911buzz

Hi All, new to Rennlist and 911 cars. I have owned and raced 944spec cars for many years but this is my first 911.
I am looking for advise on camber, caster and toe, shock and spring rate settings for a racecar I recently purchased.

Car was converted to racing by Sam Shalala for Dan Pastorini (NFL Fame) around 1991. It is a 1976 911 converted to 993 rear suspension and 935 front suspension. 3.8 lt dual plug with G50 trans. Empty weight is around 2450 lbs, race weight will be close to 2,700.
Car is currently set up with 550 and 850 rear springs. 160/161 Bilstein front shocks and an unkown Bilstein rear but suspected to be an RSR valving based on Porsche number on shock but does not show up anywhere online. Rear sway bar is 17mm and front is a Nascar style 1.25" hollow front bar.

I am looking for a starting point so when I go to test vehicle we can try to get as much done in one day as possible.

Thank you in advance for any and all help.

911buzz

Wow not a single reply.

Just looking for a starting point for my first test day. Somebody must have some intel about these cars.

Cory M

What tires are you planning on using (brand, model, size)?

911buzz

Hi Cory, thank you for your reply. Sorry it took me so long to get back to you. On vacation now.
This car is currently on Hoosier slicks S100. Not currently able to see actual sizes because I am out of town but the comparable sizes in DOT R is 245-40-18 front and 325-35-18 rear.
I may end up on Yokohama slicks if I race in POC GT3 class of similar size.
I have never raced a car on slicks but have raced for 20 years on DOT R compound tires. It is my understanding that slicks use less camber.

Thanks

Cory M

Great looking car. I haven't run the Hoosier slicks so I don't have any direct experience with them. Radial slicks (like your Hoosiers, Yokos, etc) generally require the same or more camber than R-comps. Bias ply slicks require less. I would think you would want -3 degrees or more. You might want to change the title or start a thread to something like "Hoosier Slick Alignment Recommendations" since this one isn't getting any love..

Slakker

Here's my base alignment on a 996 that is similarly weighted running Pirelli DH slicks. It still needs a little more camber but the toe setting are good. Ultimately a pyrometers is necessary to dial in the values but this should be a good starting point.

Front: -3.8 deg camber, .5mm toe out.
Rear: -3.2deg, 1mm toe in.
Caster: 8 Degrees
Spring rate 700F/900R


I wouldn't worry about your spring rates though until you are try to solve a specific problem as your dampers will probably have to be revalved.

Dan Jacobs

Slakkers aligment is good but I would set the rear toe at 2mm in per side to start

jdistefa

^ Agree with Dan. We run 1.5-2mm toe per side in 3-RSR.

A few other comments:

1) Looks like you have heim jointed kinematic arms (good) - important to set your kinematic with a proper gauge. It is essentially rear caster but if it's way off it can affect dynamic toe. In any case I would start with a setting of around 2.

2) I would absolutely replace your inboard toe control arm eccentrics with lockout plates. The eccentrics can slip under load which can be... bad. Lockout plates here: http://www.tarett.com/items/993-964-...t01-detail.htm

3) Depending on your skill level, speed, how much you lean on the tire, etc.... you may want to start with less camber but a 0.5 deg front/rear split is good. Refine from there with tire temps as mentioned by Slakker.

rlm328

Yut Heckler built the chassis for the car for Sam Shalala. You can contact him at Predator Motorsports in Houston. Email me and I will give you his telephone number. He can give you the specs for the car as built.

He presently has the sister car on the lift in his shop.