Looking for first hand subjective opinions on the following springs:
1, H&R standard springs(readily avail from most performance shops)
2, RSC (custom made by H&R)
3, Cargraphic (also custom made by H&R)

Questions;
-general quality/difference over stock ride?
-improvement/deterioration over stock springs on rough/imperfect surfaces?
-measured drop in ride height?
-performance improvement(on track or aggresive driving)?
-More/less Body-roll or "flatness" of ride(does the car still lean/dip into corners?)?
-any other input??

Hopefully this will spawn some valuable information for those looking to tweak their rides. Personally, I'm searching for similar to stock ride compliance/quality with less body roll and only a slight +/- 1" drop in ride height....hopefully from one of the above noted springs.
Cheers!

 

Check pm on springs. The N400 anti-sway bar does wonders for the roll.

 

IMHO - and I'll lay off the technical terms so I do not confuse myself!
I have driven the 2009/10 AM suspension upgrade/option (often called N400 upgrade) and it is very good - for a non-fully adjustable suspension - also can be "retro-fitted" to any model year V8V. The only dislike is it does not lower the car (which I want). I currently have RSC springs, RSC custom made spacers, stock AM shocks and stock AM 19" wheels. I think originally the RSC springs were paired w/ 20" non-AM wheels (Stuart can confirm) and offered the ability to have a lowered ride w/ "softer" feel on the road so the 20" wheels did not beat you to death in real world daily driving. Also do not rub w/ bigger wheels! Lowers my car at least on inch, probably slightly more.
I have driven my set up for 2 years and no quality issues - and I like the lowered effect. Yes a slightly bit stiffer than stock but not bad - been on the track and 10 hour trips w/ wife. A good system for the price. I do not know the difference between RSC, H&R or Carpraphic. I have not driven a car w/ the other two spring sets. Slight rebound/pogo effect over dips (not bumps) w/ 19" wheels but that is probably due to stock shocks. Handles better on track than stock.
The only draw back is no spring set will be perfect w/o a fully matched shock set/design/system. The positive is these springs are less expensive option for a basic stock set up.

A fully adjustable suspension (springs & shocks designed together w/ adjustments to bound/rebound) is the best way to go (also can lower car and geometry shock/spring design will adjust per change - keeps handling at max going up or down). There are several companies, for example that offer fully adjustable suspensions for Porsche - I have not found any for AM V8V. I know there are customers, but you probably need 20 (?) to get a payback on R&D if you are a "big" company (Bilstien/Koni). Also price will be about 4X vs just the springs (about $4K vs $1K on a Porsche - check out Bilstien PSS9 - had that system on several P-cars). BUT the ride handling is MUCH better on twisty roads and the track AND you can adjust for max effect according to your driving/comfort/ability. Then add in an adjusable set of sway bars and now you are ready for any track and get the real flatness going thru a curve. But no one makes these bars for V8V either.
Guess my point is I am waiting for someone/company to offer a fully adjustable suspension for the V8V. Until then you have just a few choices - and that depends on if lowering your car is a priority.

I think Stearnsn has some experience w/ AM and RSC sets maybe he can offer some thoughts too ...

 

Gents, thank you both for the very helpful info, much appreciated!

 

the ride height is great on the RSC but too soft and bouncy for me - I've heard the stock HR springs are tighter.

 

I have the basic H&R on my vantage and LOVE it...Ride height is not too low and ride quality isnt impacted either.

 

+1 ...

 

I've had 4 sets of springs on my car.

For performance:
1- AM handling package
2- AM Stock or H&R, can't tell since I have other stuff on now with the H&R's
3- RSC-- They "pogo" over bumps, very annoying. They worked ok on the track but not on the street. I have 19" wheels and Pirelli Corsa tires. They may work better with 20's.

For height--highest to lowest:
Stock- off road?
AM Handling pkg. (maybe 1/2" lower than stock)
H&R-at least 1-2" drop. Cheap.
RSC- about as low as you can go, looks cool. Too expensive.

Install of rears takes some time so be prepared to spend some $.