top of page

N62 Z3 Part 28: Even More Driving!

With the power steering working it felt like a whole new car... it felt like a real car

The color combo matches the tan/green colors of the desert pretty well, lol

The day after that little cruise was my birthday and the roads were a little more dry, I set out with a goal to get a sub-5 second 0-60... I drove around for about an hour doing a few runs at a few different private roads, I work in a construction related field and know of a lot of roads closed to the public where I can do runs safely. The main problem though was most of these roads were covered in dust, gravel or the road surface was just overall very poor. Meaning very poor traction... I beat it harder than I've ever beat any Z3, here are just the runs that I saved

As you can see from the last run of the day, I hit the sub-5 seconds with a 4.88. Accounting for the 1 foot rollout (how magazines review cars, for some reason) it did a very respectable 4.64 - so I was very happy with this

And the run wasn't even perfect, it definitely has a little more to give. The launch was well done in this run, but it spun a considerable amount into second. I am starting to suspect I am becoming somewhat limited by tires - I do have good sticky Yokohama Advan A052's out back, but at only 255 wide it seems the V8 torque just overwhelms them. 275 or 285 wide tires may be in my future...


I'm going to experiment a bit with getting a bit easier on the throttle when getting it into second gear to see what I can do with it as-is

Here is another run where I spun even more dramatically into second

When building the car I wasn't too concerned with 1/4 mile times or even 0-60 but now that it's finished, I am definitely interested in seeing what it is capable of. And on that note, I was talking to a friend of mine who said he would be impressed if it got into the 12's in the 1/4 mile

So, that is my next goal. I think with it setup like it is now, 12's would be very difficult as I'd have to shift three times and each shift risks losing precious seconds - but after running some calculations, it seems like a 2.93 rear diff ratio (it currently has a 3.15) would put it right around the ~108mph range at the top of third. A few sources seem to indicate that a 105mph trap speed is approximately a 12.98 quarter mile. A 2.93 diff ratio does exist that fits Z3's but it is quite expensive... if I can get away with a 3.07, that would be much better, but I'm not sure


But first is something I've sort of been putting off... and that is the struts and springs. Right now my front suspension has non-M stuff everywhere but with M strut mounts which adjust the angle of the strut. The car also sits much higher than stock (despite having springs meant for the iron block engines) and I realized after a recent drive that the outside edge of my tires is wearing. At first I thought my toe was wrong, since I did a string alignment myself. The toe seems good, but closer inspection revealed I actually have positive camber. I attribute this to the M strut mount and the raised ride height. So, I am going to tackle both of those issues at once with new non-M strut mounts as well as brand new Koni strut inserts and H&R springs

There is a slight complication to this though and that is because my front wheels don't actually fit properly. I bought them from an enthusiast advertised as fitting Z3's so I didn't check the specifications as closely as I should have, but as it ends up, the wheels poke. Pretty badly too. The offset is et30 and they really should be more like et40, they stick out about 10mm further than they should. At the raised ride height this isn't an issue. But once lowered, the tire will be rubbing straight into the hood... so I will need to address that as well


But first I had to install the Koni struts and H&R springs. These were the "cut a strut" Koni's so I had to remove the stock strut insert from the housing

I couldn't find my strut nut socket so just made one. A hex key has to go through the middle in order to counter-hold the strut shaft

Cut and removed the stock strut insert

Koni's installed!


0 comments
bottom of page