johnc Posted October 30, 2006 Share Posted October 30, 2006 Is that something you can share with us? Penske 8760 triples and yes I can build a set for your 240Z! Price to be determined... The upper bearing is pretty special on this shocks. Its about two inches long and is made out of some unobtanium stuff that always stays slick. Quote Link to comment Share on other sites More sharing options...
zbloke Posted October 30, 2006 Share Posted October 30, 2006 Guys, I don't know if you have seen these but they claim to reduce bending load on the shock absorber by upto 96% Hydraulic Spring Perch Any use to you? Tim Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 30, 2006 Share Posted October 30, 2006 They don't work on struts. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 30, 2006 Share Posted October 30, 2006 I never saw those perches offered in 2.5" sizes.... http://www.pegasusautoracing.com/group.asp?GroupID=HCP As I recall you can use one per spring... but they suggest 2 per spring... The price is redidulous... even for only 4 of them.. the price of 8 would be astounding... The prices for Penske shocks are... well... shocking... $775 typical... OUCH I found some bling bling shocks you guys might not know about... I can't read Japaneese.. and the translator does not help much... www.bils.jp CC40 model... Quote Link to comment Share on other sites More sharing options...
johnc Posted October 30, 2006 Share Posted October 30, 2006 They don't work on struts. I'm probably the source for this information. Its not totally true. After talking with Hyperco and the guy who supposedly invented these things, the hydraulic spring perches will reduce side loads on the strut from spring tension only if the upper and lower spring perches are the hydraulic type. Just a lower hydraulic perch won't work. My research was part of a build of a Solo2 SM2 240Z and both I and the customer thought spending $700+ on upper and lower spring perches for the rear only was excessive for something that may not help at all. There was also some additional cost machining the camber plates to accept the Hyperco hydraulic spring perches. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 30, 2006 Share Posted October 30, 2006 Don't worry, you weren't "The Source"... Maybe it was that the side loading from ours being a strut suspension was so much greater than the side loading from the spring winding up, that it just wasn't worth it to spend that much money to reduce the side load by such a small amount. I can't remember. Maybe The Source will pipe up... Cary??? Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 31, 2006 Share Posted October 31, 2006 You guys keep in mind that some of the upper mounts... Like John C and some others will force the spring to bend... For Coffey's design the spring perch is held parallel(in the same plane) to the top of the strut tower... the mono ball at the top of the strut rod is able to swivel and flex... this means that the spring upper perch angle can be out of whack with the strut rod angle... and it changes throughout the suspension travel... This misalignment is probably too much for hte hydraulic perches to account for... If I were to fix this I would employ a hydraulic upper perch ONLY... Some of the other designs like the AZC set up use the strut rod to hold the upper spring perch in relation to the strut rod itself... The benefit of Coffey's design is that it has a lower stack height... Quote Link to comment Share on other sites More sharing options...
tube80z Posted October 31, 2006 Share Posted October 31, 2006 Don't worry, you weren't "The Source"... Maybe it was that the side loading from ours being a strut suspension was so much greater than the side loading from the spring winding up, that it just wasn't worth it to spend that much money to reduce the side load by such a small amount. I can't remember. Maybe The Source will pipe up... Cary??? Yes, I was probably the original source. And that info came from Richard Pare who was one of the designers. Richard has a business with Steve Lathrop called ICP. They build a number of special parts for formula cars. Richard and Steve used to go around the country teaching a club racer race engineering class. I learned a lot more from those guys than I did from Claude Roulle's seminar (not to say that it's not good). And the best part was it was only $250 to attend. Sadly they quit doing it because they couldn't get enough attendees. Richard shared that these were super secret and used by WilliamsF1 a some years back. Williams was one of the last remaining cars that ran coil springs. And these almost won at Monaco. And for what it is worth, Richard said these won't help strut cars at all because we already have so much side load on the shafts. He said to do the standard racer trick of using bearings under the spring to reduce friction and that's about the best you could hope for. I guess I should also mention you don't need these if you don't have a coilover arrangement, meaning the spring is separate from the shock. Just another thing to think about Cary Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 31, 2006 Author Administrators Share Posted October 31, 2006 He said to do the standard racer trick of using bearings under the spring to reduce friction and that's about the best you could hope for. Cary Cary, I was just thinking about this a couple weeks ago. You're talking about running needle thrust bearings between the spring and perch right? Have you tried this? How much benefit are we talking about? Would they normally go top and bottom (of spring) or is one bearing per spring typical? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 31, 2006 Share Posted October 31, 2006 http://timken.com/industries/torrington/catalog/pdf/needle/n_thrust.pdf FNTA-6590 + the hardened washers fits a Ground Control 2.5" coilover spring perch for a 240. Quote Link to comment Share on other sites More sharing options...
tube80z Posted October 31, 2006 Share Posted October 31, 2006 You're talking about running needle thrust bearings between the spring and perch right? Have you tried this? How much benefit are we talking about? Would they normally go top and bottom (of spring) or is one bearing per spring typical? Two, one on top one on bottom. Jon gave you the part number above. The procedure to determine the friction reduction for this or any other mod is as follows. You press the car down slowly and let it rise back up and measure the ride height. Now we raise the car and let it lower back down and measure the ride height. The difference in ride height x 2 x spring rate at the wheel = the force required to move the chassis. The goal is to make this number smaller. I don't recall the actual reduction in pounds but there was a measureable, but small, laptime reduction on the enduro course -- damn you more secrets extracted Take a look at the hyperco perch video and you'll see why this works. Cary Quote Link to comment Share on other sites More sharing options...
johnc Posted October 31, 2006 Share Posted October 31, 2006 The benefit of Coffey's design is that it has a lower stack height... I can't take credit for the design, Erik Messley of EMI Racing came up with it way back in 1990. I just sell them for him. And yes, if the upper spring perch pivoted with the monoball the spring would distort less and impart less side load on the strut. It was a compromise built into the design to comply with SCCA Solo2 Street Prepared rules at the time. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 31, 2006 Share Posted October 31, 2006 That same torrington bearing design is used on the GC, EMI, and TT plates, and I'm sure others. I think the benefits are a friction reduction when turning the wheels, and it eliminates most of the load from the monoball. Still it makes me wonder if we might not be better off with the AZC style where the upper spring mount sits directly on the monoball. The whole thing makes me want to get some upper spring perches that rest on the monoball directly and do some back to back testing... Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 31, 2006 Share Posted October 31, 2006 I have one pair of those EMI plates.. most likely they will go up front... I am using a set of poor man's, home-made plates in the rear.... Quote Link to comment Share on other sites More sharing options...
heavy85 Posted November 1, 2006 Share Posted November 1, 2006 I have one pair of those EMI plates.. most likely they will go up front... I am using a set of poor man's, home-made plates in the rear.... The front and rears are different - the fronts have the needle bearings while the rear do not ... at least mine are that way. Cameron Quote Link to comment Share on other sites More sharing options...
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