Porsche 550 spyder 1.2

One of the first Porsche mods for AC. It's not a very fast car but it can be fun on the circuit. Especially for club type events.





Here are the release notes:

We developers are proud to release version 1.0 today 25th July '15, cheers !

Warning
Do not distribute this mod other than this Assetto Corsa forum, share the forum link. And do not modify this mod without author agreement.

Therefore, as per author's request, we'll only link towards the AC thread (which contains the download option ofc).

The two physics set
The base 1955 Porsche 550/1500 RS (110 BHp, Dunlop R3 natural rubber tires - overheats at 80C, huge slip angle possible)
And the "s1" version being a late 50's hillclimb prepared version with RSK engine part upgrade, increased displacement (1650-1700cc) and new Dunlop R5 tires (synthetic rubber) slightly wider rubber at the rear. Such a car finished 2nd at the 1960 Pikes Peak with Roger Ward at the wheel. We used dyno curves of a 547 1755cc engine.

Porsche 550 physics background
The 550 was basically the first ever mid-engine road car, so its design is not perfect. Suspension was all based on VW parts. Front was the double torsion bars (a Porsche patent) and rear was a basic swing axle - both causing horrible camber change under cornering. On top of that, the frame was weak and twisted a lot. It has drum brakes and 50's tires less than 100mm (4'') wide.
However, aerodynamics was very sleek. Weight and inertia are extremely low (under 600kg) and the 4-cam 547 engine was way ahead of its time, revving easily up to 7500 rpm. It would be Porsche's race department workhorse for an entire decade.

Overall the car has good handling for its time, but it was notoriously oversteering . Many period pictures show 550's in oversteer.
Ken Miles (aka "Spyderman") said: "Steering the 550 was very much a matter of very large steering movement to produce the desired result",
He also mentioned this about the 550 vs 550A (not in the mod currently) “The change in handling is unbelievable. Gone was the excessive oversteer (of the original 550), the RS (550A) was now as forgiving a car as one could possibly wish to meet."

Credits
Ensyuya (Mitsunari Ishii) : Project lead, 3d Model, textures, animations, shaders, sounds
Patrice Cote : Physics, UI car history
Engine sound sources except high rev sound : Citytea
Beta tester : Phil E, Maseratialfa, Jon Uyan and Hutch from the CMS Historical racing league (cmsracing.com)

About sounds
The engine sound is from real type 547 engine that Citytea recorded around 2006 at Salzburgring with his old Boss R-1 digital-recorder. He gave us permission to use with pleasure.

Other sound samples are recorded by Ensyuya from real classic VWs or Kunos original ones.

Polycounts, file size and distance for optimization are about

LOD A 230000 95mb from 0 meter
LOD B 131000 79mb from 6 meters
LOD C 45000 32mb from 32 meters
LOD D 14000 5mb from 48 meters

Damage model function fully works.
550 spyder mod got all functions that should be in this mod. All functions Kunos implemented in AC are working properly.