Suspension tuning

[JDMClifford]

so i am looking at suspension stuff for my s13 and i was wondering what specs people tune it to. i will have the fallowing isntalled on my car.

all adjustable

front lower control arms
front tension rods
rear upper arms
rear traction rods
rear toe arms

solid subframe bushings real solid ones not collors.

what i have on my car right now, except im still working on the motor.

s13 redtop with s15 turbo. gona run about 250-280 hp.
front and rear strut tower bars, c-pillar bar and rear lower arm bar.
stock s14 teardrops in the front and 215/45 17 rims in the back. to they are the same size but the rears are a little wider. stainless steel clutch lines and brake lines. and q45 front brakes.



what camber, caster, and toe settings would be good for an s13 for timeatack and mountian driving because i will probably drive the car to school after i finish it it a cupple months. the road i will be driving to school is in the santa cruz mountians. what do i do about tuning the traction arms? i know it moves relative to the chassis, but do i tune it to how i like the feel for how well it hooks up?

any input would be helpfull, and maby if i am missing anything?

[abunai the drifter]

I say take it to a perfromance shop thay can help you more than any one on this site

[TheWolf]

Some of the stuff is going to be hard to tune because most shops will not have a proper bump steer gauge to allow you to setup the traction rod. What kind of spring/shock setup are you running?

[kawika219]

change your front rims...i assume that those are 15's, the 17's will only push the front tires causing understeer...

[jspaeth]

Unless you have little to no experience with tools, I would say install all that shit yourself....

The only thing on there that I am not sure of is the front LCA because of the ball joint....other than that you are wasting money by paying someone to do it for you.

You can eyeball the alignment good enought to get the car from your house to a shop...

I would guess that if you pay someone to install all that stuff you are gonna pay at least 4-5 hours labor or more


Also, if you are badass/crazy enough to get adjustable front LCAs, then you definitely should spend the money to get aftermarket inner/outer tie rods.....will tighten up your steering for sure


In general the static settings recommended OEM are pretty good, but you have to remember (especially for camber settings) that with all this aftermarket stuff, your suspension is gonna be hella tighter. So when you go into a corner hard, normally you woul gain a crapload of camber on the outside wheels....with aftermarket RUCAs, you are gonna be so much stiffer, that the camber shouldn't change much at all as you corner.


Just some thoughts

[bigOdom1]

take it to a shop that can corner weight will also help since i suppose that you also have coilovers

[Wahl 136]

Install the parts yourself and then put it on scales. A race shop will have them. Or if your rich you can buy them http://www.jegs.com/webapp/wcs/store...10002_93086_-1

[RBbugBITme]

First, JDMClifford, if you are going to drop all the money on a suspension like that I hope you are planning on tracking it a lot and don't kill yourself on those daily mountain treks. I also suggest you spend a little more money on the (almost) end all be all of suspension books, Race Car Vehicle Dynamics. A cheaper start and less in depth book would be Tune to Win by Carroll Smith. I haven't gone through it yet so I don't know how much he deals with suspension types other than the SLA type.

Until you do at least read through some of that stuff I would hold off on buying anything for your suspension, you may come to the realization that you don't need certain things.

Now most of my experience so far is with SLA suspensions so I'll let my partner now about this thread and see if he wants to say anything.

The stock settings are not ok if you are going to be lowering your car which I'm sure you are. As far as camber goes, you would want to find out the roll in degrees per g you will see most and set up your static camber so in the corner, after camber gain on the outside wheel, the wheel is near perpendicular to the road surface. There is a lot of crap that goes into this which is why I think this is over your head at least for now. There is no point to all those parts unless you are capable of adjusting (i.e. tuning) everything based on road surface, tire makeup and condition, weather/surface temp, etc etc etc...

Anyone better at this then me feel free to slap my comments around...

[DriftSpecial180]

Sport compact car did an awesome set of articles regarding suspension dynamics. perhaps you can search they website, they had a lot of good info and setup suggestions.


Here i found it but its only part 1 of like 3 or 4:

http://www.sportcompactcarweb.com/te...ing/index.html

[RBbugBITme]

I hope the other articles are better than that, I didn't really like how some of the info was put and is far from in depth.

"Anti-roll bars don't affect the ride as much as stiffer springs and have no effect on dive or squat."

First of all the terminology is getting mixed up, ride is dive and squat, when both front or rear wheels move up or down together. Second, ARB's can affect the "ride" (roll would be the term they are looking for) just as much or more so than the springs depending on the design (otherwise torsion bar suspension's would never work).

More than just this bothered me... If you think I'm being nit picky I am. This is the reason I started PdV Motorsports, so my partner and I can help people that really do care about a proper setup but aren't sure what to do and only have crap like that article to help them out.

Maybe the other articles cleared things up better, I don't know...

[DriftSpecial180]

I don't think you're nit picking, i think you're misunderstanding it, or perhaps misreading it. I understand it and it makes perfect sense.

Originally Posted by RBbugBITme

"Anti-roll bars don't affect the ride as much as stiffer springs and have no effect on dive or squat."

The reason they don't affect ride as much is because spring can help minimize roll (lateral forces), dive, and squat (both longitudinal forces). Anti-Roll bars only assist lateral forces. So yes, they are correct.

All that other junk you're talking about makes no sense to me what so ever. you're throwing in ride for roll, tomato for potato, carmen for pamela...

[RBbugBITme]

You're doing the same thing as the article. You first state that ARB's don't affect ride as much and then go on to say they only counteract lateral forces. The point I was trying to make is these are two different things, ride quality (a soft compliant setup) and ride (when both front or rear wheels move up or down together).

"you're throwing in ride for roll"
No, I'm using the actual term that anti roll bars are used for.

If you honestly think that is a comprehensive article then you had better pick up a real book and start reading. I'm not getting into this with you anymore than I already did, you're trying to make it seem like I don't understand and I'm just trying to clear up terminology and let people like you know there is way more to suspension kinematics than this article leads inexperienced people to believe. Otherwise the author and every reader would be jockeying for a spot on an F1 suspension team.

[azndoc]

I didn't see tie rods and tie rod ends on the list. Just a thought since your getting everything else, might as well.

Oh and front and rear tanabe sway bars for the win.

[JDMClifford]

wow most of this is some great info. another thing i forgot to mention is i am also looking at swaybars and endlinks. i understand how most of the suspension works and ya... i am going to install it (ALL!) and take it to my local tire ship 500 feet away to get it alighned before i drive it to a performance shop to get it tuned. one thing i think is really crazy is who was the space to test out camber adjustments? most shops? or would i need to go to the track and read what gs my car can handle before it breaks loose?

also here are a cupple pics of my car to show why i am going to buy this stuff right now and wait for coilovers and swaybars. jsut going to do it right and i dont have 4 grand more to spend on coilovers. i think the only parts that are goind to wait is swaybars, endlinks, coilovers, and tie rods and tie rod ends.




here is what my car looks like right now. just took the pics. and a small video of my broke ass ball joints. but the ball joints should be coming in the main this week with the new oem arms.

and this is before.






oh and dont buy these they are crap this broke!




Custom c-pillar bar.




and i need to make the same bracket for this bar. the bolts for some reason are to short.

[jspaeth]

^^ +infinity for Tanabe Sustec f/r swaybars.....

I drove around on just coilovers for about 3 months before finally adding my Tanabe sways.....by far the best suspension upgrade to a stock 240sx is aftermarket sway bar, and I personally recommend the Tanabes

Also,

for just ~$80, a really good upgrade would be aluminum subframe spacers/collars from SPLparts.com.....really reduces the mush in the rear subframe, can definitely feel the difference upon accelerating/decelerating

[R33GTS-T]

while i think your enthusiasm is a wonderful thing, you may have been led a bit astray when receiving advice on suspension parts...i'll explain further....

Originally Posted by JDMClifford

so i am looking at suspension stuff for my s13 and i was wondering what specs people tune it to. i will have the fallowing isntalled on my car.

all adjustable

front lower control arms.
not worth the high price if you aren't a decently experienced racer (on the track of course). the level of adjustment and the ease of completely screwing up your car's setup make adjustable lower control arms a futile purchase for most people.
plus, if you don't purchase adjustable rear lower control arms (for adjustable roll center front AND rear) its pretty silly
front tension rods
definitely a good piece to pick up. i personally love my SPL tension rods (with brake ducts as well). I run 7.5* of caster on the street (any more would be way too twitchy and the car would track too violently). However, on the track I would probably run something closer to 8.0* of caster...maybe a hair more. Road courses are relatively smooth and the further increased initial turn in response would be rather nice
rear upper arms
also a good idea, i currently run -1.5* of camber on my rear wheels (stock RUCAs until i make my own) at which point I will run -2* of camber for track events and -1.5* again for the street. Running too much rear negative camber, even at the track is not always a good thing. It creates more mechanical drag when going in a straight line, thus wearing your tires out much faster (on the track)
rear traction rods
this is a common misconception....the rear "traction rods" are simply a method for adjusting bump steer. In all honesty, I would hold off on them if I were you. That's the last piece of the multi-link that I intend on replacing. No offense, but since it sounds like you're just starting out, having adjustable bump steer in the rear could only lead to further complication if the suspension shop does not properly set the car up.
Instead I would recommend that you save this money and spend it on a set of inner and outer tie rods (from SPL of course....i have them and they definitely rock the house). Be sure to also get the steering angle spacers...that extra 20* of angle makes a world of a difference
rear toe arms
again something I would highly recommend, having rear toe arms really just give you piece of mind that you're not going to break your suspension arms when you run over the curb on a road course

solid subframe bushings real solid ones not collors.
hmmm....to be perfectly honest with you, there isn't anything wrong with getting the collars. they take up the slack that has developed over the years in the stock squishy rubber bushings. If this car is to remain driven on the street (in any capacity other than on the occassionaly sunday drive) you're going to drive yourself nuts and worry all the time about the noises being transmitted through the solid bushings

while you're at it, be sure to pick up a set of solid diff bushings
what i have on my car right now, except im still working on the motor.

s13 redtop with s15 turbo. gona run about 250-280 hp.
front and rear strut tower bars, c-pillar bar and rear lower arm bar.
stock s14 teardrops in the front and 215/45 17 rims in the back. to they are the same size but the rears are a little wider. stainless steel clutch lines and brake lines. and q45 front brakes.
if you're going to upgrade your calipers i STRONGLY recommend upgraded your master cylinder. it will provide you with greater ability in brake modulation as well as increased feedback.

as for the wheels and tires, they're stock, just run the widest, stickiest (RT-615) tire you can safely put on those skinny wheels

c-pillar bar......negligible amount of chassis rigidity, if its too stiff you'll end up cracking your rear windshield when the chassis flexes as you pull in and out of a driveway

rear lower arm bar......i'd pick up a Nismo power brace or a front lower arm bar.....better yet, scrap the c-pillar bar and lower arm bars and just pick up a 4 pt roll bar. far superior chassis bracing when compared to those other components, plus adds a little extra security


what camber, caster, and toe settings would be good for an s13 for timeatack and mountian driving because i will probably drive the car to school after i finish it it a cupple months. the road i will be driving to school is in the santa cruz mountians. what do i do about tuning the traction arms? i know it moves relative to the chassis, but do i tune it to how i like the feel for how well it hooks up?

you shouldn't run the same setup for a time attack event as you would on the street. i also would not recommend trying to enter any time attack events until you have a few years of extensive, instructed, road racing seat time.

i already addressed what to do about the rear traction rods

any input would be helpfull, and maby if i am missing anything?
despite everything i have said already....buying all of these parts is a complete waste of money without being able to control all of that weight atop your wheels

do yourself a favor, replace your busted ball joints with new OE direct replacement ball joints, upgrade your tension rods and inner and outer tie rods, a decently spec'd wheel and tire package, upgrade your rotors and pads (CarboTech Bobcats would serve your purposes very well imho) pick up a set of good coilovers, none of that cheap crap.....and then go out and have at it on the track

come back next season and throw on a set of RUCAs and rear toe arms, as well as any other minor chassis bracing parts you may have in mind

[jspaeth]

^ Good post....

Also, the MAIN point of most suspension mods is what????

To keep the tires planted as flat to the ground as possible.....traction is directly proportional to contact patch....

Get yourself some nice, wide wheels and GOOD tires......all the suspension mods in the world aren't worth it if you are running crappy tires

[RBbugBITme]

OH DANG That R33 guy really knows his stuff!

[gordonliu]

front lower controller arms-> wayyy overboard, wait until you have a truck, a trailer, and tons of money and time to track the car for that upgrade.

all rear links and no coilovers and or swaybars? NO

fix your ball joints
get sway bars (if your end links are busted, just get oem end links, most of the solid spherical bearing type adjustable endlinks will introduce adjustment parameters that you probably will not be in a place to properly adjust ie: cornerweighting)
get shocks and springs and/or coilovers (+camberplates/eccentric bolts if going with aftermarket oe replacement shocks +springs)
new tires
wider wheels
brake pads, maybe even rotors, maybe lines if you can stick with stock calipers for a while
MAYBE get some RUCA.
MAYBE get tension rods, if your bushings are busted

if youve got more time and money at that point, get inner and outer tie rods.

stop at this point. drive the car a bunch. go to track day events. go to as many auto crosses as you can possibly attend. dont try to drift the car until you have tons of empty space and LIGHT (not at night).

then come back and ask about the next round of suspension upgrades.

[JDMClifford]

and ii think the stock s14 teardrops are 16s.

Originally Posted by kawika219

change your front rims...i assume that those are 15's, the 17's will only push the front tires causing understeer...

[JDMClifford]

opps i guess its a good thing im not going to buy aftermarket front lower control arms. i was refering to oem replasement ones with the new bal joint and bushings pressed in already.



and i have q45 calapers with hawk pads. one thing i am still confused about is when i look up replasement master cylinders for the q45 they all look the same as the z32 and 240 replasement ones. is the plunger biger in the z32 and q45?



ohh and all the parts im getting are from splparts.com. are they good quality?

SPL v2 tension rods S13 $189.00
SPL v2 tension rods brake deflectors $30.00
SPL pro rear upper arms S13/Z32 $252.00
SPL pro rear traction rods S13 $197.00
SPL pro rear toe arms S13 $205.00
SPL solid subframe bushings $129.00
SPL brake lines S13 Axle: Front $45.00
SPL brake lines S13 Axle: Rear $45.00

so i should save the money on the traction rods and save up for coilovers and swaybars and endlinks?

[kevtrinh]

for most drift setups Ive noticed that -3.0 camber in the front and -1.5 camber in the back is ideal. 7.5* of caster is awesome as well for fast, responsive feedback. But like jspaeth said, tires tires tires!



I would go tie-rods
(coilovers-rucas-rear toe)
tension rods
anti-sway bars etc.

You should try one at a time to see how it effects your car...but try the coilovers/rucas/rear toe at the same time and every other part individually one at a time.

[JDMClifford]

Originally Posted by gordonliu

front lower controller arms-> wayyy overboard, wait until you have a truck, a trailer, and tons of money and time to track the car for that upgrade.

all rear links and no coilovers and or swaybars? NO

fix your ball joints
get sway bars (if your end links are busted, just get oem end links, most of the solid spherical bearing type adjustable endlinks will introduce adjustment parameters that you probably will not be in a place to properly adjust ie: cornerweighting)
get shocks and springs and/or coilovers (+camberplates/eccentric bolts if going with aftermarket oe replacement shocks +springs)
new tires
wider wheels
brake pads, maybe even rotors, maybe lines if you can stick with stock calipers for a while
MAYBE get some RUCA.
MAYBE get tension rods, if your bushings are busted

if youve got more time and money at that point, get inner and outer tie rods.

stop at this point. drive the car a bunch. go to track day events. go to as many auto crosses as you can possibly attend. dont try to drift the car until you have tons of empty space and LIGHT (not at night).

then come back and ask about the next round of suspension upgrades.

well i dont like drifting so i wont have to worry about that part. and i think autocross is boring. oooo parking lot racing. just not for me. props to people that do it and enjoy it. i just dont. i live about an hour and a half away from laguna seca and sears point. my plan was to do scca and get my racing lisense through them because it costs less and you get more track time. thats what ive herd dont quote me on that. my friend and busness partner met someone who is an instrictor at laguna seca i belive. he does the whole mazda miata thing.