cones36
cones36 New Reader
9/12/20 11:45 a.m.

When I was a kid (teenager?)  I thought these were the coolest. At the time, they were also very expensive. Over the years I've sort of forgotten about them. 

Now that I'm an adult and can spend money more irresponsibly, they've started to enter my project/toy car thoughts again. How would a non-M Z3 coupe serve as a base for an autocross/HPDE car with some weekend cruising thrown in?

They're certainly small and fairly light. With some suspension work, can they handle the cones? 

Any major reliability issues? Parts hard to come by these days?

Thanks for the input.

buzzboy
buzzboy Dork
9/12/20 1:03 p.m.

Mechanically the front is e36 and the rear is e30 but with a much shorter wheelbase. Plenty of good suspension knowledge from both those groups. Engine wise you get either an M52B28 or an M54B30. Depends on power goals which is better. Reliability issues to look out for are the cooling system, which will need to be replaced if it's still factory, and rear subframe mounts, which have been strengthened by the aftermarket.

I've got a lot of street miles in a Z3 3.0i. Truly fantastic street car. My only complaints come from my height. At 6'0" with a 32" inseam my head hits the glass on the sunroof and I can't see the speedo from 40-120mph. If it weren't for the sunroof my head would hit the headliner and bend sideways. That has been solved with seat track mods.

 

CyberEric
CyberEric Dork
9/12/20 1:21 p.m.

I owned an E36 M3 and driven a few M coupes (never the non-M though).

I like them, but I found the handling to be a bit spooky with the shorter wheelbase and the suspension design from E30 compared to the E36 I owned at the time. I've heard other people not have that experience, so it must be possible to fix with better tires and suspension modifications. Stock on pilot sports, it felt like the rear wanted to come around in an alarming fashion.

I too love the way they look. I imagine you could find a well-sorted one now that has a lot of the things Buzzboy mentioned all sorted out. Not sure what they are priced like now though. Back 15 years ago, the M coupe I test drove was $22k.

dps214
dps214 HalfDork
9/12/20 1:29 p.m.

With stock non-M power I think it's just going to be an understeer fest without a lot of suspension work...and maybe even with the suspension work. Give it some power and as long as it's got appropriate tires it's a riot of "loose but predictable and controllable". Also note in stock form the rear suspension has no adjustability to the alignment. The stock seating position isn't great, easily the best thing I ever did to my M roadster was a race seat on custom mounts that sat ~4" lower and made a world of difference. But the cavity the seat sits in is oddly deep and narrow and not many seats fit without modification.

ojannen
ojannen Reader
9/12/20 6:02 p.m.

There is a piece of foam behind the driver seat that keeps the drivers head off the rollbar on the convertible.  You can remove it without any downsides on the coupe for a bit more room. A 150k mile 3.0 coupe is a nice street car at a reasonable price.

pimpm3 (Forum Supporter)
pimpm3 (Forum Supporter) UltraDork
9/12/20 7:26 p.m.

The 3.0 liter cars are only down 20 horse power or so from an s52 m coupe.

I picked my 2000 m coupe for 12k a few months back.  I have spent almost $2,000 since getting the deffered maintenance caught up.

CyberEric
CyberEric Dork
9/12/20 8:46 p.m.

And isn’t the 3.0 an aluminum block too?

Less weight over the nose?

buzzboy
buzzboy Dork
9/12/20 9:07 p.m.

In reply to CyberEric :

M54s are all aluminum. M52s are aluminum in the Z3.

dps214
dps214 HalfDork
9/12/20 9:23 p.m.

In reply to pimpm3 (Forum Supporter) :

I got the feeling from mine that without S54 (...or supercharged S52...) power it would have some understeer issues. Mine was great as long as the rear end was doing its thing but once you got below the threshold where you could steer the car with the throttle it got pushy in a hurry. Back when I was shopping it started out with me wanting to build a semi-competitive STR autocross car. Before I came to my senses of how awful of an idea that was I did a bunch of research and I think came to the conclusion that the 3.0 was the best balance of weight, power, torque, and gearing for autocross purposes.

The M54 is all aluminum and dual VANOS, but I believe is also the high point of the oil pump gear failures.

wspohn
wspohn Dork
9/13/20 11:48 a.m.
buzzboy said:

In reply to CyberEric :

M54s are all aluminum. M52s are aluminum in the Z3.

They had some engine issues with the early S54 - of the bearing durability sort, which is probably why the reverted to an iron block on the later versions.

The handling on the Z3 is a bit...looser?... than on the Z4 but that can be fun too, if you can manage it.

There are other options out there if you like the Clown Shoe look but don't like the increasing prices.

This is an interesting comment on the Z3 coupes  https://www.bmwblog.com/2020/01/29/the-bmw-z3-m-clown-shoe-makes-us-miss-the-good-ole-days/

 

Slippery (Forum Supporter)
Slippery (Forum Supporter) GRM+ Memberand UltraDork
9/13/20 12:48 p.m.
wspohn said:
buzzboy said:

In reply to CyberEric :

M54s are all aluminum. M52s are aluminum in the Z3.

They had some engine issues with the early S54 - of the bearing durability sort, which is probably why the reverted to an iron block on the later versions.

This is incorrect. S54 was always iron. 
 

The bearing issue is present on all years of S54. The later years 2003.5+ use wider bearings. You still need to do them at the 100k mile mark or so. Its the nature of those motors and the high revs. 

dps214
dps214 HalfDork
9/13/20 1:59 p.m.

I'm getting rusty on this stuff...but the S54 in the Z3s had a lower redline (also why it's derated a bit compared to the M3) which I thought most people agreed was enough to make the bearings a non-issue or very close to it. But maybe I'm misremembering.

CyberEric
CyberEric Dork
9/13/20 2:37 p.m.

In reply to buzzboy :

Didn’t know the M52 was aluminum in the Z3, thanks.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/13/20 3:09 p.m.
CyberEric said:

I like them, but I found the handling to be a bit spooky with the shorter wheelbase and the suspension design from E30 compared to the E36 I owned at the time. I've heard other people not have that experience, so it must be possible to fix with better tires and suspension modifications. Stock on pilot sports, it felt like the rear wanted to come around in an alarming fashion.

 

That's part of the charm of a trailing arm suspension.  Side loads make the outside wheel toe out.  You get used to it.

 

In the 80s, Mazda made a big deal out of designing links and putting a separate knuckle on the trailing arm with bushings of varying floppiness so that this didn't happen, and most people lock that all out.  So it can't be THAT bad.

 

The biggest thing I've noticed about the Z3 is how exposed you feel when driving it.  I am a bigger guy and can drive an NA comfortably.  When I drive a Z3 it feels like the only place for my left arm is outside the window.

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