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Old 10-28-2019, 10:34 AM   #1
my_dog_barney
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Default Bugeye Wagon Suspension Setup Help?

Hi Bugeye handling gurus - I'm hoping for some advice on my 03 wrx wagon which recently got a full suspension upgrade.* I ran the stock struts/springs since new, with only a rear sway bar/links upgrade (Epic Engineering adjustable) .* A few months ago, I put on new KYB struts, "new" Whiteline springs (from a nasioc member), and a Perrin front sway bar/end links.* (also got new tophats, engine and transmission mounts, etc).* The difference from the 16 year old suspension was night and day, and I love the turn-in and cornering but I have 2 major issues - ride is too stiff on gravel/dirt/bad urban roads, and I think my front*swaybar is too big relative to the rear.**
Swaybars:* I have a Perrin FSB (22 mm I believe- also bought "new" off nasioc) set to the softer position, and the Epic RSB with Kartboy endlinks set to firmest position (also ~22mm effective at stiffest I believe).* as I enter a corner I get pretty considerable understeer, followed*by a bunch of body roll as I transition through the corner a the weight shifts to the rear.* Is there an option for the front that will be softer than the perrin but stiffer than stock?* Or, should I look for an even bigger rear bar?* (Hesitant to go that way as I am hoping to soften the overall ride a bit.)
Springs: Will a set of Swift wagon-specific springs be noticeably softer than the Whitelines?* (Anyone interested in a barely used set of Whitelines?).* Will a softer front bar make any NVH difference on rough roads? (I am guessing not much).
I know that in a perfect world I should have done the upgrades one of a time, but I had a huge amount of work needed and just got it all done at once at Mach V (about 2 hours away).**
Any comments appreciated - hoping to dial it in and enjoy it for the next 16 years.* Thanks in advance for any advice!
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Old 10-28-2019, 05:34 PM   #2
2pot
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The Whiteline sub001 springs are 200/189lb/in -30mm front -25mm rear. Your stock bump stops are 60mm front/120mm rear. The later models used a 90mm rear stop. On poor roads, I'd suggest you're frequently engaging, or riding on the bump stops - particularly as your dampers are rebound biased. Did your bump stops get changed/shortened?
Stock springs were 163/132lb/in
Your current bars are too big for poor roads - 19/17mm 19/19mm 19/20mm. On poor roads, your bigger bars are transmitting the majority of a suspension movement, on one side of the car, to the other = destabilizing the tyre contact patch
Front bar: 19mm to 22mm bar is roughly an 80% increase in stiffness

What are your alignment settings?
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Old 10-28-2019, 06:35 PM   #3
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Many people that frequent dirt roads remove sway bars altogether. This allows suspension to travel through its stroke easier. But those people rarely lower their cars either. If your spending a lot of time on dirt roads ditch the bars and get a set of king OE length springs. You'll lose some handling on primary roads but gain control on dirt roads.
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Old 10-28-2019, 10:06 PM   #4
my_dog_barney
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Thanks 2 pot - that is helpful.

camber f/r -.33/-1.45
toe 0.000 all the way around.

I dont drive on dirt roads a lot, but when i do its nice to be able to hoon it around a bit without things flying out of door pockets.

I am now thinking the front bar is actually 25 mm - I also need to confirm I have it set on the softer setting, (it looks like Perrin claims 50% stiffer than stock on soft, and over 200% on firm). If I had it wrong that would explain a lot. It is hard to tell which end is which as the two holes are right next to each other and I did not install it.

I will switch it up and see if that helps.

Last edited by my_dog_barney; 10-28-2019 at 10:32 PM.
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Old 10-29-2019, 10:27 AM   #5
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Perrin did make a 22mm bar years ago but dropped it and only made the 25mm the last few years. As for which setting is stiffer. The holes close to the bar itself are stiffest.

Before I had coilovers I installed a 20mm rear bar to match the front. With OE dampers it was fine on dirt roads. Once I switched to coilovers driving on dirt roads went to hell. These cars actually have great handling at OE height. The geometry once lowered isn't optimal unless you change the roll center. This did help a little on dirt roads once I did that but my spring are just too stiff to really be comfortable on dirt. My point being is you have a choice. You can make it better and more aggressive for paved roads or you can make it better for rough and dirt roads. You can kind of smear the line with stiffer chassis bushings, OE springs, and small sway bars. But that's only going to take you so far. But I don't think you'll get the handling you're looking for on dirt with the car lowered on stiffer than stock sways.
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Old 10-29-2019, 11:53 AM   #6
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Pretty sure perrin's 25mm bars are hollow, which is the equivalent of 22-23mm solid.

More negative camber up front will help a lot. Generally it's better to have more camber on the front end than the rear for handling balance. I have like -2.7 degrees up front and that makes it pretty close to neutral with 22mm front and rear bars (front soft, rear stiff, plus an ALK, offset top mounts, rce black springs, and some other bushings).
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Old 10-29-2019, 03:02 PM   #7
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Quote:
Originally Posted by jamal View Post
Pretty sure perrin's 25mm bars are hollow, which is the equivalent of 22-23mm solid.

More negative camber up front will help a lot. Generally it's better to have more camber on the front end than the rear for handling balance. I have like -2.7 degrees up front and that makes it pretty close to neutral with 22mm front and rear bars (front soft, rear stiff, plus an ALK, offset top mounts, rce black springs, and some other bushings).
Perrin bars are solid not hollow. At least according to them they are.
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Old 10-29-2019, 07:30 PM   #8
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Well it is on soft so I guess I just underestimated the impact of the front sway on ride quality. Does anyone know if I can drive on the front bar disconnected? Id like to try it out - maybe zip-tie things in place?
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Old 10-29-2019, 10:54 PM   #9
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Quote:
Originally Posted by my_dog_barney View Post
Well it is on soft so I guess I just underestimated the impact of the front sway on ride quality. Does anyone know if I can drive on the front bar disconnected? Id like to try it out - maybe zip-tie things in place?


It doesn't need the sway bars. Rally/Rally X drivers usually remove theirs so the suspension articulates better. You'll just have more body roll.
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Old 10-29-2019, 11:27 PM   #10
jamal
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Well that explains it then. I think it was cobb's 25mm bar that was hollow then?


Go to a 22mm front bar and you'll be a lot happier.


And swaybars can still be useful on dirt/gravel. Depends on how rough the surface is and the amount of grip and the spring rates. I wouldn't jump all the way to removing them unless you are spending a lot of time on really rough roads at slow speeds. Much more roll stiffness comes from the swaybars than the springs, you will have a huge amount of body roll without them.
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Old 10-30-2019, 06:25 AM   #11
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Quote:
Originally Posted by my_dog_barney View Post
Well it is on soft so I guess I just underestimated the impact of the front sway on ride quality. Does anyone know if I can drive on the front bar disconnected? I’d like to try it out - maybe zip-tie things in place?
You only need to disconnect one end link, where it attaches to the bar, for the influence of the bar to be removed.

You need more front camber. If you're always on the freeway, I'd adjust to neg 1deg per side.
Or, fit Whiteline kca335 front top mounts and adjust to neg 2deg per side.

I'd also run with some rear toe-in (0.05 deg per side) You'll get quicker steering response, due to running a rear slip angle. You'll also benefit from more high-speed stability and increased stability when high-speed braking.

I wouldn't use an alk, as the increase in dive will put you on your front bump stops - made worse by your lowered front ride height. The stock, rebound-biased, damping will then hold you on them 'jacking down' = understeer and poor ride quality/grip.

If you are experiencing corner exit understeer, stiffen the rear stops.
If using non-inverted dampers, add clip-on packers, on the rear, to change the engagement.
https://www.amazon.com/Raid-HP-30002...1390812&sr=8-1

Last edited by 2pot; 10-30-2019 at 01:27 PM.
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Old 01-02-2020, 02:59 PM   #12
my_dog_barney
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In case anyone is interested, I swapped out the Perrin 25mm for a used whiteline 22mm I picked up here on nasioc. I set it on soft and I have my front suspension back. I will miss the instant turn-in and flat cornering that I had always assumed were impossible in the WRX - apparently just impossible with a nice Daily Driver ride... Thanks for all the input, I now believe I can live happily with my springs, and the car is tolerable on bumpy roads. I will still have to see how it fares on the crummy dirt roads I frequent in the summer, but I think it should be OK.
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Old 01-02-2020, 06:12 PM   #13
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Fixing the camber bias will help you a ton. -1.5 up front and -1 in back.
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Old 01-03-2020, 08:31 AM   #14
Norm Peterson
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Quote:
Originally Posted by my_dog_barney View Post
In case anyone is interested, I swapped out the Perrin 25mm for a used whiteline 22mm I picked up here on nasioc. I set it on soft and I have my front suspension back. I will miss the instant turn-in and flat cornering that I had always assumed were impossible in the WRX - apparently just impossible with a nice Daily Driver ride... Thanks for all the input, I now believe I can live happily with my springs, and the car is tolerable on bumpy roads. I will still have to see how it fares on the crummy dirt roads I frequent in the summer, but I think it should be OK.
If your dirt road driving only happens during the summer, you might want to at least try out the firmer front sta-bar setting during the "off-season".

For handling, you do need the front cambers to be more negative, at least -1. Or more, but past some point your normal, everyday cornering needs to be enthusiastic enough to justify that much.

Some of your perception of roll might be coming from the outside tires "rolling under". What tire size and rim width are you running? And inflation pressure(s), because tires do have finite vertical stiffness and do contribute to overall chassis roll - which could be as much as a full degree at 1g, that adds directly to however much roll/g comes out of your suspension roll stiffness. 25% of your perceived roll could be coming from tire compliances that nothing you do to the suspension will have any effect on.


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Old 01-27-2020, 01:48 PM   #15
my_dog_barney
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Hi Norm- thanks for the input. I do have my winter tires on now- 215/45/17 and they are noticeably softer than my summer Michelin super sports (worn out- looking for replacement that is less than$200/tire). I will look into adding some negative camber when I have the chance.
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