BrandenZ

Thanks all for the responses. Everything said here only confirms my observations from reading and re-reading the FAQ (which is a really exceptional breakdown of all the options, John, thanks!). Camber plates it is!

ComicArtist -- You're exactly correct! Thanks! Jon -- It's for autox and track, intending to run BSP next season along with a few track sessions. I'm definitely going to go either plates or arms in the rear, the question is which.

I recall there being a particular sticky in this forum that used to describe all of the various options for both front and rear suspension modifications in extraordinary detail, also outlining the pros and cons of the various possibilities. If anyone can link me to that thread (presuming it still exists), I'd appreciate it! In general, I'm really looking to determine the most appropriate choice for dialing camber into the rear. My understanding is that it's very preferential to dial in camber in the front with plates as opposed to arms. However, my understanding is also that the rear doesn't have the same binding characteristics as the front, so I'm wondering what's ideal there. For my particular build, I've got Z31 hubs upfront which extend the track width 3/4". As such, I'm leaning towards the idea of dialing in rear camber with control arms. My thinking is that I don't have to worry (at least as much) about the possibility of binding in the rear, and it gives me the opportunity to widen my track width to better align with the wider track with of the front, providing (theoretically) more balance. This would also give me the opportunity to dial toe in (it's an old car, it sits at -1/16 driver, +1/32 pass today). Thanks for any advice, or link, that can be offered!

To the OP: Possible reaction disk issues? http://forums.hybridz.org/index.php/topic/69706-reaction-disk-pictures-and-walkthrough/

Ha. I may take you up on that some time, but I'll admit that I'm way more interested in seeing the LS2 swap bits than the 1/4" of extra caster! Let me know if you get to a point where an extra set of hands would be useful. BTW -- Is there a similar bind issue in the rear? Is it better to use plates for camber adjustment there as well?

Interesting. In my particular case I had the opposite problem. I've got a set of Mikelly's adjustable LCAs and T/C rods, and the alignment guy stopped adjusting the LCAs out for camber at near -2 degrees, stating that he was close enough to running out of threads to be uncomfortable going much further, while the adjustment on the T/C rods had to stop because the wheel was pushed into the fender when turned a bit on the passenger side. If it's best to dial in all the camber with the plates, why even bother with adjustable LCAs on the front, then? Is it strictly to prevent binding by going with rodends instead of bushings?

Thanks for taking the time to document and post all of this! This is exactly the issue that I'm struggling with currently, wondering how much caster I can get out of the car without cutting up the fenders. I'll be very interested to see how much of a change you were able to get from stock with the combination of the street-spec T/C rods and the EMI camber plates (rotated). Please update this thread in the future once you get your official alignment specs in! Can you describe in a bit more detail the change you made to the camber plate in favor of caster adjustment? Given that I see a swaybar, I assume this is the driver's side of the car. It looks to me like in picture #6 you could actually adjust for more caster (at the T/C rod) than in picture #7. When you say #7 gave you more caster, is that because you ran out of adjustment, and rotating it put you slightly further forward? Again, it seems like if there were adjustment threads left on the T/C rod, that #6 would've allowed you more room to push the wheel out, but perhaps I'm looking at things in the wrong way. Also, when you say you lost camber my rotating the plates a bit, can't you just easily get back to 3.5 degrees by adjusting the LCAs? Or is your goal to keep the LCAs at stock length and ONLY dial in camber at the towers instead?

260DET - I would love to see a few pictures of this as well if possible. Welding isn't a problem if it's necessary. Again, I'm more interested in doing what's "correct" and has the least amount of unintended negative consequences than what's quick, or aesthetically painful. I suppose I'm misunderstanding the camber/caster plates in all of this. I would expect that units like the K-Macs that offer caster adjustment would essentially allow me to 'artificially' relocate my strut tubes closer towards the firewall. To me this would seem to be perfect, as there's a _ton_ of room in the 'backside' of the wheelwell towards the firewall, just practically none on the frontside towards the bumper. Also, by going the route of either redrilling the towers or locating further back towards the firewall, won't this cause the front control arms to essentially be angled as opposed to being perpendicular to the hub? If so, is there a danger of compromising the the control arm(s) or fastening points by doing so?

Thanks for the quick responses! Jon -- From what I can tell, K-Mac only sells the stage3 kit for Z's, which appear to be the sandwich monoball style, but perhaps someone who has experience with the units can confirm. John -- Always appreciate blunt honesty! Is that a "No, but you can get maybe 5 degrees with the K-Mac's", or a flat out it isn't going to make a darn bit of difference? Presuming I go the flare route, which it sounds like isn't optional at this point, is it still to my benefit to have the K-Mac's, or some type of camber plate? From what I've read, it seems like from an engineering perspective, it's better to dial the camber in at the tower than the control arm. Also, going the flare route -- does this mean _all_ 6-8 degrees come from the T/C rod?! I feel like I'd be dangerously close to running that sucker out of threads. Thanks again for the help and clarification!

My current predicament is that I can't get more than 2.5 degrees of positive caster out of the car without rubbing my tire against the fenderwell / front bumper. Before the start of next season, I'd like to be able to dial in between 6-8 degrees of positive caster. However, if at all possible, I'd like to avoid cutting / flaring my stock fenders. Is this even possible? Here's the rundown of my current setup: 245/45/16 tires 16x8 wheels with a +26mm offset MM Z31 hubs (+3/4" further outboard than stock) Sectioned struts with GC coilovers, hypercoil springs, and tokico illumina struts Mikelly adjustable front control arms Mikelly adjustable T/C rods MSA bumpsteer spacers This is how it sits in it's current configuration: I've been looking at these: http://www.k-mac.com/pages/newprods/datsun/datsun.htm But no one can seem to tell me exactly how much caster I can expect out of them. It's almost like I need caster plates, not camber plates! The car is intended for autox, light track, and light street duty. I'm more concerned about what's right from an engineering and handling perspective than comfort. Any and all advice would be greatly appreciated... even if that advice is "just suck it up and cut cut cut if you want track alignment specs!"

Ha! Sorry for the confusion, guys! It's definitely an issue of the wheel being too far forward, not too far up in the wheelwell. The coilovers have been set so both sides of the car are at roughly 6.5" from the rocker. Dan -- Thanks for the tip. I'll see if I can hunt anything down. I suspect that "it's just the way it is", which leads me back around to my original question of whether or not fender flaring is a necessity in the future. However, I'm going to look over the entire front suspension again with a buddy to see if I missed anything obvious, or bolted something back in the wrong way.

Thanks for all of the replies! To add some additional info: I've got 10" 250lb hypercoil springs up front, on the ground control coilover kit with the MR2 tokico illuminas I'm also running a set of Mikelly's adjustable front control arms and adjustable tension compression rods. I also replaced everything I could think of in the process of the rebuild -- the ball joints, outer tie rod ends, the poly-urethane T/C rod kit, steering rack bushings, etc. Lastly, I added on bump steer spacers at the knuckle I can't speak for the shape of the crossmember, but the car (supposedly) has never been in a wreck (minus a tree limb falling on it and damaging the hood). I would certainly hope that the LCAs would be okay, coming from one of Mike's batches. I'll certainly check both out, though. Unfortunately I didn't perform any similar measurements to the car when the 4-lug 14's were on it, which would've gone a long way in determining if this is something new as a result of the "new" components or an install mistake, or if the car sat with the same "offset" on all of the stock gear.

I just recently finished sectioning the fronts and attempting to squeeze 245/45/16s with 5" of backspacing (-3/4" for Z31 hubs) under the factory fenders. I noticed a strange oddity after-the-fact where the passenger side wheel appears to be nearly 1" closer to the fender than the driver's side wheel. As such, I only felt comfortable having the alignment guy push the caster out to around 2.75 degrees. Ideally I'd like to be able to go up to 6 degrees in the front (autox and track days). It looks like I can get 0.7" out of both height and width if I switch the fronts to 225s, but I'm still not convinced that's enough, as I can induce scrub right now on the passenger side even with the fender rolled and the front valence trimmed a bit. I'm pretty sure I already know the answer to my own question -- that I need to flare the fenders if I want to run any more caster. It's just frustrating knowing that 3 out of 4 wheels have absolutely no issue, and if the passenger side had the same clearance properties as the driver's side, I likely wouldn't have any problems. Although short of shimming the passenger side fender, and leaving massive body gaps around it, I'm not sure what else I can do -- other than turn to you guys for either suggestions or confirmation. Thanks any advance for any advice offered! Passenger centered, roughly 1" clearance: Driver centered, roughly 2" clearance: Passenger turned worst-case, virtually no clearance: Driver turned worst-case: Roughly 1" clearance...

I'm in the process of replacing what appear to be the original 1973 struts and springs with a coilover setup. I've got the entire rear setup ready to go, and I can't decide whether or not I should replace the insulators. I'm fairly certain that they've never been replaced in the lifetime of the vehicle, but I'll be darned if they don't look perfect. There's zero play in the studs, the rubber doesn't seem to be cracked or torn. However, I have no idea if internally the thing is beat to hell or not. Any suggestions? My gut says just suck it up and pay $50 per corner to be sure, but the external condition makes me second guess that. Thanks!

A couple of points of interest from my working session last night: 1) The pinion seal appears to be a straight pull and replace. I pulled the input flange (have to swap them anyway!) and the seal is directly accessible once the 27mm nut and input flange (I used a punch + light tapping as opposed to a puller) are removed. 2) The studs are _not_ interchangeable between the rear covers. The covers themselves appear to be identically cast, but they're tapped differently. Unfortunately I did not receive studs with my Subi diff, so I'll personally be cleaning up the Z's rear cover and bolting it up. I'll probably pick up a diff cover gasket for the Z as opposed to the subi also. Just wanted to give everyone a heads up -- again, my 73 diff studs did not fit into the 2005 subi diff, slightly different thread pitch.

I've already pulled both of my 240z studs out and intend to install them in the WRX STi diff myself. Once I pull the STi studs I'll measure the exact difference for you if no one else has chimed in by then. BTW -- Did you order the front cover gasket from Kragen also? I couldn't find the gasket on there, and was hoping to order all of the seals and the gasket at the same time.

Thanks John! I'll look into the Koni progressive bumpstops, and also measure the Strutmates replacement bumpstop that I have on the ready. Based on what you mentioned, it sounds like sectioning is going to be the safer route to take, regardless of how much I fear having to source a 240z hub and strut tube assembly if it doesn't go well!

My understanding is that if I do not intend to lower my car more than 2 full inches of suspension travel (as opposed to ride height), I probably don't have to worry about sectioning my struts. I've taken several measurements and combined them with some guesstimates, and wanted to post them to ensure correctness and also to gather opinions from those more seasoned than myself. *All rear of the vehicle Previous configuration: Stock springs, stock struts, 215/60/14s Future configuration: 10" Hypercoil springs, 250in/lbs, Tokico Illuminas, MSA Coilover kit, 245/45/16s Presumptions: 14" factory springs, estimated 125 in/lbs, 2300lb car, 575 lbs per corner, yielding: 14" no tension 9.4" compressed using factory perch New configuration: 10" no tension 7.7" compressed given that the lower adjustable perch (not the welded perch) sits exactly where the factory perch used to sit This equates to essentially 1.7" lower than stock at the same relative perch height in regards to suspension travel. Factoring in the new tires/rims, which are 1.25" heigher than the previous rims, this yields a literal ride-height difference of ~1.025" lower than the previous configuration. If all of my faux-math works out, I believe this will be an ideal ride-height for this set of parts. What I'm concerned about is the 1.7" of reduced suspension travel and whether or not I'll be at a risk for binding / bottoming issues. I do intend to track and autox the vehicle. Please feel free to chime in and bash any of my estimates. Unfortunately I did not do any sprung or unsprung measurements prior to disassembling the entire rear. My gut tells me I should likely section the struts at least 1-1.5", but despite having a buzzsaw and welder at my disposal, I'm still rather uncomfortable with the idea of doing it to all 4 corners. However, I'd rather attempt it as opposed to losing my car at 100mph due to suspension travel issues. Thanks in advance for any and all advice!

RacerZ -- Have you read up on the replacement procedure for the input shaft at all? The output shafts appear as simple as using a seal puller and popping the new seals back in, but I'm concerned that the input shaft will require essentially pulling all of the guts out. Any idea? Thanks!

RacerZ -- Thanks for the info! I decided to go the safe route and just picked up an 05 differential with no "open doors". For the sake of others also on the hunt, I paid $500 shipped for it. Also as a word of warning to anyone considering using the later model Torsen-based diffs (07+), apparently they use a different weight differential fluid. According to some threads that I've read, do _not_ use Motul 90PA with these diffs. Motul 300 is apparently more appropriate, but out of safety sake, I'd simply use the Subaru fluid spec'd for the diff as that's what owners seem to have the most success with currently. To echo RacerZ's sentiment in terms of what the diff itself can handle, my research on several Subaru forums leads me to believe that in high torque applications, it's the half-shafts and/or u-joints that are going to be our weakpoint, not the differential itself. Of course, anyone with genuine concern on this front should do their own homework prior to investing in a solution that may not allow them to reach their long-term goals. Personally, I'm going to use RT's front differential mount solution to straighten out the driveline angles, upgrade to the 1-0029BF u-joints, and hope for the best. =)

Count me in as well, depending on the timing. I'm looking to reassemble my rear suspension in the next month, and then tackle the front shortly thereafter.

$200 is incredible. The best I could find on craigslist so far is one for exactly $600. Does anyone know off hand a good place to source replacement parts for the diff? Out of the gate I'll probably pull the cover to inspect it, and go ahead and replace that gasket, and one of the diffs I'm looking at now is missing it's filler plug. Just as an FYI -- I've read recommendations on various forums to either use Motul 90PA fluid, or to just stick with the stock Subaru LSD oil. Also torque spec on the drain and fill plugs is 36.2 ft-lb, and the factory service manual recommends using "three bond 1105" thread sealant for reinstallation.