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Thread: Sway bar

  1. #1
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    Sway bar

    OK guys, my donor had a cobb sway bar, so I figured I'd try to use it. The bushings were TORE up so I waited to order more. Might have been a bad move. I don't think it's gonna work. Can y'all take a look at this video here and tell me if I'm hosed?

    Also, I remember reading that some of the R guys were running without a sway bar. Anybody recall if that's correct, and why?

    https://youtu.be/ib6LdjXFLyo

    Thanks

  2. #2
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    After a few hours of reading, it seems this question has been asked before of the cobb sway bar, but I don't know that it's been answered definitively. There have been reports of rubbing against the wheels, so I'll bolt up the stockers tomorrow and see how that goes.

    As for running without the sway bar, looks like I could expect more oversteer. More than what? I dunno. Maybe finish up and see how it goes? Not a 5 minute job to put it in later, but it could be worse.

  3. #3
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    I purchased an aftermarket rear sway bar to install on the front of my 818 and it wouldn't fit. It would contact the coilover.

    You can run without the bar and have neutral handling but it all depends on the spring rates you are running. A few people are changing spring rates up to get to an ideal balance. On my 818S, with 500# rears and 350# front springs, it's still too loose in the rear with a large custom sway bar I made for the front. I'm moving down to 400# rears next.

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    Which bar was it? Probably cheaper for me to find a sway bar than new springs. Thanks.

  5. #5
    Senior Member UnhipPopano's Avatar
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    The lighter the springs that you use, the stiffer the sway bar you would want. Do you know what your corner weights are?

  6. #6
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    I think the bar i got was a whiteline or something. But looking online, all the aftermarket bars look the same in terms of shape. The passenger side has a really aggressive V bend in it that is not going to clear the coilover. That's why a couple of us have fabricated our own bars.

  7. #7
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    Quote Originally Posted by UnhipPopano View Post
    The lighter the springs that you use, the stiffer the sway bar you would want. Do you know what your corner weights are?
    somewhere around 100 pounds, lol. I'm just getting started. I have about half the suspension bits on and wanted to ask this swaybar question before it got any more difficult to pull it out.

    Quote Originally Posted by Hindsight View Post
    I think the bar i got was a whiteline or something. But looking online, all the aftermarket bars look the same in terms of shape. The passenger side has a really aggressive V bend in it that is not going to clear the coilover. That's why a couple of us have fabricated our own bars.
    On the Cobb, once it makes the bend, it just sticks straight out. It gets past the coilover, but there isn't much room to wiggle. I'm on my way out there right now to check wheel interference. I just fired an email to a guy who bought a lot of my donor stuff. He's local, which is great. With any luck, he'll take this sway bar, the front, all the links, the new bushings I bought, and give me his old rear and a couple bucks so I can buy more bushings. Wish me luck!

  8. #8
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    OK, definitive answer...no way will this work without creating a ton of trouble.
    Factory Five wheels...
    20171212_200505.jpg

    Stock wheels...
    20171212_200937.jpg

    It's worth noting that this is at full droop, but it seems pretty obvious that there is no clean, easy way to remove the interference. Chopping stuff up, welding stuff together, limiting the steering rack...all for the luxury of a few inches of travel.

    I wanted to make sure these pictures got into this thread, though, so it comes up in the future with FF recommended wheels and the stockers in case anybody else searches.

  9. #9
    Senior Member Bob_n_Cincy's Avatar
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    Just my experience with body roll.
    This is body roll on donor with a Whiteline stiffer 22mm bar in the rear and stock bar in front.

    front roll.jpg

    This is my 818 with 350 front springs and 500 rear with no sway bars. About 1.1G in a turn.
    roll.jpg
    The 818 ride is harsher but acceptable on the street.
    Bob
    Last edited by Bob_n_Cincy; 12-13-2017 at 12:54 AM.
    818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
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  10. #10
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    Quote Originally Posted by turbomacncheese View Post
    OK, definitive answer...no way will this work without creating a ton of trouble.
    Factory Five wheels...
    20171212_200505.jpg

    Stock wheels...
    20171212_200937.jpg

    It's worth noting that this is at full droop, but it seems pretty obvious that there is no clean, easy way to remove the interference. Chopping stuff up, welding stuff together, limiting the steering rack...all for the luxury of a few inches of travel.

    I wanted to make sure these pictures got into this thread, though, so it comes up in the future with FF recommended wheels and the stockers in case anybody else searches.
    The sway bar needs to be pushed up quite high. The OEM bar will hit the wheel if you don't do that. But it will clear the wheel if you push the ends way, way up. You are using the WRX *REAR* bar on the front right? Also, for the aftermarket bars, the passenger side is the side that hits the coilover.

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    Yeah, that's as high as it goes with the wheels drooped. Hits the spindle bracket. You can see in the video that I got a little more range when I jacked the control arm up, but the frame isn't heavy enough to make any significant difference. Plus, the sway bar end sticks out kinda far past the end link (if I stick the end link straight up). I'm not much of a quitter, but I don't see this working. If I can find a sway bar at the pick a part, they'll give it to me for $10 and a morning of my time. Seems like the smarter choice.

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    I personally found my Orange 818S cornered better without a front sway bar. The car is so light and stiffly sprung for street duty it drove better without one. JMO.

  14. #14
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    Wallace, thanks for chiming in. I'm not a racer, and I'm sure this car will be more capable than I am anyway. Maybe I'll give it a go without the sway bar.

    On another note, it seems that everyone who is running without a sway bar has stiffer springs on the rear than the front. I noticed that the stock setup puts the heavier springs on the front. I'm sure this is a complex subject, but does anyone have some cliff's notes or links that can explain why/when/how spring rates are calculated/changed?

  15. #15
    Senior Member UnhipPopano's Avatar
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    Some of the racing simulation games, like Forza, allow you to change most of the suspension settings. pick a car similar to the 818 and then play with the settings. One of these games is a lot less expensive than purchasing parts. On line, you can find information on how to set the different settings. Play with the settings long enough and you will understand the correlation of how the car behaves and what changes you can make to make it better.

  16. #16
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    Hey I was cleaning out my garage today and found my stock sway bar. I could ship it to you if you wanted it and paid for the shipping and box etc.

    There is a lot of info online about sway bars. I spent months researching and reading books on it. But generally speaking, stiffer springs on the rear will make the car tend toward oversteer. Stiffer on the front will make it understeer. A sway bar on the front will make it understeer and a sway bar on the rear will make it oversteer. I don't mean to say that any of those things will make the car under or over steer, only to say that is the direction things will move toward. And when I say stiffer on the front, I don't mean stiffer than the rear, I mean stiffer that what's on the front already. Same for rear. Spring rates are calculated by determining the suspension frequency you want for your car. You might want 2.0hz or less or more depending on many things. You have to find the motion ration of the suspension (which we already know for the 818) then take your corner weights and then use a formula to determine the what springs you'd want to get your desired frequency. Once you have those, then you track it and see how it handles in terms of balance (over/understeer). You can then fine tune the balance with either springs or sway bars. Different people have different opinions but IMHO you should set your spring rates for proper energy absorption (going over curbs and bumps) and front to rear weight transfer under acceleration and braking, and you should set your cornering balance with sway bars. But that's just me.

    You also have to factor your aero into your spring rates. Aero effectively adds weight. It starts getting really complicated there because the car handles differently at different speeds.

  17. #17
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    This is my understanding also. You'd want your springs to be soft enough to allow suspension compliance over bumps, but not harsh. This allows the tires to remain in contact with the tarmac. The sway bar helps share the unused spring resistance from the inside wheel, allowing softer springs to be used. Tuning your shock absorbers will control frequency of suspension.
    As for sway bars, adjustable is better if possible. I used 4140 solid round bars for mine, heated & bent where necessary, using various diameters for adjustability. For the final topper, I'll send them out for heat treatment. My front bar is adjustable, however I actually made 2, one with longer lever arms, but I had to add a second mount since they reside at different locations relative to the suspension. For my rear, I've made 2, one smaller diameter than the other. This for tuning, as the working end is non adjustable on the rear. Hope this helps. Lots of books on the subject are out there. It's not black magic.
    Now, keeping your motor from blowing up, that's black magic! Good luck.

  18. #18
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    Lance, do you have any pics of your rear sway bar installed?

  19. #19
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    Thanks guys. Just to show you my level of aptitude here, I've never heard of frequency as it relates to suspension before. As it is I have a bunch of studying to do for work over the next few months, so I probably won't have much time to learn suspension. Seems like it would be worth my while when the schedule frees up, though. Thanks guys.

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    Not at the moment. I'm terrible about taking pictures, but I try. At the moment I have my motor & suspension members in place, so you can't see anything. I'll take some pics as soon as the motor comes back out.

  21. #21
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    Plan on heading to the u pull it Saturday. If all I can find is the skinnier bar from an NA, is it worth it? I think they are 13mm VS 17.

  22. #22
    Senior Member Bob_n_Cincy's Avatar
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    Quote Originally Posted by turbomacncheese View Post
    Plan on heading to the u pull it Saturday. If all I can find is the skinnier bar from an NA, is it worth it? I think they are 13mm VS 17.

    Here is the diameter of the stabilizer bars.

    diameter.jpg
    818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
    My Son Michael's Turbo ICE Build X22 http://thefactoryfiveforum.com/showt...rts-818S-Build
    My Electric Supercar Build X21 (on hold until winter) http://thefactoryfiveforum.com/showt...e-Build-Thread

  23. #23
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    Thanks Bob. How big a difference would you expect between the 13 and 17? With Wallace's feedback on no sway bar, it seems a skinny bar might be more than adequate for.me (if not too much bar). . I won't be racing real tracks. Maybe those large sweeping on ramps, ha! Opinions?

  24. #24
    Senior Member Bob_n_Cincy's Avatar
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    Quote Originally Posted by turbomacncheese View Post
    Thanks Bob. How big a difference would you expect between the 13 and 17? With Wallace's feedback on no sway bar, it seems a skinny bar might be more than adequate for.me (if not too much bar). . I won't be racing real tracks. Maybe those large sweeping on ramps, ha! Opinions?
    I didn't do a sway bar. I changed rear springs from 275# to 500# to prevent body roll.

    roll with 275 rear springs
    roll.jpg
    In this picture my left rear was squatting and the right was at full extension.



    roll with 500 rear springs
    roll2.jpg

    Below is a letter from Jim at FFR to me back in 2015:


    We have found that mid-engine cars have a tendency to creep more and more toward oversteer as the corner speeds go up, basically it is a pendulum affect of the mass of the engine being more toward the rear of the car.

    For a non aero car that is going to be run at higher speeds the safest setup is to tune for neutral in the fast corners and then live with some push in the lower speed corners.

    For an autocross car that doesn't see the high speed stuff, and a lot of times likes to be on the looser side anyway, this doesn't apply.

    The best case though is when you can tune the high speed balance with aero and the low speed stuff with the springs, shocks, and sway bar. The setup we give is what we found worked best on a medium downforce car with a functional rear wing.

    For a more aggressive setup like our current car has you will most likely want to raise the rates front and rear to account for the extra downforce.

    Also a lot of spring rate selection is driver preference as some drivers like the car with some body roll and others want more like a go-kart type feel.

    Also the differences in peoples cars in split between front and rear tire widths can play a roll in balance as well, meaning what we are giving for springs is what we feel is a good starting point for most people but is something that many people will experiment with and come up with setups to best fit their own styles.

    Even just between the three drivers we had testing these set-ups there was a noticeable difference in preferences. (Between John, Wayne, and Myself)

    On a non Aero track day car I would start conservative with the front bar hooked up and the stiffer springs in front, this should give understeer as a baseline.

    If the car has a lot of push then I would disconnect the bar and go from there.

    Your car may be a little different with the tank up front and radiator out back but I still think you would be in the ballpark with the stock S model set-up and then tune based on how the car feels to you.

    If you could can find a good balance at track days with the sway bar hooked up then you may be still close for an autocross set-up with the bar disconnected.
    Last edited by Bob_n_Cincy; 12-22-2017 at 12:13 PM.
    818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
    My Son Michael's Turbo ICE Build X22 http://thefactoryfiveforum.com/showt...rts-818S-Build
    My Electric Supercar Build X21 (on hold until winter) http://thefactoryfiveforum.com/showt...e-Build-Thread

  25. #25
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    Well, i definitely a low speed guy. No more questions from me until I drive it. No bar for now. Thanks Bob.

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