No overboost in 1st or 2nd, respond with short tires?

Discussion in 'Fiesta ST Autocross' started by AlanBDahl, Nov 12, 2013.

  1. AlanBDahl

    AlanBDahl Active Member

    From someone who has a boost gauge it appears that C&D was right, there is no overboost in 1st or 2nd gears. I'm wondering if there are any low-profile tires smaller than the stock size, perhaps on 16" rims that might allow the car to run in 3rd on fast courses?
     
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  3. WScottCross

    WScottCross Well-Known Member

    You can get Yokohama S.drive in 215/35R16 with a diameter of 21.9" from TireRack.
     
  4. limbo

    limbo Active Member

    You're going to be hard pressed to find a tire that is both (a) competitive in the corners and (b) smaller diameter than stock. The gearing difference from running the 215/35 s-drive would not be worth the time lost in the corners (s drives are horrible in comparison to the competitive tires out there).

    Maybe if you could run a 15 inch wheel?
     
  5. WScottCross

    WScottCross Well-Known Member

    I never said the S.drive was a great tire. Potenza RE-11's are available in 205/45R16 which is 23.2" vs the stock 23.5". Probably not enough difference to run in third though. Glad our courses here are pretty tight and twisty.

    If you do drop to 15", which will bump you out of stock/street class, the Direzza II are available in 195/50R15 with a 22.7"diameter.
     
  6. limbo

    limbo Active Member

    Could always short shift to third on longer straights? This is a bit of a bummer for all the auto-x guys. Car didn't feel low on power when I drove it but now I want more.
     
  7. WScottCross

    WScottCross Well-Known Member

    Doesn't matter for me. Our courses here are so small we don't really have any longer straights. Most of our courses don't get speeds over 40-45 anyway so leaving it in second is fine.
     
  8. AlanBDahl

    AlanBDahl Active Member

    I'm planning on Street class so wheel size needs to be 16", 17" or 18" and 7" wide. I'm planning on campaigning the car nationally and if I can have multiple gearing options by changing tires that would be great.
     
  9. eRic

    eRic Active Member

    how much boost are you getting in 1st and 2nd gear? I read that the "normal" amount is 18.9 psi vs. 21 psi in over boost. also I ran 205/45-16 RE-11's on 16x6.5" SVT Contour wheels on my 2011 Fiesta and bumped into the fuel shutoff in 2nd gear on occasion.
     
  10. WScottCross

    WScottCross Well-Known Member

    What do you think of the RE-11's for autocross? I also autocrossed my 2011 and had lots of fun. I can see the ST will be capable of higher speeds and will benefit from better tires. I ran 215/35R18 BFG g-Force T/A KDW 2 and was quite happy with their performance, but the RE-11's got really good reviews on TireRack so I'm interested in your opinion specifically for autocross.
     
  11. limbo

    limbo Active Member

    RE-11 or RE-11a? Are you looking for a dual duty or an auto-x only tire? The RE-11 is a great dual duty tire but not at the grip levels of the top tier street tires. The new RE-11a compound is a bit stickier, likely at the sacrifice of some life but a great tire nonetheless. For local competition I doubt you'll be disappointed with either tire.

    The top street tires right now are the Dunlop ZII's, Hankook RS-3, and BFG Rival (debateably, they didn't do well at nationals). Each have their pluses and minuses but in general they are very close in overall grip levels.
     
    Smokin likes this.
  12. WScottCross

    WScottCross Well-Known Member

    RE-11a's are only available in limited sizes from what I've seen, none of which I consider acceptable for autocrossing the ST. The RE-11's are available in 205/45R16 which will still leave me in street class with the rims I already own. They also have a treadwear rating of 200, which will still be legal for the 2015 autocross season.
     
  13. limbo

    limbo Active Member

    The z2s are available in 225/45/16 as well.

    Re-11 is a pretty predictable longer life tire. From my experience with them, driving a couple events in a friends s2000 they def do not have the grip levels of the z2s or the kooks. All of which are 200 tw tires.
     
  14. WScottCross

    WScottCross Well-Known Member

    Will those fit? Grip is what it's all about and you obviously have experience with them so that's what I'm looking for. If the 225/45R16 fit without rubbing, the ZII's sound like the best choice.
     
  15. Cligedy

    Cligedy Active Member

    I have only driven this car once in anger, and that was at the Ecoboost event, and one of the biggest impressions I came away with was that it needed taller tires to get a few extra mph at the top end. I was probably banging the limiter for 50-60 feet at the end of the straight.

    It sounds like you have a good feel for the course types you will run, so use your best judgment, but I don't feel like being down on power in second is a problem in this car.

    I may decide differently after a few events, but it is too early to know for sure. Good luck with this one.
     
  16. limbo

    limbo Active Member

    I sure hope so I just bought a set hah. They fit on the wheels well.

    They should fit the car fine. I believe they are .2" taller and they will be only 20mm wider. So gearing is very close to stock and I don't think that will be enough to have to worry about rubbing.
     
    Smokin likes this.
  17. WScottCross

    WScottCross Well-Known Member

    Let us know. I may well be ordering the same tires some time between now and April.
     
  18. wash

    wash Active Member

    Its not always wise to trust the manufacturer's width measurements on performance tires...
     
  19. limbo

    limbo Active Member

    Right, but it's still stock suspension, wheel width and offset is close. I'm doubting it will be an issue.

    First autox event is 12-1 so I will have them on before that and will report back.
     
    RodMoe likes this.
  20. eRic

    eRic Active Member

    the RE-11's worked great on my 2011 Fiesta. There were basically two tires to chose from in a 205/45-16: The Bridgestone RE-11 and Toyo R1R. I chose the RE-11 because the R1R warning about handing in cold climates scared me. Sometimes in snows in April and I have been caught on summer tires when that happens. Heck it snowed here the other day and my Fiesta ST is still on the RE050A's. D'oh.
    Here is a photo of the RE-11's on my 2011 Fiesta in action http://detroit-scca.org/e107/page.php?11
     
  21. WScottCross

    WScottCross Well-Known Member

    I wouldn't care about the cold climate handling because these will be primarily autox only tires. The other down side to the R1R's is the 140 treadwear rating will put them out of street class for the 2015 season. Now I need to decide if I want the wider Direzza ZII's or the RE-11's. Our season doesn't start back up here until April, so I have plenty of time to read other people's opinions and make a decision. I'm leaning towards the ZII's since they're wider and also cheaper through TireRack. As long as they fit...
     

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