures in the article, it's the same on a real car.

Good explanation Def.

Do you have their knuckles? If so, did you get the parts kit and do it yourself?

PoorMans180SX · 07-14-2010, 05:40 PM

Quote:

Originally Posted by Slidin' Sam

Do you have their knuckles? If so, did you get the parts kit and do it yourself?

No I don't. I'm going to let them do it when I do get a set.

95KA-Turbo · 07-14-2010, 05:56 PM

Quote:

Originally Posted by Def

For drifting you probably want zero or very close to zero ackerman(aka parallel steer). Ackerman gives you more steering angle on your inner wheel so that it follows a tighter arc than the outer wheel. This is good when you're cruising in a parking lot or at lower speeds on the street/autocrossing etc.

When you're drifting, you've got extreme amounts of steering angle put in, and so the ackerman effect is really huge, especially if you add more angle to the car. You end up having a really loaded "inner" tire in the drift that dictates the car's direction, then the "outer" wheel(the trailing front wheel in a drift) has quite a bit less steering angle on it. You essentially drag that outer front wheel along to some extent.

That's why some people find it's easier to drift with a ton of preload on their coilovers which kills droop travel and picks up the outer front wheel in a drift. The car would be fastest if it had all four wheels on the ground and the front wheels pointing the same direction, but it's better to just pick that dragging outer front up and let the inner one do all the work with stock ackerman.

So parallel steer or something close to it is probably the best way to go for drifting.

Thanks for the explanation.

To put it in terms of the article, I would want true ackerman with zero toe then? It doesn't tell you how to measure for parallel steer.

I've always run zero toe, but I am about to cut and weld my new knuckles up, so I want to try and get it as close to 0 ackerman as possible, and want to be sure I measure it properly.

Def · 07-14-2010, 06:05 PM

True ackerman usually means 100% - S13s have LESS than this stock. You want LESS than stock.

Basically line up the tie rod pivot with the ball joint pivot to get a parallel steer setup. Adjust toe for best turn-in and steady state grip during a drift . You can basically use small amounts of toe as a set amount of differential angle for the front wheels. I'd think the car would respond well with a bit of toe out and parallel steer for a drift, but the only way to know is try it out.

Slidin' Sam · 07-14-2010, 06:06 PM

Is it just me, or does it seem like it would be really difficult to measure this properly?

Def · 07-14-2010, 06:09 PM

Quote:

Originally Posted by Slidin' Sam

Is it just me, or does it seem like it would be really difficult to measure this properly?

It's just you.

Get a square and jig it up. Make it the same side to side.

Slidin' Sam · 07-14-2010, 06:17 PM

Quote:

Originally Posted by Def

It's just you.

Get a square and jig it up. Make it the same side to side.

Haha, at least your honest. Sounds like a good idea...I gotta work on the knuckles when I get off work tonight, so I will try and figure something else out. Thanks!

Slidin' Sam · 07-14-2010, 06:22 PM

Ok, I have a question....WHY HASN'T THIS THREAD BEEN STICKIED YET??? lol

PoorMans180SX · 07-14-2010, 06:28 PM

Quote:

Originally Posted by 95KA-Turbo

Thanks for the explanation.

To put it in terms of the article, I would want true ackerman with zero toe then? It doesn't tell you how to measure for parallel steer.

I've always run zero toe, but I am about to cut and weld my new knuckles up, so I want to try and get it as close to 0 ackerman as possible, and want to be sure I measure it properly.

Make sure that when your wheels are pointed straight forward, your tie rod holes are inline with your ball joints holes (front to back). This makes zero ackerman because the knuckle rotates around the ball joint.

Quote:

Originally Posted by Slidin' Sam

Ok, I have a question....WHY HASN'T THIS THREAD BEEN STICKIED YET??? lol

Because I am formulating a much better post than my original one, since I have learned a lot since then and can't edit it anymore.

GripTerror · 07-14-2010, 06:45 PM

I'm still trying to understand how it would be possible to improve this with grip in mind... everyone's talking about drift

How does an m3 or s2000 have its ackerman? Those are pretty well put together cars... the m3 also has a mcpherson strut front like our cars. What about porsches? Although porsches are rear engined...

GripTerror · 07-14-2010, 06:49 PM

While looking up s2000 ackerman angle i came across this:

Get more steering angle

Slidin' Sam · 07-14-2010, 06:58 PM

Quote:

Originally Posted by PoorMans180SX

Make sure that when your wheels are pointed straight forward, your tie rod holes are inline with your ball joints holes (front to back). This makes zero ackerman because the knuckle rotates around the ball joint.

Because I am formulating a much better post than my original one, since I have learned a lot since then and can't edit it anymore.

Why can't you edit your previous posts? I still think this thread should be stickied, even if you plan on making it better at some point. I think this thread is always getting better.

Quote:

Originally Posted by GripTerror

While looking up s2000 ackerman angle i came across this:

Get more steering angle

I can't see this from my computer at work and I don't have internet at home...SOMEONE HELP ME!!! lol

95KA-Turbo · 07-14-2010, 09:09 PM

I think this is making sense to me now.

I feel like I'm beating a dead horse but......basically, if the ball joint hole on the spindle is angled just slightly then I want the tie rod hole angled just slightly.

OR

Does the ball joint hole need to be in a straight line from ball joint hole...

My photoshops explain what I am asking better. Do I need to make sure both of these are changes are made, or is just the angle of the bolt hole important? I understand the angles are not right in these pictures, but they illustrate what I am asking.

or

PoorMans180SX · 07-14-2010, 09:25 PM

Quote:

Originally Posted by 95KA-Turbo

This picture.

In order to have zero ackerman, you would move the tie rod hole (up) so the center is perfectly aligned with the ball joint hole.

You can see by the angle they're sitting at that the MA-motorsports ones have less ackerman.

Slidin' Sam · 07-14-2010, 09:31 PM

FAIL! I can't see these pics at work!!!

Z33dori · 07-14-2010, 10:08 PM

but would lining up the Ball joint and tie rod cause the steering to over center at full lock?

DC Dan MAX USA · 07-15-2010, 01:05 AM

Quote:

Originally Posted by Slidin' Sam

Ok, so with the max knuckles parts kit, how would you want to set up the knuckles so that you can get minimal to 0 ackerman?...I am currently installing my knuckles...

As said on the last page you only want an extreme reduction in Ackerman if you have lots of horsepower because you are mostly steering with the rear at around 500hp. If you have 300hp at the wheels you want a mild to medium reduction in Ackerman depending on if you want to deal with heavy steering at lock in exchange for a few more degrees of angle. The MAX SAK should be installed by a professional.

The reason the Ackerman is adjustable is this:
When you look down on the steering arm of the knuckle, if the extension is welded evenly/ centered on the arm then it is about 49 degrees of steering angle and a mild reduction in Ackerman. Now if you shift the part 1/4 inch to the outside then you get 52 degrees of angle and additional reduction of Ackerman as seen here:

One of the benefits of the Super angle kit is more angle with no sticky steering at lock but when you offset the parts for more angle and less Ackerman then you are also reintroducing overcentering. A more extreme offset that was pictured on the gold knuckles a few pages back was offset about .5" for a car with mad horsepower. Here is a better view:

Slidin' Sam · 07-15-2010, 01:55 AM

WOW! THANK YOU! That is EXACTLY what I was looking for! lol @ the CAPS I just used. So since my car has roughly 300hp I should maybe move the extension about 1/8" to the outside from the centerline then? Thanks for your help Dan. Oh, quick question about the kit...with the LCA, do you weld the threaded back-plate for the bumpstops to the LCA, or just leave it?...I can see it working either way, just wanted to know what you recommend. Thanks!

DC Dan MAX USA · 07-15-2010, 02:31 PM

Sure that sounds good.

For the SAK, you should look here for more info:
POWERED BY MAX: Forums?????? / ??????MAX??????????Parts Shop MAX Products Forum / ????????????? Super angle steering knuckle project

But basically this is how the standard method LCA mod goes: (flush mount the base plate!)

There is also a more extreme LCA mod, but its the same compromise, more angle but more overcentering, so it should only be used in combination with moving the rack forward.

*!Zar!* · 07-15-2010, 02:37 PM

The only way to move the steering rack forward is by cutting the crossmember and welded it forward, yes?

JeremyR · 07-15-2010, 03:01 PM

what about the driftworks rack spacers that move it forward? could you use those in conjuction with your SAK parts?? i've been wondering this for a while..

Slidin' Sam · 07-15-2010, 07:46 PM

Quote:

Originally Posted by DC Dan MAX USA

Sure that sounds good.

For the SAK, you should look here for more info:
POWERED BY MAX: Forums?????? / ??????MAX??????????Parts Shop MAX Products Forum / ????????????? Super angle steering knuckle project

But basically this is how the standard method LCA mod goes: (flush mount the base plate!)

There is also a more extreme LCA mod, but its the same compromise, more angle but more overcentering, so it should only be used in combination with moving the rack forward.

So basically you just notch the LCA so that the thread base plate will sit in place of the piece you took out. Then weld the plate in place and thread the adjustable bump stops in from there. Right?

DC Dan MAX USA · 07-16-2010, 01:51 AM

Quote:

Originally Posted by !Zar!

The only way to move the steering rack forward is by cutting the crossmember and welded it forward, yes?

For the maximum move forward, yes. But a more conservative move forward and much easier method would be to install eccentric rack bushings from URAS

Quote:

Originally Posted by xdarkrune

what about the driftworks rack spacers that move it forward? could you use those in conjuction with your SAK parts?? i've been wondering this for a while..

I have no idea, don't know of anyone with that combo

Quote:

Originally Posted by Slidin' Sam

So basically you just notch the LCA so that the thread base plate will sit in place of the piece you took out. Then weld the plate in place and thread the adjustable bump stops in from there. Right?

Exactly

Slidin' Sam · 07-16-2010, 01:59 AM

^^^^^^^

はい　ども！　愛してる　ダンーサン！

nieko · 07-16-2010, 04:41 AM

do you guys mod the LCAs along with the knuckles when you pay the 550?

Pandapants · 07-16-2010, 12:09 PM

In addition to ^^^, could you press in new ball joints if we send them with the arms?

07-14-2010, 05:30 PM	#1262
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	For drifting you probably want zero or very close to zero ackerman(aka parallel steer). Ackerman gives you more steering angle on your inner wheel so that it follows a tighter arc than the outer wheel. This is good when you're cruising in a parking lot or at lower speeds on the street/autocrossing etc. When you're drifting, you've got extreme amounts of steering angle put in, and so the ackerman effect is really huge, especially if you add more angle to the car. You end up having a really loaded "inner" tire in the drift that dictates the car's direction, then the "outer" wheel(the trailing front wheel in a drift) has quite a bit less steering angle on it. You essentially drag that outer front wheel along to some extent. That's why some people find it's easier to drift with a ton of preload on their coilovers which kills droop travel and picks up the outer front wheel in a drift. The car would be fastest if it had all four wheels on the ground and the front wheels pointing the same direction, but it's better to just pick that dragging outer front up and let the inner one do all the work with stock ackerman. So parallel steer or something close to it is probably the best way to go for drifting. __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

07-14-2010, 05:32 PM	#1263
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	Ok, so with the max knuckles parts kit, how would you want to set up the knuckles so that you can get minimal to 0 ackerman?...I am currently installing my knuckles... __________________

07-14-2010, 06:05 PM	#1268
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	True ackerman usually means 100% - S13s have LESS than this stock. You want LESS than stock. Basically line up the tie rod pivot with the ball joint pivot to get a parallel steer setup. Adjust toe for best turn-in and steady state grip during a drift . You can basically use small amounts of toe as a set amount of differential angle for the front wheels. I'd think the car would respond well with a bit of toe out and parallel steer for a drift, but the only way to know is try it out. __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

07-14-2010, 06:06 PM	#1269
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	Is it just me, or does it seem like it would be really difficult to measure this properly? __________________

07-14-2010, 06:22 PM	#1272
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	Ok, I have a question....WHY HASN'T THIS THREAD BEEN STICKIED YET??? lol __________________

07-14-2010, 06:45 PM	#1274
GripTerror Zilvia Addict Join Date: Nov 2009 Location: Canada Age: 36 Posts: 685 Trader Rating: (0) Feedback Score: 0 reviews	I'm still trying to understand how it would be possible to improve this with grip in mind... everyone's talking about drift How does an m3 or s2000 have its ackerman? Those are pretty well put together cars... the m3 also has a mcpherson strut front like our cars. What about porsches? Although porsches are rear engined...

07-14-2010, 06:49 PM	#1275
GripTerror Zilvia Addict Join Date: Nov 2009 Location: Canada Age: 36 Posts: 685 Trader Rating: (0) Feedback Score: 0 reviews	While looking up s2000 ackerman angle i came across this: Get more steering angle

07-14-2010, 09:09 PM	#1277
95KA-Turbo Post Whore! Join Date: Jul 2005 Location: LA Age: 36 Posts: 3,402 Trader Rating: (19) Feedback Score: 19 reviews	I think this is making sense to me now. I feel like I'm beating a dead horse but......basically, if the ball joint hole on the spindle is angled just slightly then I want the tie rod hole angled just slightly. OR Does the ball joint hole need to be in a straight line from ball joint hole... My photoshops explain what I am asking better. Do I need to make sure both of these are changes are made, or is just the angle of the bolt hole important? I understand the angles are not right in these pictures, but they illustrate what I am asking. or __________________ Instagram - SJKnoop

07-14-2010, 09:31 PM	#1279
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	FAIL! I can't see these pics at work!!! __________________

07-14-2010, 10:08 PM	#1280
Z33dori Post Whore! Join Date: Dec 2006 Location: Riverview, FL Age: 32 Posts: 5,557 Trader Rating: (12) Feedback Score: 12 reviews	but would lining up the Ball joint and tie rod cause the steering to over center at full lock? __________________

07-15-2010, 01:55 AM	#1282
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	WOW! THANK YOU! That is EXACTLY what I was looking for! lol @ the CAPS I just used. So since my car has roughly 300hp I should maybe move the extension about 1/8" to the outside from the centerline then? Thanks for your help Dan. Oh, quick question about the kit...with the LCA, do you weld the threaded back-plate for the bumpstops to the LCA, or just leave it?...I can see it working either way, just wanted to know what you recommend. Thanks! __________________

07-15-2010, 02:31 PM	#1283
DC Dan MAX USA Zilvia.net Advertiser Join Date: Aug 2005 Location: San Diego Posts: 2,478 Trader Rating: (79) Feedback Score: 79 reviews	Sure that sounds good. For the SAK, you should look here for more info: POWERED BY MAX: Forums?????? / ??????MAX??????????Parts Shop MAX Products Forum / ????????????? Super angle steering knuckle project But basically this is how the standard method LCA mod goes: (flush mount the base plate!) There is also a more extreme LCA mod, but its the same compromise, more angle but more overcentering, so it should only be used in combination with moving the rack forward. __________________ How To order: You can order directly from our zilvia advertiser threads. When you add to cart, you get an instant shipping estimate, & the cart will remember all of your items as you move between forum threads and our website www.poweredbymax.net until you remove them or check out. I can also calculate estimates manually for you but the cart's estimates are way faster and more accurate. Order Inquiry: IM me your real name and paypal address. Thanks for your business!

07-15-2010, 02:37 PM	#1284
!Zar! Premium Member Join Date: Nov 2004 Location: North Korea Posts: 14,576 Trader Rating: (27) Feedback Score: 27 reviews	The only way to move the steering rack forward is by cutting the crossmember and welded it forward, yes? __________________

07-16-2010, 01:59 AM	#1288
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	^^^^^^^ はい　ども！　愛してる　ダンーサン！ __________________

07-16-2010, 04:41 AM	#1289
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 30 Posts: 2,694 Trader Rating: (14) Feedback Score: 14 reviews	do you guys mod the LCAs along with the knuckles when you pay the 550? __________________

07-16-2010, 12:09 PM	#1290
Pandapants Zilvia Junkie Join Date: Mar 2008 Location: SoFla Age: 32 Posts: 302 Trader Rating: (4) Feedback Score: 4 reviews	In addition to ^^^, could you press in new ball joints if we send them with the arms?

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