xxjoeyxxeb Posted August 27, 2008 Share Posted August 27, 2008 Lots of good info. so far. I can't wait to learn more, almost time for mine to be done. Quote Link to comment Share on other sites More sharing options...
blue72 Posted August 27, 2008 Share Posted August 27, 2008 I hope this applies, so I'm chiming in. I have two 225mm flywheels at my disposal. One is the stock Z L24 flywheel (23#), and the other I pulled from an early eighties Maxima (17.8#). For illustrative purposes I thought I'd show where the difference between the two that makes one lighter than the other. Namely where the extra material is located, or what I could see. Unfortunately the only picture I have is of the stock Z flywheel. The Maxima flywheel looks exactly the same except for not having this "bump". It continues flat up until it meets the machined part of the inertia ring. Based on what I've seen and the comments here, I'd say that if you were to remove the excess material from this area you would achieve the same weight savings. My Maxima flywheel spins up to 8k no problem. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted August 27, 2008 Share Posted August 27, 2008 Doug, did the same shop rebalance the flywheel after shaving it, or did you have to take it somewhere else? I had the flywheel balanced with the rest of the rotating assy. You zero out the crank, then put the flywheel on and zero, then the front pulley and final balance to zero. My flywheel looks very similar to Nigel's, maybe a bit more taken out of the outer ring and behind the friction surface. I have my SDS magnets in the outer ring of the flywheel, with the mag pickup installed in my bellhousing. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 27, 2008 Share Posted August 27, 2008 I have my SDS magnets in the outer ring of the flywheel, with the mag pickup installed in my bellhousing. That is an outstanding place to have them! Speaking as someone who brke off two distributors in shunts on-track, I was bound and determined to figure out a place that would not be affected in such minor accidents where the radiator kisses the front of the engine and wraps around it. I settled on a flywheel based setup similar to what Chrysler used on the 2.2 engines. Anybody else who uses this setup is a Genius in my opinion... /Threadjack/ Quote Link to comment Share on other sites More sharing options...
Zeerari Posted August 28, 2008 Share Posted August 28, 2008 I just picked up one of these: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=190244484169 Looks like Valeo lightened it already! Can take closer pics when it arrives if anybody wants to see them. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 28, 2008 Share Posted August 28, 2008 I can't believe they don't show a weight on it. That's the important part. Put it on a scale and tell us what it weighs. Quote Link to comment Share on other sites More sharing options...
Dan_Austin Posted August 28, 2008 Share Posted August 28, 2008 A week or so ago I called the seller to confirm that it was a lightened flywheel in the kit. Nope. They claim they just used a generic photo, so it is a stock 240mm replacement. I also asked about the weight, but the 'tech' had no idea. Quote Link to comment Share on other sites More sharing options...
Doc Hawk Posted November 24, 2008 Author Share Posted November 24, 2008 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. 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 Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted November 25, 2008 Share Posted November 25, 2008 I'm interested to see what tony thinks of that lightening job Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted November 25, 2008 Share Posted November 25, 2008 A week or so ago I called the seller to confirm that it was a lightened flywheel in the kit. Nope. They claim they just used a generic photo, so it is a stock 240mm replacement. I also asked about the weight, but the 'tech' had no idea. That Valeo one is about 23.5 pounds. I got one of those and got it lightened to around 18 pounds. The machine shop I took it to is quite good, and they wouldn't go any further because they said these are made in China and the metallurgy isn't as good as the original ones. It should be fine for me for now though. Greg Quote Link to comment Share on other sites More sharing options...
Zeerari Posted November 26, 2008 Share Posted November 26, 2008 Speaking of the Valeo flywheel, here is the clutch and flywheel I got from them. As you can sort of see, there are no lightening holes, it's a solid flywheel. Also note there are holes in the clutch basket for 9 bolts but only 6 holes in the flywheel. Working great so far. For those of you swapping from an auto, the spacer in my hand is what you have to remove from the crank before mounting the flywheel. Quote Link to comment Share on other sites More sharing options...
Doc Hawk Posted November 26, 2008 Author Share Posted November 26, 2008 That photo makes three Hybrid Z'ers I know of that do all their automotive work in flip-flops! Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted November 26, 2008 Share Posted November 26, 2008 thanks for the updated pics. I'm really liking the idea of lightening the factory flywheel instead of paying the huge bucks for AL flywheels. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted November 27, 2008 Share Posted November 27, 2008 Just buy a Fidanza. $300 on ebay, and you don't have to worry about it exploding, plus you can replace the friction surface if its worn out. I had one shaved down... I drew it in solidworks, removed material, did Finite Element Analysis, and got it down to about 16 lbs. The result? A flywheel that scares the ♥♥♥♥ out of me. I trust my FEA/design skills quite alot, but with something like that there are so many unknowns regarding material quality, fatigue etc. It costs me $100 to shave it down, and it was not worth it. As soon as I get the Fidanza on I'll know for sure, but I'm about 200% sure it will rev faster, and not scare me. Quote Link to comment Share on other sites More sharing options...
Daeron Posted November 28, 2008 Share Posted November 28, 2008 That photo makes three Hybrid Z'ers I know of that do all their automotive work in flip-flops! Add to that list Cobra_tim (me brudder) and count my old man for my citizenship. My uncle, half the time says "You guys, and your safety shoes!" and the other half of the time he cannot because he is guilty too. I prefer to be barefoot, period. Flipflops are my best friend due to the compromise; I will NEVER wear them to the shop. I value my little toes far too much, and soccer players by their nature take care of their feet. You don't see a masseuse working with a hammer often, do you? Quote Link to comment Share on other sites More sharing options...
woldson Posted January 21, 2009 Share Posted January 21, 2009 For information to the site here is mine. As you can see some of the holes drilled for balancing can be seen in the rear of the flywheel. Also he said he took off about 6 pds. So it should weigh in at 17.6lbs (when weighed by machinst it was at23.4), but I have not confirmed. Note the amount taken out of the pressure plate in order to bring that into balance. It is a "new" beck arnly clutch assemble. One last note BIG thanks to Z-ya for the 240mm flywheel, it was in fantastic condition and as a bonus, looks like his children had drawn some winter pics on the shipping cardboard!! Lastly, the minimum thickness at the point where the stock groove is one the clutch side to the back,,, at my best measurement,,, is 5/16 of an inch. about 7.9mm. Quote Link to comment Share on other sites More sharing options...
woldson Posted January 21, 2009 Share Posted January 21, 2009 Oh and here removed the pins and put them back without even me asking! Quote Link to comment Share on other sites More sharing options...
woldson Posted January 21, 2009 Share Posted January 21, 2009 I just picked up one of these:http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=190244484169 Looks like Valeo lightened it already! Can take closer pics when it arrives if anybody wants to see them. So, what did you end up with? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted January 21, 2009 Share Posted January 21, 2009 I'll chime in that 4 years ago I went the machining route to get down to 16.5 lbs and have been very happy with it. I have no issues with stalling etc. That said, when I did it, the Fidenzas were going for over $400 and I spent around $150 and several hours driving between machine shop and balancing shop. If I was to do it again today, I'd keep an eye out for a deal on a Fidenza (I've seen them several times in the $250 range). Quote Link to comment Share on other sites More sharing options...
Careless Posted January 21, 2009 Share Posted January 21, 2009 I got my fidanza on my Z31 and I cannot comment on the driveability (as it's not on 4 wheels yet due to weather restraints), but it does feel like a quality piece and it does not vibrate to hell. I'm not sure if I would bother having a flywheel lightened, especially if I was to do racing. I'd rather have an SFI Rated Flywheel for that purpose. But as mentioned in the post above, trekking to have it balanced and machined is a chore, and I would expect my machinist to have machines to do both in all honesty. My Z31's factory flywheel was (from what I know) machined and it was starting to show small cracks in the mating surface. That did not make me feel good. Has anyone tried a KA24 flywheel or something from another nissan with the same trans? It's a good way to get an oem quality flywheel at sometimes 65% of the weight, whereas most aftermarket are somewhere between 40-55% of the weight. Quote Link to comment Share on other sites More sharing options...
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