Building fast road/track day E21

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melaniewalker
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Posts: 1
Joined: Wed Apr 10, 2024 11:10 am
My E21(s): 79 US 320i manual

Building fast road/track day E21

Post by melaniewalker »

New to this forum, building a fast road/track day E21 from bare shell. Restoring and strengthening shell and exploring suspension options. I am considering a complete F20 rear subframe conversion and wondering if anybody on here would have any comments or experience around this? Any input appreciated. I know the rear track would be approx 6.5" wider in total but arches will be dealt with for wider wheels anyway.


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nic65
Upcoming E21 fanatic
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Joined: Tue Sep 18, 2018 2:12 pm

Re: Building fast road/track day E21

Post by nic65 »

Hello and welcome,
the chassis of the e21 is very delicate and flexes easily, I think it should be used as it is and with preparations from its era, if it needs to be modified a lot I think it would be better to move directly to a more modern chassis, I wish you good luck anyway
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Jeroen
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Joined: Tue Sep 14, 2004 12:23 pm
My E21(s): '81 323i Baur
Location: The Netherlands
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Re: Building fast road/track day E21

Post by Jeroen »

Welcome! Wouldn't mind seeing an extensive mod, definitely curious!
Regards/groeten, Jeroen
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polov8
E21 Pro
Posts: 513
Joined: Wed May 29, 2013 6:30 pm
My E21(s): '83 Polaris silver 316
Location: Dronfield

Re: Building fast road/track day E21

Post by polov8 »

I wouldn't hack about an E21 for the F20 back axle. By the time you've cut the rear of the chassis to fit an axle that's way too wide, and pretty heavy compared to the original, then the front will need some similar chopping up to get a comparable set up. Now you've got 2 decent suspension set ups joined by the flimsy E21 centre section. Might as well start with an E36 or E46. Way better selection of engine and transmission possibilities.

If you do go down the E21 route, take a close look at this E30 M3 DTM rear axle: https://racecarsdirect.com/Advert/Detai ... tm-group-a

Full range of toe and camber adjustment, in an axle that bolts on to the shell without modification.
Andy
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