Anyone here have any experiences with lightweight flywheels on the KA24DE, such as a Fidanza unit?
Somewhere down the road I will be upgrading my clutch (likely an ACT unit), and am seriously considering a lightweight flywheel to go with it.
I’ve heard a lot of things about them in general, but I want to hear from 240 owners here if they are
a) worth it
b) safe to use/reliable etc.
c) enjoyable, or annoying on the street… (clutching/rev-matching/rpm dropping/launching/low-end loss worth it? That kind of stuff…)
I have a friend who took his stock fly wheel for his 89 si crx and he used I believe an Indexing head on a mill/lathe and lightened it up quite a bit 30-40% atleast and he hasn’t had any problems. Because of the torque Honda engines seem to have his car will go to 100clicks real well. (real light car thou) but his transmission is pretty damn sluggish… hard shifts, grinding 4th and 5th gear as well… he is however a certified mechanic so the problems he says are not due to anything else… yet he doesn’t care anyway it seems?
I would never recommend lightening a fly wheel myself thou I’m sure you could do it.
I have heard of high hp B series motors blowing the fly wheel out the tranny because its too light with the amount of power trying to be put down…
well my own thoughts on a flywheel really are the weight of it is based for a reason on the engine… so if a lighter one would do a better job with no damage then it would be done already???
I always thought the idea for a lightier flywheel was just for a reaction/snap from the tranny off the line? for a quicker reaction or hole shot hopes ?
Fidanza is a nice flywheel. I believe Adam Hutchinson uses it in his race car and has no problems with it. As for driving with it? it’s still fine. It’s not light enough to make revmatching impossible and to be crap on drag launches (because of no inertia). Bomex has a TODA flywheel on his car, I’ve driven it, and it’s good.
I would say go more aggresive than you think you should. I’m running the toda flywheel and SPEC 6 puck sprung clutch and after a short adjustment period I find I could deal with a more aggessive clutch. The flywheel really has no downsides to it. Your car will feel like it has more ‘pop’ off the line. The bigger issue is the clutch. You will get used to the chatter, harsh engagement and the joy of chirping your tires everytime you start rolling Of course having a turbo helps things
Awesome! That was just the answer I was looking for. Obviously, the turbo is down the road (KA-T, 7 psi)…otherwise I would just go OEM on the clutch replacement.
It’s so true, boMex, about going more aggresive…you always go less to be ‘safe’ and wish you just went all out…and end up spending way more money!
Although, the car being my daily, i’m concerned about ‘chirping’ every gear in snowy conditions…hehehe…that’ll be part of my what you call ‘adjustment period’. :twisted:
get the flywheel. do not lighten the stock one please for your own safety. i have lightened flywheels in both my cars and it’s fine for daily driving.
i have the fidanza in my SR, although chromoly flywheels (i think toda is, Jun is for sure) are supposed to be better as aluminum flywheels (fidanza) is supposed to warp under heat.
i have no problems yet with the fidanza but i don’t drive the car enough to know.
oh yeah, do not get anything less than 10 lbs.
and not everybody on this board are ricers (even tho i consider myself one :oops: )
Don’t lighten the factory flywheel. It could possibly shatter and severe off your leg into mash potato.
IMHO, it’s not worth upgrading. Instead, I would spend the money on a lightened driveshaft which would give you the same benefits, except you won’t lose torque lose associated with lightened flywheels.
Plus, you can still retain it if you decide to switch engines.
Listen to uncle Vince kids!! Your legs are nice to have when you get older!
IMHO, it’s not worth upgrading. Instead, I would spend the money on a lightened driveshaft which would give you the same benefits, except you won’t lose torque lose associated with lightened flywheels.
Vince is right on this one too. Unless you want the headache associated with doing a KAT, swapping in an SR will mean you throw your nice clutch away. The driveshaft is a good suggestion however I feel it doesn’t delivers the same seat of the pants difference as the flywheel. Plus the torque loos can be offset with (of course) more boost.
i’d like to discuss this further. I searched through Zilvia and googled it, and have only found people telling other people that it could shatter and go through the bellhousing, never any instinces, though i believe they have happened, perhapse there was a reason, like lightening the stock one over 50%. I thought bellhousings are designed to withstand that danger.
How about removing 5-6lbs from the stock flywheel, and getting it dynamically balanced?
Balance was also brought up on many occasions, aslong as the flywheel is properly balanced i don’t see how this would hurt the engine. Can anyone expand on this (again regarding a mild 5-6lbs removal)?
People on SON were complaining about no technical discussions, heres one!
Also, lets not go into an aftermarket ones, i’m strictly talking about the stock one. There are many motorsports that will not alow you to replace the stock one, it has to still “resemble” the original flywheel.
The issue of the flywheel cutting off your legs is a bit… extreme.
I’ve heard of the flywheel’s bolts shearing so that the flywheel itself came off the motor and smashed around the bellhousing and making a general mess but it never sawed through anyone’s legs.
THink of it this way… have you ever just held a grinder lightly to a surface? It kicks all over the place, you havce to HOLD it against the surface to cut through, well what would “hold” the flywheel in ONE direction to saw through anything? It’ll just bounce around, shatter, poke some holes etc but it won’t have the momentum or the force to actually chew through anything like a saw would.
Really though it’d be rare for the WHOLE flywheel to come off, and there is just as much risk of the stock one doing this vs. a lightened stock or aftermarket flywheel, it’s more related to the bolts, the installation and the condition.
A shattering flywheel is dangerous but if your bellhousing isn’t damaged it should be able to hold the shards inside, plus even if IT breaks it still has to get through the car as well.
Rally racers etc all have “scatter” shields added to their cars but of course they are much more abusive, higher revs for longer, smashing the car around etc…
You’re still risking your life though, exploding your flywheel won’t do wonders for the control of your vehicle. If you’re going to the trouble of skimming off the surface you might as well just buy one DESIGNED for it, they aren’t even all that expensive in the scheme of things.
There are many instances where a clutch/flywheel failure has blown out a bellhousing. Take for example automotion guys, they had a Spec clutch explode, it blew out the bellhousing, the bellhousing pieces were thrown with such force that it bent the tranny tunnel. The pictures were posted on FA a while ago.
Drag cars have scatter shields, driveshaft loops and rollcage. The rally cars don’t really rev that much higher than regular cars, so I dont’ see your logic here, since a lot of people beat their cars at the track very hard as well. Obviously there are cases when the clutch/flywheel shatters in street driven cars.
