Well boys - you can't say I didn't try...if I told you this happened you'd think I exaggerated.

Here's the box of expensive hand built shocks from Bilstein.



Now missing one rear shock. I have no idea what the valving is as I was told they write the valving on the shock...no markings on mine. I have to call them anyway - so I'll see if I can get the basic bump/rebound specs. They're a lot stiffer than stock shocks.

That IS unbelievable! You would think they've shipped enough of those by now they would have the box figured out to avoid a shock blowing out the end of the box, unreal.

GAAAAHHHH!!!

No good news yet - but just for fun I asked for the specs for the shocks and have been promised the dyno sheets. That'll pass for good news for now.

I did get the dyno sheets with the shocks and struts when the replacement came. So for further reference, here's the file - these are significantly different from the values for compression reported by Dave Barton. It's taken a few days to learn how to decipher these values and learn what people are talking about with shock values. Thought I'd share this here to help clear the air a little.

http://www.calgaryvolvoclub.com/gallery/d/26765-1/Coburn_242_Damper.pdf?g2_GALLERYSID=a0d90badcbe70f2fdc222d069dd93cb9

The first problem I've had when reading the posts by the illustrious JVL over on TBrix is "what are the units" - sorry I'm a scientist, so without units what are the numbers relating? How can we compare shocks without knowing the nature of the valve stack and various slope changes and other data. So when Dave Barton reports:

R-Sport Strut Cartridge (FRONT), Volvo PN 552197, Rebound/Compression
360/100
R-Sport Shock (REAR), Volvo PN 552198, Rebound/Compression
400/100


These are the rebound and compression values in decanewtons (10 Newtons of force or 1 kg of force) at a standardized value of 500 mm/second shaft velocity. So when someone says they have front shocks at 360/100 there isn't a single number that corresponds to that on the chart. From Barton's dyno - there is no 360/100 anywhere. We have Newtons plotted against shaft velocity in mm/second. If you go to the number that is around 500 mm/second and look, you find 3610 Newtons - which is 361 decanewtons or around 360 and the compression is -967.6 N or around -100 decanewtons (which are reported without the sign for reasons that baffle).

So my front struts were valved at 115/94 and my rear shocks were valved at 267/144.

Great explanation Craig - thanks for that.

Would you mind sharing the info provided to them so they could re valve? I'm guessing spring rate, but did you also have to provide any motion ratio data?

Thanks,

Rabin

I did a quick interpolation last night of Barton's shocks, and assuming the rate is linear between the two numbers bracketing 500 mm/sec I was able to get extremely close to his posted numbers by converting newtons to kg-f using the 9.81 m/sec2 factor. I believe you're right, Craig, in that is the unit he's reporting.

Also from Barton's page, the stock Bilstein fronts are 129/75 and the stock Bilstein rears are 225/107.

Interesting to see how little changed your dampers appear to be, at least based on this "standardized" 500 mm/sec rating. As was pointed out, this is like predicting how fast a car will go around a road course solely on it's quarter mile acceleration - there's a certain amount of magic that isn't represented.

I'm more prone to believe the numbers from my sheet than the the ones reported on the web. When I compared the graphs, the dampers are quite different at 500 mm/sec but very similar at slower shaft speeds. So I don't think these numbers tell us much of anything. Barton's dyno sheet shows the rates going off the chart at higher shaft velocities...so they would be pretty harsh over pot holes and road irregularities.

We'll know in a few months I guess. What I can tell you is that at slow shaft speeds (like me leaning on them) these struts and shocks are a lot harder than stock!

Oh and Rabin, the motion ratios and unsprung weights they seemed to be well aware of - they didn't seem to care much about these (I expect they have a database with this stuff). They did want my corner weights and new spring rates and a virtual drive along so I could tell them what the car does. I sure hope this works.

Thanks Craig. Last question - can you tell me why
Bilstein and not revalved Koni?

Just curious - I've read pros and cons with each, so genuinely interested on your decision to go with Bilstein.


Rabin

Working at a fevered pace these days. Tonight's I switched cars to get the struts modified for adjustable coil overs. They are getting a full rebuild with new SKF bearings and seals. I had to get these done and get them in for powder coating.

So here's the process. First a look at my starting point. I'm still shocked at how clean these struts were. Unreal really - not a spec of rust anywhere. NONE. So odd.




I then pulled them all apart as I'm getting the full thing including hubs coated. Changing the studs out to longer Kaplhenke parts and turning my adapters into spacers on the front for right now. I'll do the rears later.

So here we are stripped a few minutes later.



Now for the hard part - cutting into these perfect struts.

I very carefully ground the weld bead back then used a fine cut off blade to break the weld penetration. Not much more than the odd nick here and there.



A few taps with a hammer and bingo - both spring perches popped right off.



Seriously - I feel bad about doing this.





Kaplhenke sleves fit right over the tube - no grinding or savagery required.



Measured 1" down the tube to spot the mount the stop ring and mark the area to clean the existing coating off the tube.



That's where I left it for the night. Total time - about 1/2 hour for all prep work. Crazy easy to do. I'll TIG them up Friday as they go in for coating on Saturday.

There are no limits to questions. Koni's cost a lot more than what Bilstein's charges for a revalve - $65 for the Billies, $150 for the Koni's. I've also had great luck with Bilstein's over the years - I can't say enough good things about the service department either. They were responsive to my requests for information, got my replacement done in record time when UPS savaged the package and lost the shock. Sent dyno sheets when asked. Also when we found that the DeCarbon's were not revalvable - they cut me a great deal on the replacement struts (lowest google search price) - I didn't have to ask - that's spectacular service.

The struts on my car were originally Matt's, then Greg's now mine. They're well used and fine. They are the finest in monotubes according to guys that build them. Koni also makes a great shock (the race line at least) and lots of people swear by them. For my budget, the Bilsteins were literally half the price of comparable Koni dampers.

Done - off to get powder coated all pretty.

Fun times this weekend finally saw all the Kaplhenke suspension stuff make it's way into the 242. I don't have pictures of much of it, I'll post a few, it's a suspension...it looks like a suspension. The difference between this set up and what I was running is like night and day.

First the details.

Front
400 lb/in front springs, roll correctors (set with the 5 degree Ackerman shim) and steering arms set in the second hole. New brake hard lines for the front end from the distribution block to the wheels, new stainless flex lines. Struts rebuilt with new bearings. Wilwood brakes still working fine after 50,000 km. We cut the strut towers to accommodate the new full mac-daddy strut bearing tops with luxe steer bearings and tender springs. Custom valved Bilstein HD's.

Rear

Set the adustable sleeves into the FRAME RAIL and mounted the spring cup on the lower control arm. Installed the new custom valved Bilstein HD's (which I could barely compress onto the stud to mount...they are very stiff). 250 lb/in springs. Stock sway (19 mm). Cut the rear fenders at the rear to avoid tire rub. New stainless flex lines. Powder already rusting on the LCA's after one winter. It wasn't done very well I guess.

First driving impressions were just down my back lane (a pot hole fest) and then to Greg's - not the smoothest track in town. Then around the streets where we live (the camber is set too high, so nothing serious) and I can say that the car feels very well planted and turns sharply. It doesn't rattle or make odd noises over bumps and is much improved over what I had. I would describe the ride as firm, but not brutal. The steering feel is fantastic - point and shoot sports sedan tight. Unlike any 240 I've ever driven. Transition response is great. Can't wait to get the summer tires on it to see how it runs at autocross now.

So everything aligned up just fine - I'm still not 100% happy with how this car aligns, but I guess the former front end whack may be affecting things. With the new front and rear suspension I can now get -2 degrees camber (no less, but lots more) but the caster is below the spec for the car (which is min 2 degrees). I've got 1.5 on one side and 0.8 degrees of caster on the other. I'd need to cut the strut tower tops and weld them back in place to get this thing square. That's all we can do with it for now.

Then I found that my 215 winter tires are just kissing the strut coil over adjusters. Dammit. Really. I can't run more spacer as this would kick the tire out and cause rubbing problems, so I just had to order two shorter springs. I could ditch the tender springs to move the spring up the coilover, but I like having them there for when I jack the car up. Less drama if the spring doesn't find it's home right away and with the Luxe steer aluminum parts, that would get ugly.

So the springs are now ordered. Tires are in...and I bought the wrong damn tire and in a 225 so it'll rub for sure. I'll be rolling BFG Sport Comp-2's instead of Rival-S's (both UHP summers, but the Rival S is a great autocross tire and the Comp-2 is a little older and is a 340 wear rated tire instead of a 200). I hate buying tires. So it will be slower - but it will still be better than my worn out, nail hard Ventus EVO 12's. This isn't that serious a mistake in the grand scheme of things. The fact that I can't run them at all is a bit of a piss off.

Here's the old outmatched 300 lb ghetto spring front struts.



This is the replacements.



On the car.





New front brake lines, new flex lines and new lines from the calliper to the strut.