So dumb me bought the donor car for an EP Z3 !
- I think these are the coolest cars in EP currently, I kick myself daily for not buying Chris Drydens, it was a mind blowing fantastic deal when he sold it. I just didnt have the room for it (and I was getting divorced). Im still kicking myself.
bodywork:
does anyone make fiberglass for these cars ? open top cowls ? hoods etc. ? i see only crazy vented " body kit type stuff "
- Not that I am aware of or that I have ever seen.
driveline:
should i start with 3.90 - 3.73 rear gear ? arent the shorter rations available in some automatic cars ?
- If you are starting with a 6 cylinder Z3 version that will have what is commonly referred to as the "Medium Case Diff", its a 188mm Ring Gear and they were used in TONS of BMWs from the E30, E28 and I think the E34. Get a diff from any of those models and just change the diff cover and the output shafts for the Z3 ones.
Factory BMW gears available via wrecking yards or new for medium case diff range from 2.79 to 4.45. Lots of ratios available.
I think your rear gear selection will depend greatly on the engine build and trans high gear ratio.
I can speak for E30s in that if you use a trans with an OD 5th gear the hot setup is the 4.27 or 4.45. If you use a 1:1 high gear the usual choices are 3.73, 3.9 or 4.10. I have at least one of every one of those ratios. They are out there in wrecking yards. Its a very very robust and overbuilt diff, buy one, clean it, re-do bearings and seals and go race it.
For the person looking for every last bit, the later DTM cars had an alloy diff case and there is someone reproducing them now. It was a noticeable weight savings (at a co$t for sure). It was a BMW Motorsport part and in the past few years someone with connections to sand cast parts re-made some.
suspension;
these cars basically have E36 fronts with E30 ?? rear trailing arms right ? so there should be lots of off the shelf parts to make that work Any advi
Yes E36 front, E30 rear. All wheels are E36 offset.
The E36 fronts are easy many people make many choices.
I think all the faster BMW club racers currently fawn over the Bimmerworld MCS setups.
BMW Coilover Kits
www.bimmerworld.com
The choices are almost infinite. Ground Control also offers tons of E36 based options.
The best part of building a suspension for a Z3 race car is that ALL the things BMW did for the E30M3 DTMs cars are direct bolt ons to a Z3 chassis.
The stock front suspension uses the lower control arm that was common from the E30 and E36. There are lots of busing options but its a heavy arm and its all in single shear.
You can also use the BMW E30M3 DTM front suspension parts. Thats what I have, it turns it all into fabricated arms and spherical bearings.
It looks like this:
https://mrtengineering.fi/products/...ront-control-arm-kit-3?variant=40602176192701
A few people are making knock offs of it. Its a much better setup than the stock based lower control arm.
This is an example, Amspeed Racing re-makes all the evolutions that BMW went through as they developed the Gruppe A cars.
www.amspeedracing.co.uk
The E30 / Z3 / 318Ti rear trailing arms get a lot of bad rap, but you can research the E30M3 DTM rear subframe and trailing arms.
Its a 3 decade proven path to having plenty of adjustment and a race quality rear suspension. It worked to spank the touring car world in 1987 it still works today.
There are all kinds of slotted kits and offset bushings available to do to an existing subframe and trailing arm,,, but,,, the real race quality way to do it is to modify the way the factory did it in the DTM.
There is also an even better version that came in on the late DTM92 cars that was an improvement over the early version but those had bespoke fabricated trailing arms and relocated sway bars. If you can find that either used or get someone to fabricate it,,, that is the business.
Here in the US Chris Childs / Angry Sheep Motorsports can do a recreation of the early gen DTM rear subframe and trailing arms.
If you are a great fabricator MRT Engineering sells the important bits for you to weld onto existing subframe and trailing arms.
Its not for the the average fabricator, there is LOTS to get wrong.
Thats what we used with Chris Childs doing the fabrication on my e30M3 race car.
Chris has constructed specific DTM clone jigs to do this job. He does beautiful work.
Why do you need one? When lowering your car rear end toe and camber angles will significantly change on this platform. With this kit you can correct your rear wheel angles and additionally gain sharp and precise steering fele with optimal grip on any applications.
mrtengineering.fi
There was a source for the late DTM92 version in New Zealand a fella named Conrad Timms, he had a specialty E30M3 business called Motorsports Concepts but that shop shut down. Currently the best spot for it might be Vink Motorsport (owner Ton Vink).
I believe both Amspeed Racing in the UK and Muzzi Motorsport in Germany also offer versions of the E30M3 DTM rear suspension.
www.vinkmotorsport.com
Gr.A/DTM Rear Axle & Trailing Arms 90-92 Specification. Reproduced from standard E30 M3 rear axle & fully fabricated trailing arms to the specification of the late E30 M3 Gr.A/DTM rear suspension, with Toe/Camber adjustment, Caliper Mounting and all Strengthening.All components used to produce...
www.amspeedracing.co.uk
www.muzzimotorsport.com
I know Ton has recreated the the early version and I think he acquired the jigs for the later DTM92 version when Conrad / Motorsport Concepts shut down.
Hopefully that gets you started. If you ever want any more info just ping me.
Im certainly not a championship Prod car builder, I'm just a regional hack that races an old M3 that I love in SPU because that's where it fits and I can do whatever I want basically.... BUT.... I'm a complete E30 race parts nerd so I can help with that aspect.
Good wishes in your new build.
Jimmy P
