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View Full Version : Factory hollow rear sway bars that fit on S chassis


Def
07-21-2009, 07:02 AM
I'm trying to get some information out there about what factory Nissan rear sway bars are hollow and still fit on an S13/S14.

So far it seems like ALL S13 sway bars are solid = heavy.
The S14 has a 27.2 mm hollow front, and I've heard a hollow rear(15.5-16 mm). The front fits on the S13(original endlink holes a bit past the LCA, but it works). Does the S14 rear sway work on an S13?

I've heard J30 rear sways are hollow, and they are either 20.3 or 18.8 mm(HICAS model). gsracer swapped one on his S14 a while ago, which I'm guessing means it'll work on an S13 since the track width is only 10 mm off in the rear. Are both J30 bars hollow?


Any other factory rear sways that are hollow and work on these cars? Trying to avoid a super heavy solid aftermarket bar and not spend $200 on just a non-adjustable bar as most the hollow ones seem.

94_240sx
07-21-2009, 07:13 AM
idk, I'm skeptical about hollow sway bars. They are light, but I don't think they are as strong as solid bars. I'd rather loose weight and have solid bars.

Def
07-21-2009, 07:21 AM
idk, I'm skeptical about hollow sway bars. They are light, but I don't think they are as strong as solid bars. I'd rather loose weight and have solid bars.

I'm not overweight at all.

A hollow bar has (approximately) 90-95% of the torsional strength of a solid bar and usually less than half the weight.


The math is simple, and hollow sway bars are the most effective use of weight/material. I didn't start this thread to debate the merits of hollow vs. solid bars.

warauto
07-21-2009, 07:21 AM
I will be watching this thread, i would definately want to know.

I didn't even know the j30 sway bar could work on my s14......where did that come from ?

Def
07-21-2009, 07:41 AM
j30 rear sway bar on an s14 [Archive] - FreshAlloy.com Forums (http://www.freshalloy.com/forums/archive/index.php/t-159755.html)

warauto
07-21-2009, 08:02 AM
Thanks bro, i was reading that but which one works...the hicas or non hicas, year model i am confused and they are hollow ?

ranger240
07-21-2009, 08:38 AM
on some other forum... a guy with a white coupe doing a vq swap installed 350z sways front and rear you could probably search google and find his thread

Def
07-21-2009, 09:07 AM
Z33 sways are likely a bit too stiff for an S13.

Def
08-03-2009, 02:02 PM
on some other forum... a guy with a white coupe doing a vq swap installed 350z sways front and rear you could probably search google and find his thread

Looked at it some more and a rear 350z sway bar could work out. I've googled a ton of different terms but can't find the thread. Can anybody link it here?

racepar1
08-03-2009, 02:28 PM
JDM s-13 rear swaybars are 21mm hollow bars. I used to have one, but I sold it to my buddy. Now I want to find a way to get it back. I think the 21mm hollow bar might be too stiff though, maybe with the s-14 rear subframe. I'm thinking about trying to use the 350z front bar, but it's 34mm thick and I think that is too much. I think the older g-35 sedans might have a bit smaller bar though. I'm 99.999999% certain that the 350z/g35 front bars will fit fine on our cars with custom sway to frame bushings. There is a chance that they would interfere with a "power brace" though.

slider2828
08-03-2009, 02:37 PM
Do you guys know if ST's are any good and whether if they are hollow or not?

racepar1
08-03-2009, 02:56 PM
Do you guys know if ST's are any good and whether if they are hollow or not?

I wouldn't use ST's. I don't think they are hollow, but it's been a while since I removed my buddy's ST swaybars.

stinky_180
08-03-2009, 03:58 PM
JDM s-13 rear swaybars are 21mm hollow bars.

oh wow interesting! when i installed my rear jdm s13/180sx sway bars, they looked thicker than stock but def weighted less. didn't know it was because they were hollow, good to know, thanks!

PoorMans180SX
08-03-2009, 04:53 PM
Aren't S13 HICAS rear sways the same size as 180SX rear sways?


I don't like the idea of using aftermarket sways on our cars, and I don't see the need for them really. You can buy springs stiff enough to control any body motion while preserving the independence of the suspension.

Need more rear roll stiffness? Buy stiffer springs. Most professional level drift guys are running the same or greater spring rates in the rear as the front. This will help balance the tire stagger that most people run while preserving the independence of the rear suspension throughout it's travel.

Koguchi -
7kg/mm front
7.5kg/mm rear

Yashio factory 180SX
6kg/mm front
7kg/mm rear

racepar1
08-03-2009, 05:18 PM
Aren't S13 HICAS rear sways the same size as 180SX rear sways?


I don't like the idea of using aftermarket sways on our cars, and I don't see the need for them really. You can buy springs stiff enough to control any body motion while preserving the independence of the suspension.

Need more rear roll stiffness? Buy stiffer springs. Most professional level drift guys are running the same or greater spring rates in the rear as the front. This will help balance the tire stagger that most people run while preserving the independence of the rear suspension throughout it's travel.

Koguchi -
7kg/mm front
7.5kg/mm rear

Yashio factory 180SX
6kg/mm front
7kg/mm rear

US hicas rear bars ARE 21mm, but are NOT hollow. Maybe some of them are, but definitely not most of them. As good as those spring rates may be for drifting, they would be hell at a trackday or time-attack.

PoorMans180SX
08-03-2009, 05:39 PM
US hicas rear bars ARE 21mm, but are NOT hollow. Maybe some of them are, but definitely not most of them. As good as those spring rates may be for drifting, they would be hell at a trackday or time-attack.

Yeah, I know they're not hollow, I was just saying, it's probably easier to find a HICAS bar than a 180SX one.

Why? A bigger rear anti-sway does the same thing as stiffer rear springs, only it's better. A drift setup should be almost exactly the same as a grip setup.

Also, the 240SX was not designed to run with a staggered tire width, which is why most guys need to run more rear roll resistance.

Def
08-03-2009, 05:52 PM
I have 9.2 kg/mm frt and 6.6 kg/mm springs, can't go any stiffer on street tires.

So anybody know if a 350z rear sway will fit on an S13?

racepar1
08-03-2009, 06:59 PM
Yeah, I know they're not hollow, I was just saying, it's probably easier to find a HICAS bar than a 180SX one.

Why? A bigger rear anti-sway does the same thing as stiffer rear springs, only it's better. A drift setup should be almost exactly the same as a grip setup.

Also, the 240SX was not designed to run with a staggered tire width, which is why most guys need to run more rear roll resistance.

Because more rear roll stiffness is NOT what you want. With 9k/6k springs the rear of my car gripped the best without any rear swaybar at all. It is common for 240sx autocrossers/road racers to run without any rear swaybar. 240's, especially s-13's, suffer from tons of on-throttle oversteer. That makes them easy and predictable to drift, but a handful in a roadrace/autocross setting. I have never run staggered tire sizes and I never will unless I truly feel the need to.

Def: What size is the stock 350 rear bar? I was looking at some pictures of 350z aftermarket rear bars and it's hard to tell if they'll clear the exhaust. Some look like they will, others look like they won't. There are a couple 350's at the bodyshop next door. I'll try to shimmy under one of them and see how the 350 rear bar compares to the 240 bar.

PoorMans180SX
08-03-2009, 08:44 PM
240SX's suffer from on-throttle oversteer because they don't have enough squat. The best solution for this is to adjust the angle of the lower control arm to gain more squat and thus traction. This is why Koguchi runs a 5kg/mm spring plus a 1.5 kg/mm helper spring in the rear, so under throttle the car compresses the 1.5 spring and transfers more weight to the rear.

The ideal suspension setup is one that allows you to do four-wheel drifts, where all tires lose traction at the same time. With our cars near perfect weight distribution and non-staggered tire sizes, the front and rear roll couple need to be the same for it to handle neutrally.

My 240SX with 10/8 springs and stock anti-roll bars (with urethane busings) UNDERSTEERED in solid state turning.

Why are you looking for a bigger rear anti-roll bar then?

Def
08-03-2009, 10:50 PM
Def: What size is the stock 350 rear bar? I was looking at some pictures of 350z aftermarket rear bars and it's hard to tell if they'll clear the exhaust. Some look like they will, others look like they won't. There are a couple 350's at the bodyshop next door. I'll try to shimmy under one of them and see how the 350 rear bar compares to the 240 bar.

Not sure. I'll probably jack up my sport package '06 G35 Coupe and take a look at the rear swaybar some time this week to get an idea. The size is supposedly bigger than earlier models, but I can't find any firm measurements.

Def
08-03-2009, 10:52 PM
240SX's suffer from on-throttle oversteer because they don't have enough squat. The best solution for this is to adjust the angle of the lower control arm to gain more squat and thus traction. This is why Koguchi runs a 5kg/mm spring plus a 1.5 kg/mm helper spring in the rear, so under throttle the car compresses the 1.5 spring and transfers more weight to the rear.

The ideal suspension setup is one that allows you to do four-wheel drifts, where all tires lose traction at the same time. With our cars near perfect weight distribution and non-staggered tire sizes, the front and rear roll couple need to be the same for it to handle neutrally.

My 240SX with 10/8 springs and stock anti-roll bars (with urethane busings) UNDERSTEERED in solid state turning.

Why are you looking for a bigger rear anti-roll bar then?

You don't know much about suspension tuning, so please stop quoting Japanese drifter spring rates and what not.

If you must know, I have an S14 rear subframe(less anti-squat), spherical bearings and rod ends on all links/pivots, and 1 kg/mm tender springs as well(which don't do jack when you're driving the car). They're not helper springs btw...

My car has very pronounced oversteer due to a lack of rear roll stiffness with no rear sway, hence I'm looking for a swaybar that'll actually do something vs. the heavy/tiny solid stock S13 15 mm rear sway.

PoorMans180SX
08-03-2009, 11:41 PM
You don't know much about suspension tuning, so please stop quoting Japanese drifter spring rates and what not.

If you must know, I have an S14 rear subframe(less anti-squat), spherical bearings and rod ends on all links/pivots, and 1 kg/mm tender springs as well(which don't do jack when you're driving the car). They're not helper springs btw...

My car has very pronounced oversteer due to a lack of rear roll stiffness with no rear sway, hence I'm looking for a swaybar that'll actually do something vs. the heavy/tiny solid stock S13 15 mm rear sway.

I'm sorry, I must be confused. Forgive me for posting incorrect information if I have done so.

How does adding more rear roll stiffness decrease oversteer?

TheWolf
08-04-2009, 04:54 AM
When I converted my S14 from the factory bars to tanabe hollow sway bars. The weight savings was about 15 on the front and 10 on the back. I doubt a S14 rear is hollow. I did not cut it in half though. If it is then it's not much for weight savings. I found the tanabe's to be the best value in weight and performance.

You are skilled enough to build your own sway bars.
http://www.speedwaymotors.com/Universal-Rear-Sway-Bar-Kit,4053.html
this is to give you an idea.. that bar in the kit is solid. The site has hollow ones splined or unsplined available. It's really not hard.

racepar1
08-04-2009, 07:15 AM
My car has very pronounced oversteer due to a lack of rear roll stiffness with no rear sway, hence I'm looking for a swaybar that'll actually do something vs. the heavy/tiny solid stock S13 15 mm rear sway.

I've noticed nothing but positive benefits to running no rear sway, that is with the s-13 rear subframe. I still think it is better to run a swaybar though. I am going to run a little softer rear springs and put the stock rear sway back on for now. When I get the new chasis built with the s-14 rear subframe I think I am going to try the 21mm hollow bar. I'll just have to find a way to get my buddy to sell it back to me, shouldn't be too hard.

gsracer
08-04-2009, 08:02 AM
lol, funny that this comes back up now, i just took the j30 rear sway bar off and went back to stock, because with the spring rates i am running i found the rear of the car way to stiff and wouldnt transition weight well at all, it got a little better with the stock one.

PoorMans180SX
08-04-2009, 08:45 AM
Sport compact car article that helped me understand this a little:

Compact Car Questions - Technical - S13 Modifications - Sport Compact Car | Sport Compact Car Magazine Article at Automotive.com (http://sportcompactcar.automotive.com/75261/0701-sccp-compact-car-questions/s13-modifications.html)

racepar1
08-04-2009, 08:57 AM
I looked under the z, but unfortuanetly I can't put it up in the air since it's not at our shop. It looks like the z-33 rear sway is about 22-23 mm thick, definitely hollow, and will most likely clear the s-chasis exhaust. I don't think the dimensions will work though. The z-33 rear bar steps back (towards the diff) through the center of the bar. It bends just inside the bushings and steps back a good 2-3" and it also looks to step down 1-2".

Def
08-04-2009, 09:03 AM
I'm sorry, I must be confused. Forgive me for posting incorrect information if I have done so.

How does adding more rear roll stiffness decrease oversteer?

Just because one end of the car takes more lateral load transfer does not mean that end will become "loose." there are many factors that go into it.

For those that are curious, the S14 front sway bar is hollow. It doesn't weigh 15 lbs by itself IIRC, so not sure how a different sway could save that much...

slider2828
08-04-2009, 09:48 AM
It also depends on roll center as well, you can't say just based on spring rates that it will lose traction or not.... I have 12-10's and they are horrible on the track, but at an autox (which is a completely different sport) it works really well at an airport track. Personally I have ST Sways and I like them, although heavy they work... I really need to go 10-8....

I noticed messing with dampening settings (MR coils) that it really makes a difference how the car reacts... Springs is one thing, but dampening also makes a huge difference doesn't it?

projectRDM
08-04-2009, 11:23 AM
I love how 'drifters' try to put their two cents in on a thread clearly aimed at grip driving. They are nowhere near the same. You want oversteer when drifting, the more the better, while in autocross/track you don't want to fling through corners sideways.

PoorMan - You make great points if the thread was about sliding on a flat surface. It's not, it's about driving, over off camber corners, flats, on camber hills, and everything in between. Please don't keep digging a hole for yourself.

Def
08-13-2009, 05:56 PM
Just a bit of info. I picked up a J30 rear sway bar from a guy who said it was from a non-HICAS car. It is about 19 mm(19.2 mm exactly) outside diameter and hollow. It is about 1.5 lbs lighter than my stock 15 mm solid S13 rear sway bar.

I've test fit it, and it looks like it should fit with no problems since the driver's side "hump" is in about the same place as the stock S13 bar's exhaust bend.