Mr Preuninger made me buy a pyrometer!!
07-05-2011, 01:21 PM
#20
Had a long chat with Andreas at the Porsche Cafe at Goodwood on Saturday. I was very keen to ask him a few questions:
Q1) Why did my car have to have it's rear ARB bushes and drop links changed at the 12,000 service (as in the service manual)?
A1) They had found that the material that the bushes were made from could 'dry' over time and could create a notchy movement of the ARB causing irratic rear axle movement under load. Changing the bushes and the droplinks at 12,000 and 24,000 miles illiminates this risk, long before it could occur.
Q2) Are the new Centre Locks the same?
A2) Yes - exactly. Just the 500Nm script removed. He faught against this but the legal people wanted it changed.
Q3) My ABS seems to activate very early compared to other cars I've driven.
A3) He asked what Geo I had. I told him 3 degs up front and 2.5 at the rear. He almost spat his dummy and asked why you track boys go so extreme on road tyres!!! He said that these figures would cause early ABS activation and upset the balance of the car. He said that the 1'30" that is in the manual has been proven by his team to offer the fastest track set up!
He did however say that the factory settings should be checked when new as he thought the accuracy of the fac setting might be a little suspect!!
So - I've bought a probe type pyro and will get some figures this weekend. I'll be torn between cooling the PCCBs down and getting the tyres in hot!!!! I feel a rather faster in lap coming on - with no brakes!!!!
Thanks Andreas!!
Q1) Why did my car have to have it's rear ARB bushes and drop links changed at the 12,000 service (as in the service manual)?
A1) They had found that the material that the bushes were made from could 'dry' over time and could create a notchy movement of the ARB causing irratic rear axle movement under load. Changing the bushes and the droplinks at 12,000 and 24,000 miles illiminates this risk, long before it could occur.
Q2) Are the new Centre Locks the same?
A2) Yes - exactly. Just the 500Nm script removed. He faught against this but the legal people wanted it changed.
Q3) My ABS seems to activate very early compared to other cars I've driven.
A3) He asked what Geo I had. I told him 3 degs up front and 2.5 at the rear. He almost spat his dummy and asked why you track boys go so extreme on road tyres!!! He said that these figures would cause early ABS activation and upset the balance of the car. He said that the 1'30" that is in the manual has been proven by his team to offer the fastest track set up!
He did however say that the factory settings should be checked when new as he thought the accuracy of the fac setting might be a little suspect!!
So - I've bought a probe type pyro and will get some figures this weekend. I'll be torn between cooling the PCCBs down and getting the tyres in hot!!!! I feel a rather faster in lap coming on - with no brakes!!!!
Thanks Andreas!!
07-05-2011, 01:31 PM
#21
Advanced
I use an Anritsu Pyrometer with a 1000 C max temp and recalibration capability.
There is a difference between cheap and expensive pyrometers (mainly the quality of the thermo-sensor, the length of the probe, accuracy, etc...)
A good one (like the ones used by pro-teams, etc...) will run you around $1500 or so for the unit and sensor. For inexpensive and foolproof temperature checking, rotor thermal paint is always great.
The Pyrometer is only as good as the person behind it, and the quality of the equipment. Brake temperatures need to be logged right as the car comes to a stop in "pit lane". Also, the pyrometer readouts can change on many variables (length of pit lane, car's position in pit lane, etc...)
For the average DE driver, and for a lot of pro-teams even, thermopaint is still the most trusted way of checking rotor temperatures (on steel and C-Composite disks).
There is a difference between cheap and expensive pyrometers (mainly the quality of the thermo-sensor, the length of the probe, accuracy, etc...)
A good one (like the ones used by pro-teams, etc...) will run you around $1500 or so for the unit and sensor. For inexpensive and foolproof temperature checking, rotor thermal paint is always great.
The Pyrometer is only as good as the person behind it, and the quality of the equipment. Brake temperatures need to be logged right as the car comes to a stop in "pit lane". Also, the pyrometer readouts can change on many variables (length of pit lane, car's position in pit lane, etc...)
For the average DE driver, and for a lot of pro-teams even, thermopaint is still the most trusted way of checking rotor temperatures (on steel and C-Composite disks).
07-05-2011, 01:50 PM
#22
Rennlist Member
I'd rather have even tire wear, instead of premature cording anyday of the week. Andreas isn't paying for his tires.....
I'm open to opinions on other settings.
I only use my stick it into the rubber pyrometer for tire temps only. I know when the brakes are too hot ;-)
My car is daily driver, so for that reason and better tire wear on track I go medium settings.
Hoosier rear needed -2.5. Perfect even wear, temps very close inner middle outer.
When going to Toyo, I dropped rear camber to -2.1 ->1.9 ->1.7 still wearing a bit on the inside, but left them there.
Front I don't car much because they barely wear anyway so I left them at -2.5 seems to wear even.
Lowered the car 10mm front and rear.
Zero toe front. Toe out would be a bit better but it gets annoying on the street. It works OK with bar full soft.
Rear toe; 2mm in each side, bar middle. With new tires maybe the rear bar could be full stiff, but usually rear tires are crappy, so I leave it in the middle.
CUP lip, Max wing + Gurney and CUP 38/52 LSD.
With this setup, I have to make sure the front is planted before going on the throttle on tight corners, so maybe most other drivers might hate it because it will understeer a lot if you drive understeery.
With Hoosiers the bars might have to be different.
07-05-2011, 02:56 PM
#23
Drifting
07-05-2011, 05:19 PM
#25
Racer
Thread Starter
I'll be driving the car ar Donington this weekend. Hard. Will see how 3' and 2'30" takes it's toll on temps and make a call after.
Let you know how I get on.
07-05-2011, 06:11 PM
#26
Rennlist Member
07-05-2011, 06:42 PM
#27
Rennlist Member
I always go with an alignment which cheats toward even tire wear. Sure, the pyrometer doesn't lie, but I'd much rather go with an alignment which is fun to drive (no understeer) and gives me good wear which doesn't require tons of rotation or flipping.
You also have to remember that you gain dynamic camber on less stiffly sprung cars, so the camber needed may actually be less than on a more stiffly sprung car, depending on the driver. I love RA1's and NT01's, but with my 700#/800# springs, and big bars, they need lots of camber to wear evenly because of softer sidewalls.....and no suprise when the wear is even, that the handling is very neutral.
You also have to remember that you gain dynamic camber on less stiffly sprung cars, so the camber needed may actually be less than on a more stiffly sprung car, depending on the driver. I love RA1's and NT01's, but with my 700#/800# springs, and big bars, they need lots of camber to wear evenly because of softer sidewalls.....and no suprise when the wear is even, that the handling is very neutral.
07-05-2011, 11:34 PM
#28
Very much dependent upon tire choice. And as Mvez noted- the stiffness of the car. Much angst and gnashing of teeth as one driver has one comment and another tries to make sense of it for his set-up. Wrong! And no need... only look at you own specific situation !
My 2RS is perfectly fine with stock alignment settings ("geometry" for my Euro friends
) on its Michelin Pilot Sport Cups. No need at all for deviation from suggested factory settings. It handles quite neutral out of the box. Voila' and lovely. I would not, and have not, changed a thing.
Running the Trofeo's (on my 3RS, on an adjustable coilover set-up)...well they love the camber and don't bite worth a crap unless you have -2.4 or more. As Adam mentioned, the Hoosier slicks love the camber as well.
For a stock car on stock tires, the suggested factory camber is a very good place to be for a variety of reasons. Try and fix under/oversteer with ARB's not camber. If you don't know or understand how to tune with your ARB's then you shouldn't be adjusting anything on the suspension. Invest the time and effort into learning all the ways you can tune your cars handling.
My 2RS is perfectly fine with stock alignment settings ("geometry" for my Euro friends
) on its Michelin Pilot Sport Cups. No need at all for deviation from suggested factory settings. It handles quite neutral out of the box. Voila' and lovely. I would not, and have not, changed a thing.Running the Trofeo's (on my 3RS, on an adjustable coilover set-up)...well they love the camber and don't bite worth a crap unless you have -2.4 or more. As Adam mentioned, the Hoosier slicks love the camber as well.
For a stock car on stock tires, the suggested factory camber is a very good place to be for a variety of reasons. Try and fix under/oversteer with ARB's not camber. If you don't know or understand how to tune with your ARB's then you shouldn't be adjusting anything on the suspension. Invest the time and effort into learning all the ways you can tune your cars handling.
07-05-2011, 11:59 PM
#30
Race Director
Savy....for the stupid in me....what is ARB's? Anti Roll Bars?