Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 05-17-2008, 01:44 PM   #1
Track rat
 
Topless's Avatar
 
Join Date: Nov 2006
Location: Cucamonga CA
Posts: 3,658
Garage
New Understeer Problem

A little background first:
98 Box 2.5L, 75k miles, tires PS2's 225/45/17Front, 255/40/17 rear, performance alignment Camber -.7 deg. Front, - 1.4 deg. rear, zero toe front and rear. Two years Auto-X / track experience.

Last year in Oct. my rear tires were down to the wear bars, lap times were suffering a bit and I had a few spins on corner exit with snap oversteer on rough surfaces. The tires were actually 4 years old and I figured the rears were toast. Front tires were only 1/2 gone and still felt ok. I put new PS2 rubber on the rear and added a lower stress bar to reduce chassis flex. Now the rear of the car is completely predictable. I feel I can put the rear exactly where I want it with my right foot and no surprises. I am carrying higher speeds and some high 2nd gear turns are now moderate 3rd gear. So far so good.

The problem:
Now on downhill off camber turn in's and carousel turns she plows like nobody's business. I feel like I am crawling through these sections. Even if I really pitch the rear out the front just howls through. I am turning faster times. It just looks and feels really stupid when it plows.

Possible solutions:
A. Learn how to drive.
B. Lose those front tires cuz they're 4 yr old hockey pucks.
C. Add a front strut tower brace to balance front/rear chassis stiffness and precision.
D. Fine tune the alignment.

Anything I am missing here?? Your input is appreciated. The more track and Auto-X experience the better.

__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor
Topless is offline   Reply With Quote
Old 05-17-2008, 06:49 PM   #2
Porscheectomy
 
Join Date: Mar 2006
Location: Seattle Area
Posts: 3,011
How about dropping the front tire pressure a bit or a little softer front sway bay (or stiffer rear)?
blue2000s is offline   Reply With Quote
Old 05-17-2008, 08:12 PM   #3
Track rat
 
Topless's Avatar
 
Join Date: Nov 2006
Location: Cucamonga CA
Posts: 3,658
Garage
I did vary tire pressures to see if it would help. Started at 32 cold, tried 34 cold...no change, went to 29 cold... a little better. Both days were unusually cold at around 55 degrees F. Probably worst conditions for old front tires. It was difficult to get heat in the tires and the track was nearly always cold. About 3pm on the second day the sun came out and warmed the track. We saw a lot more grip but still had understeer in the suspect corners.
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor
Topless is offline   Reply With Quote
Old 05-17-2008, 09:20 PM   #4
Registered User
 
Join Date: Apr 2006
Location: Fl
Posts: 91
Get new front tires, they just cant match up to your new rears. I used to have really cheap tires all around and the car acted like a snow plow. It sounds like you have enough experience to not be driver error.
__________________
Kyle Tarr

2000 Porsche Boxster
-Straight-piped from cats back
-MOMO race seats
-Schnell short shifter
-RJS Harness
-High flow intake
-Eibach lowering springs
-Bilstein sport shocks

Last edited by kyle986driver; 05-17-2008 at 09:22 PM.
kyle986driver is offline   Reply With Quote
Old 05-18-2008, 03:26 PM   #5
Track rat
 
Topless's Avatar
 
Join Date: Nov 2006
Location: Cucamonga CA
Posts: 3,658
Garage
Ok, it seems the consensus is to put fresh tires on the front to match the grip in the rear. The old PS2's are just fine on public roads but protest too much when driven hard around the track.

So now the $$ question: Do I put a new set of PS2's the same size 225/45/17, upsize to a PS2 245/40/17 or go with a little stickier tire like the Advan Neova in 225/45/17? Any thoughts? Front wheels are 17x8 so both sizes would fit.

__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor
Topless 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 03:30 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page