There has been a little dicussion on lighten flywheels lately, the lotus 7 guys have bene going for it. Check it out here This discussion is very relevant for hte VG30DE (TT), and there are a lot of myths put to bed.
Arrggh.. This thread doenst help. Its confusing as hell. This question is very pertinent to me at the moment and would like some other zed owners input on what kg range they think are appropriate for a zed. Now that I am as confused as can be, what would be a ball park weight for a zed with the following characteristics: GT28R, 3 inch dumps going into 2.5 in cats, Forged Internals, Stock head/cams, Lightened Crank Pulley, Nismo 555 running NA 5 speed with NA master and 4.1 leader gears in the diff. (Car is for the road, not a daily driver weekend getabout) What weight do those in the know recomend for the above, is the stock too heavy? but what weight would be too light? Whats middle ground here?
found this very interesting if you had two identical flywheels both weigh 6 kg, ok so you have 2kg machined of the center of 1 and 2kg machined of the outer of the other while still retaining the exact dia of both, which one will spin faster with less energy loss, its all about Moment of inertia, also as an approx guide 1 kg off the outer dia of the flywheel is equivalent to removing 10kg from the vehicle
I'm running the the 6kg chromo flywheel. other option is 4.8kg. but take into consideration my U/D pulley is only 800grams I find it a great combo
Was a good read, and the points they made were most interesting. From personal experience, with a Fidanza Alloy Flywheel, lightened further as they don't come balanced from the factory (figured why the hell not). Easiest thing to remember is that with a lightened flywheel on a Zed, you trade off the line starting simplicity for noticeably increased responsiveness. Being a lower compression motor, they are already a bitch to take off from the line (fine line in the rev range between bogging down and wheel spinning). This is only amplified when you add a lightened flywheel. Accelleration responsiveness, OVERALL responsiveness is significantly increased, both positively and negatively- the car revs up a LOT quicker, but is also noticebly jerky under decelleration. And that's with a custom single plate, so its still relatively forgiving and can be "ridden" somewhat. Would hate to think what it would be like with a button clutch. Beyond that, its the decision of getting a flywheel that is capable of your proposed horsepower outputs. General consensus is that a Chrome-molly fly (although heavier than Alloy) is much better for increased HP application. Dont stop there however, go for lightened pulleys as well. 1. Ross Racing Harmonic Balancer (if you dont want to go the solid crank pulley. Much heavier than the Alloy 1-piece, but lighter than standard) 2. Alloy Pulley set, with optional U/D Pulley for Water Pump (if going the alloy 1-piece. Ross Pulley is same O/D as factory). Again, many arguments both for and against compensating water pump pulley with decreased crank pulley circumference. 3. Do away with clutch fan. Never a good idea, as most thermo attempts fail. Mine is "borderline", but definitely wouldnt recommend it.
2nd. As I was reading the first post, few bits jumped out at me that didn't seem quite right so was left confused. Then finished reading the thread and I was even more confused. Almost every part of the guy's article was torn apart and stated as wrong. To make it worse, the end just resulted in teaching the guy how to better 'articulate'. All that aside, I think I will go with a lighter flywheel... not as light as they go, something mid way, if the stock is 10kg, and the lightest are about 4kg, i'll go with 6-7kg flywheel. Considering im now already running an 800 gram crank pulley, so it'd be a decent combo for a daily that is also running a Full Face Organic clutch. MoulaZX
Well, m8, really, there isnt any "middle ground"! Nothing is too light nor too heavy. Its pretty much subjective/personal preferrence and depends on what characteristics of the motor you personally like. If you like the engine to rev quicker and drop revs quicker between the gears, when "blipping" in exchange for a poofteenth of increased possibility of stalling at the lights with a careless clutch foot or the odd rougher than expected gearchange? Lighten away. In your case, you are running a stock tune engine so youll be unlikely to notice too many of the very few disadvantages of a light flywheel. If you had some really wild cams and giant heads installed with a couple of big fark-off throttle bodies and badly tuned low rpm range youd notice the increased choppy and unreliable nature of idle and low speed driving allright! Couple that with a very snatchy clutch and you have a.... ahhhhh...... less than friendly car to drive in traffic and learn not to like it BUT thats about as bad as it gets! Thing is, your not likely to notice much of the very few REAL advantages either such as a slight increase in accelleration! Its all close to academic in the real world as far as increased performance is concerned! So, in general, the lighter you go, the more choppier the engine will tend to respond to light throttle down low and the slightly more likely you will be to accidentally stall the engine on initial takeoff. In a stock tune engine with a "soft" clutch action, these are no real biggies at all but as you go up in the state of tune, and down in the QUALITY of tune stakes, then these disadvantages tend to me magnified..... quite a bit! Like anything different, you just get over it and make some technique changes and in short time, you wonder what all the fuss is about. If you are confident with the throttle and clutch controls then run the lightest fly'/pulley set you can find/afford. Good bragging rights at a bench racing session and the engine sounds real crisp when you blip it out of gear at the lights! Your woman will dislike you tho if shes has to drive home when ur pissed tho!!!!! Disregard any outrageaous claims for AND against light flywheels!! They are usually just that....CLAIMS! L8r E
I've got a light pully, light flywheel and tripple plate clutch. To drive off smoothly I need to use in excess of 2500rpm to start with. It revs real nice quick, but very awkard in start stop. It's not horrible but definatly uncomfortable in traffic. But light flywheels and button clutches wernt made for traffic.
In addition to whats already been said, a lighter flywheel may result in wheelspin due to being able to apply power quickly. Basically a heavier (stock) flywheel is smoother and easier to drive with. One of the heavier chrome moly ones is a good compramise.
