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Thread: WCM Ultralite S2K bump steer

  1. #1
    Join Date
    Sep 2015
    Posts
    3

    Default WCM Ultralite S2K bump steer

    I have just purchased this WCM 7.

    http://www.usa7s.net/vb/showthread.p...-Ultralite-S2k

    It has quite a bit of bump steer. When I hit a bump on the street, it wants to jump side to side. I also took it out for a few laps at Gingerman. When I stab on the brakes, it would dart side to side like it was toe'd out.

    I know Jay, the previous owner, added some toe in because the car has a history of bump steer.

    Im curious if anyone has a starting point alignment I should try. If not I'm going to put on a rack and see what it looks like and start experimenting.

  2. #2
    Join Date
    Sep 2007
    Location
    PA
    Posts
    702

    Default

    Congratulations, and welcome to the WCM club. If you send me your email ill send you the current "manual" for the car. It has some starting points for alignment in it.

    Roman
    Roman

    WCM S2k Ultralite , formerly miatalite.

  3. #3
    Join Date
    Oct 2006
    Location
    Cincinnati
    Posts
    3,630

    Default

    Also: do a search for the words bump steer in the search box. This is a popular topic, much has been written here. I know member JohnK to be obsessively thorough. His post on his Ultralight's bump steer, which he calls "ride steer" will no doubt be educational. Hopefully the (many) other bump steer posts will also help. What u r describing sounds dangerous!
    Kitcat:AKA, Sir Spinsalot
    '97 Caterham Super Sprint, 1700 Crossflow-sold
    '09 Birkin S3, Duratec-sold
    '03 Caterham Zetec track car
    '19 Honda Civic, Type-R

  4. #4
    Join Date
    Sep 2006
    Location
    Southeastern Pa.
    Posts
    2,817

    Default

    I don't know about WCM Ultralights, but on Caterhams, shimming under the steering rack is the cure. Good luck. Tom
    Mangia bene, Ridi spesso, Ama molto, Guidare veloce

    2000 Caterham Superlight #123
    1.8L VHPD Rover K Series
    2009 Caterham SV
    2.3L Cosworth Duratec

  5. #5
    Join Date
    Feb 2009
    Location
    NYC
    Posts
    4,553

    Default

    Oh I feel that pain. I am starting to dial bump steer out of my BMW CSL restoration project. I thought it was toe out but then a quick check told me it was bump steer.

    I second JohnK's posts as I am using them to think it through on my problem - link was easy to find as i had it bookmarked.
    http://www.usa7s.net/vb/showthread.p...ght=bump+steer

    I found this youtube helpful as I began my journey into curing bump steer:

    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration - engine and dry sump install time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore Group A (restoration - engine rebuild)
    1982 Ferrari 400i (will repaint to original color in 2020)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (fettling after long period of storage)
    1990 Range Rover 2 door Classic

  6. #6
    Join Date
    Oct 2012
    Location
    Shelby Twp, Michigan
    Posts
    187

    Default

    Hello, Loudes13. I am the member that started our WCM manual. Roman has the last edition. I am happy to announce that a new edition featuring a brand new parts list, a chapter on bump-steer remedies (the Caterham contributor below is on to something), alignment, shock selection and much more, is ready to roll out. I have assembled a Google email group that includes all the addresses for folks who want manuals. Please send me your email address and I will add it to the manual group.
    ​CURRENT:
    2015 Alfa Romeo 4C coupe, turbocharged. 6 speed DCT, heims/links, monoballs, swaybars, 2,440 lbs, 312 hp

    1982 Porsche 935 "Flachbau"
    tribute, supercharged & intercooled 964 motor, built G50 trans, Albins LSD, heims/links, 2,500 lbs, 425 hp

    EX Street & Track:
    2004 Ultralite S2K, Honda S2000 drivetrain, Mugen baffled sump,
    transverse/diff braces, heims/links, anti-surge fuel tank, oil accumulator
    2007 Backdraft Racing Roadster, Roush 402, heims/links, Wilwood big brakes
    2008 Lotus Exige S2, supercharged, chargecooler, 346 hp
    1993 Caterham, 1.8 liter Cosworth
    1991 Caterham, 1.7 liter crossflow
    1995 Mazda RX-7 FD, 2.6 liter Wankel, 276 hp
    1987 Dodge Shelby Charger, turbocharged

    1976 Triumph TR-6, Paris blue
    1963 Mini-Cooper S 1071 cc
    1964 Jaguar XKE drophead coupe, 4.2 liter, BRG

    EX Track Only:
    Panoz GTS, car # 23 from Panoz Racing Series, 4.6 liter V8
    2005 Toyota TRD Celica Junior NASCAR, V6 motor, Jericho 4-speed, "Clabber Girl" livery
    2003 OMS D Sport Racer, Yamaha R1 motor, sequential flat-shift trans, mid-rear engine, ALMS coachwork

    ". . . breakin' up is hard to do" Neil Sedaka


  7. #7
    Join Date
    Aug 2017
    Posts
    2

    Default WCM Ultralite S2K bump steer

    Sorry friends. I posted my responce to bump steer under the topic of brake bleeding. I can learn to do better.

  8. #8
    Join Date
    Oct 2006
    Location
    South Lyon Michigan
    Posts
    206

    Default

    Loudes13
    Are you located in Michigan, [I see Gingerman reference].
    I'm in SE Michigan. I have a bump steer gage if you would like to use it.
    Dave W

  9. #9
    Join Date
    Oct 2012
    Location
    Shelby Twp, Michigan
    Posts
    187

    Default

    You need a copy of the manual. S2K bumpsteer derives primarily from a non-straight steering rack. If the rack arms point up or down when the suspension is at rest - not straight across - the car will likely bump steer. Solutions are in the manual. Request a manual copy by emailing bruceakopitz@gmail.com. There was also an informed thread from a Caterham owner on this subject (further down this page).
    ​CURRENT:
    2015 Alfa Romeo 4C coupe, turbocharged. 6 speed DCT, heims/links, monoballs, swaybars, 2,440 lbs, 312 hp

    1982 Porsche 935 "Flachbau"
    tribute, supercharged & intercooled 964 motor, built G50 trans, Albins LSD, heims/links, 2,500 lbs, 425 hp

    EX Street & Track:
    2004 Ultralite S2K, Honda S2000 drivetrain, Mugen baffled sump,
    transverse/diff braces, heims/links, anti-surge fuel tank, oil accumulator
    2007 Backdraft Racing Roadster, Roush 402, heims/links, Wilwood big brakes
    2008 Lotus Exige S2, supercharged, chargecooler, 346 hp
    1993 Caterham, 1.8 liter Cosworth
    1991 Caterham, 1.7 liter crossflow
    1995 Mazda RX-7 FD, 2.6 liter Wankel, 276 hp
    1987 Dodge Shelby Charger, turbocharged

    1976 Triumph TR-6, Paris blue
    1963 Mini-Cooper S 1071 cc
    1964 Jaguar XKE drophead coupe, 4.2 liter, BRG

    EX Track Only:
    Panoz GTS, car # 23 from Panoz Racing Series, 4.6 liter V8
    2005 Toyota TRD Celica Junior NASCAR, V6 motor, Jericho 4-speed, "Clabber Girl" livery
    2003 OMS D Sport Racer, Yamaha R1 motor, sequential flat-shift trans, mid-rear engine, ALMS coachwork

    ". . . breakin' up is hard to do" Neil Sedaka


  10. #10
    Join Date
    Jul 2009
    Posts
    1

    Default Wcm manual

    ROMAN Please send me the WCM manual Robert m_287@msn.com Thank you

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