vivaspeed Posted December 18, 2012 Share Posted December 18, 2012 I've seen a flywheel let go on an RX7 and it made a big mess, pierced the floorpan like a can opener, took out brakes and fuel lines along the chassis and the guy had to coast to a stop with no brakes and fuel pissing out. Made a big mess on the track too. What it did to steel makes it quite clear that soft fleshy bits attached to your person would not come out too well. Dude got out quite shaken... What's your personal appetite for risk (consider cost of nice steel one vs. cost of repairing car vs. loss of use of limbs). You could get a standard one and give it a gentle skim in the right places, and this was commonly done, take a little meat out of it but not radically reduce its strength/weight. Quote Link to comment Share on other sites More sharing options...
Bling Posted December 18, 2012 Share Posted December 18, 2012 If quality aftermarket options weren't around I guess i'd consider it. Since they are available though, i'd go for the quality option every time. Not a big cost when considering the total cost of the car. Peace of mind > money saved. Quote Link to comment Share on other sites More sharing options...
Ridal Posted December 18, 2012 Author Share Posted December 18, 2012 I'm fully aware of the potential risk and the amount of energy that is stored in a flywheel doing 7 or 8 thousand rpm. The potential gains aren't worth $650 to me, well not at this stage. I think I'll give it a whirl and report back with success/disaster story. I would think most cases of flywheel failure would be a result of high rpm, heat, a certain amount of power/torque, and an abusive left foot. Being behind a 5k putting out around 90 rwhp and using an organic clutch I think I'll take the risk. Am I right in thinking the flywheel will experience less torsional force due to the lower mass? Quote Link to comment Share on other sites More sharing options...
KKtrips Posted December 18, 2012 Share Posted December 18, 2012 Am I right in thinking the flywheel will experience less torsional force due to the lower mass? Correct but that will mean it will have more agressive waves of momentum - making for a very easy to stall motor and jerky driving when at low RPM. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted December 18, 2012 Share Posted December 18, 2012 Solution = more cylinders Quote Link to comment Share on other sites More sharing options...
Dell'orto Posted December 18, 2012 Share Posted December 18, 2012 Is that my old flywheel? It wa sin the race car for a reasonable short period of time, but it held up to dyno runs. I was too scared of it to use though! Quote Link to comment Share on other sites More sharing options...
Ridal Posted December 18, 2012 Author Share Posted December 18, 2012 Possibly. The clutch, flywheel, and cover look like they've been hardly used at all. I bought it off Trade Me a while ago. It has a 190mm machined surface and came with a K series clutch and a heavier than standard cover. If it was yours, do you remember what the clamping pressure of the cover is? What did the machinist think of the strength? I just bought a TA22 clutch to use in my T50. Quote Link to comment Share on other sites More sharing options...
sentra Posted December 18, 2012 Share Posted December 18, 2012 Huh??? yeah see on the rotary video how it doesn't explode on the burnout, but when he is slipping it doing the launch. Quote Link to comment Share on other sites More sharing options...
Ridal Posted December 18, 2012 Author Share Posted December 18, 2012 And also in the tractor video you can see he has come to a complete stop but still has throttle on. Must be sizzling the clutch/flywheel. Quote Link to comment Share on other sites More sharing options...
sentra Posted December 18, 2012 Share Posted December 18, 2012 *this is not to say its a good idea, just an interesting side point. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted December 18, 2012 Share Posted December 18, 2012 Dave, I get you now. It took me a while to restructure your message to understand it. Haha. So what you are saying if you are using a lightened flywheel then it's best to use a puck clutch so there will be minimal slippage. Minimal slippage means minimal heat and less chance of flywheel failure. Ridal, re the videos. I was never arguing the cause of failure. Just saying that flywheels do fail. Along with a comment that in day to day driving the benefits a heavier flywheel offers is not worth losing for what you gain with a lightened one. Quote Link to comment Share on other sites More sharing options...
KIRK Posted December 18, 2012 Share Posted December 18, 2012 the Suzuki rotang van exploding flywheel was orsum. come up thru the floor on van I think and chopped out part off the head rest of the dudes seat then out the roof? edit: is the worst video ever. blows at like 26 second then catches fire haha Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted December 18, 2012 Share Posted December 18, 2012 if you want to run it then run a blanket. or get a new fly made. or do whatever you want ( shouldn't have asked) edit. your fuckin thread asks if your fly will explode. people say yes ( basically) and you are just like " I'm fully aware of forces bla bla am going to do it anyway" I mean.. what the fuck. Quote Link to comment Share on other sites More sharing options...
ryanfels Posted December 18, 2012 Share Posted December 18, 2012 I'm fully aware of the potential risk and the amount of energy that is stored in a flywheel doing 7 or 8 thousand rpm. The potential gains aren't worth $650 to me, well not at this stage. I think I'll give it a whirl and report back with success/disaster story. I would think most cases of flywheel failure would be a result of high rpm, heat, a certain amount of power/torque, and an abusive left foot. Being behind a 5k putting out around 90 rwhp and using an organic clutch I think I'll take the risk. Am I right in thinking the flywheel will experience less torsional force due to the lower mass? What dosnt Sheldon and the guys down south do with there flywheels? If i was you, i would do what ever they do Quote Link to comment Share on other sites More sharing options...
phatt20 Posted December 18, 2012 Share Posted December 18, 2012 i take mine down to around 6kg, while leaving heaps of meat where it needs it, then get them balanced. never had a problem with any of them, must of done over 30 by now, many of the engines they have been bolted to do 8500rpm +. Quote Link to comment Share on other sites More sharing options...
Roman Posted December 19, 2012 Share Posted December 19, 2012 When you dont have your foot on the clutch, what is the total amount of things that your engine needs to rotate/accellerate? It's the total weight of Crank pulley, (and accessories I guess) crank, flywheel, clutch plate, clutch cover plate, gearbox internals, driveshaft with UJs, differential, axles, disc brakes, wheels, tires. The engine needs to rotate all of this, so what percentage of weight out of this do you think you lose by having a lighter flywheel? Probably 2%? In say 1st 2nd gear the speed of the engine is much higher than the speed of the rest of the driveline, but as your vehicle speed increases the ratio of difference (and the benefit of a lighter flywheel) diminishes. When your foot is on the clutch it makes a much larger percentage of difference, but whoop de doo how does that help? I've never seen any quantified accelleration gains from installing a lighter flywheel. Significantly increasing the odds of physical harm to yourself or others for the sake of mythical performance gains isnt a good trade off in my opinion. 1 Quote Link to comment Share on other sites More sharing options...
Ridal Posted December 19, 2012 Author Share Posted December 19, 2012 I'll try to get a before and after dyno run in for some conclusive data although the current tune is too lean to allow a full run (undersized carb). I'm hoping it will pick up revs quicker between downshifts when I blip the throttle regardless of power/torque figures. Quote Link to comment Share on other sites More sharing options...
Jase Posted December 20, 2012 Share Posted December 20, 2012 just get it re heat treated after you lighten it , especially if it was cast initially, balancing first also. it'll be fine or a custom billet one will cost $500 from steel surgeon etc Quote Link to comment Share on other sites More sharing options...
Roman Posted December 20, 2012 Share Posted December 20, 2012 I'm hoping it will pick up revs quicker between downshifts when I blip the throttle regardless of power/torque figures. Yep should do exactly that. Quote Link to comment Share on other sites More sharing options...
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