AutoX Koni Shocks: Best Setup?

Discussion in 'Fiesta ST Autocross' started by Phreak, May 22, 2016.

  1. Phreak

    Phreak New Member

    There is a ton of great information on this site, but nothing recently. I wanted to see how people are liking their Koni's and what kind of adjustment you are using with them. Also, if you have a front or rear sway bar, I'd be interested to know how that affects your setup.

    For my ST I ran it completely stock last year so I could really learn the car.

    My conclusions are that the car is very balanced as it is in stock form, and the biggest issue is that the rear end starts to get very loose when you get near the edge of traction, but only at low speeds and in situations where you need to back off the throttle. Meanwhile the front has miles of traction in virtually all situations, which is quite amazing for a FWD. I am used to just plowing when I reach those limits, and that never happens with the Fiesta.

    So now that I've gotten comfortable with it, I want to start tweaking things.

    My first tweak is going to be rear dampers only to help reduce roll and hopefully be able to increase my rear traction in those low speed elements like hair pins and reducing radius corners. I have a set of Koni's coming in for the rear in two weeks, and I have 2 practice days coming up at the start of June where I can try to fine tune the adjustment.

    In addition, I have a "special" alignment coming where they are going to massage out the camber through bolt tolerances. Basically they will loosen up everything, then strap it down, and tighten it all back up. I have seen some amazing results for other cars using this process, I will post up my alignment sheet whenever I get around to getting this done.
    Common Platypus likes this.
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  3. Common Platypus

    Common Platypus New Member

    Definitely looking forward to more info about your alignment setup. I'm looking to do something similar. I know you recently got the Konis installed too. Looking to hear your thoughts on just doing the rears.
  4. Phreak

    Phreak New Member

    I actually just wrapped up a 2 day test & tune weekend. The first day I was trying tire pressures at decreasing increments of 2psi for each run. For the venue I was at, the sweet spot seemed to be 44psi front, and 39psi rear. Pretty dramatic change from our other airport venue where I run 47 front and 44 rear.

    Regarding how the dampers perform, I currently have them set to the stiffest setting. On the trip up, which is about 2 hours on the highway, it was pretty noticeable. My gear crashed up and down every time I hit a bump on the road, and while it did it before, the new dampers have certainly amplified that effect.

    For the first day, I didn't really notice any change at first (I was busy trying to dial in the perfect tire pressure), but once I got that settled I started playing around with driving techniques that involving upsetting the car. One of the most noticeable differences I picked up on was the improved ability to drive into a corner, jab the brakes to induce some rear rotation, and then power through the corner. I've been able to do this with the OEM dampers, but it wasn't exactly a controlled maneuver and when I pushed it too far it usually resulted in undesirable consequences. With the Koni's in the rear I was able to do it consistently and with a crazy amount of control.

    When I started really pushing the car, my times were all just tenths apart.... which is a really good consistent result. Not only that, but the end of the day on Saturday I posted the fastest pax time in the afternoon.

    When Sunday came around, I decided to really just crank up the aggression level and see what kind of times I could pull in. Which was fun because our local Corvette club came out to turn with us. Classic David VS Goliath! The Result? Top Pax for the day, even beating out some of our top drivers. Not only that, out of 38 cars, I posted the 6th fastest raw time.

    Now I don't want to read too much into the results, it was a test & tune and lots of people were just there trying out new settings. However the only time I have ever gotten results like this has been in the pouring rain, never even close on a hot sunny day.

    I am really pleased with the car how it is setup now and I honesty can't get over how dramatic the change in control is. As I mentioned, I could go way too hot into a corner, induce a slight drift by jabbing the brakes with a bit of steering input, and then power out of it like I was driving a 300hp RWD car or something.

    Some of my ride alongs for the day were making similar comments, the car was just pure control through the run.

    Here is a video of my suspension btw... as you can see, I prefer driving on 3 wheels!

    Last edited: Jun 7, 2016
  5. jkinan100

    jkinan100 New Member

    Very interested in your experience with the Koni's. I'm running a similar setup, 205/50 R16 RE71Rs but with an Eibach front sway bar. I've settled on 38 PSI front, 42 PSI rear. The result is night and day over last year without the sway bar, and on 225 Star Specs. I find the heavier sway bar makes a turn in much crisper, but a little harder to get power down which may explain the rather soft front pressures. Also the sway bar really tames the three wheeling (I had another FiST driver ask me if I was turning off my ESC, as if!) Have you moved away from full stiff on the rear Koni"s (Yellow Sports, right?), and any change to your front struts? Planning my mods for next season.
  6. pinchvalve

    pinchvalve New Member

    To weigh in, I am currently running Koni Yellows, stock springs, Eibach rear bar, OEM front, with 215/45-16 BFG Rival S 1.5. I ran the Eibach front bar with no rear bar first, and it was completely unmanageable IMHO. I had severe brake lockup at the front and lots of push. No way to get power down coming out of turns either.

    Going to the rear bar, almost full stiff out back and ½ turn off full stiff in the front seemed to be the ticket. I can really bite in the corners, better traction out of tight corners too. Way faster, more predictable and more forgiving. I am still playing with tire pressures, but 34 as a base, +/- 2psi to balance the car for the specific track seems to be about right.
  7. jkinan100

    jkinan100 New Member

    Thanks, I'm planning to run the BFG's this year after running the RE 71R's last year.

    On stock shocks with the Eibach front bar I did not feel the car push more than before, but it tamed the three wheeling while reducing rotation some. Koni Yellows in the back set to about 3/4 turn back from full brought the rotation back nicely. Breaking seemed unaffected, but getting power down out of a turn was a challenge.

    I'm planning to put Koni's in front this year, but figure set to almost full soft rebound to allow the tires to track the road surface better while powering up might work. We don't start racing until mid may up here in Canada, so I'll let you know how it goes.

    Here is a video from an SCCA event in Davenport Iowa from last year - RE 71R's with Eibach front bar and stock shocks. Really overcooked the last sweeper, but had my foot in it too early I think.


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