Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC General > Motorsports

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 05-10-2004, 11:31 AM   #1
STI-C-YA
Scooby Newbie
 
Member#: 56825
Join Date: Mar 2004
Location: Guatemala City
Vehicle:
2003 STI
Silver/Gold/Euroversion

Default Slick Tires In Racing

Hi everyone!

I have this question. I'm racing my Sti in the circuit track every 45 days and I want to use slick tires for that. Someone told me that slick tires may damage the drive train of my car due to the amount of pressure that the car puts in it. I want to know if this is true because I also use my car for daily drivig and I dont want to damage it. Thanks
* Registered users of the site do not see these ads.
STI-C-YA is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-10-2004, 11:47 AM   #2
jmott
Scooby Guru
 
Member#: 6713
Join Date: May 2001
Chapter/Region: TXIC
Location: Houston TX USA
Vehicle:
2007 Prius
brown

Default Re: Slick Tires In Racing

Quote:
Originally posted by STI-C-YA
Hi everyone!

I have this question. I'm racing my Sti in the circuit track every 45 days and I want to use slick tires for that. Someone told me that slick tires may damage the drive train of my car due to the amount of pressure that the car puts in it. I want to know if this is true because I also use my car for daily drivig and I dont want to damage it. Thanks

track driving puts a whole lot of abuse on your car and may damage it, race tires or not.

however, the STI can put up with extremely sticky tires, that would be the last of my concerns.

a good track tire is the Kumho Victoracer. If you want to step up to something better and more expensive, then try the hoosier road race DOT tires. (R3S04s? I think they are called)

neither of these are techinically 'slicks' (they have token grooves), but most track day guys run tires like these.
jmott is offline   Reply With Quote
Old 05-10-2004, 02:42 PM   #3
STI-C-YA
Scooby Newbie
 
Member#: 56825
Join Date: Mar 2004
Location: Guatemala City
Vehicle:
2003 STI
Silver/Gold/Euroversion

Default Re: Re: Slick Tires In Racing

Thanks a lot for your advise. I will like to know wich things I need to check after each race to try to keep the car in optimum conditions. Thanks
STI-C-YA is offline   Reply With Quote
Old 05-10-2004, 03:35 PM   #4
jmott
Scooby Guru
 
Member#: 6713
Join Date: May 2001
Chapter/Region: TXIC
Location: Houston TX USA
Vehicle:
2007 Prius
brown

Default Re: Re: Re: Slick Tires In Racing

Quote:
Originally posted by STI-C-YA
Thanks a lot for your advise. I will like to know wich things I need to check after each race to try to keep the car in optimum conditions. Thanks
brake pads
brake rotors

might want to step up to a good DOT4 brake fluid, might change your tranny and diff oil more often.

be sure to run high quality gasoline at the track, watch engine temps and such. If you can buy 100+ octane gas at the track it wouldn't be a bad idea.

Don't do too many hard laps in a row.
jmott is offline   Reply With Quote
Old 05-10-2004, 04:01 PM   #5
STI-C-YA
Scooby Newbie
 
Member#: 56825
Join Date: Mar 2004
Location: Guatemala City
Vehicle:
2003 STI
Silver/Gold/Euroversion

Default



Thanks again. Actually I'm using Motul DOT 4 brake fluid, Red Line's Water Wetter along with a Crucial Racing Thermostat and 98 Octane Gas. I also have my Camber set to -1. What I been having are high raises in the preasure of the tires, sometimes more than 10 pounds. I heard someone said that inflating them with nitrogen will reduce this. Is it true?
STI-C-YA is offline   Reply With Quote
Old 05-10-2004, 09:54 PM   #6
jmott
Scooby Guru
 
Member#: 6713
Join Date: May 2001
Chapter/Region: TXIC
Location: Houston TX USA
Vehicle:
2007 Prius
brown

Default

Quote:
Originally posted by STI-C-YA


Thanks again. Actually I'm using Motul DOT 4 brake fluid, Red Line's Water Wetter along with a Crucial Racing Thermostat and 98 Octane Gas. I also have my Camber set to -1. What I been having are high raises in the preasure of the tires, sometimes more than 10 pounds. I heard someone said that inflating them with nitrogen will reduce this. Is it true?
you can crank the camber all the way to -2.5 or so if you want =)
jmott is offline   Reply With Quote
Old 05-10-2004, 10:09 PM   #7
afpdl
Scooby Guru
 
Member#: 26361
Join Date: Oct 2002
Chapter/Region: TXIC
Location: Sugar Land (Houston), Tx
Vehicle:
My shenanigans are
cheeky and fun

Default

Quote:
Originally posted by STI-C-YA
What I been having are high raises in the preasure of the tires, sometimes more than 10 pounds. I heard someone said that inflating them with nitrogen will reduce this. Is it true?
The pressure raising in tires comes from moisture in the air thats in the tires, filling them with an inert gas like nitrogen instead will get rid of the pressure fluxuation dramatically.
afpdl is offline   Reply With Quote
Old 05-10-2004, 10:13 PM   #8
D_REX
Scooby Specialist
 
Member#: 8945
Join Date: Aug 2001
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
MY02 WRX
Blue

Default

Quote:
Originally posted by afpdl
The pressure raising in tires comes from moisture in the air thats in the tires, filling them with an inert gas like nitrogen instead will get rid of the pressure fluxuation dramatically.
]

PV = nRT

This s the ideal gas law, if temperature increases so will the product of pressure and volume.

I'm trying to figure out how moisture would effect the pressure rise due to temperature. I'm really not very clear on it. You have any links to info?

Thanks,
Dustin
D_REX is offline   Reply With Quote
Old 05-10-2004, 10:33 PM   #9
TyrannoSullyRex
Scooby Guru
 
Member#: 8891
Join Date: Aug 2001
Chapter/Region: International
Location: Houston, TX
Vehicle:
2002 WRX Silver
'02 SV650

Default

yep not moisture, just the good ole PV=nRT, nitrogen (a major component of breathable air, ~70%) is more temperature stable than oxygen (IIRC).


Do a few laps, your tires will heat up to operating temp and then adjust pressures. They will stay (or at least stay close) to that pressure when the tires are hot for subsequent laps.
TyrannoSullyRex is offline   Reply With Quote
Old 05-10-2004, 10:57 PM   #10
speedyHAM
Scooby Specialist
 
Member#: 48377
Join Date: Nov 2003
Chapter/Region: MWSOC
Location: "They eat fish soaked in lye"
Vehicle:
1996 Gutted, built
XP class Impreza L

Default

If you have moisture in your tires some of it will be in liquid form as small droplets on the inside of the tire for normal driving. Hard driving will heat these droplets into vapor, which makes a huge difference in the pressure in the tires. If you fill your tires at a typical gas station air line you can usually see water droplets coming out of the line when you start the air flowing. That water in your tires causes the pressure build up.
speedyHAM is offline   Reply With Quote
Old 05-11-2004, 09:05 AM   #11
D_REX
Scooby Specialist
 
Member#: 8945
Join Date: Aug 2001
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
MY02 WRX
Blue

Default

Quote:
Originally posted by speedyHAM
If you have moisture in your tires some of it will be in liquid form as small droplets on the inside of the tire for normal driving. Hard driving will heat these droplets into vapor, which makes a huge difference in the pressure in the tires. If you fill your tires at a typical gas station air line you can usually see water droplets coming out of the line when you start the air flowing. That water in your tires causes the pressure build up.
This is the part that's not so clear. Water droplets represent a reduction in volume, water is essentially noncompressible at these pressures. When in turns to vapor you trade off that volume reduction for an increase in the n term of the ideal gas law. So does this produce a net increase in pressure???? And if so is it greater than the increase due to just the temperature change???
D_REX is offline   Reply With Quote
Old 05-11-2004, 03:45 PM   #12
jprowland
Scooby Specialist
 
Member#: 7298
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Mckinney, TX, USA
Vehicle:
2008 STI Black
2002 WRX Wagon White

Default

Speedyham has the right of it...Rule of thumb #1 for thermodynamics, air is not an ideal gas and does not behave according to the ideal gas law (my professor used to mark problems with air wrong if we used the ideal gas law!) Too many impurities, like moisture which expands faster than gas when heated. That's why something like pure nitrogen works better...

--
JP Rowland jeremyrowland -at- mac.com
Co-Driver, Wazoo Racing Subaru WRX, PGT
http://homepage.mac.com/jeremyrowland
jprowland is offline   Reply With Quote
Old 05-11-2004, 03:54 PM   #13
D_REX
Scooby Specialist
 
Member#: 8945
Join Date: Aug 2001
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
MY02 WRX
Blue

Default

So, how different is dry air than nitrogen? Dry air is much easier to get than nitrogen.
D_REX is offline   Reply With Quote
Old 05-11-2004, 05:46 PM   #14
STI-C-YA
Scooby Newbie
 
Member#: 56825
Join Date: Mar 2004
Location: Guatemala City
Vehicle:
2003 STI
Silver/Gold/Euroversion

Default

This gets more interesting with every reply
STI-C-YA is offline   Reply With Quote
Old 05-11-2004, 10:45 PM   #15
hillman
Scooby Specialist
 
Member#: 1303
Join Date: Apr 2000
Chapter/Region: MWSOC
Location: Westmont, IL, USA
Vehicle:
2007 Not a Subaru,
thank God.

Default

Quote:
So, how different is dry air than nitrogen? Dry air is much easier to get than nitrogen.
With dry air, I have to work very, very hard to see much pressure increase. Like 10 laps per pound of increase.

Nitrogen may be better, but you have to be running stints longer than a sprint race to find out.
hillman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Used (cheap) DOT race tires in Cent FL Oceanus South East Region Forum 14 03-18-2008 06:12 AM
Wood bridge + rain + slick tires Howl Off-Topic 15 09-22-2007 02:39 PM
racing slick tires adofly Motorsports 11 07-19-2007 01:49 AM
Attn: Luke - Help with Slick Tire Sizing zoomfactor Tire & Wheel 2 09-11-2005 09:11 PM
How do I scrub/break in race tires? N8S_WRX Brakes, Steering & Suspension 4 10-11-2001 07:33 PM

All times are GMT -4. The time now is 10:17 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.