JMortensen

Quite literally woke up this morning saying out loud "Tri-Y". If you did a Tri-Y you could have 2 2.5" tubes round the corner on top of each other and get your long primaries and the rest of them would stay about the same length. Build cost goes up because you'd need more Y's and not sure if they have merge collectors for Tri-Y's or if you need a particular length ratio for the first Y and the second, etc, but having done the 4-1 I think it might be a good idea to check it out.

No, don't think you could use the headers as is. Even if you cut the tubes as far back as possible and put a collector on and then added a 90 to turn it away from the wheel, just wasn't going to happen. The collector would point out just behind the strut on my car with the engine moved back about 1.5" from the JCI position. If I had more resources at my disposal I would have done one of two things: 1. Make the rear cylinder primaries twist around the fronts, so that the front cylinder primaries had the long route around the corner and out to the side of the car or 2. Put the collector inside the wheel well and then run a 2.5" tube around the corner. Either would have made the primary length more equal. As it is I think what I have will work fine and there is a theoretical advantage to the longer tube primaries over doing #2, but there is SUCH a large difference in the length of cyl # 1 and 2 vs 7 and 8 that I wonder if #2 would have been the better way to go even with the disparity. Also, being that I am using a smaller 5.3 I went with smaller tubing. I'd probably bump it up to a 3" merge collector for an LS1 and been wondering about going bigger yet for anything larger.

Supposedly the tripod style 280ZXT CVs take less effort to articulate than the Porsche or Z31T style with 6 big ball bearings. But anything you can do to reduce or remove the knuckling of a U-joint, especially one that is run at an extreme angle is a good thing. Wolfcreekracing.com says 2-3% more power with their Porsche CV upgrade, but I think that was measured on 510s and they have much worse u-joint angles than Z's as a result of the semi-trailing arm setup, especially on really lowered cars. Another thing that you can do that doesn't hurt longevity is REM the gears in the trans or diff. I honestly don't know what kind of gains you'd get from it, but gears are supposed to run cooler afterwards as well: http://www.remchem.com/services/. I've seen a ring and pinion set after this treatment was done, and they really do have a mirror finish as it says in the video with the horrible electronic beat music on the site. Just looking at your signature, it doesn't seem like your car is built for a particular class, so the best way to get more power to the wheels might be to just get a more powerful motor. You could up compression, go turbo, V8, etc.

I bought the Mr Gasket kit (there is a Moroso version too) intending to use it, ended up switching to a V8 and finding out that exhaust PCV setups aren't allowed in the racing class my car is in. Actually, I don't think they're allowed in any SCCA class. Did discuss it here like 10 years ago and there was some mention that you might get too much vacuum and cause the seals to fail. I was willing to run that risk to play around with it, but just never got there. I had a guy who was a Z mechanic give me some positively outlandish hp numbers for the mod, which I never believed, but I do think it might be worth a few hp. Would like to know if it works after all this time...

Don't know why Datsun#1 bumped a 4 year old thread, but my understanding is that even for a turbo you'll get better spool up earlier with a taller gearset than the T5 has coupled with a taller diff ratio. Clifton used to be a member here and he ran his turbo racecar with a NA ZX 5 speed for that reason, he discussed it in several threads if I recall. I seem to remember him saying that the NA ZX 5 speed was at least as strong as the T5 also. He had problems with both. Even with a short rear gear on a NA car, the T5's gap between 1-2 and 2-3 is too big. I remember going to the track with my buddy who was racing a 510 with an L16, 44 Mikunis, and a 280Z 5 speed. Coming onto the front straight he would shift to 3rd and I would absolutely drive away in my Z with the close ratio box. Otherwise the cars were always a couple tenths off at autocrosses. Very closely matched. Too big an rpm drop in the 280Z 5 speed left him "off the cam" and he had to wait for all the hamsters to get him back up to 5000 rpm or wherever the power came back on. By that time I had 10 car lengths on him. Again, this wide ratio thing is much more pronounced with NA/cammed/sidedrafted motors, but if you gave me a T5, I'd sell it and buy a couple spare closer ratio 5 speeds. YMMV.

Just use non-serviceable u-joints. The 4x4 guys figured that one out a long time ago. The newer forged cross 1310 should be strong enough for most people here. I bought the driveshaft end from JCI and then had a local driveshaft shop make a 3" shaft for me. They told me that they could have sold me the adapter cheaper than JCI. Just FYI...

My HF helmet is about 5 years old and is starting to flash when I start a weld. Time for another $49.95 helmet.

I had a roommate when I first bought my Z who was the local guru. He had worked in a Z shop for years, raced a 510, was a Nissan master tech, etc. Very well qualified guy, and very knowledgeable. Then the internet happened. I had taken all of his advice to the letter, and it turned out that his advice was disagreed with by other people out in the Z world. Things like "You should set your front camber at -1.2 and rear at -1.5 for autocrossing" or "stay with small cams for L series" were suddenly things that were for the first time in my experience (correctly) disputed. Many of us were somewhat guilty of the small pond syndrome at that point, too. I got on the zhome email list with the attitude that I had this incredible resource at my disposal, and he was probably right (which made me right by proxy) and the people out there were probably wrong. He remained right a lot of the time, but one of the things that access to knowledge should do is to make you more humble about what you know or the value of a single source. Nobody knows it all, not even close. But if you can take a little from this guy and a little from that guy, a little from this forum and a little from that one, you can make some very surprising leaps forward. This is not a car issue either. The spread of all kinds of knowledge in the last 20 years is just astonishing. Truly an amazing time to be alive.

Right you are.

14" wide tires will fit nicely under IMSA flares. Never heard of the flares you have coming. 10's up front isn't uncommon on race cars, does take some effort to turn. Power steering might be something to look at next.

Right now your gears are very long, and the rpm drop from gear to gear is too much. The 4.11s will be better in every respect, especially with that cam. Faster acceleration, less rpm drop between shifts, a lot more snap. Mileage wouldn't even be that bad. The ZX trans was used with a 3.90, so it's really just one step shorter. This calculator is really useful: http://webspace.webring.com/people/cz/z_design_studio/

Do you have a one way valve? You're supposed to according to Canton, see fig 2: http://www.accusump.com/accusump.pdf/instructions.pdf

In this case, the dual plane is taller. I believe tube80z has pics of the two side by side.

I wish I had some kind of retort for that jab, but I don't. Almost done though! Can't wait to see how PP goes for you. That's a big commitment. Good luck.

Oops. Dual plane is taller than single.

I can tell you that the edelbrock single plane is .75" taller than the single plane. I made my own mounts, so my experience might be a little different than others, but using a NASCAR air box with a drop base, I've got about an inch and a half to the hood. I'm going to make a cowl induction scoop to clear a 4" filter.

I have to agree with one of the comments on ls1tech.com about that pump. If you're running a screen with 1/4" holes, why run a screen at all?

I know there is a galley plug right behind the alternator, but looking at this diagram I don't think you're going to get any different result based on where you put the oil in. Looks like the cam feeds down to the mains. My setup goes has a remote oil filter so I'm plumbed in there.

That's good news. Thanks.

So Cameron, are you saying that your light comes on when the accusump kicks in, and that you only see it flicker on when your in a long left or on the brakes really hard? If that's the case, I'm thinking (hoping) I should be fine with a larger sump and manual valve.

Arizona Z Car has a combo bumpsteer spacer/short steer knuckle.

Grinding into reverse is usually the first sign of bad hydraulics. Dry slave cylinder indicates bad hydraulics as well. Pull the boot off of the master up by the pedal on the firewall, and the slave on the trans. If you see fluid, replace. I always replace both as a set.

Ya know, it might help if I correctly read what you wrote. You did the ISKY cam, not the Schneider cam that I've seen the lackluster results with. I'd keep what you have, tune it, and see what happens. Not a fan of the Schneider cam. Don't know much about the ISKY one, but my impression is that ISKY does a pretty good job on their Datsun cams. Rebello obviously knows his stuff. BRAAP has a favorite Rebello cam, want to say it has .520 lift. That was the one that I was eyeing before I decided to go V8.

Don't up the compression on that cam. That cam really isn't that big. I ran a similar .490/280 cam on a stock short block with 8.3:1 compression and everyone was telling me it would be a dog, no low end, etc. The low end loss wasn't even noticeable, but it was MUCH better on the top end. I then moved to a higher compression bottom end at about 11:1 and had massive pinging and needed 96 octane in order to run the full amount of advance that I wanted (mid 30's). I'd go after the fuel issues first. FWIW, I know a couple people who put together motors with that cam that were sorely disappointed with the results. One guy built a pretty stout engine and ended up with 180 whp on triples. Kinda sad. Only guy I've seen have good results with it, and they were pretty damn good, was MONZTER. He figured out a way to get something out of it, and that made me wonder what he could have done with a better cam...

Not a whole lot of tire choices for 15x12. Good to see you around again.