Results 1 to 9 of 9

Thread: Alignment info

  1. #1
    Join Date
    Aug 2013
    Location
    Massachusetts
    Posts
    426

    Default Alignment info

    My 308 needs new rear tires. They are Vredestein Spring Classics 205 70R 14 with a high speed V rating. Basically they are a modern substitute for the Michelin XWX and priced a bit less, but still expensive.

    The rear tires are close to the wear bars and show wear on the outside edges, but not inside edges. (With the rear camber settings I expected more wear from the inside edges.) The tires have about 8k on them. Fronts are fine. Tires have never been rotated. Alignment was done about 3 years ago and everything was within spec. I have the factory specs from the owners manual as well as a later update. Specs were done according to the later update and are specific for the GTS. The car does not exhibit any pull or irregular tendencies that I can feel. I have the stock suspension and springs.

    The info that I'm looking for is how to make some fine tuning to the alignment specs. My car is street driven only. My preferred routes are New England back roads with limited highway driving.

    1. Ideally, I would like more even tire wear from the rear. Maybe I need to start to rotate tires from front to rear.


    2. I would like to try to get a quicker feel at initial turn in when entering a turn, but I don't want the car to feel "skiterish" going down the highway.

    (I am a bit spoiled here because my my only other sports car is a BMW Z3 2.8 that has a 50/50 front to rear balance, 4 wheel alignment with corner balancing, upgraded suspension, heavier sway bars and Michelin Pilot Sports tires in staggered sizes (225 45 17 and 245 40 17)

    I realize these are two different cars but I looking for the feel of having the front end enter the turn a bit quicker, and have the back end come around more smoothly. I don't know if this is possible due to the chassis, engine location, suspension and tire differences, but this is the goal. I don't expect to fully achieve this, but some change in this direction would be nice.

    3. Do the alignment settings need to be fine tuned because of less rear weight?

    I know the weight distribution is more biased toward the rear. I have probably taken off 75 to 100 pounds off the engine (exhaust emission parts, muffler shielding and original muffler). So the back end is a bit lighter

    4. How do you load the seats to duplicate the effect of t wo people?

    Factory specs say the car should have a full tank of gas, tool kit, spare tire, and two people in the seats. (Original manual mentions 44 pounds of luggage in the trunk but is not mentioned in updates.) When I drive the car, 95% of the time I'm the only one in the car. Do I put 150 pounds in each seat and floor? I don't think my alignment guy would allow me to sit in the car.

    5. Outside tire wear due to high speed cornering? Would it wear only on the rear tires?


    Here are the updated factory specs for a 78 308 GTS USA version

    FRONT

    camber angle
    +0 degrees 05' min.
    +0 degrees 25' max.

    Top to bottom difference
    -0.02" -.5mm min.
    -0.10" - 2.6mm max.

    Toe in
    -0.08" -2mm min.
    -0.12" -3mm max.

    Caster angle
    4 degrees


    REAR

    camber angle
    -1 degree 05' min.
    -1 degree 25' max.

    Top to bottom difference
    +0.26" +6.7mm min.
    +0.35" +8.8mm max.

    Toe in
    -0.14" -3.5mm min.
    -0.18" -4.5mm max.

    Any suggestion would be appreciated.

  2. #2
    Join Date
    Sep 2009
    Location
    In the big house
    Posts
    6,979

    Default

    To reiterate from our conversation last week, the alignment was done incorrectly. It still is incorrect, based on your tire wear observations. It is impossible to have tire wear on the outer edge with negative camber and toe-in. Impossible!

    Regarding specs;
    Toe-in (the leading edge or the tire) points in. This is expressed as a positive number. Most sports cars, including all Ferrari's run toe-in on both the front and rear. The numbers you have annotated are expressed as negative numbers. This is incorrect. Ferrari has always expressed toe as total toe; the sum of both sides. They express this in mm. Both of these units of measure are uncommon. To assume, as you told me on the phone, that the tech used what the "machine provided" for a 40 year old car is asking for trouble.
    Ferrari Service of Bedford, LLC
    "The Fluent in Ferrari Guys" celebrating 35 years of service excellence
    **An independent facility with no affiliation with Ferrari SpA**
    Bedford, NH 03110
    www.fluentinferrari.com

  3. #3
    Join Date
    Aug 2013
    Location
    Massachusetts
    Posts
    426

    Default

    Help me make sense of this info from Ferrari. Some of it seems to contradict itself

    This is the updated service bulletin info I have from Ferrari. 78 308 GTS USA (can't seen to get these to open up directly on the page)

    I'm using the 308 GTS row with "Michelin XWX Tubeless" (The Vredestein Sprint Classic is a duplicate of this)

    308 service-bulletins-81-82.pdf

    It shows positive camber front camber, negative rear camber and positive toe in for both front and rear




    These three pages are copies from my owners manual.

    Front suspension

    front suspension.pdf

    front suspension 2.pdf

    It shows positive front camber, and negative toe (is that a negative sign or just a dash from the manual?)

    Rear suspension

    It shows negative rear camber, and negative toe (again, is that a negative sign or just a dash from the manual?)

    rear suspension.pdf


    Bottom line: I just want the correct specs.

  4. #4
    Join Date
    Sep 2009
    Location
    In the big house
    Posts
    6,979

    Default

    There is no confusion. Ferrari states toe-in, not toe-out. Nothing ambiguous there....
    There's a diagram on how to measure it if you don't have a alignment machine. Assign a number to either variable and solve for the other. You get toe-in.

    308 service-bulletins-81-82 seems the simplest to understand and exactly what I stated over the phone.
    Ferrari Service of Bedford, LLC
    "The Fluent in Ferrari Guys" celebrating 35 years of service excellence
    **An independent facility with no affiliation with Ferrari SpA**
    Bedford, NH 03110
    www.fluentinferrari.com

  5. #5
    Join Date
    Aug 2013
    Location
    Massachusetts
    Posts
    426

    Default

    "308 service-bulletins-81-82 seems the simplest to understand and exactly what I stated over the phone."

    Thanks. That's the one I'll use.

  6. #6
    Join Date
    Jun 2007
    Location
    Massachusetts
    Posts
    13,144

    Default

    Fahey Tire in Wakefield does all my alignments. They did a great job on the 308. Used that laser-guided sucker. I have to tell you though Fireman, you need to get 16" wheels. Such a difference in handling. Drive mine if you want to feel the difference.
    Birdman308 for parts and tutorials!

  7. #7
    Join Date
    Aug 2013
    Location
    Massachusetts
    Posts
    426

    Default

    Thanks for the info. I have thought about 16" wheels, but then I have to get wheels and tires. I actually like the look of the 14" "balloon" tires. Very period correct. An added advantage is with the 70 aspect sidewall there is a lot of cushioning. The car rides very smoothly over all the cracks, ruts, potholes eat on our crappy roads. There is enough performance in these Vredestein Sprint Classic to really scare me on the public roads.

    I may take you up on a comparison test drive, however.

  8. #8
    Join Date
    Jul 2014
    Posts
    154

    Default

    Quote Originally Posted by Birdman View Post
    I have to tell you though Fireman, you need to get 16" wheels. Such a difference in handling. Drive mine if you want to feel the difference.
    +1 on the 16" wheels!
    I jumped at the chance to buy my friend's 16" wheels off of his 86 308 GTS when he wanted something shinier. Even with a wearing rack they made a huge difference, and after having the rack repaired I couldn't believe the improvement over what I had for many, many years on my 14" wheels.

  9. #9
    Join Date
    Apr 2014
    Location
    Pretoria, RSA
    Posts
    93

    Default

    keep the balloon's ! hehe

    how's it going guys !

    Wolfman

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •