Thanks, Bill!

I am currently planning to go for 21/27 mm torsion bars, stock sways, KW V3, 225/50 15 and 235/50 15 Toyo R888R on 7/8 15 Fuchs, sport (85 shore) bushings all around. Mountain / canyon roads only.

I was just wondering if it would make sense to go to larger torsion bars on KW V3 with digressive valving. But I guess 21/27 mm is a safer bet to not make the car too stiff on roads. Also hope the sport rubber isn’t going to be too uncomfortable but I guess I’ll just have to try out :)

Best,
Dennis

Cannot answer your question about KW V3s on a torsion bar car (I have them on my 964), but I am running those Toyos on my 930 (w/16" Fuchs), and they aren't harsh at all. Noisy, yes. But not harsh.

Thanks for the feedback! Have you noticed any increase in paint damage around the fender from road debris pickup with the Toyos? People are warning me about it and I am starting to get second thoughts about them…

Does anyone have an image of the „modified“/ grinded control arm to accommodate the 15 inch wheel with the 19 mm raised spindle?

Does anyone have an image of the „modified“/ grinded control arm to accommodate the 15 inch wheel with the 19 mm raised spindle?

Look at Jonny's Heavy Metal build thread, I'm pretty sure he posted pictures.

I tried this with my 19mm raised spindles and it was a non-starter. I needed about 3mm which would have been a lot of grinding.

For same price, I bought MCS 1WNR and set spindle height at 16mm. I could have gone 2WNR for only slightly more but you give up a lot of low speed compression unless you go remote reservoir with that design.

Raising the spindles is a step to restore compression travel, another step is shortening the shafts and/or bump stops

The other primary issue is bump steer which needs adjustable height steering knuckle and/or raised height steering rack

What did you do to correct the bump steer issue.

I've been looking at 4 options for mine which is at ~170mm(a-b) w/ 8x17 225 tires

option 1
MCS2WNR, + is you can specify spindle height, and shaft length, adj. digressive valving, issue is that I haven't found a bump steer solution other than raise the steering rack

option 2
Bilstein b8 RSR strut or insert, + here is the shorter shaft, issue is that the valving sucks for street use but they can be digressive revalved and there is a readily available adjustable height steering knuckle.

option 3
regular Bilstein hd b6, modified w/ a cut down shaft, digressive revalve, shorter shaft seal, and adj. height steering knuckles.

option 4
Vonn inserts for Bilstein strut. plus is you can specify which level of digressive valving you want, same steering knuckle mods as for a b6, the shaft can be shortened as w/ b6

I discarded all the twin tube designs as inappropriate for my use

Bill, I have an elephant bump steer kit. That got all of the bump steer out when I was running 16s on 19mm raised spindles. I haven’t done the math yet on how that changes going to 16mm raised spindles (all else equal).

I spent a good amount of time with Wyatt at MCS going back and forth on 1WNR and 2WNR. Wyatt’s strong view was 1WNR for road. I’ll butcher the engineering but here goes … 2WNR have two pistons and not much volume in that small package. That’s fine for high speed compression but does severely limit low speed compression against the 1WNR. So I went the 1WNR and if I ever change use case for car I can upgrade to 2 or 3W with reservoir. Can’t upgrade the 2WNRs.

I’ll be installing it all this week.

So you just had the Elephant double knuckle kit welded on locally?

I agree w/ Wyatt about the volume issue, but don't know how big an issue it might be, The external cans have issues as well because of the hose restrictions not to mention mounting issues

didn't know that the 2wnr wasn't upgradeable


did you go w/ a shortened shaft?

Before you install, any chance of measuring the full compression travel and force? It would also be interesting to see where the ride height compression sits within the full range of travel.

I seem to recall that MCS uses a higher internal pressure than Bilstein and that the force to compress is commensurately higher

Bill,

I’ll send photos of current setup. I didn’t raise spindles and adjust bump steer first time around. That was all Tyson Schmidt. I’m going to tackle this time around.

In discussion with Wyatt, he never brought up shortening the shaft. We covered just about every other base and ended up at 16mm raised spindles only.

I don’t have a good set of scales but let me see if I can rig that test up. I did ask Wyatt about some tests I’d seen that forces to compress are higher. I must admit my eyes glazed over when he was explaining why that wasn’t the case … presume something to do with suspension already under load when on car so you’re “in the curve” already?

Bilstein and MCS are high pressure mono-tube shocks, that's the absolute best for performance

stock Bilstein have ~300psi internal pressure that provides ~42# of extension force this rises to around 52# at full compression

I can't find the specs right now but MCS specs a higher internal pressure which provides a higher extension force, the thing is the MCS internal pressure is user adjustable.

Getting facts for this stuff is maddening, I know that Bilstein b8 are shorter than b6 but Bilstein refuses to say by how much, When I've looked at them side by side it appears to be ~1" and they use a special shaft shorter seal as well.

The more a 911 is lowered the more mods are needed to correct issues.

Lower from stock, say 110mm to 135mm Ie by ~1" and theoretically you want to raise the spindles by ~1" and raise the rack by ~1", but physical limits prevent both w/ 15" wheels w/ 16s you can raise the spindle ~1" but the steering rack can only be raised by ~1/2",

when you get to 3" drop you need a shorter shaft in addition to the raised spindles and raised rack, and you also need the adjustable steering knuckles. 18inch wheels ought to help as well.

Bill,

Very happy to measure the MCS struts any which way if you send me what you’re after. I can try and grab some scales and measure compressive force against my bilsteins (can’t recall shocks … were for 930 of same period but I recall those coming in a couple of different guises).

I don’t intend to run the car overly low. 25.5 using the fender method. Not sure what that translates into in terms of hub center to torsion center. Needless to say, I am going to have a bugger of the time resolving bump steer.

Ant metrics would be greatly appreciated
This is a very rough estimate but as far as I can relate the 2 , 25.5" fender is around 150mm a-b

That is ~40mm lower than stock spec or ~1.6" lower if you prefer.

The relevant curves are in the top left here, the red line is roughly where your car will be at ride static height. The dashed line is the bump curve, the linear portion is as good as it gets for a 911, where it flattens is where it is getting worse, you will be approaching the flattening section. A simple set oof rack spacers will move you further back into the linear portion, the Elephant adj. knuckles will move it further, not even much shimming down will be necessary to center it.

http://forums.pelicanparts.com/uploa...1755990124.jpg

Hope this is clear enough

x is the total length of the shock, I would like to know x at full extension, full compression and at static ride height

y is the length of the lower leg of the strut

Z is the length on center of the a -arm

TR is the

http://forums.pelicanparts.com/uploa...1755990755.jpg

Thx Bill. Very helpful. Have a bit of reading up to do but will report back.

As promised … my best attempt at science. Very surprised by how short the struts are.

Went with 16mm raised spindles for 15” wheel. Difficult to do the strut body to spindle collar measurement given how MCSs come together but looks a near true 16mm (15.54mm to be exact).http://forums.pelicanparts.com/uploa...1756257820.jpg
http://forums.pelicanparts.com/uploa...1756257820.jpg
http://forums.pelicanparts.com/uploa...1756257820.jpg

Was a busy day but it all came off very easily.

This inner bearing was disappointing though. It looks to just be a pinched housing, and I was tempted to use a made in Germany bearing, but will probably have to swap all bearings and re-pack.

http://forums.pelicanparts.com/uploa...1756258119.jpg

THX!, Very helpful

I see the adj steering knuckle setup on the Bils but not the MCS

For a very much lowered car the shorter shock is another tool that is very helpful.

Sortta surprised that they hadn't mentioned that to you, it was one of the things that I really liked about MCS, I believe that they allow you to spec the length w/i in a reasonable range.

Were you able to get compressed length and the compression forces?

I just started to look into a 5th possibility for mine, Ohlins, has a Bils. insert for my modified Bilstein struts, it looks promising, but I need more details, which aren't easy to come by

I just don't understand the reluctance of these companies to provide complete factual information on their products, Bilstein even provided demonstratably false information to me and to several others who I am in contact w/ . That's even worse and it tarnishes their reputation.

Will see what I can cobble together with some crappy bathroom scales tomorrow, Bill.

MCS were very assured and that was reassuring. The strut height however was a surprise but may have been assumed knowledge (apparently MCS etc always shorter). Interesting tid bit … the Tuthill 911K uses 1WNR with Richard’s special valving.

Re: bump steer kit. Am I crazy for thinking I can run that in single sheer. I’ve read all the threads and folks using the Rebel or Tarrett kits have satisfied themselves that it’s OK.

Some guys even really hard-core track aficionados do run single sheer, I just don]'t trust it.