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Upgrading '99 suspension w/Bilsteins, QA1, FCM

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Old 09-14-2007, 03:46 AM
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Default Upgrading '99 suspension w/Bilsteins, QA1, FCM

So I'm thinking about ordering Bilstein Sports from shox.com and I only say sports because they are designed for a lowering spring but would I be better of getting HDs considering i'll be using adjustable perches? Plan to use FCM 46mm bumps and adjustable perches with the set screw instead of the extra locknut. All for 2.5" race springs. Plan is to use some QA1s but i'm not sure what spring rates, just curious what spring rates you guys would recommend? I know I can get the QA1s from summit racing though. Shaikh said that 8" tall front springs and 9" rears would work for me but that seems a little strange to me can anyone confirm that? I ask because I have seen reference to The Bilsteins can't handle anything over 400. Shaikh recommended 300 front and 220 rear but that seems a little weak. Just curious what anyone else might be running.

I've also noticed that some people with a similiar setup have used 400/300 or 375/250 and liked it. I have access to a mazdaspeed front sway bar as well but I don't have it in front of me so I really don't even know if it's bigger than my stock NB one. How's this sound? This suspension will be coupled with my 6ULs that should be close to being on their way here with 205/50 Azeni 615s.

This isn't going to be a dedicated track car by any means. It'll be mostly street, the occasional autocross and I want to be able to have a good time during a HPDE when I decide I want to get into that.

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Old 09-14-2007, 05:50 AM
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Check it with Shaikh's spreadsheet to see if it'll yield the qualities you're looking for. I think the Mazdaspeed front bar is 1mm bigger?

I am doing similar right now. I've acquired 2.5" race springs to use with my R-pkg Bilsteins, 350/275, which, when paired with an NB front sway and no rear, looks like it'll be what I want. Reason I'm not going stiffer is because of the harshness in rebound of the R-pkg Bilsteins...don't want to be too underdamped in compression.
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Old 09-14-2007, 08:02 AM
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I have an NA, but called a Bilstein engineer to talk about valving and rates. He insisted there's enough low and high speed compression (and more than enough rebound) for 450lb springs in the front. I wanted them to do a set with upped valving, but they insisted its not necessary.

I bought bilsteins for the reliability and longest life of any shock. I've had great experiences with them before, and I plan on keeping these on for a few years until they need revalving. I got 120k out of my old H&R monotube bilstein dampered coilovers on my vw. I hope I get the same out of these.

I run the 440/375 GC, FCM linear bumps, rear RM upper mounts, NB front mounts, and RB hollow front / solid rear swaybars with "lanny's alignment" (needs more camber), corner weighted and I'm happy with them, but if there's something better then I don't know what I'm missing. I've had no problem hitting 1.12g (bel accelerometer) sustained lat acceleration on flat corners at a track while running Azenis, which is better than two other cars runnign tein flex. I had a ton of body roll on stock sway bars though at the track. I dropped 1.2 seconds off my personal best with an RB front and rear swaybars last weekend
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Old 09-14-2007, 11:35 AM
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I've put it all in Shaikh's spreadsheet but i actually don't know what values i want to look for. I can make estimates based on the tutorial. The things that matter most to me is do I want the HD or the Sport Bilsteins and what length springs do I want to use for front and rear. Guess I can always call shaikh again.
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Old 09-14-2007, 11:52 AM
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K got my answer, i'm going with the HD's.
Shaikh said,
"You should end up with some spring preload at full droop with the Sports, while the spring will be free of the upper mount on the HDs. Easier to adjust ride height with the HDs but Sports will keep things seated better. Honestly, I'd go with the HDs since you won't be at full droop in normal street driving (though bumpy backroads could be an exception) and it's convenient to have the spring unloaded to make ride height changes. I personally don't like limiting suspension travel to keep a spring seated."
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Old 09-14-2007, 12:16 PM
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Decided on 325/250 both 8" long with stock front rollbar and most likely no rear.
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Old 09-14-2007, 05:39 PM
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If you ever track that car, you might desire higher rates. My car wasn't too bad on the street, but now I wish I had more spring, even with my higher rates.
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Old 09-14-2007, 07:06 PM
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Figure I can always upgrade. The problem is the NB bilsteins aren't valved for real high spring rates supposedly. Shaikh said he has found that they can't hold as much as the NA ones for some reason.
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Old 09-23-2007, 12:43 AM
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I have a lead on some Bilstein PSS9 coilovers for $600. Been reading about them till my eyes bleed. Seems people love them or hate them and their linear springs. No consenus on them though. Any of you guys have any experience with them?
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Old 09-23-2007, 10:32 AM
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Well looks like they sold anyway oh well.
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