Custom anti-roll, anti-sway and anti-squat/dive help

[SxyBeast]

Most important question is regarding anti squat/dive. I want to make custom anti dive/squat bars, will be made of steel AND/OR carbon fiber wet layup. When I say and/or I mean I may make it out of steel and then wrap it several times in CF. I'm curious where an anti dive/squat bar would connect at either end. and should it connect throughout the middle or the underbody? Maybe also connecting to the transmission mount? Just throwing out ideas here, I have no idea what to do.

I also want to reinforce sway bars with extra steel geometry AND/OR carbon fiber, is this alright? It does seem wierd to me that at either end where the sway bars connect to the suspension members there is a very weak small and long bolt. As you can see I don't want to spend crazy stupid cash on "brand name" bars.

For the strut bars I'm thinking of just adding extra geometry to the stock front and rear bars and maybe CF wrap. Should the strut bars be adjusted in any way? like tighter? Or just install with car on level ground?

As alwayse I value any input. Thanks.

[frankiman]

i don't see how wrapping steel in carbon fiber would make it stronger/stiffer

anti-squat
i'd suggest making a bar resembling the sway bar, or just a flat piece of metal, but straight, bolted at each end where swaybars are bolted to the RLCA and running underneath the subframe/diff
bump stop would need to be attached to the underneath of the subframe

basically you want something to add spring rate when compressed, but not modify it when in tension

so when to car if sitting at normal ride height, the bar just hangs underneath,
same thing when suspension is in ''droop'', when the spring are under tension,

but when you compress the suspension, dive under acceleration, the bar touches the bump stops and starts to bend and acts exactly like a spring, making it much harder to compress further

this a little image i just drew up

[CanadianGTR]

What dampers/spring rates are you running?

[Skym]

Dive, Squat is suspension setup related.

For example with antisquat -

http://www.desertrides.com/reference/images/terms/anti-squat.gif

Bumpstops at top of shocks usually act as anti squat bars, as they don't let shock / spring compress past a certain point. Enlarging the height of bumpstops should have a similar effect.

I was told that strut bars are adjustable, due to when car ages, strut towers are not usually in the same spot, so you adjust strut bar to suit. That's if car has no strut bar from factory. But also might apply to cars with strut bars from factory, as they are adjustable.

Best front strut bar is the non adjustable reinforced R34GTR Nismo, Carbring type strut bar.

Or bars that go on a angle from strut towers and towards, through firewall. Then connects to rollcage (look at Gibson R32GTR to see what I mean) -

http://www.skylinesaustralia.com/forums/uploads/gibson_engine_3.jpg

Strut towers move inwards and towards firewall on a angle. Look at the position / angle of the top suspension arm, 4x bolt pattern on engine bay side of strut tower to see what I mean.

I think Tein created a strut bar for R32 Skyline that goes on a angle, towards, firewall and between strut towers. But without a rollcage to connect to, I think it won't be as effective. Seen similar front strut bars on rally cars like Evo's, etc and Toyota Treuno (newer, fwd version of Toyota AE86), etc.

For rear, something like this -

http://image.superstreetonline.com/f/9283325/130_0712_13_z+nissan_240sx+strut_brace.jpg

You'll notice at 2:01 in videoclip below that Nismo on the prototype R32 Group-A racecar made a extra bar on top of the rollcage bars that go on a angle from stut towers to rollcage inside cabin -

http://www.youtube.com/watch?v=08VZxs2kvzE&feature=related

They used the same bar on GTS-R. So there must be an extra lateral benefit from running it that way.

So there's many ways to accomplish the same job.

[archaeic_bloke]

i like franki's idea...

but honestly im using a set of tein coilovers and i really don't have a whole lot of dive and roll.... how much are you experiencing? maybe better coilovers would help

[frankiman]

very stiff spring rate cures every problem, except your back ache

[CanadianGTR]

Suspension works best when it isn't.

[Transparent Skyline]

I guess no ones ever heard of 3rd springs... But at any rate none of this is needed. If i was you i would look more in to things like roll center and learning how suspension is meant to work and not try to re-invent it.

[SxyBeast]

Transparent, I believe your comment would be more suited towards someone more technically knowledgable like others who have responded to my questions. I would yes like to know more about this stuff however, under the circumstances I just want something better than stock and EASY to do just like Franki's idea. Very cool idea Franki thats most likely what I will do. I am thinking about making the bars adjustable for street/track.

Correct me if I'm wrong but I was reading a racing school book and the author talking about suspension says normally the softest spring rate possible is best under most circumstances to allow grip of the rear under accel. I think that's what it said. I will double check later. Ultimately I will simply play with different suspension setups and find what's best.

I bairely even remember driving my Skyline, that's how long it's been. All I remember is that there was alot of roll, and some dive/squat. Mostly because of my crappy shocks. Yes they weren't even coilovers, so that would explain alot, but, if I can go the extra mile for no extra cost why not? I will most likely be picking up a set of Buddy club racing spec coils or Tien.
And remember: if it's not broken don't fix it, BUT if it's not broken your not driving hard enough! Therefore right now while the car is under the knife I'm looking to reinforce everything I can because I can't wait to break stuff!

Skym: I like those strut bar ideas, ispecially the rear, just one question. Should the strut bar be swivelable, so to speak. Like how almost all strut bars are not 100% stiff, they can swivel at ends. Or can I make mine one big stiff bar?

Lastly, Franki, I believe that if these things could be made of CF entirely by tuning companies why not wrap in CF to add stiffness/strength. I'm pretty sure that with enough CF something will happen, no? Although when it comes to using your idea I will most likely shy away from CF because some flex looks like it would be better to have.

Could someone clear my confusion please, sway bar, roll bar, which one is where and does what and is a roll bar the strut bar?

[NismoS-tune]

Have you thought about buying aftermarket adjustable sway bars?

[frankiman]

the sway bar is also called an anti-roll bar or torsion bar

it connects both front, or rear wheels, to each other,
it acts like a spring (in torsion) linking both wheels, when 1 tries to move upwards or downwards, it pulls the other wheel to do the same, thus reducing the car's roll

the strut bar is a strut brace, or strut tower bar
is connects the top of the strut towers together, why?
because most cars since the 80's are monocoque (not sure what it is in english)
so the chassis (frame) is the body
so throughout its life, the chassis flexes and bends with each drive
with enough time, the metal chassis will suffer from metal fatigue, meaning it will fill much softer, love its ridgidity
the strut bar adds to the ridgidity of the chassis, reducing overall flex

[CanadianGTR]

BUT if it's not broken your not driving hard enough!

No... if it's broke it's because the part wasn't the right part (old, not up to part) or because it was not installed correctly. The correct part, installed the correct way, used in the correct circumstances... should not break.

Honestly, good dampers/springs will solve 90% of your problem.
No need ironing out the last 10% of the suspension tuning process when you haven't even taken care of the first 90%.

As for wrapping bars in CF... it won't do anything at all... period.
If the part is so weak that it's flexing... then refer to my first blurb... and buy the right part. Simply wrapping things in CF is only cosmetic and will not help at all..
unless you have access to a pretty serious composites facility.

[archaeic_bloke]

No... if it's broke it's because the part wasn't the right part (old, not up to part) or because it was not installed correctly. The correct part, installed the correct way, used in the correct circumstances... should not break.

Honestly, good dampers/springs will solve 90% of your problem.
No need ironing out the last 10% of the suspension tuning process when you haven't even taken care of the first 90%.

As for wrapping bars in CF... it won't do anything at all... period.
If the part is so weak that it's flexing... then refer to my first blurb... and buy the right part. Simply wrapping things in CF is only cosmetic and will not help at all..
unless you have access to a pretty serious composites facility.

+1


******

[Skym]

Swaybars are more for lateral grip, as swaybar combines left and right spring rates (like Frankiman mentioned, pushes both springs up when one side is loaded) and adds it to loaded side (doubles the spring rate on loaded side of car) which pushes more on loaded side and pushes inner wheel onto the ground which increases lateral grip. They also adjust under, oversteer and work with spring, valving inside shocks and need to know them before selecting swaybars. Also can adjust which wheel gets max grip. Your talking about 4 sec per lap faster if you have the correct settings. It's often a area that they play with on Mini racecars to get faster laptimes.

You don't want car to sit too flat, as lose grip on loaded side and car loses traction, car skates across racetrack.

Strut brace keeps strut towers from moving around, so alignment settings are near to perfect when car goes around a corner. On Monocoque car, you have the subframe underneath for bottom of strut towers, but nothing on top of engine bay. The strut brace becomes the top subframe, so to speak. Stronger the strutbrace, the better it will work. Also like Frankiman mentioned, increases chassis rigidity. A good strut brace will be wider on strut tower side, brace part, as it spreads load across strut tower.

Another way to increase chassis rigidity and reduce body roll, is to fit these Ultra Racing bars under car -

http://www.ultraracingaustralia.com/

They connect the frame rails together, as floorpan on Skylines is only a sheet of thin metal, etc. They are becoming popular downunder for trackcars.

[Driftacular]

Didnt read everyones post, so wat i say may have been said..

full cages will add wonders to chassis rigidity, u can make them so that they aid in places where a strut bar might do (rear strut towers).

as for the anti-squat stuff, tbh as others said.. a rlly good suspension set up should sufice, just make them stupid hard. and get a nice massage chair..cuz ull need it when u get home...