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914World.com _ 914World Garage _ tirepressure for goodyear R250 ???

Posted by: SirAndy May 21 2005, 08:14 PM

anyone now what's a good baseline (cold) for my goodyear R250 racing schlicks?
never ran them before ...

24 cold sound about right?

HELP!
Andy

Posted by: nebreitling May 21 2005, 10:10 PM

i think 60 cold sounds about right, andy.

Posted by: J P Stein May 21 2005, 10:50 PM

When I asked this same Q for mine, I got 16 to 24 lbs. I did 22 but have no clue if that was gud.....other than they didn't roll off the rims or explode

Posted by: SirAndy May 21 2005, 11:05 PM

QUOTE (nebreitling @ May 21 2005, 09:10 PM)
i think 60 cold sounds about right, andy.

Posted by: SirAndy May 21 2005, 11:06 PM

QUOTE (J P Stein @ May 21 2005, 09:50 PM)
When I asked this same Q for mine, I got 16 to 24 lbs. I did 22 but have no clue if that was gud.....other than they didn't roll off the rims or explode

humph ...

i guess i'll find out tomorrow!
Andy

Posted by: Racer Chris May 22 2005, 12:28 AM

On the track about 18-20 cold.
At an autocross probably 23-24 cold.
They won't feel good until the last run probably.

Posted by: redshift May 22 2005, 12:31 AM

Ooops! Chris meant kilos Andy!

M

Posted by: Racer Chris May 22 2005, 12:34 AM

QUOTE (redshift @ May 22 2005, 02:31 AM)
Chris meant kilos Andy!

lol, goodnight Miles.

Posted by: nine14cats May 22 2005, 11:01 AM

Hi Andy,

With those slicks on my car I was running 21 to 22lbs cold and I'd stick around 24lbs to 25 lbs hot. My car was a little lighter than yours but that's where I ended up.

I hope that helps!

Bill P.

Posted by: SLITS May 22 2005, 11:07 AM

Race car at 2200 lbs....18 - 19 hot (Willow Springs) to get full footprint (we were using Nitrogen in tires too). Pressure settings were obtained thru hot laps and a tyre pyrometer.

Posted by: TimT May 22 2005, 12:12 PM

we start our car with 16lbs front 19lbs rear

Posted by: SirAndy May 22 2005, 07:33 PM

started out at 19lbs all around (cold) ... they went up to 21lbs after they heated up.

i was fighting understeer all morning so i dropped them down to 17lbs in the front and 19lbs in the rear.
which worked pretty well!

in fact, i think trekkor took a picture of me on 2 wheels! that was damm scary there for a second.
i went through a tight right hand turn when all the sudden, i see the pass. front fender come up, blocking my view ...

disconnected the sway bar for the afternoon runs, which helped with the understeer but made the back a bit squirly. still managed to put down a good run.

back to the drawing board! time to get rid of those soft 180lbs springs in the rear.
i'm thinking 250lbs ...
Andy

Posted by: 9146R May 23 2005, 02:23 PM

Good tires, better driver...man, you cooked out there yesterday. Watching you come thru the back corners was unreal...carried a ton of speed. You stuck like glue with those tires.

Posted by: trekkor May 23 2005, 09:59 PM

Andy you will be VERY fast. No doubt.

As soon as your suspension is sorted, that is.
I can't wait to see you bidding for TTOD. Very real scenario.

Power is good, but even I can see it's tires, tiars, tyres...

Nice driving, Sir.

KT

Posted by: SirAndy May 23 2005, 10:21 PM

QUOTE
Good tires, better driver...man, you cooked out there yesterday.

QUOTE
Nice driving, Sir.

thanks for the fish guys!

this was my first time out in over a year and it was quite a "leap" from my tired old stock 1.8L and cheap street tires to a motor with powah and schlicks !!!
i like it!

the engine was running great and i had no problem braking those schlicks loose at the start or in the corners. in fact i was playing with that to counteract some of the understeer. nice!

now, of course, i want a limited slip ...
will this ever stop?

talked to brad and he confirmed what i had suspected for a while, my front shocks are completely TOAST. those are still the original boges that came with the 911 front end.
they're now 20 years old!

i guess i have to sell myself on the street corner to be able to afford a nice set of adjusteable konis all around with some nice 250lbs springs in the back ...
Andy

Posted by: trekkor May 23 2005, 10:33 PM

Are 250#'s enough?

I thought that was a bold move, removing the front bar like you did.
It worked!

Why don't you go with more rear schpring? ( ask Bill P. )
wasn't he running 300-400 #er's depending on the track?

With monster rear spring rate you could run a monster front bar...

KT

Posted by: nebreitling May 23 2005, 10:39 PM

yup -- the car looked really good, andy, as did your driving. i was dumbfounded how hot you were able to take those corners. the car just STUCK. (well, 2 wheels usually stuck).

let me know if you need a hand replacing those shocks or springs or anything.

Posted by: grantsfo May 23 2005, 11:55 PM

QUOTE (nebreitling @ May 23 2005, 08:39 PM)
yup -- the car looked really good, andy, as did your driving. i was dumbfounded how hot you were able to take those corners. the car just STUCK. (well, 2 wheels usually stuck).

let me know if you need a hand replacing those shocks or springs or anything.

Nathan and I were watching you from similar place on the course. Those tires stick like frickn glue!!! It seemed like you could do anything and not lose traction. Your car stayed better hooked up than the race cars out there. You do need to sort out your suspension. You were lifting that rear wheel and losing ability to put down full power on the exit of some corners when you took off the front bar. ...the tires that were on the ground seemed to be gripping very nicely

Posted by: SirAndy May 24 2005, 12:12 AM

yepp. i could feel that loss of grip in the rear in some corners, the inside tire would just spin freely (doh!) ...

another thing i need to do: get rid of some of the negative camber!
brad took tire temps and i was cooking the inside of all 4 corners. you can actually see it on the tires too, the inside is well worn, the outside is still prestine ...

them tires like 0.8 neg., right now, i'm close to 2 deg. neg. ...

i'll figure it out, eventually ...
Andy

PS: anybody wants to take my car for a spin next time? just ask ...