SCCA Autocross setup thread

Discussion in 'Fiesta ST Autocross' started by AlanBDahl, Oct 21, 2013.

  1. Des

    Des Active Member

    Maybe 55-60? If you are on Dunlops I wouldn't worry; they work best when very cool. Rivals I would drop a pound or two, and RS3s you'll have to treat like Hoosiers.
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  3. Mightymango

    Mightymango Active Member

    Yeah, I will be running the ZII. I was going to run Toyos but I figured the tires will last me at least two seasons and the toyo with the 140tw won't work for next year.

    Too bad the new star specs aren't out yet to try.
  4. AlanBDahl

    AlanBDahl Active Member

    I’m planning on ordering my wheels and tires in the next couple of days. I’m leaning towards the ZII in either the 225/45-16 or 215/40-17 size both of which are about 23.9” in diameter. Any suggestions on which would be best? I’m leaning towards the 16s if for no other reason than the wheel/tire combo is $250 cheaper that way. Or should I put something else om my radar? The 235/40-17 sounds interesting but I wonder if there is enough clearance to squeeze them on there (not to mention mounting them on 7” rims would be a bear).
  5. Des

    Des Active Member

    Alan, no recommendation here but the 235/40/17 on a 7-inch rim is the go-to size for folks running the FRS and BRZ. We didn't hear a peep from the chain-store tire shop that mounted them.

    Personally I think the 235 is going to be the way to go (assuming it fits) for folks using a single set of tires. The Fiesta has the same wheel size and is the same weight as the FRS, and we are asking the front tires to do a lot more. It'll get a couple mph more in second gear than stock, too.

    I think a +42 wheel (compared with +47.5 stock) might make it doable.

    Also, there's a wait for the Eibach bar, so if you plan to add one you might want to order now.
    Last edited: Mar 5, 2014
  6. limbo

    limbo Active Member

    I picked the 225/45/16, can't argue with a little more width.
  7. Slowclimb

    Slowclimb Active Member

    I would like to see how the 235s fit, hopefully someone mounts some up.
  8. AlanBDahl

    AlanBDahl Active Member

    How much clearance do the 225/45-16s have? I should be able to calculate from there.
    Slowclimb likes this.
  9. Slowclimb

    Slowclimb Active Member

    Hey Limbo,

    What kind of clearance to you have...I would love to get Alan's input on what the 235's will be like squeezed under there.
  10. limbo

    limbo Active Member

    I've never had rubbing problems but I've also never measured clearance. I'm out of town for work but will try to see what I can come up with this weekend.
  11. EBinVA

    EBinVA Member

    I'm going to be purchasing my wheel/tire setup soon too, first event of the season and in the ST is in 10 days! I haven't run since 2010 too, I can't wait to be back involved.

    I'm going with the 225/45/16 Z2 setup, has anyone done a few races on these yet? What are you guys settling on for tire pressures f/r? From what I've been reading a few guys seem to like 42psi in the fronts, but I'm not sure about the rears. Unfortunately there's no test and tune around here before the first event so I won't get any time to try and dial the car in first. Trying to find a good starting point so it's not a total shot in the dark on the first run!
  12. AlanBDahl

    AlanBDahl Active Member

    After much debate I’ve decided to go with this size too, if for no other reason than I enjoy ProSolos and the lower gearing of the shorter 225/45-16s should help there. Oh and there is the little detail of the $250 I save over the 17” wheels/tires. I’ve decided to go with the same style OZ wheels I had on my Solstice but I decided on black which will hide cone marks and brake dust better than the silver wheels which always looked dirty on the Solstice.
  13. Cligedy

    Cligedy Active Member

    That seems to be the concensus choice. When is your 1st event Alan? Real curious to hear how the FiST does with a National level driver behind the wheel.
    Also, was your Solstice a base or GXP?
  14. Nik17

    Nik17 Member

    I know a lot of you guys have already been out autocrossing your FiSTs so I have to ask..
    Are there any tips for someone like me coming from a N/A RWD car going to a Turbo FWD car? Left foot brake? Tons of rear tire pressure?
  15. wash

    wash Active Member

    Stock tires will start plowing in tight turns if you get them too hot, the brakes seem to get a little cooked toward the end of a long course too.

    For me that meant I was faster if I didn't go so deep in to the last two hairpins.

    That's course dependent but if you feel it happening you can try to back off toward the end.
  16. AlanBDahl

    AlanBDahl Active Member

    My first event is Sunday March 15th, hopefully it won't be too wet for it! My Solstice was (or rather us as I have not yet managed to sell it) a GXP.
  17. MLKN

    MLKN Active Member

    With the stock tire/wheel setup I found 38 psi front was best. For the rear I set it at 42 in the morning and never checked it again. It felt very predictable regardless or rear tire pressure but obviously it was high (42+)

    I didn't like the layout of the pedals for heel toe and the pedals are almost too close for LF breaking. See my full analysis in my other post from Sonoma.
  18. MLKN

    MLKN Active Member

    For a single run at Sonoma the brakes were solid. As you know Wash, there are tons of runs at these events and with a passenger I ran 3 in a row. There was no break left at the end. Even getting front tire pressures near 40 with heat increased understeer dramatically.
  19. AlanBDahl

    AlanBDahl Active Member

    I would maintain that if your brakes are getting cooked at an autocross event that might be an indication that you are using them too much :). I always try to minimize the number of times I use the brakes and the force used since it's way too easy to use more braking than is needed and that of course means that you've left time on the clock.
    spangenb and Slowclimb like this.
  20. Cligedy

    Cligedy Active Member

    I thought people were exaggerating about the brakes, but I think the e-diff really works the brakes hard. I didn't experience any fade, but after 4 runs on an ~84 second course, it looked like my rotors were starting to glaze. I was really surprised.
  21. AlanBDahl

    AlanBDahl Active Member

    Well then the solution is to be more controlled in your power application to prevent the e-diff from kicking in.

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