FiST in STX

Discussion in 'Fiesta ST Autocross' started by Cligedy, Nov 10, 2013.

  1. limbo

    limbo Active Member

    You can custom tune and leave torque truncation in place. This is what stx FoST have run. Should still be good for a bit of power.

    Sent from my Nexus 7 using Tapatalk
     
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  3. jimclark

    jimclark Active Member

    Yup. It'll be interesting to see how it shakes out over the next year or so. I think this time next year, we'll be having a "more nuanced" discussion, perhaps. :cool:
     
  4. spangenb

    spangenb Active Member

    Spring changes are SO much easier with these BC coilovers :) I just put on 7k fronts with 6k rears. For reference, the factory rates are roughly 3k front and 2.5k rear. We'll see what the road manners are like and next Sunday is a local autox to give it a good test. What do you all think about the stance? Nevermind the dirty wheels! uploadfromtaptalk1403994020084.jpg uploadfromtaptalk1403994076389.jpg uploadfromtaptalk1403994090316.jpg
     
  5. spangenb

    spangenb Active Member

    First road test was great. Definitely stiffer, but still very comfortable even on railroad tracks and bumpy county roads. Hard to believe these springs are more than 2x stiffer than factory.
     
  6. jimclark

    jimclark Active Member

    Hard for me to evaluate stance in the pics; my primary impression is that the whole car is a bit lower, more so in the front. Looks good, though.
     
  7. spangenb

    spangenb Active Member

    With the original BC setup the car was a little too low in the rear in my opinion especially with the trailer hooked up and a weekend of camping stuff packed. When I put the stiffer springs on I lowered the front spring seats 1/4" and left the rear alone. It had just the effect I wanted.
     
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  8. limbo

    limbo Active Member

    What are the spring rates on the BC coilovers from the factory? You sure they can handle that much spring?

    What size wheels/tires did you end up going with?
     
  9. spangenb

    spangenb Active Member

    The original BC rates (Joe @ 2J custom spec) were 6k/4k. According to BC the dampers are good for +/- 2k from the factory so I am now maxed at least on the rears. However new dampers with different rates are only $95 each so I can always up the valving if needed.

    I have Sparco 16x7 wheels with the 225/45-16 Direzzas. Very slight front fender rub at full compression, but I expect the stiffer springs and more camber to fix that. An 8" wide wheel would be nice but haven't seen any good options for that yet.
     
  10. spangenb

    spangenb Active Member

    Had my first "real" event with the car yesterday. While just a small local event, there were some quick drivers to PAX against. I just installed my 7k front and 6k rear springs and had it aligned with -2.5 degrees camber in the front and a little toe out (1/8" total). I was very hopeful these changes would help with rotation, but they really didn't :-( My alignment sheet says the rears have a little negative camber (<1 degree each) and are a little toed-in ... which certainly doesn't help the rotation at all. My first run was encouraging as the car started to drift nicely in a long fast sweeper, but I ran early in the first group and I think it was just dirty track. After that the asphalt got more grippy and I really didn't improve much through the day. Places where I really needed the car to rotate (a fast Chicago box, for instance) it just pushed and threatened to crush the exit cone of the box. The spring rates seem perfect as a compromise between street and autox. It still has great manners and comfort on the street (after four multi-hour drives in the car last week) and the stiffer rates prevent the car from "falling over" on the outside front wheel on the autox course. The stiff rears seem to help with putting the power down while turning too, though still not nearly as good as a real diff. I have only run with the ESC "full off".

    I ended up 4th in STX out of 14 drivers and a full 2 seconds behind the class winner in a BRZ (on a 45 second course), Nick Kelly, who placed 8th out of 11 last weekend at the Toledo Pro Solo ... he was 2 seconds off the class winner there. I was outside the top 10 in PAX in a field of about 60 drivers. To say the least it was not an excellent performance :-( I felt like I drove well and the car felt generally good aside from the lack of rotation.

    I think at this point my next tactic will be to run a staggered setup with the 16" 225 Direzzas up front and stockers on the rear. Next event will be 7/20 in Pittsburgh. I'm open to other tuning suggestions :)
     
  11. Cligedy

    Cligedy Active Member

    1st run group is a pax killer. It seems like it's always dusty, no matter where you are. :mad:

    What are you going to try to make the car rotate? At our last event I rode along with another FiST in my class, and one of the local hotshoes took a couple of fun runs in my car. I was really surprised by how differently they drove the car than me. I tend to use lift-throttle or even hard braking to get the car to rotate. The two I rode with were really aggressive with the steering to throw the car into the turns with a bit of sliding through the turns. I was really impressed with how the car felt like it was rotating better than with my technique. In the end though, their times were 1-1.5sec slower than me. I'm still trying to figure out what this means for the best way to get the most out of the car. I think that there may be a middle ground that will be even better. I paxed 33 out of 155. If I hadn't coned my best run I would have been 20.
     
  12. spangenb

    spangenb Active Member

    I tried a few things to help rotation like higher rear tire pressures (though not crazy high), lift throttle and braking, and some aggressive "tossing" too. It seemed like when I tried to use aggressive steering inputs to induce rotation the car just pushed rather than pitching the back end out. Lift throttle helped the most, but even then the effect was subtle. I really expected a bigger change in the dynamics of the car with those stiff rear springs, but other than having generally less body roll the car feels balanced about the same and the rear is just too planted to move around much.
     
  13. jasyatz

    jasyatz Member

    Yeah I know...disappointing how "safe" the rear of this chassis is. I've gone as high as 10k/7k and still no better rear rotation. Steering feel and turn in is vastly improved, but can't get rid of that corner entry/mid corner under steer. Upping rear tire pressure gets you oversteer, but not predictable rotation. Just makes the car nervous every time you turn the wheel and slaloms are a crapshoot whether you'll have grip or not out back. I'd like to be to slide the rear around a bit but then have some grab to it. Still working on that weird science though.
     
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  14. spangenb

    spangenb Active Member

    Have you tried the staggered tire setup with something sticky up front and the stockers out back? I plan to do that at my next autox.
     
  15. jasyatz

    jasyatz Member

    not yet. I just acquired a set of stock Miata wheels (15x6) and already learned that the Rivals don't grip well when pinched. so I'll try the 205/50 on the pinched rims on rear and then the 205/50s optimally stretched on the 15x7.5" rims up front. Front rims are ET43 and rears would be ET45 so slightly more narrow track and slightly less rear contact patch. I'll report results. test and tune and Waterfest NJ next weekend...
     
  16. jasyatz

    jasyatz Member

    Didn't need the staggered offset here. Not a high grip circuit at all. We ran the Raceway Park road course. Understeer was not bad at all. Rotation was good enough, transitions had plenty of balance and confidence. All I did was lower front pressure to Cold 27 and raise rear to cold 32. Bleed off fronts to keep at 27 and let rears run up to 34. Was really good. MetLife in 2 weeks, Atlantic City next weekend. Current spring rates are 550f and 380 rear. have the front lowered so it corners on the bumpstops. Theres not a lot in the shock to reduce porpoising but in steady state transitions and slaloms the car is awesome.. bump steer is an issuer, but better valving up front should help that. I'll report back after a smoother higher grip surface. But the spring rate helped a ton with wheelspin and overall front grip. Has reduced tripod rear to less than an inch or so and doesn't carry if around corners. Hopefully this will be the case on the higher grip surface.

    Am still going to put the well worn 150 run Rivals on the 6" rims and have them at the ready just in case it's a push pig or needs a rear kicker. Brand new 205/50 stickers up front.
     
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  17. jasyatz

    jasyatz Member

    As the saying goes, "What happens in AC , stays in AC"; I surely hope so. This was a medium grip airport circuit. In 7 runs I had 2 full spins, 3 big slides and 5 cones. Sloppy at best. The rear was completely uncontrollable oversteer. Rear tires gave up with the stiff rear setup. took all the rear shock out, and went back to 30/30 Pressures. Was able to almost scratch HS raw time (by .3 ) but coned it. New Rivas being mounted today and the 7.5" all around. The 6" rims were junk anyway, bent and excessive runout.

    So even without the RB rear bar and just a mild rear beam stiffener, the higher rear spring rate and better shock got me the rotation was looking for. transitions at higher speeds resulted in initial bite, but snap spins. Slaloms were very god, turn in was fantastic. Day 2 I ran the Mini since the 2's tires were done and was a little over a tenth back raw time.

    Report back next week after we run a high grip site at Metlife. I'll be there Friday teaching a school in the am, then the pm event. Back on Saturday to run the SCCA event.
     
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  18. Smokin

    Smokin Active Member

    Wow 27psi cold?! I have never gone below 38. At 27psi you're cornering on the sidewalls aren't you?
    Last weekend the setup was 38F/50R.
     
  19. jasyatz

    jasyatz Member

    Not at all. Actually with the BFG stiff sidewall and stretching them out on the 7.5" wheels, they run right at the arrows. Sometimes they'll scrub a bit past if I do something dumb, but otherwise are dead on.
     

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