Best Auto X setup

[CrazyB]

I am starting to plan my next suspension rebuild for my DSP 325i.
Currently running on Billy sports and IE 3 springs. I am planning to move to full coilover setup for the extra adjust-ability and tire clearance.
What would you guys recommend.
I know most people run Ground Control, but is there any other setup out there you would recommend?

[Voluted]

The BC Racing coilovers have been getting praise on e30tech:

http://www.e30tech.com/forum/showthread.php?t=91779

[e304me]

AST is a lot better than ground control

[Hellabad]

AST is a lot better than ground control

Dear e304me,

AST is a shock absorber company, and Ground Control is a complete suspension company. You can't really compare the two, even to try to make some kind of point.

Ground Control pays both Koni and Moton to make custom shocks for them, and all three are different price ranges.

If you DO want to make an argument, you can argue that the top end AST shock is better than a standard Koni, and I would not disagree, but they also cost much more than $US 750 for a set of four.

Perhaps you have seen the camber/caster plate that GC designed exclusively for SCCA Street Prepared rules, and perhaps you could recommed those, combined with AST shocks for an autocrosser?

Here is a picture, with measurements to show the advantages for Street Prepared cars.



As always, if you have questions, you may PM, email or call me.

Jay

[CrazyB]

AST is a lot better than ground control

yeah i think the 4200 kit is out of my price range, the 4100 is on the pricier end of the other kits in same category.

[CrazyB]

Dear e304me,

AST is a shock absorber company, and Ground Control is a complete suspension company. You can't really compare the two, even to try to make some kind of point.

Ground Control pays both Koni and Moton to make custom shocks for them, and all three are different price ranges.

If you DO want to make an argument, you can argue that the top end AST shock is better than a standard Koni, and I would not disagree, but they also cost much more than $US 700 for a set of four.

Perhaps you have seen the camber/caster plate that GC designed exclusively for SCCA Street Prepared rules, and perhaps you could recommed those, combined with AST shocks for an autocrosser?

Here is a picture, with measurements to show the advantages for Street Prepared cars.



As always, if you have questions, you may PM, email or call me.

Jay

thanks, for being so informative, i have not heard of this SP specific plates. What makes them different form your guys standard race springs?

[dinanm3atl]

Best? I dunno. I enjoyed my GC shortened Koni Race system... track later this year. 3-4 more Auto-X...

Sat REAL nice and flat and was able to walk it around as I pleased.

[Hellabad]

thanks, for being so informative, i have not heard of this SP specific plates. What makes them different form your guys standard race springs?

In a situation like this, I work from the rule backwards.

Autocross cars need lots of camber. It is against the rules in SCCA SP to bend the strut housings no matter what.

Therefore we need to get all the negative camber we can via the strut mount (aka camber/caster plate)

One slightly unusual SCCA rule for Street Prepared is that the center hole for a camber plate cannot be modified. I call it the "Sacred Hole" rule.

So working back from that, we need as much camber as we can get, without modifying the hole like the GC design for Improved Touring , it is obvious that the bearing needs to be 1) small and 2) slide under the sheet metal.

So we designed a camber plate that is not limited by sheetmetal, and only by the strut shaft itself. (Click here to see them)

Additionally, within the rules I posted below, we added a large amount of caster adjustment, and by using two separate bearings we were able to maximize suspension travel no matter where the spring perch is located.

F. The following allowances apply to strut-type suspensions: Adjustable
camber plates may be installed at the top of the strut, and the original
upper mounting holes may be slotted. The drilling of holes in order to
perform the installation is permitted, but the center clearance hole may
not be modified. Any type of bearing or bushing may be used in the
adjustable camber plate attachment to the strut. The installation may
incorporate an alternate upper spring perch/seat and/or mounting block
(bearing mount). Any ride height change resulting from installation of
camber plates is allowed. Caster changes resulting from the use of
camber plates are permitted.

Jay

[CrazyB]

I had one more question. I am currently running IE stage 3 springs in the back. Would you guys recommend keeping the rear sway bar for auto cross, or would you recommend to run no rear bar at all?
not sure if IE stage 3 are stiff enough to run with no rear bar.

[dinanm3atl]

Run a bar with springs. I don't think any off the shelf springs are stiff enough for no rear bar.

[Hellabad]

Run a bar with springs. I don't think any off the shelf springs are stiff enough for no rear bar.

this.


you can try a 318 rear bar in rubber bushings, but "the no rear bar trick" only works when the rear springs are kinda stiff, and the rear camber is stood up a bit.

stiffer rear spring=less camber change=more consistent alignment=easier to drive car