jmortensen

Rob, have you ever weighed the stock caliper and the 4x4 caliper back to back? I did, but it's been ~15 years. I think the difference was 2 or 3 lbs. The 4wd calipers on solid rotors had more heat capacity than the stockers did, but they had front bias issues when used with 280ZX rear disks. Not a fan of the 4x4 caliper, but it does do something and the weight disadvantage is overblown. Vented 4x4 setups are what a lot of the vintage guys run, and they run pretty hard. I wouldn't put a carbon floating rotor 14" system on my Z even if I could afford it (would require ridiculously large tires and they're just not necessary on a 2350 lb car), but I do like looking at the the pictures.

Agreed 100%. Your springs aren't too stiff, you're hitting the bumpstops. I would add going to softer springs with coilovers just means that you'll be on the bumpstops more. Your choices are to section the struts to gain more bump travel or to raise the car up. You're basically driving around near the bumpstops as it is. Many newer cars do this as designed from the factory, and different bumpstops can have a HUGE effect on comfort. Check with FatCat Motorsports and see what they have for you if you don't want to change out the springs or section the struts. New bumpstops are going to be your cheapest option. I would think this would probably be the one for you, but you might check with them before ordering: http://fatcatmotorsports.com/FCMstops_46.htm

I'm not sure what you guys are doing differently, but this info from Dennis Grant matches my experience pretty well. I wasn't smart enough to try and make the left front and rear carry the same percentage of weight, but I did have the experience that "a couple turns on the adjusters usually hit the target." I've probably done 5 cars total, so it's not like I have a whole lot of experience, but if all you're doing is trying to get the diagonals even, it just doesn't take a lot of adjustment unless there is something way out of whack. http://farnorthracing.com/autocross_secrets11.html On my Z I had the engine in the stock location and had an Autopower bar and R200 with LSD, and full interior and I came up within 20 lbs or so of even crossweights right out of the gate. Made a small change to one corner and I was within 5 or 10 lbs IIRC, and had 49.5% weight in the front. For my rebuild I moved the fuel cell as far to the pass side as possible and will move the engine right as well. That makes the corner weights more even, but it doesn't make the diagonals easier to adjust, at least in my limited experience. My buddies 510 which weighed something like 1800 lbs + driver of 225 was really left side heavy, but getting diagonals correct required about 1/4 turn on the rear weight jacks that he had installed. I think that was the very first car that I was present for weighting (his too) and we were looking at it like: "That was it?!?" I did a 911 once that was low on the LR corner and we didn't want to mess with the spring plate adjustment to raise that corner, so we tried to jack the weight around without it and ended up with a balanced car that was close to bottomed out on the RF corner IIRC. Got it done, it was a real bitch, the boss looked at it, and said: "Start all over. Adjust the spring plate first, realign, then corner weight." That was not a happy day for me, but it corner weighted out with very little trouble the second time.

No need to move components around to get the diags to match, that's what the coilovers (weight jacks) are for. It's getting the same weight on the corners LF and RF or LR and RR that necessitates moving stuff around IME.

TTT T/C rods make caster adjustment FAST. If you have to disconnect everything to make the control arm length adjustment that's where the time is, because you need to settle the car in between adjustments. When I was doing alignments I did a GOOD job, and I could set my car up (and I'd jump in the car to make sure it was even with me in it) in about an hour, but I was adjusting camber with plates and rear toe with eccentrics. Customer cars were all Porsches with full adjustability and it didn't take me much more than an hour on those either. The shop charged $100 for the alignment and I believe it was $65 or $75 per hour at that time. If you're corner weighting too that will add a lot of time. FWIW, I just paid $175 to have my Miata aligned for autoxing at the local race shop. Took 3 hours and based on the specs they got out of it I'm pretty sure there were some hydraulics involved. It was well worth it, the thing has way more neg camber than it should. For a simple recheck they'll still charge $175, but the labor isn't there after the first time. Next time they'll just be turning the eccentrics. Blue, I found this shop by searching "Porsche race alignment Seattle". I would expect that you could do something similar and find a shop that knows what they're doing.

Could be driveshaft angles. Hybridz.org has some good threads on how to measure the angles with modified laser pointers (usually done on an engine swap). I know the argument is going to be that the 5 speed is the same size and so the angles should be the same, but I think it's work checking, especially if you've tried everything else. On the early Z you can change the angles pretty easily by shimming under the trans crossmember. I think that changed mid 71...

I am going off of vague recollection here, but didn't SKs take Mikuni pilot jets and Weber mains and airs and emulsion tubes?

Yep. I think this is a pretty serious flaw. Now, to make light of it, here's Clarkson in the Reliant Robin.

Just came across something that might be helpful even at this stage in the game. Guy on another forum has a 4 post lift and he installed single tube flourescent lights on the inside rails of the lift, both sides, all the way down. You'd need to be careful when pulling a transmission or something like that, but for aligning cars or doing oil changes, etc, it lights the bottom up pretty damn nicely!

You can download the manual from the downloads section of hybridz.org. There is probably more info in the "How to Hotrod Your Nissan/Datsun L6" book. Parts are hard to come by. Rebello racing has some and they're very helpful with tuning, but they screwed up 2 of 3 jet orders for me. Todd at Wolf Creek Racing also has parts and is a very good guy to deal with.

Let me try that again.

Don't shim the arms forward or backward arbitrarily. The bad part about an H arm setup like the Z uses in conjunction with a strut is that the strut and H arm need to be perpendicular. If you shim the arm back (which would be the way most people would move it in an attempt to center the wheel in the fender) then what happens is that you get a misalignment of the strut at the top. It might be relatively easy to get the strut in at the top, but as the suspension compresses you get more and more angle between the strut and the control arm. I would imagine this is going to lead to strut issues and possibly bearing or bushing issues depending on what the control arm is using. When I did my first set of DIY arms like the middle ones in Blue's 2nd post, I took the springs out and shimmed the strut so that it came up right in the middle of the monoball in the camber plate, and then compressed the strut and verified that I didn't have a lot of side load there. About a year later the subject of rear control arms came up again, and I think my redo is the best design that I've seen. It's an A arm with a toe link, and the toe link is in front. This allows for some misalignment in the control arm and the strut top without binding, which I think is a really important benefit for a racer. Anything to reduce friction in the suspension is a good thing. Making an arm with the toe link in rear is easier, but having the toe link in front means that the solid part of the arm attaches directly underneath the strut. This thread has the discussion which led to the arm idea: http://forums.hybridz.org/index.php/topic/62776-yet-another-rear-control-arm-design/ And here is a picture of my arm:

Congrats to you too! Here is my HybridZ thread on ps: http://forums.hybridz.org/index.php/topic/97073-woodward-power-steering-project/ I think I'm going to have to do an entirely new crossmember, and it is the part of my project that has basically stalled me out for a couple years.

Congrats to you John. Nice to have a national champ customer. What was the margin of victory?

If by dead spot you mean flooring it from 2000 rpm and the subsequent hesitation, I would suggest you don't tune that part out with the O2 sensor. That was what led me down the larger and larger pump nozzle road, and it got to the point where the O2 sensor would read lean while there was black soot blowing out the exhaust. It's been 10+ years, but I think the rationalization at that time was that when you floor it the airspeed in the intake goes way down and at the same time the pump nozzle sprays a big stream of gas into the intake. It's super rich, but because it bogs due to the lack of intake velocity the O2 sensor reads lean. Once the speed comes up in the intake then everything returns to normal. Solutions are not punching the throttle at low rpms and running smaller venturis (and losing top end). Jetting is as much about the cam profile as it is about displacement, I wouldn't use any prescription for jet sizing as more than a starting point.

Use oil if for no other reason than to prevent the insert from being rusted to the tube.

zredbaron on hybridz made something like 268whp out of his stroker with 40's but I think they are webers. If you build up a 2.8 and a 3.1 the same way (compression, intake exhaust, cam, carbs, etc), the end result will be approximately the same hp per liter, and you'll get roughly 10% more power out of the 3.1. If you have the stroker crank and 9mm L24 rods, go for it, but I personally wouldn't spend thousands of dollars more on the stroker if the result is 20 hp. I'd spend a little more money on the 2.8 build rather than buying all the parts for the 3.1 build. A little more head work, a little more aggressive cam, better ignition, exhaust, etc. will yield more power per dollar IMO.

Maybe he types 5 wpm. I've run into that with other auto related businesses, particularly when owned by older men.

A fellow SoCal canyon death escapee! Congrats to you sir! I went off Decker Cyn Rd (it might be Westlake right there) about 5 turns north of Mulholland intersection, rolled 250 feet sideways (many rolls, wasn't counting) and ended up on the lid of my '82 Celica. I tore my bicep pulling my buddie's hand out. His hand was pinned between the sunroof and the boulder that stopped us. He cracked his fingernail and broke the bone at the end of that finger. That was the extent of our injuries. That was the beginning of autoxing for me... Matt, I got rear-ended in my first Z with the lap belt on. I had JUST removed the shoulder harness because I was going to turn left into a Burger King and go through the drive through and it was a bitch to roll the window down with the seat in the right position. The lady who hit me never touched the brakes doing about 50, she pushed me across the road into head on traffic where I hit an Acura Legend doing about 25 or 30. I broke my nose on the steering wheel. My wife hit her head on the dash, even with the shoulder harness on. I have to think that if I had the shoulder harness on, either I wouldn't have broken my nose, or it wouldn't have been so bad that I could hold the steering wheel up to it and have the curve match the steering wheel rim like two puzzle pieces coming together.

The distributor drive needs to be re-clocked. It is driven off of the crank and goes diagonally from the oil pump up to the distributor. You would need to drop the oil pump and rotate the shaft and plug it back in. It helps to have one guy on top and one underneath.

My wife bought me a track day package for Christmas last year, and I upgraded to the Elise (was supposed to drive a supercharged Cobalt). What a fun car! Handled amazing and it was on 185's in the front and I think 205's in the rear. Didn't really remind me of my Z though.

I've got CV shafts on order, they'll be done in 3-4 weeks and there will be several sets of shafts and adapters that aren't currently spoken for. Sign up for the group buy price. http://forums.hybridz.org/index.php/topic/105510-m2-z31t-short-shafts-group-buy-2/

Pretty sure it was a ZX and later thing, not sure what year though. My 80 transmission had it.

That expansion rate doesn't seem way out of line to me. If you have access to a sniffer you could put it in the radiator and look for HC's. An A/C leak detector works too.

There is a little confusion here because oils that meet GL-5 supposedly eat yellow metal. I did a little searching on this about a year ago and it looks like there are either NO or VERY FEW oils that are GL-5 rated that still have this problem, and if memory serves any oil that is also rated GL-4 or MT-1 is good to go. I like SWEPCO 201, and I used to cut it 50/50 with ATF to make it a little thinner and get a faster shift. Works great in Nissan transmissions either way, and I use it straight in Nissan limited slips, no LSD additive required. Lots of people like Synchromesh, which is available through Pennzoil and a couple other distributors, and I think you can get it at GM dealers as well. Really though any good quality gear oil will do.