improving handling

[95Blue240sx]

im looking to make my car more for grip and plan to auto-x. right now the car feels funny when taking a turn, but i think it is due to the cheap-o tires in the front. right now my setup is tien ha c/o, whiteline adj front & rear sways, vlsd, kazama tc rods, cusco tension rod bar, cusco front stb, sub spacers, and ruca on its way.

im planning to taking my car to get corner balanced, and maybe some camber adjustment. the car is a daily driver, but it'd like it to handle like a champ. if you could provide me with some links on suspension geometry and other advise about my suspension setup that'd be awsome. im searching daily for sites to help me, but if you have any please post them.

another question i had was about dampening and spring rates. if im going for grip would a firm spring rate and firm dampening be best? or soft springs/hard damp, or soft springs and hard damp? just some n00bie questions id like to get answered. thanks for any replies.

my search continues. :wavey:

[fastpace]

on the damping part: I have finally figured out the best setup for me while autoxing and just daily driving. I have pretty much the same setup as you but with a hicas rear swaybar and tien he's. The front setup is 10 from full stiff and 13 from full still in the rear. I always thought that full stiff was the best setup, but isn't at all. If you set your coilovers full stiff in the front it will cause mad understeer and if you go full stiff in the rear it will cause crazy oversteer. The main reason for this is because you are adding or putting more force on the tires which makes you loose traction easier. The way my car handles now is very neutral, goes where I point it and if i really want to I can bring the rear end out. I never really cared for adjustability of the sways, but you can use that to your advantage sense you have some.

So what is your setup right now on your coilovers, sways, and how does the car feel/act while at an autocross?

[Chernobyl]

When was the last time you went in for an alignment? Espeically if you have changed your ride height at all since the last alignment, go get it done. I have alaways and will always tell people to get an alignment first when it comes to weird handling.

A local Mazda shop guy that does race alignments told my buddy that 80% of a car's handling is in the alignment, and the hardware takes care of the rest. I don't know if I believe this completely, but if an experienced racer tells me something like this, I'll at least take it into heavy consideration.

[DS 240R]

A local Mazda shop guy that does race alignments told my buddy that 80% of a car's handling is in the alignment

I definitely agree with this 1 million percent! We were scrambling to get our SE-R out to the track this past weekend and didn't have chance to align it after installing our new suspension and tire/wheel package. The first session out the driver brought it back and yelled "It's totally undrivable!"

Turns out we had 1/4" toe in on the front, left rear was 3/16" toe out and right rear was 1/6" toe out! Turns out it was undrivable. Even just something as easy to change as toe makes a huge difference in handling. And ever camber or ride height change changes toe, so make sure you check it often.

[Var]

i can vouch for the above said also. I almost sold my s13 cause it was understeering so bad. than i got an alignment and i felt stupid for wasting a whole set of Azenis driving with half of their potential. The car was still driving striaght, but the alignment was way off. Also when you get your RUCA's like i just did(not installed yet) you will be able to make the car handle right at low ride heights.

[AKADriver]

Get those RUCAs and a proper performance alignment. Search the board archives for "alignment settings", there was a thread in the Tech forum a long time ago about some good baseline alignment settings for "grip" as determined by Whiteline.

Definitely square away your tire situation. Janky front tires mean understeer. Resist the temptation to stagger tire sizes, it won't help.

The hard parts of your suspension should be fine as they are. Tune with the sway bars and the damping adjustments.

[95Blue240sx]

what about wheel size? you say dont stagger? so 8" wide or 9" all around?

sorry for my ignorrance.

"no stupid questions just stupid people"

[sykikchimp]

16x8" wide all around is a good size that allows for good grippy tire sizes, that aren't too expensive.

With the whiteline sways, you should try to use them for adjusting the handling of the car. Damper's should be adjusted to the track surface first. Make sure the car doesn't "skip" over bumps, but also make sure it's not bouncing excessively. You want your dampers soft as possible but where they still do the job. Once you have that figured out, hit the corners, and begin adjusting the sway bars. Remember that you can use different opposing holes on the bars to fine tune adjustment. for example, on the front bar, you could use the #3 hole on one side, and the #2 hole on the other to create an intermediate setting b/w #2 on both, or #3 on both. (hope that's not too confusing). You can do the same on the rear. Essentially you have 5 way adjustment front, and 3 way rear with whiteline bars. That's quite a bit of adjustment.

Once you get the car as close to the handling you want, then you can make finer adjustments with tire pressue. Raising air pressure is sort of like raising the spring rate.

You should also learn how to read tires to make suree you taking full advantage of them with your alignment settings and tire pressure.

Also, I've found the whiteline suspension settings to be a little timid. Especially if your running higher rate springs like 8/6. The 8/6 springs don't allow for as much wheel travel as whiteline's springs do, and therefore you don't have as much dynamic camber. 2-2.5 degrees front camber, 7-8 degrees caster. ~1.5 degrees rear camber, and 0 toe all around. The more agressive the tires you use, the more camber you will likely need (in small amounts).

[aznpoopy]

very educational thread!


Once you get the car as close to the handling you want, then you can make finer adjustments with tire pressue. Raising air pressure is sort of like raising the spring rate.

You should also learn how to read tires to make suree you taking full advantage of them with your alignment settings and tire pressure.


hmmm, more relative air pressure rear / less front = oversteer setting; vice-versa for under? (relative to stock of course) i recently mis-inflated my tires to 35 all around (not intentionally) and the car understeers like a bitch. oops.

also i tried doing a search on google for 'how to read your tires' and i got alot of information regarding how to read tire sizes like 205/55/15 etc. got any useful links regarding this information? i know how to read tire wear but from what you are saying it sounds like you can get alot more information off them. (driving habits? understeer / oversteer prone?)

[sykikchimp]

Wear and temperature across the face of the tread are the two things too look for.

a probe type tire pyrometer is necessary to really get into it serious. You take temperature readings at the outside edge, middle, and inside edge of the tire tread immediately after you come off track. Also take tire pressure's while hot, and record all.

google search for "reading tire temps"

http://www.popularhotrodding.com/tech/0311phr_tire/

Even with a totally unadjustable suspension, you can make pretty drastic changes in the feel of the car with just pressure changes.

[95Blue240sx]

:bowdown: sykikchimp

thanks sykik. i need to start doing track days so i can really get into tuning it.

one thing i had a question on, was the swaybars. you say i can put one side on 3 and the other on 2. and this would be in middle of those two? i thought if you did this one side would respond better than the other side, since there is less travel for one side and more for the other?

[sykikchimp]

the "rate" of the sway bar is determined by useing the length of the back of the sway bar, and the total length of the arms. Nowhere does it use the seperate length's for each arm.

What your thinking of is preloading the bar.

[nightwalker]

hmmm... that's interesting about the whiteline swaybar adjustability. I thought they had to match at both ends.

[95Blue240sx]

since im not using the tien HE, and have the HA, 6/5, should i stick with that? or get some 8/6? right now the car feels kinda slippery, really needs alignment(couple weeks!!), so maybe just stick to what i got.

will that whiteline setup be okay with the spring rates im?

[sykikchimp]

The whiteline sways will work fine for you. I'm personally gonna pick up some 6/5 rates for my s13 soon...

[aznpoopy]

Wear and temperature across the face of the tread are the two things too look for.

a probe type tire pyrometer is necessary to really get into it serious. You take temperature readings at the outside edge, middle, and inside edge of the tire tread immediately after you come off track. Also take tire pressure's while hot, and record all.

google search for "reading tire temps"

http://www.popularhotrodding.com/tech/0311phr_tire/

Even with a totally unadjustable suspension, you can make pretty drastic changes in the feel of the car with just pressure changes.

great info... arigatou! :bow:

[MadScientist]

The only thing I noticed that you dont have is Tie Rods and Tie Rod Ends. Everything else that is replaced on your car basically a solid bushing.

That is the only thing I see that may help with the understeer (besides allignment, but still get allignment done)... also you could get technical and weight balance the car... as already planned... long day!

I have 10/8 setup on the 180sx (not driveable yet)... I chose this spring rate after a day of testing at the tack... I personally like a stiff suspension and beefy tires.. I do run 17s at the track (not 15s, brakes are to big). and 9.5 front and rear. Camber is only 1 deg. Front/ 2 deg. Rear. I keep the setting on everything the same at all tracks... although I know I shouldn't... just like keeping it simple to play with.

Sikiychimp is obviously a Track Whore :coolugh:

[sykikchimp]

yeah, I left out corner weighting.. I should have included that. Definately a big plus to get done. You need adjustable front end links though. Don Nimi at pdm-racing sells some ultra pimpy heim-joint links on his site to work with the whitelines that work awesome for this purpose. I have a set on my car already. Very nice.

[95Blue240sx]

about the tie rods(inner and outter), i already have. nothing special, moog. they are pretty nice for aftermarket oem replacement. which i got from my work dirt cheap =P.

yeah i've read about the endlinks, but i dont think i need those just yet. ill make due with what i got for now.

about the corner wheighting, i changed my mind about it. im on a stock exhaust right now, because of stupid apexi welds, so after i get an exhaust id like to get it corner wheighted. thats seems like the last thing after getting an exhaust and deciding if i want the battery in the rear.