Doc Hawk

Okay, flywheel is finished. 16 pounds, almost all from the inertia ring. Radiused transitions to avoid the creation of stress points. I took my time shopping for the right machine shop and settled on one who had a reputation for quality with the racing crowd. Since a flywheel explosion is serious business, it seems like a good place to spend money to have it done right. I told the machinist I was aiming for 16-18 lbs, but above all wanted a safe grind, so the weight was not as important to me as his comfort with the grind. He ended up at 16# 2oz, and it lost a little more weight after it was balanced. Here is a sample OEM 240mm flywheel: And my lightened flywheel: This is what is meant by radiused corners. Note the smooth, rounded transition from horizontal to vertical surfaces. I am extremely pleased. This can be done for around $100-$150, including balancing. I will let you know how it goes after install. Thanks very much to everyone who helped guide me to this stage in the process. David

Time for a new clutch for my 240Z with a 240mm (turbo or 2+2) flywheel. I purchased the "XTR Racing Stage 3 Clutch Kit," item #XTR-51008R3-SS, based upon the many positive reviews I've read of the XTD clutch, which is the name under which the clutch was previously marketed. The kit includes a sprung 6-puck Copper Ceramic (also known as MIBA) disc, a pressure plate rated at 420HP, 388 ft/#, release bearing, pilot bearing, and an alignment tool. There's also a simple one-page sheet with basic instructions. It was shipped and delivered with lightning quickness, and the MegaTuning customer service was good. I sent the plate to the machine shop that was balancing my newly lightened flywheel for mounting and balancing the unit. I got a call later telling me that the pressure plate didn't match up to the pins - in other words, it didn't fit. I went down there the next day and they had figured out that the first guy hadn't bothered to rotate it around to see if the three pins lined up with different holes. The master machinist had taken a look, rotated the plate 120 degrees, and the pins and bolt holes lined up perfectly. That was one stress relieved. When I picked up the assembly, they told me they were very concerned about the as-delivered balance of the pressure plate. It was out of balance by a massive amount - I don't have numbers yet but I will get them when they open after the weekend. The master machinist told me that they see dozens of pressure plates a week, mostly for race cars or performance vehicles, and they are all balanced from the factory. This one was way off, and took some significant drilling and even welding on big lugs for weight on the opposite side. Here is the finished, balanced pressure plate: Closeup of the added weight: Closeup of the drilling to remove weight: So from what they tell me, this is an extraordinary amount of balancing to do on a mass-produced pressure plate, and they were concerned that people are going out and bolting these straight up to their flywheels and driving off. The rotating mass is so unbalanced that they think it will screw up motors at best, and shatter flywheels at worst. Please, if you buy one of these clutch kits, pay the $40-$60 a reputable machine shop will charge to balance it for you. Anyway, mine is balanced and I'm happy. It goes into the car on Wednesday. I'll update once I've felt it in the car.

No, I didn't end up having to bypass anything. I did a power trace and my middle wire was hot behind the switch, so I figured it was the switch. I had already rebuilt and examined it twice, so I BFH'ed the switch until it worked.

Success! I wiggled the crap out of my newly rebuilt turn signal switch, and eventually started getting some intermittent blinking. More wiggles = full turn signal indicator function! PS: It occurs to me that some people might not realize that the ignition switch must be ON in order for the turn signals to work... didn't happen to me but that could cause huge frustration if someone didn't know that.

It dangles in plain sight. Swapping them is a 60 second process. Go try it!

Your turn signal flasher unit is under the steering column. Your hazard flasher unit is in the passenger footwell near the sidewall, up under the dash. Things I wish the service manual would tell me instead of having to learn it on HybridZ.

I just bought the same exact clutch, and I have the same exact problem. Grrrrrr... Have you called the seller yet? Let's join forces so he knows that he is selling the wrong stuff, and make sure we get our money back. Some people on here have reported success with an XTR clutch. What model are they using? Also, please note that they used to be called XTD... same company. Moderator willing to rename this thread XTR / XTD turbo clutch compatability?

Have you rebuilt your turn signal switch? It's a common failure point. I have not seen a specific writeup... I should probably post one. Here is a writeup, photos to follow. REBUILDING AN S30 TURN SIGNAL SWITCH The turn signal switch is a common point of failure. It contains several tiny parts, and the front face of the switch is open, allowing contaminants to get into the switch itself. Most often, the contact points corrode, causing an open circuit when the turn signal lever is engaged. To refresh your turn signal switch, take off the steering column cover by removing the 6 screws on its underside. Next, separate the two halves of the steering column controls, which are the combination switch (lights, wipers) and the turn signal switch (blinkers and brights). These two halves separate from side to side by removing two screws on the top and bottom of the column, accessed from the outboard (left) side. Once the halves are separated, take a look at your wires. After almost 40 years, most of our Z's have had one or more rounds of hack artists mess with our wiring harnesses. What the manual says may not be what exists on your car. Protect yourself from pain later by using masking tape to label both ends of all wires before you unplug them. You can leave your combination switch attached, so don't worry about those wires. With the switch removed from the car, go to a clean work area. Do not perform this work over carpet, as you run the risk of losing the internal fiddly bits forever. I believe an OEM unit runs about $250 right now, and the wiring harnesses differ from year to year, so this is not worth taking a chance. At the base of the signal arm there is a crescent-shaped brass colored switch housing with three wires leading into the back PC board. Hold the assembly face down, so that the board and wires are facing upward. Gently pry the three retainer tabs up, so that you can withdraw the board. A little BB and a rocker plate will probably fall down into the switch housing - this is why you held it face down. Better in the housing than rolling across the table and into oblivion! Dump them out into a little cup and inspect the switch internals. It probably looks dirty and corroded, or at least heavily oxidized. A little contact cleaner and a wire brush will brighten it right up. Once everything is clean, dab a little dielectric grease in there to help avoid corrosion in the future. To reassemble the switch, place the little BB on top of the spring in the switch housing. Put a dab of the grease in between the forks on the wired board, and place the rocker plate on top of it. The grease will help the plate stay in place until you sandwich into position on top of the BB. Gently lower the back into position on the housing, keep it squeezed shut, and give the arm a few throws and make sure everything is moving smoothly. Shake the assembly and listen for your BB - if you got it wrong, the BB will be rattling around in there. If you are confident you have it right, bend the retaining tabs back into position. Mount it back up and hopefully you have some working turn signals!

You're further than I am; my hazards work fine and my turn signals don't work at all. I'll test the turn signals while the hazards are on. For you, if you are getting a solid indicator with a turn signal, then it sounds like a simple replacement of the flasher unit by the steering column will solve your problem. Try swapping the two units and see if your hazards stop flashing and your turn signals work.

Junkyard, sorry. My parts car, to be exact. But the flasher unit I got to replace the old one is very different from the stock ones. It's only 1/3 as tall! I'll post a pic tomorrow. They look like they are pretty generic; I'd expect to find them at Kragen/Schucks/CarQuest/NAPA/whatever. I am starting to suspect a wiring issue. Tomorrow I am going to multimeter some leads and trace my hot wire back through the car. The green (middle) wire on the back of the turn signal stalk should be hot when the key is ON. If it isn't I'll start tracing it back through the harnesses and hazard switch until I get 12V. This thread should help: http://forums.hybridz.org/showthread.php?t=123434

Thanks for replying; without you I'd be talking to myself, lol. I swapped the flasher unit under the column (which serves the turn signals) with new. As mentioned above, I also swapped the footwell flasher, which serves the hazards, and that fixed the hazards from steady on to blinking. I found Ron Tyler's handy wiring diagram here (thanks Ron, where is that from?), and I think the best place to try and jump some wires is the green to green/yellow behind the hazard switch. Unfortunately that schematic is for a '78, so I am just hoping that the wires are the same color behind the '72 hazard switch.

Did you ever fix your turn signals, Panzer?

Why do 3 people come in and say "check your bulbs" or some other drivel about one or more lights being out when the OP clearly stated that the signal lights work with the hazard switch? Come on people. If you're going to try and help, at least take the time to read the original post. Yeesh. You say that you cleaned the contacts on the switch. Do you mean that you actually disassembled the contact box at the base of the turn signal stalk, or that you cleaned the contacts on the connector? You have to bend back tabs to get into the box, and there are very tiny fiddly bits in there that are a bear to get back in the box. However, breaking it open and getting the contacts clean is a must, as corrosion here is one of the top two causes of no blinkie. The other top cause of turn signal malfunction is the hazard light switch. It puts power through the light circuit both in the ON position and OFF as well, so that the turn signals can route through the switch. The contacts on the off side corrode. You have to pull the hazard switch out of the dash and check the contacts within the housing. For your new headlight problem, see if anything happens when you click your brights on/off with the turn signal selector. Sounds like you've botched a wire or harness on the reassembly. I have my own turn signal thread going right now, and I have the exact same problem as you. My hazards work, and my signals do not. At first my hazards didn't work either (just solid, unblinking lights when the switch was on), but a new flasher relay in the passenger footwell fixed that. Now my hazards work but my turn signals still don't. I have rebuilt the hazard and the turn switches and still have no go. Anyone? BTW, are you talking about a 71 240Z or a 74 260Z?

Gorgeous. I'm looking to do the same transplant.

Update: Swapped the flasher relay under the passenger footwell. Now the hazards operate perfectly. Still no response from the turn signals. Verified that the switch rebuild was good. Found one lead in the signal harness on the hot side that had backed out of the connector. Still no go! Is it multimeter time? Based on other's experience, it sounds like the hazard switch is the likely culprit, even though I pulled it and opened it and it looked clean. Perhaps I should use a multimeter to check the "off" position wires for continuity when the hazard switch is off? What lead to what lead?

Did a searchie or five already. Signals and hazards come up all the time, but I didn't find this particular combo. My turn signal switch does nothing. Rebuilt a known good one off a parts car, cleaned and lubed (I've been inside a turn signal swich a few times now... cleaned rockers, lubed, made sure the BB was in the right spot... ugh). My hazard switch turns on all four indicator lights, solid. No flashie. Does this regardless of headlights, key position, or turn signal switch position. Should I swap out the flasher relays, or look somewhere else? Where are those relays on a 72? Is that them in the passenger footwell? If someone has a photo that'd be swell. Thanks for any tips.

Drop a blob of JB Weld or high build epoxy on the back of the emblem so that it is 1/16" short of being flush with the sides. Dry upside down so it lays flat. Now you have a surface upon which to stick your double sided 3M tape. It will withstand a nuclear blast; the stuff is very sticky.

Registration is now open for the 2009 SDRev.com Grand Challenge in San Diego. Full info at http://www.sdgrandchallenge.com. PLEASE somebody, show them what a HybridZ can do! Anyone going to compete? Here is a bit of info from the site: Challenge: Buy a car and prepare it for show and go, all for $1000 or less. Cars shall compete in three event classes, and the car with the highest total points at the end of the Challenge wins the competition. Cars must have a team of at least two drivers, because the race events require the top times from two different drivers. Sponsor prizes shall be awarded for 1st-3rd place, and additional contingency prizes (event winners, best in show, Spirit of SDRev, etc.) may also be awarded depending on sponsorship levels. Receipts must be provided for all items and preparation of the car, and the original car must be presented to the Challenge Chairman prior to modification for verification and documentation of condition. Sponsor contributions of services, free work, tires, and labor performed by the team do not count towards the $1000 limit so long as these processes (including team labor) are documented. Photos help. Show Event: Cars shall compete in a judged concourse event. Cars shall be awarded 1-10 points based on overall appeal, presentation, build quality, notability/originality, concept execution, and fit and finish. Judging shall be performed by an impartial panel. Race Events: All cars must run on DOT legal tires with a minimum treadwear of 200. Three SGC Autocross races shall be run during the Challenge Season. The top finishes from two different drivers for each car shall be counted towards competition points. A first place out of all Challenge cars on one day counts for five points, second place scores four points, third scores three, on down to fifth place which scores one point. The top two event finishes are added together for a total score of up to 10 points. Only one autocross event is necessary to place in this event, but that would result in a maximum of nine points since the best two drivers could do is place first and second in a single event. Three SGC drag races shall be run during the Challenge Season. Scoring is exactly the same as for Autocross, with the top times from two different drivers counting towards Challenge Season points.

Doug, did the same shop rebalance the flywheel after shaving it, or did you have to take it somewhere else?

I'll post a before and a few afters of mine once I'm done. Remind me next month if you don't see them.

Thanks Tony, this kind of warning is exactly why I posted. I will remove the dowels and have the inertia ring turned down. I am not looking for extra ounces of savings and I want it to retain as much strength as possible, so I won't bother with the additional lightening options.

I have a turbo flywheel that I would like to get shaved (lightened) before dropping it behind my L28 (NA Maxima head). I have a six puck ACT HD turbo clutch set that I want to use, which is why I am converting. The info I found through searching mostly had to do with 225mm flywheels, so I want to be sure I have the right info. I will take it to a reputable shop, but in order to be educated when I do so, what part(s) of our flywheels are typically shaved to reduce weight, and how much should I have them take off? The back side ring running around near the outer edge? This is primarily an autocross car which I occasionally take out for an exhilirating run somewhere. Definitely not a DD, but I don't want to be forced to launch from the neighborhood light at 6K either. Edit: I saw that Bastaad525 runs/ran a similar setup. Does ~19lbs sound right for a reliable/safe/resurface-able turbo flywheel? Bastaad, how did your setup work out for you, long run? Thanks,

Even funnier because it is half true. Have you seen how they are running the cars this year on high downforce tracks? The drive wheels are set up skewed to the right in excess of five degrees, making the cars "crab" down the straightaways visibly cocked to the left. It looks ridiculous! They're doing it to increase side force on the new car design, to help them turn left.

Seafoam walks my dog and does the dishes.

Yeah, saw that at this year's WCZN show. I deeply respect the effort and the finish level, but it does absolutely nothing for me personally. 'sokay, more power to everybody!