I wanted to start a new thread on this subject so as not to thread-jack the x-brace thread.

The debate was IT cars having so much chassis flex that it renders a good damper useless.

Here's my stance:

With a properly design and fabricated roll cage a chassis can be stiff enough to benefit from better dampers (i.e. driver can feel damper adjustments). Said design would need to include a decent chassis to begin with (why I'm using a Volvo 240, both my E30 M3 and E36 M3 a flexi-flyers in comparison), a roll cage that picks up most load points (i.e. suspension mounting points), and proper fabrication techniques. With some thought, stealing with your eyes (look at current designs from top engineered cars) and attention to detail one can have a very good chassis. An engineering degree helpful here, but not required to do this well.

The dampers need not be the latest 4-way Moton/JRZ/Penske/etc. designs. Most of the IRL teams use a head valved dual bleed Penske damper (VBP-45) along with the new A1 GP cars --> completely IT legal! The adjustments allow cheaper tuning in the long run, but most folks never even mess with the adjustments making that feature a complete waste. With Koni Challenge requiring only Koni dampers for 2009 and one could get Koni 28 series dampers for a reasonable price. The Koni 28 series is a very good damper (used by the Prodrive run Aston Martin DBR9's) in the right hands (as with most modern dampers).

Here's a list (not exhaustive) of decent IT legal dampers that hands down beat the standard Bilsteins and Koni street twin-tubes many folks use. Most of these dampers are user rebuildable with some special tools and require nitrogen charging (periodically depending on the leak rate).

Afco R series - 0 adjustments
Afco T2 series - 1 adjustment

Bilstein SN - 0 adjustments
Bilstein ASN - 0 adjustments
Bilstein ASB - 0 adjustments
Bilstein BG - 1 adjustment
Bilstein BGT - 1 adjustment

Carrera GP (RIP, good if you can find them)

Fox - 0/1/2 adjustments

Ground Control Advanced Design - 0/1/2 adjustments

JRI - 0/1/2 adjustments (Jeff Ryan's new damper company)

JRZ RS - 0/1/2 adjustments

Koni 28 series - 2 adjustments
Koni 30 series - 2 adjustments

Öhlins STJ - 0 adjustments
Öhlins MCJ - 1 adjustment
Öhlins WCJ - 1 adjustment

Penske 7100 - 0/1/2 adjustments
Penske 7300 - 0/1/2 adjustments
Penske 7400 - 0/1/2 adjustments
Penske 7500 - 0/1/2 adjustments
Penske VBP-45 - 2 adjustments

QA1 6x series
QA1 82 series
QA1 92 series

Sachs - 0/1/2 adjustments

If you know of anymore IT legal 'modern' dampers please post.

**Many of these dampers can be made into struts without too much work.