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What should I be doing differently?

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  • What should I be doing differently?

    I've been driving and tracking rwd cars for about the past 10 years, my first drive in my GTR and I was a bit underwhelmed. Nothing but understeer .

    I put the car in r r r. I had the dealer do their "track" spec alignment, other than that no other track prep. I was trailbraking to try to get the car to rotate, but ultimately felt like I was man handling the car mid turn to stay on line, the front would just push push push, bad...

    Fwiw I was about 5 seconds off my Corvette's pace (2:02's at thill), its a stock c5z with r comps and brake kit. Was I wrong to think my GTR would be faster? Does this awd thing require a different technique?

    Don

  • #2
    These cars naturally understeer like a pig, and they also weigh 3800 lbs.
    The deposed former Sheriff of trackHQ . . .

    2006 Porsche 997 Carerra Coupe 6-MT - daily driver
    1992 Honda (Acura) NSX 5-MT - classic investment I couldn't resist and occasionally drive
    2004 Honda S2000 AP2 6-MT - my last track day car (FOR SALE or not, depending on how I feel when I fall out of bed tomorrow morning)
    2006 Mitsubishi Lancer Evolution IX MR 6-MT - when I need a backseat, 4-doors, or a real trunk, and still want to haul ass . . .

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    • #3
      Sounds like you are coming in too hot on corner entry. I think the real value of AWD is mid and exit of the corner. Slow in, fast out?

      I'm sure someone with more AWD experience can chime in.

      Comment


      • #4
        Well that sucks. Haha, they don't mention the understeer in all the media hype.

        I thought of another question, how much help is the nitrogen in the tires supposed to really be? I feel like i was tricked, Haha. The dealer said they checked pressure and filled with the obligatory nitrogen, set to 29#, I checked pressure in the morning and saw 30, and after about 15 min was seeing 37psi.

        Oh and fwiw, I got a whopping 3mpg, 2 sessions and the tank was nearly empty. Ridiculous.

        Don't misunderstand me though, I had a blast and really enjoy the car.

        Don

        Originally posted by Richard EVO View Post
        These cars naturally understeer like a pig, and they also weigh 3800 lbs.

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        • #5
          A C5Z on r-comps..you can get away with murder on a race track. Very easy car to drive and very confidence inspiring

          I agree on the slow-in, fast out as said above. When you're used to carrying a ton of speed in, pitching it in to scrub off speed, and hammering out...It's a big change, but applies to many cars.

          Nitrogen can be a gimmick, and is really only useful in high humidity areas (like the mid west and east coast). I say gimmick bc unless you dry ice bag the tire, you aren't going to get all the air/moisture out of the tires for the Nitrogen to work like it should..
          Last edited by SIK02SS; 08-18-2011, 02:43 PM.
          --Chris Ronson Jr--
          www.ronsonracing.com

          T1 Corvette roller for sale

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          • #6
            For AWD cars like Evo/GTR, try lowering front tire pressure and raising the rear tire pressure. Do some throttle lift oversteer mid turn. Maybe you can also try to do some weight shifting. Turn left a tiny bit then turn in right for the turn. That helps rotation too. This all helps for turn in and mid corner rotation. If you get understeer on exit, just have to keep throttle lifting and back on gas until you can wot through the exit. Lift longer for more rotation. Or just roll onto the power as soon as you can w/o causing terminal understeer and minimizing the understeer so you can track all the way to the edge of exit under throttle.

            You also might consider adding more front grip by dialing in more front camber. These are all bandaid fixes, but not really a cure for the understeer. It does work though.
            Zhong (Evo IX) | Angry Panda Racing

            1:53.396 @ BRP CW13 - 11/14/13
            1:47.2xx @ Laguna Seca - 11/28/10
            2:03.026 @ Thill CCW Bypass - 12/20/14
            2:05.100 @ CVR CCW - 1/16/11
            1:58.151 @ CVR CW - 5/5/13
            1:25.56x @ WSIR - 10/13/13
            1:23.128 @ SOW CW - 7/27/14
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            Fastest Limited/Mod Class Evo in Time Attack at WSIR
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            • #7
              DFA GTR test day at Thunderhill - YouTube

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              • #8
                Dang, that car is just soo fast. I can easily see it being a 2:02s lap with a clear track and fixing some lines and cornering speeds. Yeah, the understeer is pretty bad in some places especially T6. I think you just might be coming in a little too hot. Right after turrn in it wanted to understeer and completely miss the apex. Use more track all the way to the stripes on T8. Fix lines in a few other places and you can be down in the low 2:00 no problem. Looks like you need to sacrafice a few mph on entry speed and you will gain alot on exit speed. You should be able to hit 128-130mph at the end of the front striaght.
                Zhong (Evo IX) | Angry Panda Racing

                1:53.396 @ BRP CW13 - 11/14/13
                1:47.2xx @ Laguna Seca - 11/28/10
                2:03.026 @ Thill CCW Bypass - 12/20/14
                2:05.100 @ CVR CCW - 1/16/11
                1:58.151 @ CVR CW - 5/5/13
                1:25.56x @ WSIR - 10/13/13
                1:23.128 @ SOW CW - 7/27/14
                1:22.2xx @ SOW CCW - 7/26/14
                1:46.0xx @ ACS Roval - 11/23/14
                1:11.299 @ ACS Infield - 5/18/14

                Fastest Limited/Mod Class Evo in Time Attack at WSIR
                2nd Fastest Limited/Mod Class Evo in Time Attack at BRP 13CW

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                • #9
                  Drive to the cars style don't make it drive to yours.

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                  • #10
                    @ pure EVO, thanks for your assessment. There were places I couldn't reach my inside apex target because the front end was pushing, very obvious in 6, and in 8 I just didn't have it in me to push it harder, I did not want to risk a highspeed understeer off.

                    @ stalker, that's precisely why I posted, I need some guidance as to how to adjust my driving to suit the car.

                    Don

                    Comment


                    • #11
                      definitely need to slow down a bit more for corner entry!!
                      try turn in early with slow hands, yes "early", to better load the front tires so the car understeers less at corner entry..
                      brake early, take the tightest line possible, then rocket it out is the way I would drive an AWD

                      just my .02
                      momofoolio Racing - http://momofoolio.webs.com

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                      • #12
                        I think everyone agrees your corner entry may be a little too aggressive for the current attributes of the car, but what I wondered was was how much sidewall was being used on the front tires? This is going back to the "Track Alignment" Nissan put on it. I don't know if they are similar, but the Z uses a upper and lower a-arm config that is not camber adjustable. If the GTR has the same non-adjustability I would think that car is rolling over pretty far on the front sidewalls at around 1.5 degrees of camber. The rear seemed to be an exact opposite, it looked rock solid. I'm assuming the rear has quite a bit of adjustibility for camber and toe from the factory and this is probably where they emphasize "Track" settings. I'm curious though, how aggressive is Nissan's "Track alignment"?

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                        • #13
                          Zazz, you're right the front alignment is limited, it was set to 1.8* camber at all 4 corners. I have been under the car since the alignment and can see the front is max'd out where the rear seems to have plenty of room to go.

                          And yes the rear was rock solid. The front tires don't look like they rolled over onto the sidewall.

                          I'll try slow in and see how that works out...

                          Thanks!
                          Don

                          Comment


                          • #14
                            Its already been said, but just in case you missed it:

                            Slow in, Fast out.

                            The front of your GTR is pissed off. You are transferring all the weight to the front when you brake last minute. Also a bigger sway bar, and stickier tires wouldn't hurt.

                            Good luck.
                            tiretab

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                            • #15
                              I can't believe I missed this thread!

                              As others have said, slower on corner entry. I've done about 20 track days in my GT-R, but have never driven T-hill. Stock, the car will understeer. Here are two things I have done to mine which make the car handle very neutral. One is to use a 285 square setup. You'll get more life out of the front tires and will have less understeer. The rear 285 tires will mount to the OEM front rims with no problem. To dial out what is left of the understeer, get a set of Stillen sways and set them to the middle setting in front and full soft in the rear (along with the 285 square setup). With these two changes, the car is very neutral and corner push is gone.

                              Your cold pressures of 29 are pretty much spot on, and when up to temp, you should be seeing about 37 psi, assuming you're using the OEM Dunlops.

                              Another thing that I have recently done is put on a KW coilover sleeve kit on the OEM dampers. This gives you the ability to corner balance and lower the car a bit. Mine is dropped about 1 to 1 1/2 cm. This also allows you to get about -2 camber in front and with that I go with -1.8 in the rear. My toe settings are 1.5mm out on each side in the front and 1mm in on each side in the rear. Top Speed built a GT-R for Leh Keen to drive in OLOA on street tires, which he won and broke every GT-R record along the way. They used the new Michelins in 315 square. My sway settings are the same as theirs. They measured the final ride height at 145 mm, measured from the center indent of each corners jack pad to the ground. This is where I started to allow for my springs to settle, but corrected for diameter, I should be at about 135 mm to mimic their suspension geometry, as their tires are about 2 cm larger in diameter than mine. At their final ride height, they were able to get -2.4 degrees of camber in front. Once I get down to a 135 mm height, I should be able to get that, as well. Once at -2.4, then the rear camber will go to -2.2, as they have done. This is final step I have to dialing in my GT-R.

                              Here is their build and OLOA thread on NAGTROC: TopSpeed Motorsports - OneLap GT **2011 OneLap CHAMPIONS - NAGTROC - The Nissan GT-R Owners Club

                              Good luck!
                              Last edited by DocNrock; 08-21-2011, 11:12 AM.
                              2009 Nissan GT-R -- nicely modded

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