Are these Mtech 2 springs 33539061134

[Staszek]

I have been looking for a set of MT2 springs, I am putting my suspension back to OEM ish. I have a brand new set of fronts 31331130054, but the rears are NLA.

Here is a pic I have seen of the springs with that part number (not sure if its correct pic)



M-tech suspension package (09/87+) 33539061134:

Spring force = 4739 – 4885 Newton at Ln length 115.7 mm for springs with red dots

Spring rate at upper level: 42.22 N/mm or 241.082 lb per inch

Spring force = 5032 – 5177 Newton at Ln length 115.7 mm for springs with white dots

Spring rate at upper level: 44.745 N/mm or 255.50 lb per inch


I picked up a set of used rears really cheap that are said to be MT2, but its hard to tell, they have both white dots and the red dots.

White dots match the pic above


Have a few red dots as well on the same spring.


Part numbers are too worn to really see

So what springs do I have?

[Staszek]

Now I am thinking these rears are E30 M3 springs, which I am ok with if they are the spring rates and heights are pretty similar to the white dot Mtech, the M3's are slightly higher. I found a part number I could read on them 2226147.

[AWDBOB]

Those rears are E30M3 IIRC.

I found this on an old forum

The color doesn't bother me. They were powder coated. Also, I looked up the P/N on my red springs and they are BMW 1130046. As confirmed by an old forum lookup I found on Google below (This guy had the same exact question I had on June of 2001, my springs are certainly M3 springs...

QUESTION:
> My question is, are these really E30 M3 springs? I went to install them
> last night and discovered that they are just as tall (free coil length) as
> the stock E30 325is springs (stock OE springs) I have now. On the front,
> both sets of springs have the same number of coils (seven) and I thought
the
> E30 M3 springs had six coils. In addition, the E30 M3 springs have a
> smaller diameter wire than the E30 325is springs currently installed. In
> total, these E30 M3 springs were longer and would be softer than the E30
> 325is springs so I do not believe they are E30 M3 springs.
>
> Am I correct or not? Any ideas or can anyone identify what springs these
> are?


ANSWER:

K(spring rate) = Gd*4/8ND*3 where G = 11.5x10*6, d = spring wire dia, N =
total turns-1.5, D = spring dia.


E30 M3 front spring BMW part # 1130046
D = 5.09"
d = 0.484"
Free length = 12.69"
Total turns = 6
Spring rate 132 lbs/in

E30 M3 rear spring BMW part # 2226147
D = 5.04" (in center)
d = 0.590 (in centr)
Free length 8.38"
Total turns = 6 1/4

E30 325is 12/88 front spring BMW part # 1132742
D = 5.09"
d = 0.502"
Free length = 13.81"
Total turns = 7
Spring rate 125 lbs/in


E30 325is 12/88 rear spring BMW part # 1134702
D = 5.09" (in center)
d = 0.504" (in center)
Free length = 9.88""
Total turns = 7 3/4

[Staszek]

Those rears are E30M3 IIRC.

Thanks, I am ok with that, I picked them up really cheap. They are slightly taller than the Mtech rears, but shorter than the OE Sport springs, which is probably perfect for the application I am thinking.

Thanks!