Unexpected poor handling with Konis

Discussion in 'Fiesta ST Autocross' started by AlanBDahl, Apr 13, 2015.

  1. AlanBDahl

    AlanBDahl Active Member

    I ran my first event of the season yesterday with my newly-installed Konis and the results were poor. I'm now trying to figure out what to do next.

    Setup: 2014 ST with Dirizza ZII 225/45-16 on OZ wheels. Porterfield R4S brake pads. Koni yellows front and rear.

    1st run: Shocks full stiff rear, 1/2 turn from soft front. 38 psi front/42 rear.

    Car was all over the place, I could not keep the rear end planted. All I can do to make it through the course with just one cone. 3 seconds behind Des in his ST.

    2nd run: Shocks the same, pressures 38/38.

    Much better to begin with but still eager to rotate. Entered a fast three-cone slalom with a short braking area into a right-hander. Car snap spun on me and sent me off course into the grass and a side taxiway. Day over per our 4-wheels-off rule with a DSQ on the score sheet.

    From my perspective the common wisdom of Koni shock settings is way off. I'm thinking the middle setting rear and half-way to 3/4 front. Am I right and everyone else is wrong or did we goof up our install some way?

    Des does have a Cobb front bar but that doesn't explain the 4 second difference between us. I road with Des and his car had very good turn-in but tended to loose grip in hard sweepers. My goal is the best of both worlds, high grip with good turn-in. I think it's doable, it's just figuring out how...
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  3. TRev

    TRev Member

    Sounds to me like it is probably a combination of temp and site surface. I have almost the exact same setup, 2015 ST with Z2* 225/45-16 on Sparco wheels, Porterfield R4S pads (I agree BTW on the pedal requiring too much pressure to get them to really bite), Koni Yellows f/r.

    I had my shocks full soft front and 1/8th of a turn off full stiff rear. 38 psi front/42 rear. The reason I didn't go full stiff in the rear was because I have seen mention that shock curves can get interesting at the very far end of the curve. Not sure how true that is of the Konis though. I will likely be dialing up my rebound in the front next event. Unfortunately, this event didn't have much for fast transitions but the four sweepers did affirm that the car wouldn't rotate on entry at all and likes to push on exit a bit.

    I couldn't get the car to break loose in the rear at all but the inside front tire sure did. If a front bar makes that any worse, I don't think I want one! We were on smooooth 5 year old concrete. When I drove Mightymango's car last year, I was getting the rear loose but it was a much different surface. I mentioned it to Des that I thought the FiST rotated nicely and I think he said something like "no way must have been the surface" and I now have first hand experience.
    Last edited: Apr 14, 2015
  4. AlanBDahl

    AlanBDahl Active Member

    It sounds like you have double-adjustable Konis on the rear? Where did you get them? I have the three-way adjustable standard Koni Sports.

    I'm thinking of dumping the Porterfields for another set of stock pads. What do you think?
  5. TRev

    TRev Member

    I have Koni Yellow singles.

    I am going to wait a month or so until (hopefully) Hawk has HPS pads available.
    Last edited: Apr 14, 2015
  6. AlanBDahl

    AlanBDahl Active Member

    You said you had the rears set 1/8 turn off full stiff rear. The normal Konis are click-to-turn with three settings so they can't be adjusted in the way you describe, they are either soft, medium or hard. Which of these did you use?

    You agree with me that the Porterfields just don't work, correct? My previous experiences (admittedly 10 years ago) with the HPS were not good and I dumped them for Carbotechs in a couple of months because of so-so performance and massive brake dust. At this point I know the Ford pads work so I think I'll just go back.
  7. TRev

    TRev Member

  8. TRev

    TRev Member

    The Porterfields aren't ideal IMO...they just require too much pedal pressure. I really liked the HPS on the FoST other than having the pads smoking at more than one event and very badly at the Solo Trials. The brake dust on the FoST was about the same as stock. They had good modulation (much better than the stock pads at initial depress which try to send you through the dash). I probably needed to use 50-70% of the pedal to get on the ABS with the HPS last year depending on surface whereas the Porterfields feels like it takes 90+ percent of the pedal and even then I can't invoke the ABS too aggressively but some of that could be the characteristics of the FiST brakes vs the FoST too as I never did much threshold braking with the stock pads in the FiST.
  9. AlanBDahl

    AlanBDahl Active Member

  10. TRev

    TRev Member

    I don't remember seeing that diagram with my shocks and never had the turn style Konis so I could be doing it wrong/mistaken. I never felt any clicking through the range but did turn them toward stiff until they stopped and then backed them off about an 1/8th of a turn.
  11. Smokin

    Smokin Active Member

    That's not right.

    The Koni Yellow rear dampers are 2 turns soft to hard. There is no click stop. They ARE a bugger to set though, I almost gave myself a hernia.

    Clamp the rod in a vise, push in ALL the way (very hard to do) and keep it there.
    Rotate body left until you feel an indent and twist until the rod twists or stops the rotation.
    That's full soft.
    Stop and mark that point on the rod and body with a sharpie.

    Push in again (very hard to do) and hold it there while rotating the body right and count turns (2 times around until it stops or the rod twists).
    That's full stiff.
    From there I back it off 1/4 turn and let it extend.
    If you let off the pressure at any time while rotating you have lost the indent and have to start all over.
    Cligedy and Des like this.
  12. TRev

    TRev Member

    Here is a video that may be helpful too though I used the vice method like Smokin describes. I agree they are a bugger to set. My mechanic friend passed the duty off to me haha. Also shows a good way to verify if rebound is equal. I didn't think to do that and plan to remove them, go full stiff and verify they are as equal as possible.
    KKaWing likes this.
  13. AlanBDahl

    AlanBDahl Active Member

    Thanks for the clarification and the video! Do others agree that full stiff is too much? I'm thinking about 3/4 stiff at most and maybe as little as 1/2.
  14. Mightymango

    Mightymango Active Member

    I am about a 1/4 turn off of full stiff in the rear and about a half turn off of full soft in the front. I was going to turn them to full soft before the novice school this weekend so I can see how it acts on the asphalt that we normally drive on. But I didn't notice anything odd with the handling of the Koni Yellows. They improved the car feel and direction when on course, even though my time was off pace.

    The car did push a little bit this weekend like Trevor mentioned in his car, but I still got it to rotate as I think the push I felt was my poor driving and going too hot into the corners. That being said I am on the Hawk Street/Race rotor destroyers and they have really good initial bite, which REALLY through me off on the first application.
  15. Play around with the adjustment a bit...there is some subtlety at the "firm" end of the adjustment in the visible rear rebound rate (i.e. how quickly shock extends back out).

    In my case, for repeatability from side to side I'm going to full stiff then back off just a bit (1/8th turn is close) and checking both shocks are (very close to) the same. One observation : at "as far as you can turn it stiff" the rebound appears to spike pretty dramatically. I suspect this is not good, and given what you described may be where you are at Alan ;)

    If you had a mechanic install them, unless they are very experienced with Koni shocks that are adjusted in this manner I would immediately question exactly where they are actually set...
    Sekred likes this.
  16. Slowclimb

    Slowclimb Active Member

    I have mine set exactly the way you guys do. My first event was cold and dusty so it is tough to use as a bench mark, but the car still tended to under steer, but far less than last year. I could get the car to rotate, still not a mini though . My tire pressures were very similar. One other note the tires had about 100 miles on them. Next event hoping for warmer and cleaner.
  17. Des

    Des Active Member

    Dude, you got 1.5 runs! I had three.

    My car got very twitchy in the same place you went off, and I think the only reason it didn't spin is that i was going slower. I had the exact same thing happen -- not an off, but butt-clenching close -- two weeks ago.

    I'll wait until after Crow's but if the car continues to react the same way to surprises at the limit, I agree softening up the rear is the solution. I am sure mine are at full stiff.

    Could have been the combo of RE71s in front and Dunlops in back that brought the rear out, but I kinda liked it.
  18. AlanBDahl

    AlanBDahl Active Member

    Des, I wasn't talking about your rear end coming out entering turns but rather the chattering loss of grip mid-sweeper. This tells me the rear tires aren't generating peak grip in that situation. Ideally I'd like tail-out on turn-in but max grip once the turn is entered. in to.
  19. AlanBDahl

    AlanBDahl Active Member

    I got into an accident of sorts this AM when someone tried to merge into me when we were side-by-side. We didn't touch but were only inches apart when he forced me into the curb. RF wheel and tire are toast, will find out tomorrow if there is more damage or not (I don't think there is but you never know). Glad I decided to skip Crows now!
  20. Slowclimb

    Slowclimb Active Member

    that stinks....
  21. AlanBDahl

    AlanBDahl Active Member

    Toe knocked out a tad but no other damage. New wheel and tire installed so it's all fixed. Gonna back the rear shocks off a tad for the next event which thankfully us at s site with lots of runoff :).

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