Experiment Request: Traction at 50 psi vs 30 psi - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 12-16-2007, 09:54 AM   #11
Registered Member
 
brucepick's Avatar
 
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
No takers yet who might run the test?
__________________

__________________
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.

Now driving '97 Civic HX; tires ~ 50 psi. '89 Volvo 240 = semi-retired.
brucepick is offline   Reply With Quote
Old 12-16-2007, 12:10 PM   #12
Registered Member
 
psyshack's Avatar
 
Join Date: May 2006
Posts: 443
Country: United States
I willing to do the test. Just thinking about where I could do it. Would want to do it in both the Accord and Mazda3. The Accord with its LLR Micky's and the Mazda with its Goodyear RS-A's.

Let me ponder this a bit.
__________________

__________________
09 HCHII, w/Navi
07 Mazda3 S Touring, 5MT
Mild Hypermiler or Mad Man?
psyshack is offline   Reply With Quote
Old 12-16-2007, 12:13 PM   #13
Registered Member
 
DarbyWalters's Avatar
 
Join Date: Oct 2007
Posts: 376
Country: United States
As long as temps (tire and surface) are equal starting out...the lower inflated tire will out brake the higher inflated tire (as long as they are both within the acceptable range).

Be careful not to "flat spot" a tire and ruin it~
__________________
2006 Jeep Liberty CRD...Founder of L.O.S.T.
OME 2.25" Lift w/ Toyo Open Country HTs 235/75/16s
ASFIR Alum Eng/Tranny/Transfercase/Fuel Skids
2002 Air Box Mod...Air Tabs (5) on Roof...(3)each behind rear windows
Partial Grill Block with Custom Air Scoop and 3" Open Catback Exhaust
Lambretta UNO150cc 4 Stroke Scooter



DarbyWalters is offline   Reply With Quote
Old 12-16-2007, 12:16 PM   #14
Registered Member
 
skewbe's Avatar
 
Join Date: Jan 2007
Posts: 771
Country: United States
The comments on this site suggest that there is an optimum psi for performance, not too much and not too little. I'd rather have the extra mpg myself on the street. 'Course if everyone on the world maintained 36 psi we would save a lot of gas, not enough though.

http://grassrootsmotorsports.com/new...-vs-falken.php

Comments:
Set 1 baseline at 36 psi. Tires were at ambient temp to start.
Set 2 add 4 psi to existing pressure and performance drops by 1-2 tenths.
Set 3 drop 4 psi back out to bracket the test and performance is restored.
Set 4 drop another 3 psi and performance drops slightly. Tire gets squirmy.
Set 5 drop another 4 psi and performance drops even more.
Set 6 back to previous best to bracket the test and performance is restored.
__________________
Standard Disclaimer
skewbe is offline   Reply With Quote
Old 12-16-2007, 12:21 PM   #15
Registered Member
 
JanGeo's Avatar
 
Join Date: Jan 2006
Posts: 2,442
Country: United States
Send a message via Yahoo to JanGeo
Roads around here are covered with ice and snow and it is raining - just shoveled the driveway for half an hour to make 2 tire tracks and moved my xB away from a tree limb in preparation for the wind storm due later tonight.
JanGeo is offline   Reply With Quote
Old 12-16-2007, 02:38 PM   #16
Registered Member
 
VetteOwner's Avatar
 
Join Date: Mar 2007
Posts: 1,546
Country: United States
Quote:
Originally Posted by Erdrick View Post
M+S most certainly is the designation for snow tires. It stands for Mud and Snow. They aren't rated the same as regular (all season and most other types of tires) tires, and are missing things like tread life ratings.

While I haven't done an actual ABA test on this, I can say that my braking distances did increase after pumping up my tires. It would be interesting to see someone's results after doing this test, but there really is no reason to debate the issue. Harder tires roll better, and more rolling resistance is what you want to help you stop your car. Thus, tires with low rolling resistance that are pumped up to a high pressure will take a longer distance to stop than higher rolling resistance tires that aren't pumped up that high.

I do want to see some actual data on this though...

no theres a difference bewteen M+S and just snow tires. snow tires are made out of a soft rubber and usually pretty block like tread. they wear down VERY fast on dry pavement, but offer excelent grip on snow.

M+S aka all season are well all season tires, meaning they generally last alot longer than snow tires but not the longest lastign tires out there. thier not excelent at any one surface but a good grip on a variety of surfaces(dry, wet, snow, loose (liek mud/ gravel roads etc)

i can take a picture later of different treads(snow vs m+s) and u can visually see the difference
VetteOwner is offline   Reply With Quote
Old 12-16-2007, 03:19 PM   #17
Registered Member
 
kamesama980's Avatar
 
Join Date: Nov 2007
Posts: 742
Country: United States
Location: Columbus, IN, USA
Send a message via AIM to kamesama980 Send a message via Yahoo to kamesama980
All M+S means is that the grooves go from one side to the other and there's a lot of groove area. snow tires can be M+S or not, all seasons can be M+S or not. every tire I've owned has had the M+S designation along with all the DOT required ratings. M+S means little. the tires I'm using now are M+S rated but suck in the snow.

Again not ABA testing but when I've been to drifting and other autosport events (dry events), you never see tires under 45 psi unless someone forgot to check them. I tried at 30-35psi once and it sucked (and chewed the crap out of the tires) up the PSI to 50 and it's much easier to both break them free (less traction in back) and control the vehicle (less flex in front).

When there's some clear pavement I'll do some testing.
__________________
-Russell
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"
kamesama980 is offline   Reply With Quote
Old 12-16-2007, 07:14 PM   #18
Registered Member
 
brucepick's Avatar
 
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
Good to see a couple folks interested in testing this.
Thanks, psyshack and kamesama980.
__________________
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.

Now driving '97 Civic HX; tires ~ 50 psi. '89 Volvo 240 = semi-retired.
brucepick is offline   Reply With Quote
Old 12-17-2007, 05:46 AM   #19
Registered Member
 
psyshack's Avatar
 
Join Date: May 2006
Posts: 443
Country: United States
I want to do a 30 mph and 60 mph test groups.

Do the test with the tires warmed up. Meaning scrub them in for the first test then keep them warm with in reason thru out.

PSI on Mazda would be something like 34, 55, 34
PSI on Honda would be something like 34, 44, 34

Use chalk for a brake point marker, and stopping point for each car. So forth and so on.

Just need to find a safe place to do the test. Going to talk with the local airport auth. and see if I can do the testing out there. Small local airport. See if the good old boy network comes thru......
__________________
09 HCHII, w/Navi
07 Mazda3 S Touring, 5MT
Mild Hypermiler or Mad Man?
psyshack is offline   Reply With Quote
Old 12-17-2007, 08:05 AM   #20
Senior Member
 
Mayhim's Avatar
 
Join Date: Jun 2012
Posts: 179
Country: United States
If you're looking for quantification, carry on. If you're looking to find out if it's a fact, it is.

All you have to do is see how much wheelspin you can get at a high rpm clutch dump with 30 psi then at 50 psi.

High psi = no tire/tread deformation and conformation to the road = no grip = lots of wheelspin. Ask anyone who has a hotrod.
__________________

Mayhim 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problems with site layout. DTMAce Fuelly Web Support and Community News 2 01-07-2012 02:50 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 06:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.