jgkurz Posted November 27, 2003 Share Posted November 27, 2003 Hi all, I'm in the market for a front strut bar for my Z. I've been told the 3 point bar works better than the common 2 point bar. Is TopEnd the only place that sells the 3 point bar? Thanks Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted November 27, 2003 Share Posted November 27, 2003 Eight points better than three. PDK Quote Link to comment Share on other sites More sharing options...
jgkurz Posted November 27, 2003 Author Share Posted November 27, 2003 Huh? I've never heard of an 8 point strut bar. Please clarify. Quote Link to comment Share on other sites More sharing options...
Guest Cusp Posted November 27, 2003 Share Posted November 27, 2003 Sounds like a roll cage to me 8) http://www.pdkfabrication.bravepages.com/240%20front.htm Quote Link to comment Share on other sites More sharing options...
rc's240z Posted November 27, 2003 Share Posted November 27, 2003 PDK Fabrication: http://www.pdkfabrication.com there are a few popup adds, sorry...We fabricate a strut bar that ties into two locations on fire wall, to the top of the strut tower and to the swaybar mounts through the frame rails. This is a modular system that does not require that the whole unit be removed in order to adjust the valves or service your car. The pickup points on your firewall are at braced locations on the chassis. the brace to the swaybar includes a crush tube that will protect your frame rails from damage due to the install of oversized swaybars on your 240Z. Yes, it is an 8 point front strut bar for a Z car. http://www.pdkfabrication.bravepages.com/240%20front.htm Please feel free to look at gallery photos at the link below, there are several photos of multiple installations that we have done: http://www.classiczcars.com/photopost/showphoto.php?photo=1184&password=&sort=7&thecat=500 Quote Link to comment Share on other sites More sharing options...
jgkurz Posted November 27, 2003 Author Share Posted November 27, 2003 Thanks guys! Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted November 27, 2003 Share Posted November 27, 2003 Sounds like an awsome set up to me. I may have to look into something like that. Mike Quote Link to comment Share on other sites More sharing options...
zolorin Posted November 29, 2003 Share Posted November 29, 2003 looks interesting. can you explain how does the rear strut bar is connected to the vehicle (the lower components). Quote Link to comment Share on other sites More sharing options...
rc's240z Posted November 29, 2003 Share Posted November 29, 2003 The connection at the swaybar mount: (1) Purpose: Protect the frame rails from damage due to repeated stress from oversized swaybars. Fact: The factory frame rails have two nut inserts in which the sway bar is mounted to. Over time, with excessive cornering stress (due to larger diameter swaybars and larger stickier tires) this will apply enough stress to destroy the frame rails. The frame rails will spider crack and pop spot-welds on both the inner and outer sides of the frame rail. Solution: Our strut bar incorporates a down tube that has a larger surface area to apply the stress of the swaybar across 2 plates (upper and lower) that are attached to the top and bottom of the frame rail. Between these two plates are two crush tubes that protect the frame rail from being damaged or distorted when these two plates are bolted together. Installation: drill out both nut inserts for the factory swaybar and drill straight through the top of the frame rail, drill these holes large enough so that the two crush tubes can be inserted through the bottom of the frame rail install bottom plate and swaybar mounting bracket. Place strutbar down-tube with top plate over the top of the bolts extending up through the frame rail and bolt in place. Goal: expand the stresses of the swaybar across a larger area of the frame rail as well as across the strut bar structure to protect the weak section of the frame rail and add structural rigidity to the front suspension. (2) Purpose: Prevent twisting of the top of the strut towers due to hard cornering force. Fact: John Coffey has done extensive testing on the front suspension of a Datsun 240Z his findings correlate with ours finding that the strut towers on a Datsun Z do not pitch back and forth but rather twist clockwise and counter clockwise. Solution: build a strut bar that ties into the swaybar mounts, strut towers as well as the re-enforced sections of the firewall and triangulate all the points that exert pressure to the suspension. Goal: The down tube to the front swaybar mount is attached to the frame rail add further lateral support that prevents a twisting motion of the strut towers. That in combination with the triangulation of strut tower to the firewall and cross bar to the opposite strut tower prevents any twisting motion of both strut towers. Quote Link to comment Share on other sites More sharing options...
rc's240z Posted November 29, 2003 Share Posted November 29, 2003 looks interesting. can you explain how does the rear strut bar is connected to the vehicle (the lower components). The rear bar adds stregth to the base of the rear strut towers using a bolt and crush tube not unlike the Top End Performance solution. Quote Link to comment Share on other sites More sharing options...
jack46 Posted December 5, 2003 Share Posted December 5, 2003 Ok I'm new to this so please bear with me. I understand the rear strut reinforcement since the power is applied to rear tires and seems to me alot of bouncing and stress will be applied there. By contrast the front seems there would be alot less stress since the engine torque will try to rotate the engine about the z axis. Won't this torque mainly try to twist the strut towers inward and outward? Trying to understand the need for the 8 point on front. I agree there is a need for side to side but.... Also does anyone make a front brace that clears a V8? I use a 14 inch cleaner and seems most will interfere Thanks Quote Link to comment Share on other sites More sharing options...
zguy95135 Posted December 5, 2003 Share Posted December 5, 2003 i should invest in one of those cause my car came with HUGE sway bars. 32mm in the front and 27 mm in the back Quote Link to comment Share on other sites More sharing options...
Moridin Posted December 5, 2003 Share Posted December 5, 2003 The PDK bars are awesome. I don't have my front one on yet, because I haven't had time to send the middle bar back in to get an adjustable one. They are amazing though, and really help tighten up the whole front end. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 5, 2003 Share Posted December 5, 2003 Fact: John Coffey has done extensive testing on the front suspension of a Datsun 240Z his findings correlate with ours finding that the strut towers on a Datsun Z do not pitch back and forth but rather twist clockwise and counter clockwise. Yes, but I think the bars going from the strut tops to the firewall need to go to the center of the firewall where the hood latch is. Its a better angle to counter the twisting forces on the strut towers. But, you lose your hood latch and it requires some fabrication skills to make and install the firewall mount. THe PDK bar is a reasonable compromise for a street Z. Quote Link to comment Share on other sites More sharing options...
rc's240z Posted December 5, 2003 Share Posted December 5, 2003 thanks Moridin, for your kind comments. Please get your crossbar back to us as soon as you can. Zguy95135, our strut bar will make a huge difference in the handling of your car, and your chassis, specifically your frame rails will last longer. Jack 46, we can build a custom brace for your car, obviously we would need to see what limitations we would have to work around on your car to make this work. As far as how our bar works, there is some movement from the torque of the motor but that is applied directly to the crossmemember and disributed across the Z axis directly to the front suspension, our bar includes an adjustable cross bar to stop any kind of tilting of your strut towers. But that is only part of the equasion. Heavy cornering forces with larger than stock swaybars and tires apply huge amounts of stress to the front of early Z cars. These forces are what will damage the chassis of your Z faster than torque twist (unless you are talking about a car used for drag racing). Independent tests have shown under heavy cornering that the strut towers on early Z's twist (rotate) slightly when loaded changing the handling dynamics of the car. This twisting motion can not be solved with a single cross bar alone, it is necessary to triangulate the top of the strut towers. Also under hard cornering the swaybar mounts attempt to stop body sway or tilt. Larger than stock swaybars will damage the frame rails as the chassis of a Z car is not designed to handle such loads. By bracing the strut towers, front swaybar mounts and firewall these loads can work against our strutbar, which is designed to lower the stresses applied to your chassis. ACK!! i feel like I am repeating myself I hope this helps. Quote Link to comment Share on other sites More sharing options...
rc's240z Posted December 5, 2003 Share Posted December 5, 2003 I agree with you John, it would be necessary to remove the hood latch and weld on a brace to the firewall at the center section to support the firewall as it will flex quite a bit at the hood latch. Our solution is designed as a BOLT ON application that does not require excessive modification or welding. And is designed to be such. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted December 6, 2003 Share Posted December 6, 2003 question. has anybody that bought your product ever put it on a S30 z with a L28ET motor swap in it? im afraid if i buy one it will hit the pipping and such... thanks mike Quote Link to comment Share on other sites More sharing options...
Synlubes Posted December 6, 2003 Share Posted December 6, 2003 The triangulation may be good at the hood latch area, but there is no support there. Even if a "backing plate" was installed behind that area to mount the strut rods to, theres still no (not much) bracing. Plus (for a street car) the wiper motor is right there. Now, if you go out a little on each side (to the inside of the 2 outer vents in the cowl panel) there are support brackets running from the firewall back under the windsheid area. (take your cowl panel off and you will see what I`m tring to explain). This is on a early model S30. Just some thoughts. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 6, 2003 Share Posted December 6, 2003 The triangulation may be good at the hood latch area, but there is no support there. I get this question all the time. The cowl area is a box structure shaped like a triangle with one base being the firewall area where the hood latch is located. If you build a mount that spans the top lip of the firewall and the bottom of the cowl junction (look at the line of spot welds about 4" down from the top lip of the firewall) you've spanned the base of a triangle. Those two side supports exist to reduce lateral twisting of the cowl box. They do little (and are not deisgned nor needed) to reduce longitudinal bending of the cowl box. S&P Engineering (Bill Savage of NPTI fame) actually did some numbers on the cowl box before deciding where to put the center mount for my triangulated front strut braces. Quote Link to comment Share on other sites More sharing options...
Synlubes Posted December 6, 2003 Share Posted December 6, 2003 I went out and looked and see what/where your talking about John. The seem goes all the way across the firewall. With that said, what if you left the hood latch in place and mounted on eigher side of it? Quote Link to comment Share on other sites More sharing options...
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