Reducing Sway and Body Roll


  • Reducing Sway and Body Roll

    Hey Everyone,

    I'm wondering what I need to do to reduce my sway/body roll. It was really bad with the OE, but since then I put in new NAPA dampers f/r, poly bushings, and new springs around 235 lb/in. on the front and 210 lb/in. on the rear. This has helped a lot but it still isn't enough for me. Not only do I have major body roll, it seems almost impossible to oversteer, and its really easy to understeer. So, I guess what I'm asking is what is the next thing, that you guys think, I can benefit most from.

    Thanks

  • #2
    Cha iro

    enjoy building it yourself.
    if it fails, fuck it.
    at least you gave it a whirl.

  • #3
    So, that's what you would get if you were in this situation?

  • #4
    The MSA sway bars made a HUGE difference on my AE; chassis is so much stiffer that the ride is actually a bit too harsh, actually.

  • #5
    Ditto for the MSA sway bars, I've had them an two of my cars and they make a huge difference.



    1988 300ZX Turbo, Shiro Special #760
    1988 300ZX Turbo Automatic (wife's car)
    1991 Hard-body 2WD

    http://zccw.org/zccw/?page_id=1215

  • #6
    Those are a great upgrade. But I went with late model turbo rear and front sway bar paired with poly endlinks and some custom cromoly links that I made. They are not as thick as shiros or MSA but they helped quite a bit. I have ST springs and poly bushings all the way around, those sways helped a TON! It cornered great before, but with the sways it felt so good!

    Another part of sway is the tires sidewall stiffness also.
    My Build Thread

  • #7
    Sweet, thanks for all the feedback!

  • #8
    Search around for the Z3R springs that are discontinued. They are the best springs ever made for the Z31. 300 lb/in fronts and 325 lb/in rears. They pop up for sale from time to time, and if you have the cash when they pop, buy them immediately.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily

  • #9
    NAPA dampers are probably not working enough to fully enjoy those springs.

    For the trouble/cost/relatively-marginal-benefit of buying Z3R's and the dampers to properly match those rates, I would just go straight to powertrix/stance.

    The MSA bars are a good, cheap bolt-on in the meantime that you will eventually want anyway so give that shot first.
    Justin
    1986 NA 2-seater
    SCCA Solo E-Street Prepared #31
    Race Videos
    Build Thread

  • #10
    which brings to question, you said you got new 235lbs springs....what springs are those....?

    And definitely yes, you probably just got oem replacement dampers that do squat for performance.
    My Build Thread

  • #11
    What wheel and tire setup are you running

    MSA sways will be your best bang for the buck to reduce body roll.


    Justin,

    I actually ran the 22mm sway in the rear and now have removed it all together. I have not had the chance to go thrash on the car yet, but I am hoping for some added corner traction. On the shiro I still have in the rear shiro sway, but the car is very oversteer happy. I will probably downgrade to the 22mm bar I have laying around to see if it helps.
    86na - BlueZ
    Shiro #366 - Kouki Monster
    85t - Mr Tickles

  • #12
    Originally posted by adamvann3 View Post
    Justin,

    I actually ran the 22mm sway in the rear and now have removed it all together. I have not had the chance to go thrash on the car yet, but I am hoping for some added corner traction. On the shiro I still have in the rear shiro sway, but the car is very oversteer happy. I will probably downgrade to the 22mm bar I have laying around to see if it helps.
    Hey Adam, I found the same in my setup. The MSA rear sway made the car very tail happy on corner entry. I am running the 22mm bar in the rear right now too. I like this set up. I haven't tried no rear bar yet, but fear it might feel too pushy for me.
    Justin
    1986 NA 2-seater
    SCCA Solo E-Street Prepared #31
    Race Videos
    Build Thread

  • #13
    I agree with others that these cars are really undersprung. I've been running MSA front and stock rear sway in the dry. Took stock rear off for last event due to lots of rain and then ran a dry test day w/o it. You can feel the rear roll more, but still didn't notice any push (even in the wet) and definitely increased rear grip. I'm sold on running w/o it during wet events, but will test in the dry again once I get the new motor installed. I think I prefer the OE bar in the dry.

    YMMV, my car is about 500lbs lighter than a street car. 255 tires on 17x9s. Frost, you might not like it on an autocross when you need quick transitions and the rear to rotate a little more.
    ________________
    1987 Chumpcar

  • #14
    Question: which brings to question, you said you got new 235lbs springs....what springs are those....?

    Answer: Basically didn't want to buy used SS springs for the price people were asking so, I looked on NAPAs website for an option. They only had rear springs though http://www.napaonline.com/Catalog/Ca…400_0209698605. The fronts then aren't even for the 300zx, my friend, worked at NAPA, brought the spring, not the season, catalog to my shop so I could find something with a desirable rate, but the right dimensions.

    Question: What wheel and tire setup are you running

    Answer: Just put some Starion 16x8 wheels wrapped in some used 225/50/R16 Hankook All-Seasons off my friends SRT-4, but before I had the stock 15x6.5 with 205/60?/R15 Goodyear Eagle GT

    I don't know if it's worth mentioning, but I'm also running an OBX helical differential, Shit Is Good.

    Thanks again for the input, and I was curious are progressive rate springs not good performance wise? A trusted friend told me to stay away from the Eibach lowering springs.

  • #15
    If he said "Eibach lowering springs" he probably doesn't know what he's talking about. One of the z31 sites said a million interwebs years ago that Eibachs weren't any good and now everyone just mindlessly repeats it. Eibach makes a progressive kit for z31s which in my experience is excellent for hard street and backroad driving and pairs very well with Bilstein dampers. I replaced quite new OEM springs with them and they were definitely a performance improvement. People who want to feel full racecar will probably find the initial travel too soft, but full racecar can get old real fast. They lower the car about half to three-quarters of an inch.