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Offline Brenton

  • 300kph+ club
  • DJ's like a mad ...........

  • Joined: May 2009

  • Drives: Yes
  • Location: Adelaide
5 seconds quicker on a 1:15 -1:20sec track????

Sorry mate that wasn't loosing, that was getting crushed!!!

Which car ran first?

Wattens great positive contribution.  :thumbsup:



Offline carmooch


  • Joined: Dec 2010

  • Name: George
I'm probably the last person that would know anything about the handling characteristics of a Porsche, but just throwing it out there... perhaps the H&R springs are to blame?

Just going off my experience with "normal" cars, lowered springs tend to compensate for what they lack in height with added stiffness. This in turn ruins the dampening capability of the struts and causes the 'twitchy' handling which you mentioned.

To keep the ride "comfortable" with a lowered spring, it could also have a varied spring rate which means it has loosely packed coils at one end of the spring and tightly packed coils at the other so that at normal speeds only the 'softer' portion of the spring is being used, so you really have to lean on it to reach the stiffer, more "track focussed" part of the spring which in turn means more body roll.

Image

Also, to a lesser extent you could be compromising the roll centre height of the car (kind of where the suspension pivots against the body of the car, haven't quite grasped this one), so while the actual centre of gravity may be lower, the roll centre would be higher (the roll centre would have stayed at the same height, but the actual body of the car is now lower so the roll centre is comparatively higher).

I know the effect on a "normal" car can be quite severe, so I can imagine on a car with such precise tolerances like a Porsche these effects could cause severe changes to the handling characteristics of the car.

Driver error could also be to blame. Not to say you are a bad driver but it takes more balls to drive the Porsche around the track quickly then it would to drive the GT-R. I'd say the majority of your time was lost because you were lifting off when you should have been pressing harder - probably because the springs were making you feel as though you were at the limit. The rear-engine layout of the Porsche means to add grip to the front you actually need to accelerate harder!

We actually learnt this the hard way trying to drift a TechArt Porsche GT2 - every time our driver tried to kick out the rear end the car just gripped more and tucked its nose in!

Watch this video from around the 0:30 mark and you can see him struggling to keep the tail out - and mind you the driver was drifting in massive arcs the entire width of the runway in a BMW M5 only minutes before.

<a href="http://www.youtube.com/watch?v=VmKjxqiiq1M" target="_blank">http://www.youtube.com/watch?v=VmKjxqiiq1M</a>

Then again I could be totally wrong, but it's food for thought. My guess is that the Porsche is actually capable of being relatively on par with the GT-R.



Offline alvchua


  • Joined: Aug 2009

  • Drives: Old junks
  • Location: Adelaide
@ leburpor - I'll take the Techart mods and lowered springs off ur hands @ "mates rates" now that u r putting an order in for a GTR!  :D :p
Forgiveness is easier to achieve than permission!



Offline leburpor

  • Loves Tom Cruise

  • Joined: Feb 2007

  • Location:
  • Drives:
5 seconds quicker on a 1:15 -1:20sec track????

Sorry mate that wasn't loosing, that was getting crushed!!!

Which car ran first?

I did say I got caned :P GT-r then Turbo then GT-R.



Offline Brenton

  • 300kph+ club
  • DJ's like a mad ...........

  • Joined: May 2009

  • Drives: Yes
  • Location: Adelaide
Carmooch you could be onto somthing. I believe it is just a balance thing. You won't get to 1.14 as I believe that is what yss would get inhis 07 gt3 but you should be able to drop a couple more sec off with a bit of a balance.

Good luck and it will make a great dinner beer conversation in a couple of weeks.



Offline dkabab

This thread isn't about lap times.... Leburpor is just trying to justify the inevitable.



Offline alvchua


  • Joined: Aug 2009

  • Drives: Old junks
  • Location: Adelaide
This thread isn't about lap times.... Leburpor is just trying to justify the inevitable.
I vote a Red 2011 GT-R! :thumbsup:
Forgiveness is easier to achieve than permission!



Offline leburpor

  • Loves Tom Cruise

  • Joined: Feb 2007

  • Location:
  • Drives:
Carmooch, I did wonder about the springs but I think it's helped keep the car more stable through the tighter turns. As much as I would like to keep the throttle up, the car is just not planted the way you are describing, not at Mallala anyway. I can see what you mean at a track like Phillip Island where I can quite comfortably keep my foot down through various sweepers and bends, but even then it's still twitchier than I what I can see from the GTR or GT3RS.

I know driver skill has a lot to do with it, and that's a main reason I asked the GTR owner to drive my car, and his times were close enough to mine. I've also had professional race drivers drive my car to set a benchmark for me where at Mallala they are about 1.5 secs faster, an's at Phillip Island they are about 2.5 secs faster. I'm no highly skilled driver, but am no slouch either.

The point of this thread was to highlight the huge performance difference between the GTR and my car. Am quite disappointed actually.. I didn't think I'd be too close to the GTR but didn't expect it to be this far off.



Offline leburpor

  • Loves Tom Cruise

  • Joined: Feb 2007

  • Location:
  • Drives:
I'll take the Techart mods and lowered springs off ur hands @ "mates rates" now that u r putting an order in for a GTR!  :D :p

Well you should have bought my car then :P it's still for sale ;)



Offline leburpor

  • Loves Tom Cruise

  • Joined: Feb 2007

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