Strut size question.

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rsjon
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Sun Feb 15, 2015 7:27 pm

Bought a beautiful 1990 318i 2 door in brilliant red.
70k and never welded.
Love driving it as it is but the suspension is a bit soft...........!
An upgrade is in order but despite loads of posts I cannot find a definitive answer to this question:
In the real world of driving on public roads is there anything to be gained by changing from 45mm struts to 51mm struts before changing inserts for B4's?
Do 45mm struts take vented discs?
Over to you....thanks,
Jon.
jmc330i
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Sun Feb 15, 2015 7:45 pm

The brakes can be swapped between 45mm and 51mm struts so you can keep the 45mm struts and change to vented discs, but you'll need to change the calipers to suit.

The 51mm would be a good upgrade if you're planning an engine swap in the future, but if not the 45mm will be fine.
James
'91 325i Sport
'93 318i touring 16v
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rsjon
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Sun Feb 15, 2015 7:59 pm

Should have said, an engine swap is planned but only to an M42/44 so no weight increase.
Jon.
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Brianmoooore
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Sun Feb 15, 2015 8:08 pm

45mm struts are considerably more likely to bend than 51mm ones when smacked against a kerb or a pothole, and, based on absolutely no evidence, I would expect the larger diameter B4 dampers to last longer and fade less than the smaller version.
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