mekilljoydammit Professional Moderator Join Date: 09/22/2010 Age: Midlife Crisis Posts: 336 Rally Car: No rally car yet |
Yeah, I was trying to treat the subject kind of lightly. Ah well.
Interesting food for thought is some friends running RX-7s in SCCA EProd (roadracing) switched to Dynamic inverted struts this year. Pretty sure that's just plain bushings though, unlike the uberfancy rollerbearings that apparently showed up in touring car use across the pond. Hard to confirm what they think of the stiction and other effects vs. the old offerings though, as some of what they used to run on their cars were real, uh, crap. Personally, as someone who's more likely not going to be a rally guy any time soon with event locations what they are, I'd really go for something that has enough piston and shim options that I can make it do what I want, doesn't weigh too much, fits on the damn car, is stiff enough to not be much of a factor, doesn't fade by the end of a race, and doesn't break the bank. Probably 36mm Bilsteins, come to think of it, except for the "fit on the car" part. Yeah, this is all offtopic, but so's stuff about 50/55/60/90/1700mm struts. |
Reamer Jeff Reamer Senior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
I just remeasured my oval track Bilstiens and they are 46mm. This hole time I thought they were 50mm. That does make these more intising now as long as we can get them.
The MCA sight looks good. I wonder how fast there turn around and cost is? First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
john vanlandingham John Vanlandingham Mega Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
We are assuming you are speaking of the pistons with that 46mm, right? Cause i have piles of the normal circle track shocks and they are indeed 50mm OD on the body.. Have you compared the actual pistons and shims Bilstein to Penske? I really can't belive the Penske piston head is so much different from the linear or progressive pistons for the Bilsteins, and a shim stack is a shim stack is a shim stack...depending on diameter and thickness of course. The thing I'd love to do is machine up some alternate compression side limiting washers with an angle on the downside--specifically for high shaft speed blow off.. oh say about 7 degrees. We did that on Ohlins way back in '76 for baked earth track and rock strewn surfaces like summer in France, made a nice difference. Eventually we had 3, 5 and 7 degree washers, but I did mainly hard dirt w rocks so I just left the 7 degree in. The 3 was for sand with chest deep bumps. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
Reamer Jeff Reamer Senior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
Penski pistons are bigger. Ohlins are the same and will swap over. The Pistons I have in my oval track SLM are drasticly different. Im sure Bilstien has better quaility stuff I just havent seen it. North Carolina Nascar country has all sorts of piston manufactures that will fit ohlin and penski. I thought till today that Bilstien were smaller but it looks like most all the Nascar style pistons will work. Now to find out what piston is acttually best fore rally. My oval stuff is high flow 1degree 3degree pistons up front and linear 1 degree 1degree. I know the new tie down bump stop cars are running higher degree pistons.
First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
john vanlandingham John Vanlandingham Mega Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
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Doivi Clarkinen Banned Mega Moderator Location: the end of the universe Join Date: 02/12/2006 Age: Possibly Wise Posts: 1,432 Rally Car: 1980 Opel Ascona B |
Hey, take it easy on him, he's a troubled teen... |
mekilljoydammit Professional Moderator Join Date: 09/22/2010 Age: Midlife Crisis Posts: 336 Rally Car: No rally car yet |
You know, I can't believe all this time I never tried to put the Bilstein piston and stuff I have into the Penske tube I got for fun. Aren't the standard Penske sizes 45 and 55mm?
The shim diameters aren't the same, but thicknesses are thicknesses, no? May not line up with the linear ports on a Bilstein piston though. The inner hole on most of the Penske shims are 1/2", though there's a newish weird piston design that passes fluid through the middle of the shim stack to a secondary blowoff above them where the hole for those is 5/8; the Bilstein normal stuff is 8mm, right? Penske has all sorts of weird piston designs besides just the normal linear and digressive styles - what they call their variable bleed design has a linear stack with an amount of bypass area controlled by screw-in jets, that is then regulated by a digressive stack. Apparently the stuff with the design that bleeds the fluid through the middle to a separate blowoff is so that it can make a lot of force at zero shaft speed, and then act like a normal shock at non-zero to tie down NASCAR front ends at speed. All of this is probably irrelevant and unecessary to rally stuff, especially at the North American level. The big advantage to the Penske stuff as I see it though is that you can get bits, including clickers that work, on ebay. Necessary, no, probably not, but what the hell. But hey, I'm not an expert. If anyone cares, http://www.resuspension.com/Penske-orderby_0-p-1-c-276.html has a bunch of pictars of the Penske pistons; http://www.penskeshocks.com/files/7300_Series_Manual.pdf has, around page 13, a bunch of example force/velocity curves produced by the various pistons. |
Doivi Clarkinen Banned Mega Moderator Location: the end of the universe Join Date: 02/12/2006 Age: Possibly Wise Posts: 1,432 Rally Car: 1980 Opel Ascona B |
Penske does make rally struts. |
urr Andrew Sutherland Mod Moderator Location: Studio City CA / Camas WA Join Date: 02/22/2008 Age: Midlife Crisis Posts: 275 Rally Car: Subaru, EVO, Honda, Husky |
When I was searching for Honda EP3 options, these guys came up. Something about them solving a friction issue that would wear out the top bearing due to the design of the "whacky" front shocks on the EP3. I seem to recall that the price was around $5k and everything was built to order. Emails were prompt but I'd be worried about support from the other side of the globe. |
mekilljoydammit Professional Moderator Join Date: 09/22/2010 Age: Midlife Crisis Posts: 336 Rally Car: No rally car yet |
Yeah; for some strange reason, they never admitted they do struts over here until lately. Finally struts showed up on their site after they started showing up on some American Sedan (SCCA roadrace class) cars. Looking at the UK site you linked, I wonder what the hell a "triple tube rally strut" is. I was more thinking something on the budget end though; steel tube (there's a steel bodied 2"ish OD shock they make for some circle track class or other, or from other sources) with whatever coating, an end cap with a pin welded on one end, the normal style screw-on cap on the other, riding in a tube with a couple DU-or-bronze-or-whatever bushings. Upgrade the valving or to adjustable shafts as budget allows, schrader valve or canister at the top of the pin, etc. But realistically though, that's one of those things where it would be nice if it existed, rather than "this would be a cost-effective thing to make and market". May make a set some day, maybe not. |
john vanlandingham John Vanlandingham Mega Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Damper Prices PS-7100 From £159.00 PS-7300 £612.20 PS-7500 From £269.00 PS-8300 Remote £565.00 PS-8300 Piggyback £685.00 PS-8760 Remote £825.00 PS-8760 Piggyback £825.00 Through Shaft Damper £900.00 Optional Upgrades (when ordered with initial build) Digressive / VDP Piston £70.00 each. 8760 Eyelet for 8100 series £75.00 each. Eyelet 8760 4" Extended £133.00 each. Eyelet Mounting Spacers £12.00 per pair Thrust Roller Bearings £13.50 each. Bump Rubbers £13.29 each. Plus freight and customs duty, probably brokerage charges.. Yeah, a real deal.. Struts wil cost POA . John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
mekilljoydammit Professional Moderator Join Date: 09/22/2010 Age: Midlife Crisis Posts: 336 Rally Car: No rally car yet |
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BillyElliot Billy Elliot Mann Infallible Moderator Location: Royal Oak, MI Join Date: 08/11/2008 Age: Midlife Crisis Posts: 557 Rally Car: 1996 Honda Civic with VTEC YO! |
I had looked at doing some custom work on a triple adjustable setup for the Civic. Was going to use modified Bilstein bodies with external Penske reservoirs with high/low speed compression. The price of each external can wase somewhere $400+ range if I recall.
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Reamer Jeff Reamer Senior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
Instead of using a 7 degree tapered washer. You could use more of the base shim to raise the piston and give you the high shaft speed blow off. Penske basic shim stack would have 4 shims. .750,900,1.100and 1.300. So if you want more high speed blow off I think you could start with the flat washer then 3-.750 instead of 1 then build the rest of your stack as wanted. This should give you the same affect as a 7degree washer.
Penske does make a smooth steel body that could probably be easily ground to shaft grade. Most of the struts Ive tore into dont seem to be hardend. This may also be an option. First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
sidewaez Blake Lind Junior Moderator Location: Hillsboro Oregon Join Date: 06/09/2009 Age: Midlife Crisis Posts: 233 Rally Car: orange AE86 |
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