My STX Project / Build thread (56k warning!) - Page 2
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This is a discussion on My STX Project / Build thread (56k warning!) within the Motorsports Talk forums, part of the Community - Meet other Enthusiasts category; This pretty much catches us up to date so if people want to comment they are more than welcome. I ...

  1. #16
    Registered User ButtDyno's Avatar
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    This pretty much catches us up to date so if people want to comment they are more than welcome. I will try to fill in the last few posts over the next few days

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  3. #17
    Moderating on the run! Big Sky WRX's Avatar
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    Great thread John It's nice to see project/build threads- they always seem to be chock full of good info, some of the most important info IMO is seeing what things did NOT work on a particular build- these clearly save a lot of folks future headaches!

    Mike
    "Simplify and add lightness." - Colin Chapman

  4. #18
    Registered User ButtDyno's Avatar
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    Alright - so the season has started. Woohoo!

    You'll also note that, other than pictures, I have pretty much filled in everything up to this point. So if you are following along, check out the last few posts for some new stuff

    Event #1: Capital Driving Club: Bowie, MD: 3-30-2008

    My car wasn't ready, so I co-drive my friend Al (paranoidWRX)'s car - a 2006 WRX. He has a grand total of $300 in his suspension:

    -$50 used USDM STi springs
    -$75 used Cusco front camber plates
    -$175 used Whiteline swaybars

    This pretty much hits all the important categories.

    I gotta say, for so little invested, the car handles great! Turn-in was nice, steady state was pretty good, body roll wasn't that bad, etc etc. It's not a fully prepped ST car or anything, but if you are someone who doesn't want to drop $2K on a nice set of coilovers, it is a great bang for buck upgrade path. Add tires and Konis and you'd be set!

    I only did okay in Al's car, ending up with a 51.08 and paxing something like 16th out of 100+. The car actually had a lot of lag in 2nd gear coming out of slow corners, which was surprising. Plus it was on 225/45-17 tires, so no gearing advantage there. I've said before that I think someone could have a pretty darned fast STU 2.5L WRX if you were willing to try - the PAX gap between STX and STU is less than it was before, and the 2.5L car would be able to run 17x9's with 245's, plus the torque advantage.

    Event #2: WDCR/SCCA: Fedex Field, Landover, MD: 4-6-2008

    This was the DC Region's official test and tune day. (There is another one next weekend, less people more runs) It's a regular event, 4 runs, but it's not for points.

    STX ran heat 2. It was raining lightly for the beginning of the heat and slowly backed off to just being freakin' cold. Cy Lee was running the class (his STS car has a diff in it now, so he's probably in STX for good) in addition to the DC Region STX usual suspects.

    I sucked! I finished 4th, behind last year's WDCR champ Josh (Sentra Spec V: 52.2), Cy (Civic Si: 52.8) and Jim Harris (Mini S: 54.3). I just could not drop time fast enough. First run was a 57.5, 2nd run was a 55.3. I had a dirty 54.1 on my 3rd run, and was having a hell of a 4th run when I spun coming down the hill on the fastest part of the course. If I had gotten through that, it was smooth sailing to the finish. Ah well I ended up PAXing 27th out of 172, disappointing for a Subaru in the wet.

    Event #?: CDC: Bowie, MD: 4-12-2008

    This event was canceled because of rain. Bummer, as it turned out to be a really nice day.

    Next event is tomorrow at Fedex. It is another test and tune, and I should have plenty of runs to dial in the car on the new Neovas. Hopefully we will get some nicer weather


    Next update: Feedback from the test and tune.
    Coming soon: Vorshlag rear plates and 7" rear springs with helpers. Hopefully no more noise!
    Last edited by ButtDyno; 04-12-2008 at 04:40 PM.

  5. #19
    Moderating on the run! Big Sky WRX's Avatar
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    filled in the gaps nicely

    first the gold Enkei's look very nice

    the new Hyperco's certainly sound promising- interesting on not printing the rate on the side

    what tires did you run event #2? it'll be very interesting to have someone running both RE01R's and Advans (albeit one shaved)- should provide some good insight

    good camber #'s- it's amazing you can easily get over -4.0 (IF you wanted to)

    did you happen to measure the travel of the koni's? I'm curious how they compare to the ots 8610's

    the 8610's also have the hex nut in the front, but no provision at all in the rear- I called them on this and they really didn't have an answer

    I've got a test/tune this coming weekend- I'm seriously considering ordering a pyrometer just to see
    "Simplify and add lightness." - Colin Chapman

  6. #20
    Registered User ButtDyno's Avatar
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    Quote Originally Posted by Big Sky WRX View Post
    filled in the gaps nicely

    first the gold Enkei's look very nice

    the new Hyperco's certainly sound promising- interesting on not printing the rate on the side

    what tires did you run event #2? it'll be very interesting to have someone running both RE01R's and Advans (albeit one shaved)- should provide some good insight

    good camber #'s- it's amazing you can easily get over -4.0 (IF you wanted to)

    did you happen to measure the travel of the koni's? I'm curious how they compare to the ots 8610's

    the 8610's also have the hex nut in the front, but no provision at all in the rear- I called them on this and they really didn't have an answer

    I've got a test/tune this coming weekend- I'm seriously considering ordering a pyrometer just to see
    Only the RPF-1's are real - the RC-T4's are a photochop

    Event #2 was on the Bridgestones since it was wet and those are full-tread.

    I honestly have no good insight re: the two tires. I like the feel of the Advans better so far, but my car is not set up right. There were two courses yesterday and I did the afternoon on both tires, and my best on the Advans was 62.6 but my best on the stones was 62.0. I don't think it's significant yet because neither run was good - there were sizeable mistakes/handling issues both times. I attribute the time gap to learning the course better.

    I don't have travel #'s but stretch posted a pic with a ruler in this thread:
    IWSTI.com: Subaru STI Forums - Ground Control / Koni Coilovers (incuding 2005+ STI's)

    Minus bumpstop, car weight, etc etc.

    I'm still thinking about why the car feels so different after relatively mild changes and will write that up later on.

    John

  7. #21
    Moderating on the run! Big Sky WRX's Avatar
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    I have travel numbers w/ the ots Koni's- was curious how these compared- maybe if you ever have them off again for some reason

    I forgot to comment on your caster- that is odd, some deviation w/ something from the factory I guess- mine was 3.5 from the get go- I'm just under 4 w/ my camber plates in the camber ONLY setting (was almost 4.5 canted)- I should be in that ballpark again w/ the offset bushings
    "Simplify and add lightness." - Colin Chapman

  8. #22
    Registered User ButtDyno's Avatar
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    Can I trust my own ButtDyno?

    Test and tune "results"

    The day was split into 14 half-hour sessions where if you weren't working the course, you were driving. The first seven were on one course, the second seven were on the same course but backwards. This actually made a massive difference in how the courses drove.

    There were three other STX folks there:

    Cy Lee/Chris Shenefield: They were co-driving an STX Civic. Yes, STX Civic. This is an '89 Si with a Quaife. They are both very, very fast. IIRC, Chris has won STS in Topeka (as well as being a setup whiz with the Civic). Cy was 20th in STS last year at nationals, but would have been 10th in STX.
    Josh Luster: Josh runs a Spec V and is very fast. I rode along with him and was really amazed how much grip the car had. He has done an amazing job with a car that has very little aftermarket.

    On the morning course, Chris had a 54.8 (!!!), Cy was in the 55's, Josh had a 57.1 and I had a 58.2. In the afternoon I think the gap between me and the Civic drivers was just as bad.

    Good news: The "wheelspin at corner exit" problem is gone. That was the main push for the "more spring less bar" idea - being able to get on the gas earlier. (post 13)
    Bad news: My car doesn't feel well balanced at all. I think that most of it is understeer, but there are situations where it can snap oversteer as well. The car especially sucked in slaloms. And that's pesky as hell, because it seriously throws off your butt dyno when it comes to troubleshooting. You start doubting yourself and wondering if the car is fine or if it's just you. The worst thing is that you then have three options:
    -Leave the car alone and hope you get used to it.
    -Make the car more tight, risk understeer (trusting yourself to accurately diagnose that the car is loose, where my track record is quite bad)
    -Make the car more loose, risk oversteer (going against some of your seat of the pants guesses, based on past history of thinking that the car is loose when it was actually pushing, just because of a little snap oversteer)

    There have been a couple instances where I thought the car was oversteery just because of minor looseness incidents that later turned out to be me lifting or doing something else bad.

    So - we know that the car feels different - let's isolate the changes between my current setup and how it was at the end of last year.

    What didn't change:
    Same coilovers
    Same top mounts
    Same rear swaybar (Cobb, full soft)
    New tires (last year RE070s, this year AD07's/RE01Rs)
    Same front camber (3.5)

    Changed:
    Stiffer springs (last year: 400/450; this year: 450/500)
    More rear camber (last year 1.3, this year 1.5)
    Less front swaybar (last year: Whiteline 27mm; this year: Cobb 23.5mm)
    Different ride heights (last year 14/13.5, this year 13.9/14.0)

    The springs are a small bump, and the rear camber is pretty close. So if the car is handling a lot different than it was, it's got to be the front bar or the ride height.

    The ride height I'm running now should theoretically be more oversteer'y than the one I was running last year, with the rear higher. So, IF I am remembering accurately that the car was pushing - that means that losing (effectively) 3.5mm of front bar was such a huge change that it overwhelmed .5" of ride height difference AND overwhelmed the rest of the setup (which should be fairly neutral). That would explain a lot of the weakness in slaloms, both turn-in feel, and perhaps the understeer.

    That is possible, though amazing if true (it's only 3.5mm!)

    I remember reading a while back that swaybars had a disproportionate effect at the wheels in terms of effective spring rate - so it is starting to make sense.

    So - I need to figure out what button to push next.



    If I take the blue pill, I do something that will tighten the car up. Lowering the rear is most likely since I need to re-install the rear suspension anyway to put the helpers on.

    If I take the red pill, I do something that will loosen the car up, or at least add front grip. Lowering the front and leaving the rear where it is, or maybe a little toe out, or stiffening up the rear bar, or adding more camber in the front, or subtracting it from the rear.

    The scientific thing to do is to get as close as possible to last year's ride height, which would leave the front bar as the only variable.

    I dunno what I'm going to do yet, just documenting my thought process, wrong though it may always be

    john
    Last edited by ButtDyno; 04-14-2008 at 09:51 PM.

  9. #23
    Moderating on the run! Big Sky WRX's Avatar
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    do you still have the big front bar? that would be a quick and easy test

    I think the front bar choice could easily be (or at least partly) to blame for the snap oversteer issue- I'd say it's highly likely impacting slalom performance- that was where I saw the most dramatic changes when I swapped to the bigger bar (or any other fast transition sections)

    I'd feel lucky that you have so many good ST drivers- I know I'm not telling you anything you don't know, but good drivers usually beget good drivers

    you definitely have several options to play w/ (heck that's half the fun! )
    "Simplify and add lightness." - Colin Chapman

  10. #24
    Registered User ButtDyno's Avatar
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    I sold it to someone prepping their STi for AS Otherwise it would be back on.

    Oh yeah, updated stats on Chris S from the WDCR list:
    2002 National Champion STS
    2003 Nats 2nd STS
    2004 Nats 3rd STS
    2006 Nats 2nd STS
    As much as it's going to hurt, I do hope he shows up at the DC events

    I also want to double check that my rear bar isn't binding - it may need a regreasing at this point.

    john

  11. #25
    Registered User ButtDyno's Avatar
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    Mike can you add "(No 56K Need Apply)" to the title? I just realized the crezzy amount of pictures in here. (I was about to add more, just installing my Vorshlag rear plates)

    john

  12. #26
    Registered User ButtDyno's Avatar
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    Update to post #7: Added a picture of the Ground Control sleeve rubbing against the spring (the reason I wanted helpers)

    Rear suspension fixes

    As discussed previously, one of the issues with my setup is that I don't have independent height/preload adjustments. Just to make that concrete, here is what my setup looked like at full droop (before I added the helpers):



    There was something like 2" of slack between the spring and the perch. The result was lots of creaking/clunking/popping over speed bumps and the like - most annoying.

    In addition to that, the fact that the spring wasn't perpetually snug meant that it would sometimes rub the top parts of the Ground Control adjustable sleeve (see post #7 for a fresh pic). This isn't a big deal because I can't use that part of the perch anyway - ride height would be wayyy too tall. But it does make noise as well as scratching up the springs.

    In post 15 I talked about how I had tried to use helper springs to keep things snug, but I hadn't been able to because the height of the compressed helper + coupler + spring + top mounts was too tall and I could not hit my target ride height - I could not drop my lower perch any lower. So as a stop gap I removed the helpers and couplers. Creak, clunk, pop, etc. I could at least get to 14" in the rear.

    But I wanted a permanent solution that would let me use helpers.

    Enter "Zee Germans"

    The STi Grp N mounts, combined with a 2.5" spring adapter, are pretty freaking tall. This eats up a lot of room, and as a result it pushes everything down quite a bit to the point where you have less adjustment with the Ground Control perch. It's even more annoying that the upper perch doesn't fit smoothly on the bottom of the Grp N mount, so it might not actually be "flat" against the tophat - like so:



    I needed a rear tophat that:
    -Would take a 2.5" spring
    -Would be shorter than the stock mounts + spring adapter
    -Was available for sale by itself (i.e. no Tein, Cusco)

    It turns out this is a pretty obscure request!

    I looked at the Ground Control rear camber plates first. I called Mark at Ground Control and he told me they were designed to be the same height as the stock stuff. Doh!

    That really only left two options that I could see:
    -RaceComp's rear pillowballs (non adjustable)
    -Vorshlag's rear camber plates

    The price was pretty much the same and the Vorshlags were adjustable. That made the decision pretty easy. I had been using camber bolts in the rear, and as stretch points out, there are benefits to using plates instead:
    REAR CAMBER PLATES by Vorshlag are HERE!!! - IWSTI.com: Subaru STI Forums
    Quote Originally Posted by stretch View Post
    TiC, don't forget to mention that angling your struts inwards (which camber plates do) increases your roll center height, decreases roll center migration, alters your roll axis angle, decreases roll couple, quickens your camber curve, and decreases body roll. The inclusion of a bearing for the spring perch in the rear will also help keep your rear spring more linear, too.

    These changes are small but definately exist.

    Additionally, the potential exists to run longer springs and thus have much more suspension travel, fit much wider wheels and tires, and of course, have more negative camber in the rear.

    These aren't just for camber.
    Really though, the main things I cared about were the opportunity to get away from bolts (I have had a couple of the tabs on the magic washer disappear in the past), the decrease in height, and the benefits of swapping out hard rubber for metal. I'm not sure how many of those benefits apply when you are trying to *not* get negative camber in the rear - I can't see myself ever wanting more than -1.5.

    Installation

    First off, these are a LOT shorter than the Grp N + adapter combination, just as TiC claims.




    I put a tape measure into the top of the Grp N hat since the functional top is set into the tophat a little bit, about 3/4". But still, it's between 1" and 1.5" shorter, which made me quite happy. When I put the 7" springs, the 4" helpers and the couplers on... I still had room left!



    I could have kept the 8" springs if I wanted - ah well.

    Other stuff

    I re-lubed the rear swaybar. The bushings were pretty much completely dry. Cobb's recommendation was to re-lube once a year. It's been more like seven months, and this is a weekend car! Bah. When I started, you could barely move the bar with your arm, but it moves smoothly/freely now. It's always good to eliminate variables

    I still haven't figured out what pill I'll be taking - I'm leaning towards lowering the front a little (more rake, for better balance), adding a little more front negative camber (more front grip) and adding a little toe out (lots of people seem to like it; was previously scared away by tire wear).

    If the car still plows it may be time to pick up another Big Front Bar.

    We'll see...

    john

  13. #27
    Moderating on the run! Big Sky WRX's Avatar
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    I think a solid rear mount will make a nice difference- the Grp N tops are probably pushing the envelope a little w/ 400#+ springs

    the Vorshlags look very nice that's a pretty dramatic difference in stack heights
    "Simplify and add lightness." - Colin Chapman

  14. #28
    Registered User ButtDyno's Avatar
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    A quote from Sam Strano on the wdcr-solo mailing list that I wanted to capture here - another take on car setup, from a "#1 PAX at Nationals" guy:

    But we're talking autox secrets here.... And there is no magic formula, to start with different suspension designs have different camber curves. Some strut cars loose massive amounts of camber to roll. In those cases you tend to see very high rates. But not all strut cars are that terrible. Then consider cars that have double a-arms (like the aforementioned 96 Camaro), I don't even have static -2 in my Camaro, and the springs are just about twice as stiff as stock in front. The car
    isn't slow (at least I don't think it is, maybe someone will disagree).
    I don't care about the frequencies, and couldn't tell you what they are for my car (any of my cars). I tend to look at how the camber curve works, the weight of the car, the bars being used and make a educated guess on springs... and I tend to stay softer than stiffer so the car has good compliance. It's worked pretty well for me (and others) over the years.

    FWIW, on Subaru's I like to run around 600 front, and a LOT of front bar. I came to that not by math, but by watching how the cars worked and trying things. If you add the big roll stiffness I prefer to use from the bar to the springs, I have more roll control than a car with 700's and and a smaller bar, and my stuff works better over bumps and on turn in too (since the bar only works as it's loaded, springs are always there).

    What's more, I run softer springs than the "track crowd" does, not more. I'm not in any way, shape, or form one who follows conventional wisdom, because I often see it as being wrong. Remember I get to drive a LOT of cars teaching schools, and that has been invaluable to helping me work and understand other cars. But let's not forget I got that job by having a clue to start with. No, I don't have an engineering degree. No, I'm no good at math. What I have are tangible results, and a lot more of them than most of the guys who hop online and squawk about how to do things.
    New rule... never sell old parts, until I am sure I like the new ones I would love to throw that front bar back on right about now. We'll see how the car does with the new alignment this weekend.

  15. #29
    Moderating on the run! Big Sky WRX's Avatar
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    Sam offers a really big bar the Subaru- 32mm? I can't remember if it's hollow or solid though- either way it's a big bar!
    "Simplify and add lightness." - Colin Chapman

  16. #30
    Registered User ButtDyno's Avatar
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    32mm hollow, effectively 29.6 IIRC.

    Got the car aligned today at Andrewtech:

    -4 f, -1 r
    13.8" f, 13.6" r
    .07 deg per side toe out in front, 0 toe r

    We'll see what happens - more camber in the front with a little toe out, less camber in the rear, and a little lower after exchanging some email with someone whose opinion I trust.

    If this understeers (somehow!) the next moves would be raising the rear, stiffening the rear bar, or both.

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