rejracer Posted April 13, 2009 Share Posted April 13, 2009 Hi all, I wanted to get some feedback on rev happy flywheel / clutch combination's. I am slowly building a turbo L series. The final build is going to be approx 8.25 cr, stroker, limited to 300 hp on pump gas, and MAX 400hp with water/meth injection with race gas. Final build will also use aftermarket EFI. The goal of the final build is to be fun, responsive, streetable and stone cold reliable. I am not going for all out hp/torque. Also my definition of street is not a race car that I drive on the street, but one that is easy to drive, is stone cold reliable, not tempermental, and one that will not be inspected head to toe every 1k miles. I have looked into several options for the flywheel, and these are the options I have come up with so far: 1. factory flywheels from 240z or a Maxima -Cheap -a few lbs lighter than 280z / turbo flywheel -minimal gain 2. any factory unit lightened. -cheap -lighter than 240/maxima flywheel -questionable strength with radical amounts of material being taken off. -marginal gains. 3. Fidanza Steel flywheel http://www.nolimitmotorsport.com/prod/fz-243281 -cheapest of the steel flywheels -Weighs just about as much as stock (per fidanza application guide) -replaceable friction surface 4. Arizona Z Car steel flywheel http://www.arizonazcar.com/fly.html -more expensive than the fidanza. -No replaceable friction surface -pressed on ring gear -11.75 lbs 5. Kameari flywheels -more expensive than most flywheels -no replaceable friction surface -ring gear appears to be from the same slab of steel as the rest of the flywheel -10.5 or 9.5 lbs depending on street/race configurations 6. Tilton or other fully custom units. -lightest possible -more expensive than the Kameari/act combo -lots of combinations available. Now this is a street car, and based on that I think it eliminates the tilton unit. The reason being is I want to be able to go into any parts store and buy a clutch disk that would be compatible with the flywheel/pressure plate. But I am not opposed to it if it means increased longevity and reliability. After all we buy craftsman tools so we can take them back, snap-on so we don't have to, same principle applies. Since the build is going to use a low compression ratio, I don't think a lot of inertia is in order, as would be for a high compression n/a build. Plus since I have decided to use a stock style clutch (I picked up an ACT 225mm extreme pressure plate and 6 puck sprung disk) I have quite a bit of inertia on the setup already. What is important to me -reliability/service life -smoothness -maintenance free -rev-happy-ness Keep in mind, stock already has the first three... so does this make rev happy #1? With the above information, I have some fairly specific questions: 1. The Kameri Race flywheel: are they reliable enough for street use? 2. Would you be comfortable installing either kameari (race or street) and not inspecting it for 100k miles? 3. Do the Kameai's use a press on ring gear, or is the entire unit from one slab of steel? 4. What other clutch types are available? As of now, I am leaning towards the Kameri race flywheel, and the Act 225mm unit. One selling point for ACT is the readily available information on the units, from one site I could find and compare all the available combinations (3 pressure plates and 6 different disks) and top quality parts (NSK bearings) to boot. Any input meeting the goals is appreciated. Quote Link to comment Share on other sites More sharing options...
cockerstar Posted April 13, 2009 Share Posted April 13, 2009 Why not an aluminum Fidanza unit? Quote Link to comment Share on other sites More sharing options...
DRZ man Posted April 13, 2009 Share Posted April 13, 2009 I was going to say OS giken, but is to smooth engagement, I like it alot. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted April 13, 2009 Share Posted April 13, 2009 Or a SPEC Aluminum: Are you going with 225mm size for less inertia? I stayed with the 240mm size for more friction surface. Quote Link to comment Share on other sites More sharing options...
rejracer Posted April 13, 2009 Author Share Posted April 13, 2009 I wanted to stay away from aluminum because of the longevity issue with the ring gears as well as problems with the mounting surface where the center bolts touch the flywheel surface. I have read of folks having problems in these areas. Reading what I have read, it would always be on my mind, and for peace of mind wanted to go steel. I am staying with 225mm for less inertia, also recall I am limiting the power on this build so the extra surface area is not needed. Quote Link to comment Share on other sites More sharing options...
cockerstar Posted April 13, 2009 Share Posted April 13, 2009 At 300hp I'd definitely be going with a 240mm unit, and at 400hp I'd be going with an aftermarket 240mm one. From what I've read the bolt issue is solved by using flywheel bolts that are a few mm shorter, and if the flywheel has the pressed on steel ring I think it would hold up for "100k miles" without an issue. Quote Link to comment Share on other sites More sharing options...
rejracer Posted April 13, 2009 Author Share Posted April 13, 2009 (edited) I will add that I have read from other users that the Kameari unit's are more responsive than other manufacturers flywheels of the same weight due to the way the flywheel is constructed. Looking at the aluminum flywheels, it's clear there is a lot of mass on the outer ring of the flywheel, it's this area that is the most critical for eliminating MOI. Reducing MOI is one factor that provides better throttle response. Ryan, I believe the issue you are referring to are the bolts that are used to fasten the pressure plate to the flywheel. I am aware of the issue there, as well as the fix, I believe in other threads the part numbers for new bolts are listed from McMaster Carr. The issue I am referring to are where the flywheel mounts to the crankshaft. I recall that some have indicated that the bolts are digging into the aluminum after x miles of use and this reduces the clamping force holding the flywheel to the crank. To cope with this I recall spacers being used, which then required machining the bolt heads to prevent contact with the clutch disk. Based on those 2 issues, (and the fact that it's aluminum) I was thinking that steel is a better match for what I am looking for. Do I understand this correctly? FYI the extreme pressure plate is available on the 225mm unit and not the 240. With a 6 puck sprung disk it's good for 426 ft lbs of torque. The 225mm unit sounded like a more flexible arrangement over the 240mm unit. I like options! If there is no advantage in reduced MOI for running a 225mm unit versus the 240mm unit i may end up selling my current setup and going for a 240mm unit. Which is why I wanted feedback on the flywheel and clutch combo. At this point I am really open to any combo, but from what I understand the kameari unit's look to be the best, no-hassle-reliable unit. Thanks! Edited April 13, 2009 by rejracer spelling and clairifications... Quote Link to comment Share on other sites More sharing options...
Cobra_Tim Posted April 13, 2009 Share Posted April 13, 2009 I will add that I have read from other users that the Kameari unit's are more responsive than other manufacturers flywheels of the same weight due to the way the flywheel is constructed. Looking at the aluminum flywheels, it's clear there is a lot of mass on the outer ring of the flywheel, it's this area that is the most critical for eliminating MOI. Reducing MOI is one factor that provides better throttle response. Ryan, I believe the issue you are referring to are the bolts that are used to fasten the pressure plate to the flywheel. I am aware of the issue there, as well as the fix, I believe in other threads the part numbers for new bolts are listed from McMaster Carr. The issue I am referring to are where the flywheel mounts to the crankshaft. I recall that some have indicated that the bolts are digging into the aluminum after x miles of use and this reduces the clamping force holding the flywheel to the crank. To cope with this I recall spacers being used, which then required machining the bolt heads to prevent contact with the clutch disk. Based on those 2 issues, (and the fact that it's aluminum) I was thinking that steel is a better match for what I am looking for. Do I understand this correctly? FYI the extreme pressure plate is available on the 225mm unit and not the 240. With a 6 puck sprung disk it's good for 426 ft lbs of torque. The 225mm unit sounded like a more flexible arrangement over the 240mm unit. I like options! If there is no advantage in reduced MOI for running a 225mm unit versus the 240mm unit i may end up selling my current setup and going for a 240mm unit. Which is why I wanted feedback on the flywheel and clutch combo. At this point I am really open to any combo, but from what I understand the kameari unit's look to be the best, no-hassle-reliable unit. Thanks! Whats the price on JUST the PP? And do you know what it weighs vs. a stock PP? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 13, 2009 Share Posted April 13, 2009 My impression has been that the aluminum flywheels rev faster than most of the steel ones. I have the AZC billet steel at 12 lbs, and I can say for sure that my friend's Tilton 10 lb flywheel on his 510 revs noticeably faster. So does my other friend's HKS 10 lb (nodular?) iron flywheel. I wouldn't get hung up on the thickness of the material, because it is aluminum and you're comparing it to steel which will be heavier for a given thickness. I'd go for the lightest weight you can find. Check out MONZTER's setup. He posted pics a couple days back of his light flywheel with dual 5.5" clutch. That is a fast revving engine. You might get acceptable longevity with a dual 7.5" clutch... Quote Link to comment Share on other sites More sharing options...
X64v Posted April 14, 2009 Share Posted April 14, 2009 There's nothing wrong with the 225mm one as far as torque capacity, you don't need a 240mm to hold up. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted April 14, 2009 Share Posted April 14, 2009 Are you talking about an act clutch? If so they do make a extreme pressure plate for the 240mm clutch. its N013x where the hd one is N013. So why hasnt anybody noted that from a stock standpoint that the 240mm flywheel and the 225mm flywheel are the exact same size? Its just where the "cooling ring" is machined into it and where the pp bolts are drilled. I guess you could even say the 240mm flywheel has less inertia because it has 3 extra bolt holes drilled in it lol Quote Link to comment Share on other sites More sharing options...
X64v Posted April 14, 2009 Share Posted April 14, 2009 So why hasnt anybody noted that from a stock standpoint that the 240mm flywheel and the 225mm flywheel are the exact same size? The flywheel is the same size, but the pressure plate is smaller in diameter, giving the whole assembly less total inertia, all else being equal. Quote Link to comment Share on other sites More sharing options...
rejracer Posted April 14, 2009 Author Share Posted April 14, 2009 Tim, I don't know the weigh of the pressure plate. I know it's more than 15lbs from picking it up. Jon, Concerning aluminum versus steel, I don't have any first hand experience, so my impressions are based on threads i have read here and on z car forums, as well as the photo's that are available of the unit's online. In general the lighter the flywheel the less rotational inertia. For a given weight of flywheel, where the weight in relation to crank centerline is what matters. it appears the aluminum units have the weight towards the outside of the unit, and the hub area appears that it would be lighter. On the Kameari unit it appears that the majority of the weight is closer to centerline, especially on their race version. It's this design feature that is drawing me towards it. I do also recall TonyD making a comment that he feels the 10.5 lb aluminum flywheels feel more like other 15lb stock flywheel when machined down correctly. One other design feature I have not thought of before is how long will the friction surface of a kameari or AZC flywheel last up against the different clutch disk materials. For example I bought the act 6 puck sprung disk, after inspecting it, it's obvious that it's going to wear the flywheel and pressure plate much faster than the street disk. I did not consider this when I purchased the disk/pressure plate combo. If I were to decide to keep these parts, that would make an aluminum unit look much more attractive as a replaceable friction surface is more serviceable. So the question is, how reliable are the aluminium units, and I am primarily concerned with where they mount to the crank. Jeffer, I was aware that the Outside diameter of the flywheel is the same between the two. It's not the diameter as to where the weight is. So I believe it's not the total weight of the flywheel, nor is it the total diameter of it either, but rather where the weight (mass) of the flywheel is in relation to the crank centerline that determines it's MOI. Yes I am referring to an ACT pressure plate. Thanks for the part number. I did not know one was available, I am shooting myself in the foot by not doing enough research before I started buying parts! Lots of good info in this thread through. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 14, 2009 Share Posted April 14, 2009 Concerning aluminum versus steel, I don't have any first hand experience, so my impressions are based on threads i have read here and on z car forums, as well as the photo's that are available of the unit's online. In general the lighter the flywheel the less rotational inertia. For a given weight of flywheel, where the weight in relation to crank centerline is what matters. it appears the aluminum units have the weight towards the outside of the unit, and the hub area appears that it would be lighter. On the Kameari unit it appears that the majority of the weight is closer to centerline, especially on their race version. It's this design feature that is drawing me towards it. I do also recall TonyD making a comment that he feels the 10.5 lb aluminum flywheels feel more like other 15lb stock flywheel when machined down correctly. Based on my first hand experience, I don't think this is correct. I get what you're saying and I agree with your logic, but I think you're wrong specifically in regards to the aluminum vs AZC flywheel. The Kameari if it has holes drilled around the outside will probably be quicker to rev than an aluminum flywheel. I don't know what Tony was talking about. I can't see how any 15 lb iron flywheel could match a 10 lb aluminum one, I don't see how you could take enough meat off of the outside to make that happen. I vaguely recall the thread you're referring to and I think he was trying to make the point that where you take the material off is as important as how much you take off, not specifically saying x has less PMOI than y. One other design feature I have not thought of before is how long will the friction surface of a kameari or AZC flywheel last up against the different clutch disk materials. For example I bought the act 6 puck sprung disk, after inspecting it, it's obvious that it's going to wear the flywheel and pressure plate much faster than the street disk. I did not consider this when I purchased the disk/pressure plate combo. If I were to decide to keep these parts, that would make an aluminum unit look much more attractive as a replaceable friction surface is more serviceable. So the question is, how reliable are the aluminium units, and I am primarily concerned with where they mount to the crank. You might be able to turn the AZC or Kameari once or twice, if they weren't in bad shape. Also if they aren't in bad shape you can run them without turning them. My friend with the Tilton has been through I'm guessing 6 or 7 clutches with his flywheel and Comp Roadster pp, and he just keeps reusing the flywheel and pp, and replaces the clutch disk whenever the engine is out of the car. No problems with that yet... If you're drag racing you had best get something serviceable. Quote Link to comment Share on other sites More sharing options...
rejracer Posted April 14, 2009 Author Share Posted April 14, 2009 Yes you are correct that is what Tony was driving at. The physics behind this dictates the most important aspect is where the mass of the flywheel ISN'T, regardless of the material it's constructed from. quote from http://forums.hybridz.org/showthread.php?t=115812&highlight=clutch "How the flywheel is constructed is as important as what it's made of, or how much it weighs. I have a cut down stocker that weighs 15# that has a MUCH more radical throttle response characteristic than the current 13# aluminim flywheels from Midway/Centerforce. It feels more like an 11# tilton." And later in the same thread: "you want your weight behind the clutch frictional area (ideally the 225mm, but I won't open that can of worms), and you want the inertia ring gone. As long as the weight of the flywheel at the frictional surface equals the weight of the dampener at it's outer diameter, you will have perfectly balanced torsionals on each end of the crankshaft." I think the above is accurate, with that said, I'm not against an aluminum unit, so long as they are reliable. If they are reliable, they do sound like a good option as they are servicable. I know the outer perimeter bolts issue can be fixed. What about the hub mounting bolts? I'm going to have to do some more searching, and find the thread where the guy reported that problem. Perhaps I misunderstand the issue. The requirements for this little project have not changed from the original post: -reliability/service life -smoothness -maintenance free -rev-happy-ness from my previous reading I had dismissed an aluminum unit because of the reliability (bolts stripping) and maintenance (having to inspect the flywheel to crank bolts). If with proper installation these are not issues, I may have to reconsider an Aluminum unit. Also Tony D was referring to 13lb midway or center force flywheel, not a 10.5lb aluminum unit from Fidanza. How many aggresive street driven miles can an aluminum unit go without inspection? How long can I expect an aluminum unit to last in the same conditions? How real is the ring gear issue on the aluminum units? Thank you, Robert Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 14, 2009 Share Posted April 14, 2009 My opinions. I have never driven a car with a light weight flywheel until I installed the 11lb Fidanza on my L28ET. What a difference. The rev matching is much, much easier during gear shifts. I was struggling to tune the MS with the large injectors to give good throttle response. All the hours of tuning didn't match the improvements I got with the flywheel. The Fidanza can take either size clutch. My car now responds as if it has ITBs', even with a single throttle plate. Go light. My daily driving launch point changed maybe 250rpms. I have never heard any members here complain about an aluminum flywheel failure of sorts. Just make sure you read the thread about using the Fidanza and bolt lengths. It's pretty much common sense. The light flywheel also changed the "sound/feel" of the engine. I can feel the firing pulses a little more in the cockpit. I like it. Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 14, 2009 Share Posted April 14, 2009 Kameari has an integral ring gear, it is not replaceable, same as the old HKS units. When you have the HKS unit in your hand, you go 'wow, this is light', then when I hand you the Kameari Race unit, you say 'holy shite!' The old 9# HKS units I felt were acceptable for an L28 in street usage, but that was about the limit for streetability. The Kameari race unit might be a tad light, especially with a grabby clutch. As for reliability and not looking at it for 100K miles....you're setting up unreasonable expectations for a performance setup, and for a fractured flywheel if you have a lightened stocker! A performance engine is INTENDED to be inspected regularly. I know people who were changing two stock clutch discs a MONTH in their street cars in Japan because they were wearing them out that fast. Stock weight flywheel. Get a grippier clutch, something has got to give. Face wear on the PP, or the flywheel, something... Thinking you can assemble it and forget it will have you spending more than what you are considering now with these units! I'm not saying anything would be wrong with it...but to think a high coefficient of friction disc would just happily take abuse and hard driving with sticky tires and not have SOMETHING wear if unreasonable. Someone we all know pulled his engine out (again) and found the RIVETS of his very expensive metallic clutch were LOOSE! Seems 5 days doing pulls on the dyno and 25-50 Drag Launches killed it in less than 2000 miles. Lots of money, and it died. BECAUSE he was doing other maintenence and inspected it, he found the rivets before they sheared or let go and let the disc....well...you know! With his PP, there was 0.010" wear, as was his Fidanza Flywheel. New facing on the Fidanza installed with 75 Inch-Pounds on the fasteners and it was ready to go after Fidanza screwed around sending the wrong facing and then refusing to warranty the flywheel, and charged him another $80 to redrill the facing bolts because the holes were different in the friction surface from later flywheels. Cost him as much in shipping to get it quickly as it would have cost for another new flywheel! The PP was a different matter, but for only $150 it was replaced with a 2200# unit. The disc? It's now using 3/8" grade 8 bolts to hold the components together instead of rivets, and uses a design that doesn't let the rivets bash against the hub when the springs totally compress. You Datsun Guys and your sprung hubs. I swear. Drive a solid disc like the VW guys do and you don't have to worry about your springs compressing...and if you have any competence with your left foot control and clutch release, it drives just as nice as a sprung hub, with less to go wrong! But I digress... My other comments have been reporduced above and stand on their own. And I didn't say the 15# stocker revved as fast as the Tilton, but that it was more like the Tilton's Response than the lighter 13# Centerforce unit. Yes, that means the 15# revs faster than the 13#, that IS what I was saying. It IS possible. Weight is not as important as where it's removed. I had a diagram someplace on sectioning a stock flywheel, and how mine is done is FAR different than most lightened units I have seen here in the USA. Frankly, if there is more than 3/8" thickness (say 10mm) they haven't lightened it as much as possible. And if there is still a square edge near the ring gear, they haven't lightened it in the most IMPORTANT area. Think of a 45 ange UNDER the ring gear to a 10mm thick facing, along with a mating taper breaking the square edge starting from the outer rim of the clutch cover bolt holes... Those two things remove quite a significant amount of weight were it has MOST effect. If you don't have those done on your lightened stock flywheel, you have something that is underpeforming compared to what you could have, IMO. For the record, I buy Craftsman Tools because they are cheaper and they break JUST AS OFTEN AS SNAP ON DOES! When you HAVE to take one back...and you will...you're out of pocket less money. You were right in your analogy, kind of...you just are neglecting to realize nothing lasts forever, so if you spend a bundl of money on it...you're likely just out a bundle of money because it will break just like anything else. This is especially applicable to automobiles and their components. It's not a matter of not breaking, it's a matter of what you will have to do when it inevitably breaks or requires overhaul. Quote Link to comment Share on other sites More sharing options...
hughdogz Posted April 14, 2009 Share Posted April 14, 2009 (edited) It would be great if someone could set up a "tribulum" so that we can actually measure the PMOI for all the flywheels and clutches out there! Edited April 15, 2009 by hughdogz corrected "to" to "the" Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 14, 2009 Share Posted April 14, 2009 But I digress... My other comments have been reporduced above and stand on their own. And I didn't say the 15# stocker revved as fast as the Tilton, but that it was more like the Tilton's Response than the lighter 13# Centerforce unit. Yes, that means the 15# revs faster than the 13#, that IS what I was saying. It IS possible. I'm not arguing your point, but your facts. I was in the market for a flywheel in a weird time when Tilton and HKS had stopped making L series flywheels and there were no Fidanzas or AZC or anything else on the market. I looked at the Centerforce as it was the ONLY option and didn't buy it because it was 16 lbs and I didn't want to spend $450 and still have a 16 lb flywheel. Whose memory is bad? Mine or yours? Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 14, 2009 Share Posted April 14, 2009 Interesting pricing, must be a different Centerforce/Midway Industries unit. Mine was only $345 and was aluminum at #13. Maybe you are discussing their billet steel SFI rated model? That may be more. I have the Midway/Centerforce Flywheel on three Z's right now, the Tilton 11# on one, a "roughly" 15# JDM Lightened Stocker on one, and Two HKS and one Kameari flyhweel sitting in the wings for 'lightening exercises" in the future, but have driven several vehicles with the HKS. All within the last year or two at the outside. I'm thinking my recollection, since more recent, may be fresher? I could not explain how my JDM Stocker revved quicker than the Centerforce unit, other than the way it was lightened. They both have the exact same clutch cover assembly and are both 225mm sized as well. I'm open to other explanations if anybody is willing. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.