Custom DIY Suspensions. WHo has done it and how?

[ak-]

Only "custom" thing I've done are roll center correctors. That page showing all the DTM goodness makes me drool.

I've been on and off about this for a long time. Lots of 240 and Miata guys do it, but it scares me. I still want a solution!

[petrolhead]

No- one looks here in Warshington state... I don't even freak out
when I lose a headlight, taillight, etc. Wild Wild West, baby!

Gustave's site had a great bunch of pix, and there have been more that popped
up here not too long ago Really cool stuff! How to make an oxcart handle AND be adjustable
for roll center...

t

If "street legal" or "class rules" aren't a consideration, I'd be building a double wishbone setup. Not rocket science, basic trigonometry gets you far.

To answer the original question, look up my project. It's not off the shelf-stuff. Even then I consider my setup to be just a starting point, to be tuned as I rack up miles.

Only "custom" thing I've done are roll center correctors. That page showing all the DTM goodness makes me drool.

I wonder what that does to bump steer. I found steering rack height (relative to shock top support and lower ball joint)
to be somewhat significant to bump steer.

[djjerme]

http://www.s14.net/jakesdtmtours/suspension.html

Is the one I was thinking Toby, though the one you linked to is good as well for reference..

[e30_302]

I had my control arms made, basically. Press out the outer ball joint, install spherical bearing stuff. The tapered pin came from SLR speed. BimmerWorld has discounted their e36 race arms to $500, I couldn't replicate what I did for that.

It did make a noticeable difference in front grip. No noticeable bump steer.

[TobyB]

Magnus!

Jeremy, thanks, I don't think I'd seen that one before...

t

[djjerme]

Yeah, it gave me all sorts of ideas for the new Chumpcar..

This last weekend I got some great data points for future suspension upgrades on my own car this off season (or maybe before the 8 hour..)

Unfortunately, it was cut short by a head gasket that went to recess on the second to final lap of the group 8 enduro. It wasn't so much the gasket dying, or the fact we lost our beer bet with Ted Rees - it's that we ended up losing to a DAMN PRO44! ARGH!

[econti]

http://www.m3motorsport.co.nz/produc...ear-suspension

This company in NZ has pretty crazy DTM reproduction stuff.

Does anyone have experience or know anything about this?

[djjerme]

If you want to go full retar-errr I mean full DTM, check out S14.net.

I am sure someone over there has the full low down on that suspension. There is a small number of people/companies who do repop DTM style suspension upgrades. This is one of them, and then there is another in the EU, but I can't recall their name at them moment. Both produce some awesome (read: outside my $$$ budget) pieces.

Not a dig on R3v or S14, but here we are a bit more "budget minded" where as many of the people on S14 got nutz out on their builds! Hey, if you got the money and resources, why not enjoy it..

[econti]

The dynamic geometry of the E30 has been a concern of mine for a while, and because of the things I do and plan to do it'll likely start to break things in the rear end.
So options for me in the event of that are basically throw expensive axles at the standard rear end and deal with not great and non adjustable geometry, narrow a E28 frame, have better dynamic geometry however non-adjustable and stronger axles, or forget about my bank account and do something like that.
The way I see it I'll have the car for a very long time (I hope!)
Also it's just total engineering porn :)

[TobyB]

it'll likely start to break things in the rear end.

I am continually amazed at the amount of abuse the E30 suspension (both front and rear)
can take. I've gotten myself hit almost head- on into both front and rear wheels
(stupid spin on my part) and NOTHING even bent. Just sheetmetal. It's pretty impressive.
BMW learned a lot in 40 years of rear trailing arms, and the E30 got most of the
benefit from that development.

So while improving things is never bad, it takes a LOT to hurt the suspension
(especially compared to what one jack can do to the rocker panels in about 30 seconds)

t

[econti]

The driveshafts however don't take kindly to clutch kicks and dumps as it's the instant shock load that gets them. Hell, a friend blew both CVs with a stock M30 and semi slicks, shifting from second to third at the drag strip.

[djjerme]

Side stepping the clutch is going to destroy U-joints/Diff/Cv-shafts in ANY car.

If you want to drag race (and this is probably one of the worst chassis to start with) I would eliminate the CV shafts and convert to live axle set up. Whether its a Ford 9" swap or narrowed Dana, you will be better off and have more consistent runs with a solid rear then a half shaft set we have.

And that's 20 years of on again/off again bracket drag racing talking in many, many different chassis..

[2mAn]

Didnt someone put a Viper rear end on a turbo S52 car years ago? Maybe we should direct him that way