FiST vs FoST struts

Discussion in 'Fiesta ST Chassis Upgrades' started by Smokin, Aug 4, 2014.

  1. Smokin

    Smokin Active Member

    I posted this on my autocross thread but want to do it here:

    I got to watch a FiST close up while working a corner this weekend. It IS all bouncy, rolley and stressed on cornering.
    Comparing it to the multiple minis we have around here it looks out of control.
    I swear this guy's front right was off the ground one time.

    I'm looking for that extra second and that's where is it. Gotta stay in G-Street legal setup.

    Question 1: One of the track guys says he uses a 2011 Fiesta SES front bar. Are they really 22 mm and are they really stiffer?

    Question 2: Are FoST struts interchangeable and are they stiffer? The part numbers are the same...

    Let the discussion begin.....
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  3. McRib 1s Back

    McRib 1s Back Well-Known Member

    ...for question #1, I have heard similar from a few people. I think that's correct and makes sense to me (for that car). Dave has details and I believe runs that very part (or has one that he has swapped in). Without other changes, I'm wondering if you'll gain stability at the expense of plowing through turns.

    Even w/coil-overs, my car felt "all bouncy" like you said -- until I really cranked them up. It's great now, but I know what you mean. Running the big sway part out back without a bigger bar up front caused all kinds snap-oversteer for me when running the Mountune springs. Now with stiffer CO springs, it's actually pretty good now. If things don't change, I probably won't experiment with a new front sway bar (but that was one I had my eyes on too!).
  4. Smokin

    Smokin Active Member

    There's so much roll I don't think a stiffer front bar will induce understeer. I have Koni Sports on the rear so don't need a stiffer rear/bar. I can get trailing throttle oversteer, wheel lift easily. Just need to keep the front end flatter...
  5. moff3tt

    moff3tt Active Member

    Apparently, the stock FiST struts have the rebound cranked way up and that is why it feels so bouncy. It's not the spring rates but the shocks. This is what Mountune says so I figure they're probably right. So a more aggressive shock may not be what we are after but rather a more reasonable shock. This may increase roll but should also improve stability so finding a good balance (something the adjustables allow) is probably the best course of action. I am would be very surprised if the FoST struts fit the FiST.
  6. razorlab

    razorlab Active Member

    the FoSt front struts are a totally different design on the bottom. They get clamped by the knuckles, like VW.

    The FiST clamps to the knuckle like most standard fronts.




  7. Smokin

    Smokin Active Member

    So it's an insert so it should fit inside the FiST clamp. The part numbers are the same except for the suffix A B D E etc. Anyone with a FoST who can measure the base diameter?
  8. razorlab

    razorlab Active Member

    insert? The whole strut is a totally different design if you look at the photos above and they have two different part numbers. Or maybe I am misunderstanding you?

    Fiesta Struts:
    C1BZ18124A (left)
    C1BZ18124B (right)


    Focus Struts:
    CV6Z-18124-Q (left)
    CV6Z-18124-R (right)

  9. BRGT350

    BRGT350 Well-Known Member Staff Member

    Trying to get a Focus ST strut to work on the Fiesta ST is not going to be easy. Ride height, travels, damping, mounting, everything is different. I would go with a strut designed for the Fiesta. Given the outstanding results I had on a number of cars, I would go with a set of Bilstein HD dampers if using the stock springs or at least stock replacement springs.

    Last month I was corner working at an autocross and got a chance to watch a stock Focus ST and a highly modified Focus ST go around the course. The stock ST's all handled the bumps and dips of the course just fine, while the modified one (not sure all what was done to it as the owner did not say too much) would bounce all over the place. The rear was very unsettled and the car looked like the driver was constantly fighting it. The times were pretty good on the modified one since as soon as there was a straight, the car would launch like a rocket. I am guessing the car would have been better on a smooth road course instead of a bumpy parking lot.

    I did not get a chance to watch how the Fiesta ST did on course because I was running at the same time with my Mustang. When I ran the Fiesta Movement ST last year on the same course, I did not feel it was too terribly bouncy. I actually thought it felt very nice on course. I had 7 drivers take the car for 5 runs each and we were all very happy with the car. Of course, this was the first autocross any of us had run in a ST and most of the drivers had never even seen a Fiesta ST, let alone drive one.
  10. Smokin

    Smokin Active Member

    That's the funny thing, the Fiesta feels settled. The last four events we had were huge tarmac settings with lots of wide open hi-speed runs sweepers and slaloms. And from the outside body roll is significant compared to the other cars I was observing Sunday (a high speed 120 deg sweeper; redline cutoff halfway there).
    Where everyone else has improved this season, the Fiesta has not. I'm sure a tuner chip would help but that's not allowed.

    Cligedy, what's the update on Konis?
    Last edited: Aug 5, 2014

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