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    Apr 10, 2006 6:26:25 PM

    MHakkinen
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    MHakkinen
    Loc: SoCal-freeway shooting capital
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    Any autocrossers here? Tire pressure question...

    I've entered the SDR auto-x this saturday. My first Porsche "track" event.

    Anyone have any suggestions on tire pressure? Should I increase, or leave at stock settings? It's only one lap at a time, so I'm not sure if a "race" setting is in order.

    I'm running the stock Conti's that came with the car; I figure no regrets on burning the rubber down to the carcasses for my first P-event

    Apr 10, 2006 6:42:20 PM

    Trundle_GT3
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    Trundle_GT3
    Loc: CA, USA
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    Reply to: MHakkinen

    Re: Any autocrossers here? Tire pressure question...

    I'll be there!! #241

    the Qualcom cheese grader..

    I increase the front by 3-4#
    Rear at 44#

    You are on 19"...right

    Apr 10, 2006 6:46:59 PM

    wangt1015
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    wangt1015
    Loc: CA, USA
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    Reply to: Trundle_GT3

    Re: Any autocrossers here? Tire pressure question...

    Is it too late to sign up for the autocross?
    Signed up with PCA about 10 days ago, still haven't heard anything back from the OCR chapter yet. How long does it usually take to get registered?

    Apr 10, 2006 7:28:14 PM

    Trundle_GT3
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    Trundle_GT3
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    Reply to: wangt1015

    Re: Any autocrossers here? Tire pressure question...

    Not to late
    show-up between 6:30 and 7:30 for tech then register at the trailer
    Info & Forms Here

    Apr 10, 2006 8:31:52 PM

    MHakkinen
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    MHakkinen
    Loc: SoCal-freeway shooting capital
    Posts: 381, Gallery
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    Reply to: Trundle_GT3

    Re: Any autocrossers here? Tire pressure question...

    Cool thanks Trundle-

    I'm on stock 18's actually. Got any advise on those? No worries; just getting my feet wet- first timer out there.

    wang- email the national office; I don't have my card yet but they emailed me my membership number. I was down there yesterday checking out the driving school event and they told me just to bring a printout of the email they sent me as proof.

    Goto the SDR website and FAX the pre reg forms asap. Guarantees youur spot and also saves you $20 for lunch Keep us posted so we can hookup down there.

    I don't have a number assignment yet; Trundle I'll look for you. I'm getting excited about driving my car in anger now. P rules state 4 auto-x's are prerequisite to entering a proper track event with lapping sessions. Can't wait to get going!

    Apr 10, 2006 8:38:55 PM

    KiwiCanuck
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    KiwiCanuck
    Loc: Canada
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    Reply to: MHakkinen

    Re: Any autocrossers here? Tire pressure question...

    Why? Higher front pressures increases understeer...

    KiwiCannuck

    Apr 10, 2006 8:41:22 PM

    964C2
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    964C2
    Loc: Dallas, TX , United States
    Posts: 1434, Gallery
    Registered on: May 11, 2004
    Reply to: KiwiCanuck

    Re: Any autocrossers here? Tire pressure question...

    Quote:
    KiwiCanuck said:
    Why? Higher front pressures increases understeer...

    KiwiCannuck


    The opposite, higher front pressures reduce understeer, higher rear pressures reduce oversteer....

    Apr 10, 2006 9:02:52 PM

    wangt1015
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    wangt1015
    Loc: CA, USA
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    Reply to: MHakkinen

    Re: Any autocrossers here? Tire pressure question...

    MHakkinen - Thanks for the info. I will email the PCA to see if they can fax or email my membership info asap. I only have about 500 miles on my car so if I can get my number before the weekend, I will definitely have to take some long trips just to get to at least 1000 miles before saturday! Can't wait to test the car true ability on the track

    Apr 10, 2006 9:40:47 PM

    MHakkinen
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    MHakkinen
    Loc: SoCal-freeway shooting capital
    Posts: 381, Gallery
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    Reply to: wangt1015

    Re: Any autocrossers here? Tire pressure question...

    Recommend filling tank and head north on PCH/101 until you reach empty; refill and return to point of origen. Repeat once daily through Saturday

    Albeit cones in a parking lot at controlled speeds it will still be great fun. Instructors are included which will be of great benefit.

    I just can't wait to get onto a proper track such as Streets of Willow, or California Speedway to get experience lapping sessions on a real track. My goal is to hang a picture in my office of me, in my 997 coming down the corkscrew at Laguna Seca

    Apr 10, 2006 9:49:41 PM

    Trundle_GT3
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    Trundle_GT3
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    Reply to: MHakkinen

    Re: Any autocrossers here? Tire pressure question...

    MHakkinen....

    Streets of Willow AX...a Great event
    CLICK ME

    Apr 10, 2006 10:27:32 PM

    MHakkinen
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    MHakkinen
    Loc: SoCal-freeway shooting capital
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    Reply to: Trundle_GT3

    Re: Any autocrossers here? Tire pressure question...

    Quote:
    Trundle997S said:
    MHakkinen....

    Streets of Willow AX...a Great event
    CLICK ME





    Thanks Trundle! I've already filled out the form, just gotta confir with the wife about scheduling time off. I'd like her to come out to the event and watch, which means sleeping over at the hotel. I should have a verdict by the time I see you this weekend. I take it you're going?

    Apr 11, 2006 2:26:07 AM

    JP66 Offline
    Rennteam Pro
    JP66
    Loc: Seattle , United States
    Posts: 2199, Gallery
    Registered on: Jul 10, 2003
    Reply to: 964C2

    Re: Any autocrossers here? Tire pressure question...

    Quote:
    964C2 said:
    Quote:
    KiwiCanuck said:
    Why? Higher front pressures increases understeer...

    KiwiCannuck


    The opposite, higher front pressures reduce understeer, higher rear pressures reduce oversteer....



    So which is right???

    I too thought that lower front pressure provides more traction, thus less oversteer.....

    Apr 11, 2006 4:29:11 AM

    doc2s
    Junior
    doc2s
    Loc: boston, usa
    Posts: 113, Gallery
    Registered on: Jun 27, 2005
    Reply to: JP66

    Re: Any autocrossers here? Tire pressure question...

    increase front by 4 psi and leave the rear stock. you want a smaller different in pressure between front and rear to have less understeer. it is not only the front pressure but the difference between front and rear pressures. i'm sure you will have a blast. make sure to turn psm off (pasm to sport if you have it)

    Apr 11, 2006 2:45:39 PM

    964C2
    Expert
    964C2
    Loc: Dallas, TX , United States
    Posts: 1434, Gallery
    Registered on: May 11, 2004
    Reply to: JP66

    Re: Any autocrossers here? Tire pressure question...

    Quote:
    JP66 said:
    Quote:
    964C2 said:
    Quote:
    KiwiCanuck said:
    Why? Higher front pressures increases understeer...

    KiwiCannuck


    The opposite, higher front pressures reduce understeer, higher rear pressures reduce oversteer....



    So which is right???

    I too thought that lower front pressure provides more traction, thus less oversteer.....


    You answered your own question, less oversteer, relatively speaking means more understeer. It's not just absolute pressure but the difference between the two and whether the tire is working optimally. My comment was relative to autocrossing and starting with stock settings.
    See http://www.wtrscca.org/tech.htm this is an excellent explanation of handing dynamics and the effect of changes.

    Apr 11, 2006 3:32:54 PM

    Dan L
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    Dan L
    Loc: Santa Barbara, CA , United States
    Posts: 1957, Gallery
    Registered on: Jan 2, 2006
    Reply to: 964C2

    Re: Any autocrossers here? Tire pressure question...

    You need to keep close watch over your tire temperatures and pressures until you figure out for yourself what works for that car's setup. Suggest you keep records of this,--with a clipboard, write down the temps on the tires, meaturing them on the tread,--from inside, to outside (and middle) for all 4. Do this after each lap.

    From this they will tell you what you're doing,--by checking the SCCA guide earlier referred to.

    dan

    Apr 11, 2006 4:29:00 PM

    wangt1015
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    wangt1015
    Loc: CA, USA
    Posts: 284, Gallery
    Registered on: Mar 10, 2006
    Reply to: MHakkinen

    Re: Any autocrossers here? Tire pressure question...

    Quote:
    MHakkinen said:
    Recommend filling tank and head north on PCH/101 until you reach empty; refill and return to point of origen. Repeat once daily through Saturday

    Albeit cones in a parking lot at controlled speeds it will still be great fun. Instructors are included which will be of great benefit.

    I just can't wait to get onto a proper track such as Streets of Willow, or California Speedway to get experience lapping sessions on a real track. My goal is to hang a picture in my office of me, in my 997 coming down the corkscrew at Laguna Seca



    Hahahha, I better start driving right now then! Hope I can still make it this saturday!
     
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