Coelocanth81

Manuals are definitely "yesterday", and so is skill - with all its trials, tribulations, and triumphs. I'll happily keep living in the past. When it's time to give up on driving, I'll just buy a Tesla and let it's unparalleled performance auto-pilot me into a bridge pylon. DCTs are for passengers.

I'm experiencing a metallic clunk sound upon releasing the clutch pedal with the transmission in neutral. There is no groaning or squeaking, so I think my throwout bearing is ok. Clutch hydraulics are brand new, and the pedal is adjusted per the FSM. I can actually feel the clunk in the shift lever, and it occurs just prior to full clutch pedal release. I replaced the hydraulics because the pedal was soft, and master cylinder seal was failing. I thought maybe the hydraulics were causing a clutch drag, but now I'm not sure that was the problem. Reverse has been grinding upon engagement. Anyone have any ideas?

I have a '76 280z that has received a 5 speed swap prior to my owning it. Did the 5 speed transmissions even have a "top gear switch" for the purpose of advancing the distributor? I'm thinking about removing the vacuum switching valve when I rebuild my fuel rail.

I appreciate it, Cary. This thread got a little sideways there for a minute. I didn't see what happened on the other one. Agreed. It seems perilous for a manufacturer to let the users control that narrative. Hopefully some more information will be forthcoming.

So, 280Z heater cores have been unavailable for a while now. I've been told a Ford Escort heater core will fit, but I'm unsure of the year. There's also Brassworks - who can reproduce one for the cost of 400 dollars shipped. Anybody got any suggestions?

Like engine swaps, I view this suspension package as a fairly substantial re-invention of the car. I was looking at the AlterKtion suspension/steering package for the late 60's early 70's Mopars in much the same way. To some extent, you give up the very essence of a car the moment you dream of further empowering it. Mike Kelly talked about how far his project had taken him from the simple joy of driving a stock Z, and there's no doubt about how far one could go down the rabbit hole. I might try to pick Ohm's brain a bit more. I really don't want to trouble him too much - as I'm not a customer yet. I'd like to know what specific criteria he had in mind when designing the product. I understand the motivation for the rear suspension; it's a bolt-on solution for handling greater power, more tire clearance, and more adjustability for a variety of setups. I think the jury's out for me on the dual control arm front suspension, though. Like some of the other commenters, I'm not convinced that the McPherson strut front end is in need of a complete replacement.

Race cars are controlled by the rules established for each class, so there are as many "fastest Z's" as there are classes. Obviously, we wouldn't have a cottage industry built around modifying the stock design if it went out and won every race in showroom form. There's a lot of thoughts about how the Track Attack design "looks", but so far we haven't conclusively laid out any specific ways in which the design is deficient. Since we don't know much, let's start with what we do: 1: There could be noise, harshness, and durability issues due to the large number of heim joints - especially on the street. 2: The relationship between the front and rear suspension dynamics need to be studied to determine their overall impact on car control. (good discussion to be had here) Adjustability, weights, installation issues, and impact upon the drivability and performance characteristics of the car are all still unknowns - as are any cost/benefit ratios for various applications.

Depending on the design. If the pivot swingarm has different attachment points for the shock and strut-rod, then the leverage ratio of the spring and shock are adjustable. In doing this however, you’d want to optimize the wheel travel to match the full travel range of the spring and strut. There's likely only one ideal placement point for the respective items on the pivot, so a wide range of adjustment options may not prove as useful as they initially seem on paper.

Very good advice indeed! He also taught us to not “fall in love” with a design, and be open to continuous improvement and criticism.

For a street car, excessive noise could be a show-stopper. I watched that video, but I’m not sure that the racket we were hearing was actually coming from the interior strut assembly. It sure would be nice to get some in-car footage of a running setup to know for sure, though. As for weight - I’m not certain what the apples to apples weight comparison is between a stock Z suspension and the track attack components. As long as the weight goes towards strengthened components and improved suspension articulation, I wouldn’t mind it - although, as a 2+2 owner with factory A/C, the lightweight train departed the station before my arrival! Haha..

That's what I counted, too. I definitely feel that the design leans on them a bit much for my purposes. The cost of those R-joints are eye-watering - I think I'd only put them in locations that are external - leaving the interior joints to regular hiem joints - as they won't be subject to contamination inside the car. With respect to the noise, I'd bet shock valving would be audible if there were no slack in the joints. Being outside the car, we never hear the noise that our struts make, but I can promise you they're not completely silent. The open hole in the top of the strut tower might also be an inlet for exterior noise, depending on how it gets sealed.

If I remember correctly, R-joints use some kind of spring-loaded tapered sleeve that has a self-tightening effect to prevent slop as the joint wears. I also wanna say that the sleeves were grooved to promote a self-cleaning effect, and are made of Delrin(?) instead of teflon. They're definitely not sealed, but if they have the ability to shed/reject grit, it might bear some fruit for reliability. I agree with about their claims on poly bushings. If they're lubed correctly, they'll stay quiet. They've got a point about increased bushing "stiction" reducing the suspension performance. The upside of a bushing is also in the fact that it has some slop in it - which can save components from breaking in the event you hit a pothole in a turn, or some other "feature" that wouldn't exist on a properly groomed road course. In the end, I feel like a street car could definitely benefit from poly bushings over hiem joints in numerous locations. They gotta make a sales pitch, I suppose.

Thanks for posting this - I could've sworn that there had been an attempt at a pushrod linkage suspension before...

I was considering this as well. I've got nothing against the McPherson strut design - I'm just trying to maximize the inboard wheel clearance. It occurs to me that the inner front wheel clearance limitation on a stock system with coil-overs might actually be the inner fender (when the wheels are turned), and not the spring/strut assembly. In this case, I'd be happy to retain an improved version of the factory front suspension. This is just me thinking out loud. Any takers?

I'm not sure there's any reason you couldn't mix and match. They appear to be highly customizable for various configurations - although, I'm still trying to get some feedback from someone who's actually got it installed and running. For a street car, my main concern is the abundant use of Heim joints. These are fantastic on a race car, but they're a bit firm on the street, and are subject to damage from contamination. I'm looking into the possibility of getting the kit, and substituting Ridetech R-joints in all the external locations to help mitigate that. My primary interest in this kit is the potential for gaining inboard tire clearance beyond what is possible with a McPherson strut system with coil-overs installed. I'm trying to minimize the amount of fender flaring that will be required for tires in a 275 to 315 width range.

I'm the OP, and it's more a measure of my patience than tardiness, I promise. . Excellent. Can you please expand on what you specifically don't like about it? I'm genuinely picking your brain here. I completely subscribe to your point about the recipient vehicle. In my case, I'm building a car that will be 85% street and 15% track driven. It's a pure hobby project. I'm estimating about 600 horsepower, and I want to get as much tire on the ground as possible under mildly flared steel fenders (no bolted or bonded-on kit fenders). I liken my end goal to being something like a BMW M series - a street-friendly sleeper that's equal parts sport car, and muscle car. I intend to get as much performance as possible out of the vehicle without eliminating the factory interior, and rendering it unrecognizable as a Datsun 280Z. I realize these are opposed goals, but finding a happy balance between them is the challenge I'm most excited by.

I'm just trying to learn some things, and create a relevant thread for the discussion of this suspension upgrade - preferably from people who have some experience with the kit. Got any contributions besides snide remarks about a fellow hobbyist's project goals? Cheers. This thread is NOT about Porsche. They have their own message boards. If you have no knowledge or interest pertaining to the Apex Engineered Track Attack suspension, please refrain from posting.

Thanks for bringing that up! I'd like to learn a bit more about this point. I was also thinking that those control arms were a bit short. Admittedly, I was excited by the tire clearance made from the inward relocation of the strut - as I plan to try to keep the fender flares minimal. Point taken. As for the weight, the mounting for the struts/springs doubles as a strut tower brace - which I would have installed anyway. As a 2+2 owner with factory A/C, I'm probably not as worried about the final weight as someone who's aiming for a pure race machine. I'm probably a bit of an oddball on this forum.

Very true... When drawing the lines on functionality, the margins get pretty slim when door bars and multi-point harnesses come into play. I'll leave factory seatbelts in place for convenience, but I think I'm going to try to keep some type of welded door bars in the picture. My thoughts are that if someone won't/can't enter the car because of the door bar, then it's not the car I should be giving them a ride in - door bars or otherwise. I'll have to reserve the Datsun passenger seat for those who are excited by it. For everyone else, I've got a comfy daily driver that'll do just fine.

No offense fellas, but a 280z is in my garage, so that's what I intend to work with. If I were looking to second guess my ownership and/or consider a Miata or Porsche, I'd hit up the forums at Zcar.com. Now - about the AE Track Attack suspension... Resume.

The Australian "LS" V-12 is indeed the one I'm eyeing. I'm looking at the aluminum block option, which has a slightly smaller displacement (9.2 as opposed to 9.5). All told, I think it weighs around 650lbs, fully dressed. Definitely heavier than an alloy V8, but on par with the DOHC turbo inline 6 offerings - so I'm not too worried about the weight. Besides, I'm reaching an age now where I'm more interested in air conditioning than in shaving off all the fat. As for the partial cage, I think it's mostly for peace of mind. The idea of a side-impact on that chassis terrifies me. Secondly, having length-wise tubular structure that's triangulated to the car's floor rails would create a "box frame" that's 18 or so inches high - bracing the tops of all 4 strut towers. I liken it to the biplanes in WW1. The upper wing wasn't necessarily for more lift - it was there to create a stronger structure by bracing it to the lower wing. For what it's worth, that's the logic behind my thoughts.

...until one of you lunatics pulls it off. This is a challenge. 1st person to do it should get a lifetime supply of Fosters (Australian for beer). http://racecast.com.au/?v=3a1ed7090bfa

Thanks for all the replies, everybody. Yeah - it's looking a bit like the Wild West right now. To make things even shadier, I was going to install this suspension in a 2+2. I asked Ohm if he foresaw any problems in doing that, and he said that it should be possible. At a glance, it looks like the rear seat might even still be able to function with the springs loaded between the shock towers. No doubt, there will be some fabrication required. Other than potentially modifying the spare tire well, it looks like the front spindles get removed from the strut tubes, and welded into a ball-joint assembly as part of the front control arm setup. That's the only major chopping that I can see so far.

I'll be building a street car - although, it'll see some "weekend warrior" track use (no class-specific racing). The plan is to seam weld, re-framerail, and 1/2 cage the car (braced main hoop and rear shock towers, door/rocker bars, a firewall dash bar, with bridged load paths from the front strut tower support - almost a full cage, minus A-pillar and roof bars for street safety. I want chassis reinforcement and safety improvements for a car that will be driven mostly without a helmet. The car will retain its full stock interior - with the exception of Recaro LX seats and front harnesses (maybe rear harnesses too, for laugh value). I'm considering a 9.2L LS-V12. HP is in the neighborhood of 750, and 600lb/ft of torque. The 2+2 definitely seems to be a red-headed stepchild. I'm discovering differences between it and the coupe that I never anticipated.

Thanks Sanchez, I'd gotten to the end of those threads too, and wondered "everybody's at a stopping point before completion - is there some kind of hangup that was roadblocking things"? I wish Ohm would publish an FAQ that established expectations of what is required to complete the upgrade - i.e. cutting/welding front spindles, frame reinforcements, necessity for different brake systems and hubs. A general guidance document would encourage me to pull the trigger instead of waiting on other people to finish. I'm looking forward to seeing your write-up. I'm just down the road from you in Memphis.