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Message |
Brian stewart (Eurocardoc)
Member
Username: Eurocardoc
Post Number: 281
Registered: 11-2001
| | Posted on Sunday, May 12, 2002 - 10:12 pm: | |
I would go with a duplicate of Bill's from Truechoice, easy to adjust, raise/lower, change springs. |
Bill Sebestyen (Bill308)
Junior Member
Username: Bill308
Post Number: 220
Registered: 5-2001
| | Posted on Friday, May 10, 2002 - 10:49 pm: | |
William,
About a year ago I was faced with sagging rear springs and did a little survey of what solutions were available at the time, along with a quick assessment of each.
Roads in the northeast, especially the interesting ones, are subject to frost heaves and potholes. This argues for a compliant yet adjustable suspension for touring and occasional track use. My priorities from highest to lowest were:
A. Adjustable ride height
B. Stock style (silent block type) shock bushings are preferred over spherical rod ends for compliance and endurance considerations.
C. Adjustable (external preferred) damping for extension
D. Adjustable (external preferred) damping for compression
E. Useable range of quality spring choices (when you do the conversion of the stock spring rate in the GT-4 manual it's 185 lb/inch, ID-about 3 inch, OD about 4 inch).
The choices
1. Use existing, new, or rebuilt stock OEM shocks with adjustable lower spring perches. I would expect good touring performance but marginal track performance. Cost low to moderate.
2. Tristam Buckley has a setup (you may have seen it on ebay) consisting of custom HAL shock assemblies, adjustable by an external knob which simultaneously changes extension and compression rates in a 50/50 ratio. Springs provided are 2.5 inch OD (I think they're really 2.5 inch ID), 175 lb/in with 200 lb/inch rate available. Spherical rod ends were shown in his add, but they may be available with bushings. I'm leery of this setup because I have no experience with 50/50 shocks. In a track setting, I think they could be an asset. A car in a long bumpy turn, like big bend at Lime Rock, would be more prone to maintain ride height throughout the turn. Stock like action, 80/20 shocks, would tend to compress the suspension towards the end of the turn thus limiting suspension travel and make exiting interesting. Tristam claims suspension travel is unaffected which I believe. I suspect these shocks would be harsh on the road when set for adequate extension damping as one would have too much compression damping. Still, at $700/pair it might be worth trying. Cost moderate
3. Custom Koni setups include a variation on one of their racing shocks, possibly a variation on their 2812, 8211, or 8212 series and Eibach springs on adjustable lower perches. To incorporate OEM style bushings in lieu of spherical rod ends, some custom ends would have to be made. I should probably rule this out based upon cost as it would probably end up in the $600/assembly range. Nice to have though. Cost high.
4. Replace the existing springs with stock ones. Cost low
5. Nick Scania�s solution per Nick
*Easy 6 position damping adjustment.
*Internally vented oil chamber which protects the top seal from excess pressure and stops leakage.
*Nitrogen gas charging for fade-free damping, consistent operation and hydraulic anti-topping.
*Internal 3-stage valve control automatically accommodates variations in sudden shock impulse for consistent damping under all road and speed conditions.
*Areoshell Fluid 4 is used in the shocks for it's exceptional antiwear properties, antifoam characteristics and oxidation stability.
*Bottom threaded nut quickly changes spring preload to adjust ride height.
*9/16-inch piston operating in a inner steel cylinder assures rugged, dependable service.
*Assembly and spring changing are simple; no press required.
*Every component is made in America.$1495.00 for 4 shocks,double adjustable with springs. Approx waiting time is 10-12 days,sometimes sooner.
I eventually purchased the shock assemblies from TrueChoice for about $1300 delivered. They're custom Koni 8211's with 2.5 inch (or 2.25 inch) id Eibach springs. I modified some TRW rack boots to protect the shock shaft from grit, after delivery of the shocks. Maybe the 308 rack boots would have been a better choice, but the TRW units were cheap and available and were the only ones I could find that had a chance of working. Even with the larger 2.5 inch diameter
springs, there is very little clearance between the dust boot and the spring id. Koni NA would have done the same basic job, the same way, for about the same price. The price total was driven to a certain degree by wanting to retain the stock rubber bushings rather than spherical ends. This added about $200 to the cost of the job plus the dust boots plus the rubber bushings. I supplied new bushings and TrueChoice welded the necessary eyes onto their tubes. This welding requirement limited me to the steel bodied shocks rather than the aluminum versions, the 8212's. For the money you get 1960's vintage formula 1 shocks, with external and independent adjustment of bump and rebound damping and ride height. Plenty of things to play and get in trouble with.
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William H (Countachxx)
Intermediate Member
Username: Countachxx
Post Number: 1170
Registered: 2-2001
| | Posted on Friday, May 10, 2002 - 7:47 pm: | |
Its time to get my 308 back on the road, Any experts out there who can tell me where to find a fully adjustable suspension for a 308QV ? I want to be able to lower my car considerably & have it handle aggresively |
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