Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical chat

Reply
 
LinkBack Thread Tools Display Modes
Old 06-14-2016, 09:07 AM   #1
Registered User
 
Join Date: Nov 2015
Location: Lake Anna, Va
Posts: 10
Garage
986s autocross alignment

Hey all, long time reader, first time poster. I know this has been covered time and time again in one form or another, but I'm still having trouble deciding on an alignment set up for my car. Here's the short of my setup...

2003 boxster s (74k miles) with stock suspension, stock 17" wheels and (currently) stock size Sumitomo HTR Z III tires, but I plan to upgrade the front to 225's before next season, I also have 17" wheels, 1/2" wider than stock, but still 255 / 205 setup with p-zero's I run on the street. I am awaiting delivery of one more part before I re-allign, but I'll have new(er) junk yard bilstein struts in the rear, and Pedro's Techno brace. Can anyone give any insight on alignment settings to help with the inherent understeer?

Right now I'm looking at as much negative camber in the front as the stock suspension will allow ( not much, I know), 0 toe front (maybe slight positive) to maintain some streetability, but in the rear I'm totally lost as to optimal settings for a starting point. I've got a mechanical background, and I understand the physics and geometry behind what changes affect the handling how, but I still need assistance in figuring it out. The more neutral the handling, the better, maybe leaning more towards overseer for a more "tossable" feel on the course. I know it might not be very possible with the stock set-up, as Porsche made the car to be "idiot proof", but I have future plans for changes as money allows (camber plates, coilovers, wider, stickier tires, etc.)

So, what it boils down to is...what's a good starting point for me to tell the shop to set my alignment to? The car is a weekend "play toy", car meet go-er, and autocrosser with plans to take in some DE events in the future...NOT an every day driver. That's what the Subaru is for haha.
Seal Grey Sasha 986 is offline   Reply With Quote
Old 06-14-2016, 09:31 AM   #2
Registered User
 
Join Date: Aug 2015
Location: Florida
Posts: 193
i have been auto-crossing since 2003. I am also an autocross instructor for the SPACE COAST PCA region. I have a 2.7 2002 Boxster and I am constantly top 5 in the region. The 2 best mods after improving your skills through tons and tons of auto crosses and auto crossing schools are tires # 1 and Alignment # 2.

Bridgestone 71R's can't be match unless you have a race compound.

Aligment. Max out negative at the front and i would add 1/16 or 1/32 of toe out per side
Rear: if you can afford too.. (Tires are expensive) go for negative 1.7 to 1.8 of camber per side.
Toe IN: 1/16 to 1/8 per side

Last edited by GatorLapis; 06-14-2016 at 09:40 AM.
GatorLapis is offline   Reply With Quote
Old 06-14-2016, 02:25 PM   #3
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: San Diego
Posts: 3,296
Garage
For starters. The Sumi HTR ZIII while a pretty good street tire, not a great AX or track tire.

Get RE-71's for your play wheels and keep the sumi's for street DD use. Another tire to consider for AX id the Dunlop Direzza Star Spec. Not as much performance as the RE-71, but competitive and will last longer.

As far as Alignment

Max out camber front and back
no toe in front and a smidge of toe in the back

Do a search and you will find a few threads on this
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region, 2014 Porsche Performance Driving School
2013 C300, 2010 Jetta 2011 Mazda 3, 1998 Windstar - Dog van , 2004 F-150 "Big Red"
JayG is offline   Reply With Quote
Old 06-14-2016, 05:47 PM   #4
Rennzenn
 
j.fro's Avatar
 
Join Date: Feb 2005
Location: Virginia
Posts: 1,355
Garage
Ditto on the other posts. Max negative camber all around, toe out in front, toe in on rear... But EQUAL side to side. Find a shop (chat with local PCA, SCCA, Cars & Coffee for recommendations) that knows both the Boxster and race alignment. The tech doing the job will make or break your alignment. To really be spot on, get bags of sand, dog food, whatever and put your weight in the driver's seat/ side.
__________________
Rennzenn
Jfro@rennzenn.com

Last edited by j.fro; 06-14-2016 at 05:50 PM.
j.fro is offline   Reply With Quote
Old 06-14-2016, 07:31 PM   #5
Registered User
 
Join Date: Nov 2015
Location: Lake Anna, Va
Posts: 10
Garage
Thanks for the input, guys. You're all pretty much pointing towards the set-up I was considering, but I just needed some re-afirmation. One question that I have though, considering how much camber the rear can adjust to compared to the front, couldn't maxing out the rear still result in understeer? I know the toe angle has allot to do with it as well (along with pretty much everything else). I'm looking at the print-out from my last alignment now... I had -.1 front, and -1.5 left and -2.2 right (bent, leaking strut, hence the new struts) and 0 toe front, .15 total positive rear. Thanks for the tire recommendations as well...that's on my list for next season, and I'm always open to suggestions for better rubber
Seal Grey Sasha 986 is offline   Reply With Quote
Old 06-14-2016, 07:41 PM   #6
Registered User
 
Join Date: Nov 2015
Location: Lake Anna, Va
Posts: 10
Garage
Quote:
Originally Posted by j.fro View Post
Ditto on the other posts. Max negative camber all around, toe out in front, toe in on rear... But EQUAL side to side. Find a shop (chat with local PCA, SCCA, Cars & Coffee for recommendations) that knows both the Boxster and race alignment. The tech doing the job will make or break your alignment. To really be spot on, get bags of sand, dog food, whatever and put your weight in the driver's seat/ side.
Jeffrey, you're always fast at my PCA autocrosses, so your opinion is one I value. Any suggestions for a good shop to give me guidance? Do you still do alignments in your garage? I'll finally be starting my job at BMW in the next week, and one of my mentors used to be a mechanic for the Synergy Porsche team, so I'll be picking his brain as well...
Seal Grey Sasha 986 is offline   Reply With Quote
Old 06-15-2016, 10:50 AM   #7
Registered User
 
Join Date: Aug 2015
Location: Florida
Posts: 193
Quote:
...The tech doing the job will make or break your alignment. To really be spot on, get bags of sand, dog food, whatever and put your weight in the driver's seat/ side.
Couldn't agree more... Use a performance shop that has been in service for years. Make sure they use a reputable alignment machine like hunter's and ask when it was calibrated. Less than 1 year is a max. If you go to a Dyno shop they will charge you 200 plus if you go to a shady mechanic it will be 59.99. The guys I go to charge me 80.00 plus tip for a one hour alignment with me sitting on the drivers seat.

Last edited by GatorLapis; 06-25-2016 at 12:38 PM.
GatorLapis is offline   Reply With Quote
Old 06-15-2016, 06:57 PM   #8
Yellow986S
 
Yellow986S's Avatar
 
Join Date: Apr 2013
Location: Bay Area
Posts: 184
For track alignment I have always gone with
Front: -2.8 camber and toe Out
Rear: -2.3 camber and toe Out

Any reason why you guys run toe Out in the front and toe In at the rear?

I thought the toe out in the rear would help with turn in.
Yellow986S is offline   Reply With Quote
Old 06-15-2016, 07:06 PM   #9
On the slippery slope
 
JayG's Avatar
 
Join Date: Mar 2014
Location: San Diego
Posts: 3,296
Garage
Quote:
Originally Posted by Yellow986S View Post
For track alignment I have always gone with
Front: -2.8 camber and toe Out
Rear: -2.3 camber and toe Out

Any reason why you guys run toe Out in the front and toe In at the rear?

I thought the toe out in the rear would help with turn in.
Nice settings, but those won't happen with a stock suspension
Around .9 front and 1.8 max rear is all you get

Yes, zero toe in the front and a smidge of toe out in the back
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region, 2014 Porsche Performance Driving School
2013 C300, 2010 Jetta 2011 Mazda 3, 1998 Windstar - Dog van , 2004 F-150 "Big Red"
JayG is offline   Reply With Quote
Old 06-16-2016, 01:22 AM   #10
Rennzenn
 
j.fro's Avatar
 
Join Date: Feb 2005
Location: Virginia
Posts: 1,355
Garage
Toe out in the front helps with turn in. Toe in in the rear keeps the car more stable at speed.
__________________
Rennzenn
Jfro@rennzenn.com

Last edited by j.fro; 06-16-2016 at 01:27 AM.
j.fro is offline   Reply With Quote
Old 06-19-2016, 04:54 PM   #11
Registered User
 
Join Date: May 2011
Location: weehawken nj
Posts: 240
I'm running

Front- Total toe out 1/4"
Camber -3.4

Rear- Zero toe
Camber -3.0

Running on a square set of 275 DOT legal slicks, K sport coilovers and no rear bar.

Its interesting to see what everyone else is running.
Bigsmoothlee 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 10:39 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