Buenas tardes,
Según he leído en distintos sitios los colores van según la rigidez del muelle (tiene su lógica aunque no estoy seguro). Aquí unos enlaces de foros americanos con más información sobre los muelles:
1-
www.m3forum.net/m3forum/showthread.php?t=58671009
2-
http://www.m3forum.net/m3forum/showthread.php?t=457186&page=3
Extraigo del inicio de una de las páginas puestas:
Known spring colors so far. Rating of colors is up in the air but this is what we started with. Perhaps number of stripes indicates stiffness between the color changes: i.e. 4 yellow bands would be stiffer than two yellow bands???
Yellow - softest
Red - soft
Green - medium
Blue - hard
Pink - hardest
White - Euro / no A/C (softer)
Gray - Euro / With A/C (Firmer)
Front springs have the prefix: 31 33 2
Rear springs have the prefix: 33 53 9
BMW E36 M3 Coupes and Sedans with a Manual transmission - 96-99 only
Front:
31 33 2 228 170 (yellow)
31 33 2 228 171 (2 red stripes) (with headlight cleaning and electric seats etc..) [1997 M3]
31 33 2 228 172 (4 blue stripes) [Jim E. has listed as a Euro spring]
Rear:
33 53 9 069 132 (4 green stripes) [1997 M3 take-off][Superseded by: 33 53 2 228 190 (09/01/1995 — ), Exchangeable retrospectively]
33 53 9 069 133 (4 blue stripes) [Jim E. has a set]
BMW E36 M3 Coupes and Sedans with an Automatic transmission - 96-99 only
Front:
31 33 2 228 172 (4 blue stripes) [Jim E. has listed as a Euro spring]
Rear:
33 53 9 069 132 (4 green stripes) [Superseded by: 33 53 2 228 190 (09/01/1995 — ), Exchangeable retrospectively]
33 53 9 069 133 (4 blue stripes) [option?]
BMW E36 M3 Convertibles with a Manual transmission
Front:
31 33 2 228 176 [from 3/1/1996]
31 33 2 228 177 (pink) (with headlight cleaning and electric seats etc..)
Rear:
33 53 9 069 756 [set coil springs]
33 53 9 069 757 (pink) (with headlight cleaning and electric seats etc..)
BMW E36 M3 Convertibles with an Automatic transmission
Front:
31 33 2 228 177 (pink)
Rear:
33 53 9 069 757 (pink)
BMW E36 M3 USA Coupes - (1995 model year only)
Front:
31 33 2 227 836 (3 pink stripes- I have a set of these) [from 3/1/94]
Rear:
33 53 9 067 378 (3 pink stripes)[3' E36, M3, Coupe, S50, AUTO, USA, (BF03); MANUAL, USA, (BF93) : SET COIL SPRINGS] 11/93-1/96
USA 1995 M3 LTW
Front: (4 white stripes)
Rear: (4 white stripes)[3' E36, M3, Coupe, S50, MANUAL, EUR, (BF91) (BF92)(BF99); 3' E36, M3, Sedan, S50, MANUAL, EUR, (CB91)(CB92) : SET COIL SPRINGS
Euro 1995 M3
Front:
31 33 2 227 422 (2 gray stripes) (with A/C) [BMW Classic Motorsport, E36 M3 Gr.N, Coupe, S50, MANUAL, EUR, (ST04)]
31 33 2 227 421 (2 green stripes or 2 white stripes) (without A/C) [BMW Classic Motorsport, E36 M3 Gr.N, Coupe, S50, MANUAL, EUR, (ST04)]
Rear:
33 53 9 064 881 (2 white stripes) (Assumed with A/C) [Jim E. has a set] [3' E36, M3, Coupe, S50, MANUAL, EUR, (BF91) (BF92)(BF99); 3' E36, M3, Sedan, S50, MANUAL, EUR, (CB91)(CB92) : SET COIL SPRINGS
Euro 1996-1999 M3
Front:
31 33 2 228 171 (2 red stripes)
31 33 2 228 172 (4 blue stripes) [Jim E. has a set]
Rear:
33 53 9 069 132 (4 green stripes) [Superseded by: 33 53 2 228 190 (09/01/1995 — ), Exchangeable retrospectively]
E36 M3 Group N: 3,2L (1996-1999)
according to choice
01 COIL SPRING PROGR.240N 2 31 33 2 501 377 ENDED
01 COIL SPRING PROGR.260N 2 31 33 2 501 378 ENDED
01 COIL SPRING PROGR.280N 2 31 33 2 501 379
01 COIL SPRING PROGR.300N 2 31 33 2 501 380 ENDED
Según esta información los muelles que muestra
@Insua xy_m serían la ref.
31 33 2 227 422, que coincidirían con los de
@murueta si nos confirma que son de M3 3.0.
Los que muestra
@Txonpo, aunque no cuadra del todo serían
la ref. 31 33 2 228 171 para los delanteros (aunque dicen que son de 2 marcas en vez de 4) y para los traseros
ref. 33 53 9 069 132.
Alguno con muelles de M3 podéis mirar si viene estampada la referencia en el muelle?
P.E. se pueden encontrar a la venta estos muelles para M3 3.2 OEM:
4 marcas azules (
REF. 31 33 2 228 172):
https://www.ecstuning.com/b-genuine-bmw-parts/spring/31332228172/
https://www.ebay.com/itm/BMW-31332228172-Coil-Spring-Suspension-Coil-Spring-/162426366239?_ul=BO
4 marcas azules (
REF. 33 53 9 069 133):
https://www.ecstuning.com/b-genuine-bmw-parts/spring-set/33539069133/
A ver si llegamos a algo entre todos

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