Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
hkspwrsche's Avatar
 
Join Date: Jan 2004
Location: Richmond,Va
Posts: 910
Porsche Crest What are YOUR street car alignment specs????

Thats no track and only street at euro ride height?? Having trouble as listed in the other thread with only the front camber really. Cant get much more positive than -1.5 in the front... dont know why.. Everything else in street spec.. for the alignment machine.

thanks,
__________________
Harold
Old 10-28-2004, 05:17 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)
Registered User
 
Jeff Alton's Avatar
 
Join Date: Jan 2003
Location: Langley,B.C.
Posts: 9,861
That is kinda weird. On a lot of 911s, -1.5 is the MAX negative that can be achieved. Has your car been hit??

Jef
__________________
Turn3 Autosport- Full Service and Race Prep
jeff@turn3autosport.com
997 S 4.0, Cayman S 3.8, Boxster 2.7, Boxster S race car, 996, 955 Cayenne TT, 958 Cayenne TT
Old 10-28-2004, 07:47 PM
  Pelican Parts Technical Article Directory    Reply With Quote #2 (permalink)
Registered User
 
Join Date: May 2001
Location: Peoples Republic of Long Beach, NY
Posts: 21,149
I run about -.5 and a slight toe in myself. I watch new tire wear and wear flat across the thread. It's a balance for your routine with the rear alignment imo.
__________________
Ronin LB
'77 911s 2.7
PMO E 8.5
SSI Monty
MSD JPI
w x6
Old 10-28-2004, 08:07 PM
  Pelican Parts Technical Article Directory    Reply With Quote #3 (permalink)
Registered User
 
hkspwrsche's Avatar
 
Join Date: Jan 2004
Location: Richmond,Va
Posts: 910
The guy from elephant racing said this was a common problem for lowered cars trying to stay near street specs?
I guess it wasnt unusual sounding to him. I cant imagine there would be something bent that would allow the exact same amount of adjustment for both sides in the front...Thought something else could be figured out. I might just try to egg out the slots and get to about -1.0 degree and then make the rear -1.0 degree.
__________________
Harold
Old 10-29-2004, 06:21 AM
  Pelican Parts Technical Article Directory    Reply With Quote #4 (permalink)
Somatic Negative Optimist
 
Gunter's Avatar
 
Join Date: Mar 2002
Location: Winlaw, BC, Canada
Posts: 7,171
Garage
The whole idea behind alignments is to give the best possible adhesion to the road for straight-driving and cornering. For a street car, 1deg negative makes no sense. If you watch the wear-pattern, you'll notice a definate wear on the inside edge. That tells you, that you don't have a full foot print on the road surface. There goes your performance. The rear tires are even wider than the front ones, with -1deg, you are definately running on the inside edge. I tried different settings and found 3/4deg front, 1/2deg rear, with a 1/16" toe-in front, 0" rear, the best for performance and tire wear for mildly aggressive street driving. Fender height is 25inch front and 24.5inch rear. Track driving is a different story with different settings. Don't fall into the "Negative-camber-mania" accompanied by eccessive lowering. I am sure that there are many Porsches out there that have too much of either without any benefit other than bad tire-wear. Cheers.
__________________
1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.
Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".

Last edited by Gunter; 10-29-2004 at 10:18 AM..
Old 10-29-2004, 07:23 AM
  Pelican Parts Technical Article Directory    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Aug 2003
Location: Denver
Posts: 1,219
The best they could do on mine was -1.3 on the front passenger side. It appears that the PO slid it into a curb or something and bent the strut housing. Just got the housing fixed and it's at the alignment shop getting readjusted.
__________________
1999 996 C4 Cabriolet
1997 BMW M3 (Hail)
1985 928 S (Sold)
1982 SC Targa (Sold)
Old 10-29-2004, 07:44 AM
  Pelican Parts Technical Article Directory    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Join Date: Dec 1999
Location: Folsom CA USA
Posts: 1,390
Garage
I am running 24-5/8"" front, and 24-1/8" rear ride heights.
7 & 9" fuchs
Bridgestone RE730s in front (205/55)
RE750s in rear (245/45)

I drive aggressively on the street.
I also want good high-speed stability.
Initially I was running more negative front camber (-1.2), but I saw my inside tires wear.

Now my front outside tires are wearing slightly more than the rest of the front tires. I will try a slight toe-in change to toe-out.

My rears appear to be wearing evenly.

Front
I have -.7 and -.6 camber

Stock caster (not sure what this is)
as I recall, caster affects your camber when you turn your tires...
and 1/16" toe-in

Rear
-1.3 and - 1.5 camber
toe-in is 1/32"

Have fun, good luck.
__________________
Nick
'85 Carrera
Old 10-29-2004, 09:44 AM
  Pelican Parts Technical Article Directory    Reply With Quote #7 (permalink)
Registered User
 
hkspwrsche's Avatar
 
Join Date: Jan 2004
Location: Richmond,Va
Posts: 910
I think your are in specs for the rear still..if I remember which I dont. You are right about caster and camber changing when you turn the wheel - it is the steering angle inclination. or SAI that you see on your print out.
__________________
Harold
Old 10-29-2004, 10:05 AM
  Pelican Parts Technical Article Directory    Reply With Quote #8 (permalink)
Somatic Negative Optimist
 
Gunter's Avatar
 
Join Date: Mar 2002
Location: Winlaw, BC, Canada
Posts: 7,171
Garage
Just eyeballing F1 cars, the front camber is noticably more negative than the rear. There must be a reason for this. So, why should the opposite be true for a street car?
__________________
1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.
Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".
Old 10-29-2004, 10:16 AM
  Pelican Parts Technical Article Directory    Reply With Quote #9 (permalink)
Registered User
 
hkspwrsche's Avatar
 
Join Date: Jan 2004
Location: Richmond,Va
Posts: 910
Step on it in a formula one car and the traction control kicks in. Launch control is outlawed but, traction control is not. Remember when jeff gordon test drove the williams bmw and kept spinning out because he didnt know to keep his foot in the throttle the first time? Honda was recently caught trying something similar on the front of their cars. I have a feelng that has something to do with it on top of a million other things like running a little more rear wing than front etc...
__________________
Harold

Last edited by hkspwrsche; 10-29-2004 at 10:27 AM..
Old 10-29-2004, 10:24 AM
  Pelican Parts Technical Article Directory    Reply With Quote #10 (permalink)
Back in the saddle again
 
masraum's Avatar
 
Join Date: Oct 2001
Location: Houston, TX
Posts: 27,139
Quote:
Just eyeballing F1 cars, the front camber is noticably more negative than the rear. There must be a reason for this. So, why should the opposite be true for a street car?
Because a stock 911 and an F1 car are so completely different that the comparison isn't close. Besides the fact that our cars are compromised for the street, not 10/10ths racing, you also have the fact that the main similarities are that they both have 4 rubber tires.

I ran my car with -1* front and -1.5* rear and drove aggressively and had even wear front and rear. When I bought the car from the PO it had the same alignment settings and with him driving it or possibly due to the tires he was running or a combo of both the insides wore much faster. So with the same alignment settings but different drivers and different tires I saw radically different wear patterns. I believe the main reason for more neg camber in the rear is due to the desire to leave a bit of understeer for safety. Todd Serota from Rennlist and track junky and owner of Track Quest recommends the same camber front and rear.

Usually the desire for toe in is a little more in the rear than in the front for straight line stability. In the front you want something between 0 and just a little (1/32" or maybe 1/16") and for the rear you want 1/32" to 1/16. If you have 0 in the rear you are more likely to be tail happy.
__________________
Steve
'08 Boxster RS60 Spyder #0099/1960
- never named a car before, but this is Charlotte.
'88 targa SOLD 2004 - gone but not forgotten
Old 10-29-2004, 12:23 PM
  Pelican Parts Technical Article Directory    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Dec 1999
Location: Folsom CA USA
Posts: 1,390
Garage
Quote:
Originally posted by hkspwrsche
I think your are in specs for the rear still..if I remember which I dont. You are right about caster and camber changing when you turn the wheel - it is the steering angle inclination. or SAI that you see on your print out.
The front camber is supposed to be 0 front, and -1 rear.

Bruce Anderson suggests -1 front, and -1.5 to -2 for the rear.

I think I am going to try some 225/50 or some 215/50 front tires next. I need some front tires.


I think Mausram's info regarding toe is correct too.
__________________
Nick
'85 Carrera
Old 10-29-2004, 12:47 PM
  Pelican Parts Technical Article Directory    Reply With Quote #12 (permalink)
Somatic Negative Optimist
 
Gunter's Avatar
 
Join Date: Mar 2002
Location: Winlaw, BC, Canada
Posts: 7,171
Garage
Keeping in mind that we are talking street driving.
Porsche factory settings: Front +30' +or- 10', Rear 0 deg +or- 10'
Toe-in Front 0 deg, Rear +10' +or- per wheel for stock wheels & tires
Of course, most people don't go by that. The moment you lower the 911, all the dynamics change.
Bruce Anderson specifically states on page 202, that:
"For a compromise street and competitive setting increase the negative camber settings front and rear by 1 to 1 1/2 deg. Increased camber will improve the cornering potential at the expense of GREATER TIRE WEAR. You will want MORE front camber if you are autocrossing the car to get more bite in the front. The desired camber will change depending on the tire construction."
I have seen a lot of tire wear with increased negative camber.
So, it comes down to what you want; it's an individual choice, nothing is set in stone. The proof comes with trying out different settings, wheels and tires. But it is still true that competition cars for the 24h Rolex, or the ALMS, have more negative front camber than the rear. They must know something.
__________________
1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.
Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".
Old 10-30-2004, 08:32 AM
  Pelican Parts Technical Article Directory    Reply With Quote #13 (permalink)
Registered User
 
RallyJon's Avatar
 
Join Date: Oct 2002
Location: SE PA
Posts: 3,188
On any strut-suspension car, ideal front camber depends on how stiff the suspension is. It also depends on the camber curve of the front wheel, which depends on the ride height. 911s also run gobs of caster, which gives you more negative camber as the wheel is turned.

Worst case is a lowered car on stock bars, which will have lots of body roll and the camber will go positive (or less negative) with only a bit of compression. Add that to the positive camber from body roll and your outside front tire could go several degrees positive in a hard turn.

On my car--light weight with fairly stiff suspension and not overly lowered--I couldn't even use -1.5 of static front camber at street speeds. It was cornering so flat that it wasn't "using up" the camber it had. Front end bite was actually much better with -.8 front camber. At the track, I'd probably want that -1.5 or even more.

Just saying that there are a lot of variables here, and the same settings can have very different effects on different cars.
__________________
993 911 STI S4 rally car
Old 10-30-2004, 08:48 AM
  Pelican Parts Technical Article Directory    Reply With Quote #14 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 07:17 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2016 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.