TimZ

Okay - I'll buy that I was mistaken - I know that bias follows piston size for a diagonal split, since the pressures front to rear (before the prop valve kicks in) are equal by definition. My thinking was that since we have a front/rear split, and the MC was still displacing the same amount of fluid for a given amount of pedal travel, the smaller piston in the rear should drive the pressures on that circuit higher (all else equal). I believe my mistake was that the MC has a relief valve that still keeps the front/rear pressures equal. So I stand corrected. On to gutting the prop valve - can you do this without tieing the front and rear circuits together? If so, then fine, but if you can't you'll be giving up a pretty important safety feature of having a redundant hydraulic system. I just removed mine altogether and plumbed in the adjustable prop valve.

Very nice, Rob. The bar does bend pretty much as you described - you can kind of see it in this pic: Unfortunately you can't quite tell the mystery dimension from this. However, in this pic, you should be able to get a feel for how far the diff protrudes behind the uprights: I'll try to get under the car tonight and get a pic with a better perspective on this. Seems like once you know the correct offset you should just be able to change the offset in the 'minibar' to accomodate - it almost looks like you could just flip the existing one over, provided it clears the pumpkin.

First off - I'm with Jon on this - don't put a prop valve on the front. Is the OEM prop valve still in the circuit? If so, then this could be the problem, and your idea above should work. If you are still front biased after all this, then you will want to do something to increase the braking force for a given pressure in the rear. I'd try playing with different pads before changing out the calipers - this can make a pretty huge difference. If you want to do a caliper upgrade, it might not be as straightforwarward as you might think. Because of our system's front rear hydraulic split, if you want to change the brake balance to the rear you will need a caliper with less piston area than what you currently have. So, for a given amount of fluid displaced by the MC, the piston will have to move farther - make sense? You could also keep the current caliper and go to a larger rotor, but that doesn't sound particularly easy. Try replacing the OEM prop valve with the adjustable one (in the rear circuit) first.

That's pretty much exactly what I was thinking of - the implementation of the moustache bar is a nice touch. Just keep in mind that the shorter you make the bar, the more bushing deflection you will get, and I'm pretty sure the less NVH isloation for a given bushing. The length you have there will probably be fine, but I don't think I'd go much shorter. You could probably use a standard suspension bushing to limit the amount of deflection. One question - does this setup put the m-bar bushing in single shear, or does the m-bar have another mounting ear on the backside (like a clevis)? I can't tell from the pic. If the bushing is in single shear, you'll put a twisting moment on the bushing. Also, 45mm? Is that a typo?

I was going to suggest something along this line of thinking - if you triangulate the assembly out to the moustache mounting bolts, you would add a ton of strength for lateral forces - Jon already mentioned the tendency of the uprights to tear out under repeated high lateral loads. This would most likely eliminate that problem. You would have to mount it directly to the body, and then install the moustache bar directly to it, so you'd probably have to make a new moustache bar, like the AZ Zcar piece, but 'flatter'. Or you could come up with a way to mount it without the moustache bar as Terry suggested. On the mount that you showed for the nose of the diff, don't underestimate the forces that will be presented to that mount - it will take the bulk of the stresses presented by the diff. If you figure an engine with 400lb-ft of torque hooking up through a ~3:1 first gear and 3.7:1 diff, the nose will be pushing on the mount with about 4400lbs of force. I used a similar approach with my r230 mount, except I made everything bolt up from the bottom:

The center gear case from the WC T5 should bolt up to the ZXT bellhousing and tailshaft housings, so that should not be an issue. However, check the diameter of the output shaft on the WC T5 - I don't think it will fit in the ZXT tailshaft housing without some mods. Also, check the spline of the input shaft and the size/length of the pilot shaft - you'll probably also need a custom clutch and will have to do something about the pilot shaft/bushing, depending on which WC T5 you have.

http://forums.hybridz.org/showthread.php?t=99499 Kevin at the Gear Box is still doing these for the Datsun T5. I'll vouch for his reputability and quality of work. The Gear Box 26405 Northline Rd Taylor, MI 48180 (734) 946-6088

Mine was on a 280 (front mounted bar), and I had more clearance for the bar than I did with the 280zxt CVs. I used the same technique to attach the bar to the LCA as before (i.e., short link with no spacer between the bushings)

That was my point - I can't tell the difference from stock with them in the front either. Having them inside the cabin is a whole different animal. It doesn't make 'happy' noises like a loud exhaust, supercharger whine, etc. It makes "WTF is that?" kind of noises. Constantly. I just got tired of wondering whether something was broken, and of having to tell passengers that "it just does that" to explain the hooptie noises. These things weren't cheap - I didn't take sh1tcanning them lightly. I guess this is my day to preach about racing stuff in street vehicles If you need an upgraded harness for the track that's fine, but don't get rid of the stock belts. Racing harnesses are all but useless on the street. I'm guessing that the problem was more about sliding around in the stock seat. You might consider getting a more suitable seat... Where did you set your idle speed? Try setting it a bit higher - that will help recover some of that lost inertia for rolling off from the lights.

Agreed. That's a lot of camber to get by moving the bottom of the strut outboard. That brings to mind one other point about the camber plates. The camber plates that use the three stock mounting holes in the strut tower (Carreras, for instance) don't allow negative camber adjustment greater than stock without relocating the three mounting holes inboard. You can adjust the top mounting point farther outboard than stock, but not farther inboard. My feeling was that if I needed to slot the holes to get camber, I could do that without camber plates. Am I missing something here? As I said before, I'm not disagreeing with JohnC's diagnosis - I just really hated having camber plates in the cabin on my street driven car, and I'm trying to come up with a viable alternative.

Stainless Steel is not such a great solution for holding the exhaust manifold on - it expands and contracts too much with temperature changes and will work its way loose. Also, I'm not convinced that the grade 10.9+ ratings will help that much, as the heat treat tends to get 'cooked' out. Honestly, I've not found anything that I like better than the OEM studs with prevailing torque nuts for this - the OEM studs have a longer 'head side' than the aftermarket ones did (at least the ones that I was able to come up with), and get much better penetration into the head. Also, if you can locate "Jet" or "Kay" style nuts (racer wholesale, pegasus, truechoice, etc) , the hex head is smaller, which allows far better access for tightening.

Not questioning Johnc's suspension tuning prowess, as his suggestions are always spot on. However, is there some reason that you can't get the rear camber change with the LCAs? Also, the ride height issue can also be addressed by using front isloators in the rear - they are about 1" shorter. The adjustable spring perch and 2.5" id springs can still be made to work with this setup. Granted, adjusting camber with the LCA alone is not ideal, as you will be coupled to other settings there (track width, for instance), but in my experience, camber plates were just WAY too noisy for a street driven car that sees occasional track time. I had Carrera camber plates in mine and took them back out after about 6 months. I couldn't stand them any longer - every little suspension movement seemed like it was being trasmitted directly into my brain. Maybe some of the other brand plates will be better in this regard, but if they lack some sort of NVH isolation, I seriously doubt it. If you plan on using this car primarily at track events it won't matter, but my impression was that you were going to use this car substantially on the street.

Watch the units - I was assuming that he meant 0.25 and 0.30 mm (not inches), which is roughly the same as 0.010" and 0.012". Also, as I recall the 8 and 10 thousanths clearances are for a cold engine, not a hot one (clearances get larger with temperature).

me too. I tried searching on "r230" in "all active forums" and it only pulls up 15 posts out of the Chevy V8 forum, and nothing anywhere else - including the Drivetrain forum, where I'm looking right at two posts with "r230" in the title.

For the Datsun T5, the output shaft is also way smaller than the upgraded gearset's - to the point that the tailshaft housing has to be welded up and re-bored. You'll need a new driveshaft yoke. Mike: Talk to Kevin at: The Gear Box 26405 Northline Rd Taylor, MI 48180 (734) 946-6088 He upgraded my Datsun T5 with what I'm 99.9% certain was the same gearset that Gforce was using - he was getting them straight from the manfacturer of the gearset (it didn't sound like he was dealing with gForce directly). Anyway, I've been happy with mine so far, and he recently did one for Rick Bowers and shipped it to Florida, so your being out of town should not be a problem. Also - I'll vouch that he's honest, easy to work with and does good work.

Still not sure what the advantages are? Assuming that the gundrill happens at the axis of rotation, the effect on rotational interia would have to be about equivalent to leaving off a balancing weight (how much material are you removing?). Am I missing something? (Sorry - I just like to be a pain in the ***, and haven't posted in a while )

Was this what you were looking for?

Am I looking at this correctly? It looks like you have an upper and lower mounting point for the supercharger, and that's all. If that's correct, I think you are going to have a hard time keeping tension on the belt - this arrangement doesn't have much strength in the direction that keeps the blower from twisting around the axis drawn between the two mounting points. I think you at least need a third mounting point.

Yikes! Never run any kind of fuel line inside the cabin. If you want a permanent gauge, use the electrical kind. Otherwise, tape it to the windshield. Sorry Len, but us Zappa fans gotta stick together - can't have you burning yourself up...

Mine too

I should mention that tightening the spring in the AFM will make the car run uniformly lean. You then have to comnpensate for this by increasing the fuel pressure.

Once you go to 2.5" id coilovers, the only "kit" that you are likely to find will be for the spring perches and upper mounts. In addition to adjustable ride height and cornerweighting, one of the main points of the coilover suspension is to allow you to spec your own springs, and that is exactly what you will have to do. There won't be a size that says "for Datsun 280z" - you have to spec the spring by rate, id, free length, and bound length. Here is Eibach's application guide: http://eibach.com/cgi-bin/htmlos.exe/00205.11.6568698995900031888 ...if you look at some of the other links on the left side of the page, they have some info on how to select the correct spring for your application. Here is a link to a place that sells Carrera and AFCO springs: http://www.behrents.com/shocks.htm