JMortensen

That is a two piece driveshaft and you can't replace it with a one piece because there is no slip yoke on the tail end of the transmission, it has a flat flange that the driveshaft is bolted to. On two piece driveshafts it is possible to get them assembled "out of phase". If someone took the driveshaft apart and didn't put it back together in the right orientation, that will cause a nasty vibration. This website shows driveshaft phasing: http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html I've only seen that driveshaft on the steel synchro 5 speed transmissions. If that's what you have it might be worth some money to a racer, especially if it is the close ratio version. It could be something else entirely that I'm not aware of and not of any great value, but it's worth checking out.

It's either poo or mud. I'm thinking poo.

What's the story behind the accident?

Rick I was thinking about this some more. One simple suggestion: flycut the pistons. If your stuff is being machined they should be able to do that for you too. BRAAP showed me a tool to do this easily a couple years ago. Put the cutter in the valve guide, put the head on the block and cut the notch in the piston right in place. Still a good idea to check and see if it needs doing.

Messed with the pedal box again today. Realized that the hole in the firewall was just a bit too small, so I had to take the box back out. Then I was thinking about the bias adjuster. Going to need a cable support, and there is nothing even remotely close to hook the cable to. So I welded on a tab about 5" long to attach the cable to. Figured I couldn't make it too close because it might prevent the cable from moving far enough to keep up with the adjuster as it slides back and forth in the pedal assy. I suppose the other option is to cut it shorter and use a too large Adel clamp so that the sleeve for the cable can move with the adjustment. Pics of the pedal box with the brake masters installed (no reservoirs yet).

Wow. They've really been downgraded. Back about 10 or 15 years ago the 4 piston setup was advertised as (paraphrasing here) for Z cars that regularly see 200+ mph.

Nope. Doesn't work. Your car will explode in a fireball if you try it. http://forums.hybridz.org/index.php?/topic/77189-is-the-e12-80-module-required-with-msd-6al/page__p__734547__hl__msd%206al%20module__fromsearch__1entry734547

I have to agree and point out that the suspension can be as big a problem as the hp, I had a TON of fun with my Z when I started and it worked up from probably 150 to 200 whp. By the time it got to 240ish whp, the suspension was so modified that a friend remarked that the car wasn't any fun anymore because you couldn't push the limits on the street without risking death in the event of the smallest mistake. Now that my focus is track only, the hp is going way up, tires are getting much wider, etc. It's going to take some time to get used to, so my plan is to autox for a couple years before I hit any track days. Even then I assume it will be a bit of a sphincter puckering experience the first few times out.

Interesting. You can see the inside is the only part contacting in the pictures, I just would have figured that there wasn't that much wear going on there due to the weight transfer to the outside tire...

So you're also thinking lower your car and up the spring rate? I don't think the diffuser is going to help the problem you're having. I'll be happy if you prove me wrong though...

Exactly why I started the thread in the first place.

Unless you have a flat undertray and a diffuser in the back of the car. It is interesting and I was just using that same CFD image to prove a point elswhere about a week ago, fig 4-14 if memory serves. The diffuser would be illegal for most SCCA classes, but certainly worth doing if you don't have those constraints. The high pressure in front of the wheels isn't so bad on a sedan, and really isn't bad on a lowered race car. On an open wheel car I seem to remember they're responsible for a majority of the drag. If you just get the air directed at the wells the low pressure will do the rest. Unless you have your diffuser quite a bit lower than the frame rails, I don't think you'll have too much room to raise it up where it won't be in front of the wheel.

That's the same camera I have (I love mine). I'm going to make a mount with U bolts and a flat plate and the 1/4" wingnut and have the camera mounted upside down, then just flip the picture afterward, and mount the camera as high as possible. If that doesn't work well I'll put it in a padded box like John suggested with a lipstick camera and mic, probably mount the lipstick front and center in the grill area.

I think it's much more likely to be a toe setting than droop causing that problem. If it's not set for a lot of static toe out, I'd look for some dynamic toe out. In the rear that's going to be bushing compliance or control arm rigidity I think. I've been thinking about this a lot recently, and I've come up with a theory on what exactly is the problem with the Z suspension that makes the droop limiters an advantage. Here's the problem with "excessive droop" as I see it: the struts lean inwards. Let's say for example that you have a high roll center, at least above the ground. One would expect that the outside suspension would want to jack up due to the effect of the tire pushing laterally on the inclined control arm. Similarly the inside suspension should want to jack DOWN because the pull on the tire would tend to level the control arm. This also does not happen in practice. Why? The weight transfer of the sprung mass to the outside compresses the outer suspension overriding the jacking effect on the control arm. On the inside the jacking effect is also overrun by the PULL of the sprung mass on the inside strut. I think the sprung mass is effectively sliding up the strut due to the g forces. If the struts were straight up and down, the lateral load on the strut wouldn't cause any jacking at all. The end result of all of this is that the outer tire should wear more on the outside edge. I don't think it would affect inside tire wear tremendously because most of the weight is being transferred to the outside, and that's where the wear is occurring. I came to this realization as to how the suspension is jacking just a couple days ago when I was thinking about these pictures (the grey car was really the one that got my wheels turning): These don't have droop limiters: This car has droop limiters: The fact that the droop limiters have a noticeable effect seems to vindicate my theory. If the suspension didn't extend past the regular droop of the spring rate and sprung weight, the limiter wouldn't do much of anything, as I believe the yellow car has his limiters set to that length. Dan has his front limiters set at 1" which is similarly very close to the natural amount of droop the car would have and came back with a pretty positive experience after trying them. If my theory is correct then I think it's a pretty safe bet to say strut based suspensions with the struts canted inwards would probably benefit from droop limiting. The more traction they have, the more g's they can pull, the more benefit there will be. If you could somehow cant the struts to the outside the suspension would jack down and there would be no need for the limiters. That's my theory anyway. Feel free to poke holes in it. FWIW I did go back and get some much shorter turnbuckles for the front. If I'm lucky I might be able to use the cables I have, maybe with a spacer if necessary, if not I'll make some cables with the wire rope and eye terminals that I have to mount it all up. I'll have to wait to get the car on it's suspension and see what it looks like before I mess with it too much more.

I was referring to the braided SS lines. The fittings don't fit the stock Z brackets with the U shaped clips to hold them in, so I was going to clamp the braided SS lines to the outer edge of the frame rail. I think this will allow the line to move without rubbing the frame rail. I don't really see too many options here...

Thanks John. Any thoughts on the SS lines? I was calling them d rings, but Adel clamps is what I have, and I have the right size to use for the SS brake hoses.

I'm into plumbing the brakes, I've put it off forever because I really hate plumbing and flaring, the whole job is annoying. Only thing worse for me is electrical. Anyway, I have 4 Goodrich SS lines with -3 fittings 90* and straight, -3 adapters for the Wilwood calipers, the dual Tilton masters came with -3 fittings. I'm using 3/16" brake line, have an AN flare tool and have a hand bender. First thing I noted is that I forgot to order any T fittings, going to need a couple of those obviously. Other than that the main issue that I've seen so far is that the SS brake lines don't fit in the stock locations, so no clips to hold them in place. My thought was to run the hard line to the middle of the frame rail and then hook into the brake line and use a d ring to fasten the line to the bottom of the frame rail at the outside edge. This will keep the SS line from abraiding on the frame. Is there a better way to do it? What are you others doing in this situation? Second issue is regarding the SS lines. I really think I should have gotten the straight fittings on both ends, although if I do the above then I can use the 90 degree end on the frame rail side and that solves that problem. Haven't decided if I'm putting the hydraulic prop valve in the car or under the hood, since I'll have the balance bar in the car. Thinking under the hood on that one. Any other suggestions would be appreciated. I know with a double flare it's a good idea to chamfer the end of the hard line, so I was planning on that. I've been thinking I'll put a curly Q under the masters so that they can be pulled off the firewall without removing the hard line, but that is pretty much the only other "trick" I know to do, so any of your hard earned knowledge would be appreciated.

I think it is desirable to ITS racers because it ups the compression a little bit over the other heads. The Z is becoming less and less competitive in ITS. You can look around and see what they're going for, but if it's just a stock E31 that needs a valve job and all the rest, my guess would be that it's value is about $150.

Seems that there is less positive pressure at the base of the windshield than what can be vented along the sides and possibly the back of the hood. If the lift is reduced, the underhood pressure is going somewhere. I think you'd have to do some yarn tests to figure out where air goes in or out. I know we've talked about one guy who did such a test with a cowl induction hood and he found that the yarn went alternately in AND out of the cowl. Even if it is venting out the back of the hood part of the time, it certainly doesn't seem like the best place to do it. I'm convinced that the better way to deal with air under the hood is to prevent it from getting there in the first place. I'd like to see a yarn test on a popped hood or a cowl induction hood from someone with a radiator duct and the rest of the grill blocked off. I would put money down that the air goes solidly into the cowl under those conditions. I'd up the money on such a bet if there were hood vents installed. A good hood vent would allow the high pressure under the hood an escape and would actually help to suck it out with low pressure on top, making the pressure differential at the cowl greater still.

I assume you know that your threaded adjusters will have to be installed quite a bit higher than shown in the picture.

You can grind some washers with a step in them so that they fit both flanges, or you can grind on the header so that it is as thick as the manifold. My Cannon was a good 1/8" taller than the exhaust, so I had to remove metal from the manifold to work.

I suppose if it makes him happy that's great. A 3000 - 3500 lb car with a mid rear turbo V8 and Chevy Citation and Chevette suspension is not a good expenditure of time and effort and money by my standards though.

You can do the fronts without taking them off of the car. Just unbolt the top and undo the brake lines and swaybar, and you can swing the strut out of the fenderwell. Put your spring compressor on right there, take the top hat off and swap in your new springs and shocks, then put it all back together and bleed the brakes. Pretty easy, and you can even bolt the strut back up with no spring to give yourself a lot of room to get those damn gland nuts loose.

That is the worst crap I've heard in a long time. Interesting to note that Michael and Ralf Schumacher are race car drivers, but younger brother went for the horrible prison tats, ninja rap, progeria sidekick thing instead.

He did send me the instructions, I posted here but apparently the picture was lost in the software migration. I don't have the scans anymore. Suffice it to say that if you contact Ground Control they will sell you some spacers which fit the top shaft of the Bilsteins and the monoball and space it up about 1/2" to keep the thicker part of the shaft from interfering with the top hat. Then they have machined the center hole in the hat larger to allow clearance. They also put a spacer on top so that when you tighten down the nut on top it tightens against the spacer, not against the monoball itself. The top spacers are very thin, it's the bottom ones that do the work of spacing the strut shaft down and are thicker. With the spacers in place the Bilstein factory locknuts don't engage the plastic part of the locknut. That didn't bother me much since the last nuts I had were modified lugnuts and had no locking feature and never had a problem backing off. I still think that some of the top hats that you find in Coleman Racing and similar places would work, but I haven't tried them so I can't say for sure that this works and that doesn't.