lightened or not flywheel

[hdswanny]

i posted over there when i understood your explanation in this thread. i just could't explain it as well as you. hehe, now i feel like a tool
i still don't think they uderstand the concept or read this thread. oh well.

 

[NosLaser]

Bah, don't worry about it. I personally think these boards are great for the newbies to soak up as much info as possible, and for the not-so-newbies to expand their knowledge. If you or someone else has learned something valuable, then I have done my 'job.'

Regards,

 

[HITNRUN]

Lightening a stock flywheel is just dangerous. There is already a thread on this: http://www.dsmtuners.com/forums/sho...=&threadid=6992
Just watch this:
http://www.machv.com/lib/machv/flywheelboom.wmv

 

[SPEEDY]

Originally posted by NosLaser
Bah, don't worry about it. I personally think these boards are great for the newbies to soak up as much info as possible, and for the not-so-newbies to expand their knowledge. If you or someone else has learned something valuable, then I have done my 'job.'

Regards,

That's killer dude! I'm so glad that you look at it that way. I think you are one of the best, if not the best, when it comes to explaining things, and you have a very good knack, and or "TALENT" on how to word and explain discussions very clearly. I will always appreciate your knowledge. I'm learning slowly, even though I'm considered by some, as an old fart. When ever I come on these forums, and if I've noticed that you have made a post on something, I always try my best to read what you have posted, even though it might not pertain to anything that I may do, or be interested in, I will still read it to try and learn anyways, just to get the knowledge and info. Thanks Asian, your a good man!!

 

[hdswanny]

they still don't get it over "there"
i quit, you can only beat a dead horse so much:slam:

 

[umiami80]

Here is a good argument from DSM Talk.com, I believe this one the best.

lighter flywheel would benefit any car when it comes to speed (as well as turbocharged cars). the less rotating mass means fast revs. less weight that the engine has to turn over. if you think about it for a turbocharged car's case, it would benefit because if you think about it, a turbo's power is created from exhaust. if the engine is able to rev faster, that's more exhaust for the turbo to be able to spool it faster.

the downside of a lighter flywheel......
the main reason factory's use a heavier flywheel is for drivability reasons. the momentum of the flywheel keeps the engine turning when you let off the gas (you keep speed and it would slowly drop off). with a lighter flywheel there's nothing to keep the momentum of the engine going. for some cars a really light flywheel can mean that when you let off the gas, it's like hitting the brakes. this would be really good for a rally car when you need to stop on a dime and get out of the corner fast. but for your everyday granny, i doubt she would wanna have her face plastered in the windshield everytime she lets off the gas. i use to have a roadrace lightened "stock" flywheel and it made power but it didn't effect the car as bad when letting off the gas. it wasn't as light as say....an 8 pound flywheel. for me though, an 8 pounder would be stock equipment

did i answer everyone's questions?

Anyone currently running one? I just bought one

 

[hdswanny]

yes and i'll be getting rid of mine. I am goin back to the stock flywheel.

 

[umiami80]

More Testimony from people who actually own them.


Cazzo:

OK after 7 weeks I finally got my car back.


Fidanza is AWESOME, plain and simple. Car revs quicker and rpms fall much faster, which requires quicker shifting. Spool up is much faster too. On my setup, I'm getting full boost (21.3psi) at no more than 3300-3400 rpms, and much less in the lower gears. I did have other things done though so I'm not saying this is all because of the Fidanza, but I know it helped.

With the fidanza and cams, there is very little driveability problems rolling around at 5-10mph. Nothing too severe or even worth mentioning, but you will notice little things.

Only problem I had was on a few startups, car kept dying because of the light flywheel. Now after the ECU has had a couple days to learn, everything is fine.


Here is another

TALONTED TURBO:

Hey I just installed the new fidanza with an ACT 2600 on my 1990 Talon. HOLY CRAP... one word, AWESOME. Anyone who bad mouthed this part witht eh negatives like "stalled between shifts, and crap like that", and other comments, you are a #@%#@%#@%#@%#@%, this thing is GREAT, the car feels smoother, drives better and the power, DAMN, LOTS OF POWER. Full boost hits so fast its a joke, spoolup must be 40% faster! If anyone is thinking about getting this and not sure, Im tellin you, get it. My car is a DAILY DRIVER, I drive 100 miles a day sometimes, I communte, I drag race, I do everything, and its worth it. Yeah its $400, but I would get it again, ESP if youre changing your clutch, cause then install is simple. All the old reviews on this should be deleted unless they were good, I was VERY skeptical when i heard all the negative things on this but Im just letting everyone know its BS, so get it! Also, 2600 clutch is dope. Thanks guys, hopes this helps in some decision making.

Both these guys are on DSM Talk.com, can't argue with that.

 

[Dieselboy]

Originally posted by NosLaser
I personally think these boards are great for the newbies to soak up as much info as possible

Regards,

Hee hee, that be me!

So, whats the price ranges were looking at? Not what about the Clutch Masters lightened flywheel? Its only 7lb, yet retails for around $350-$400. Im interested in the Fidanza/ACT 2600 combo, as Im going with an ACT 2600.

 

[dolemite]

Does anyone here actually have like, a degree in Motorsports Engineering or anything? I am actually going to do a chromoly flywheel pretty soon and I would like to hear from someone who really knows whats up.

 

[dolemite]

OK, I am about to do clutch, flywheel, and LSD on my 95 GST and I feel like I've absorbed enough info from reading and asked the experts to be able to say a few things about aluminum and chromoly flywheel upgrades for turbo cars (or any car, for that matter). I don't esteem myself as an expert, and everything below is mostly fact-based opinion, so feel free to correct me if you disagree.

NosLaser-

What you said about load is partially correct.. I definitely feel that the load that the engine operates on creates the exhaust gas to spool any turbo; however, every engine has a specific displacement (i.e. 2.0L/122 cubic inches), compression ratio, bore/stroke, cam duration/lift, runner size, etc that will make the amount of exhaust gas it creates EQUAL as long as intake air volume & CFM stays the same. At WOT, an engine will not create MORE exhaust gas simply because it is going up a hill. Engines are more about air CFM than they are load. More air + more spark + more fuel (and timing, for that matter) = power = exhaust energy. So if you have a 16G that flows 505CFM, your engine will not receive any more than that, and thus your exhaust flow will not be any more that that. Exhaust gas volume and CFM is basically what spools any turbo, and a flywheel will do nothing to change that; an engine can only work so hard at full load if it's only given a certain amount of air volume.

An aluminum or chromoly flywheel will obviously reduce the weight the engine must rotate, and that has side effects including less rotational inertia and the RPMs will drop much faster making any driver have to "recalculate" his transitions between gas and clutch when shifting gears. The aluminum/chromoly flywheel will hold less energy when launching but that is not necessarily a drawback, I actually see it as a benefit. Wouldn't you rather engage at a higher RPM where you have more torque/HP? It takes longer for the car to launch based on the fact that the flywheel is not holding any energy and the engine must transfer all the energy almost immediately and directly through the clutch notwithstanding any inertia.

So, as I see it, there are only benefits to an aluminum/chromoly flywheel.... yes, it will take some getting used to, but there will be more power due to the fact that the engine must work to rotate less mass, and of course launching I understand can be somewhat inconsistent. Personally? I don't really care about launching, because I don't do that much drag racing anyway. With an LSD, I will probably do clutch slips at close to 5k in my FWD without any problems.

Anyway, hope that offers some insight into the whole discussion.. anyone who would like to propose a different viewpoint please do, I'm anxious to see what you have to say. Sorry for the long post guys, I'll step down from the podium now....... peace.

~Wes
Clt, NC
95 GST
XS Engineering hairdryer =]

92 AWD Laser 11.8 @ 117 - 20G, HKS cams, etc - R.I.P.
91 AWD Talon 13.6 @ 104 - intake, exhaust, clutch - R.I.P.

 

[GVTalon]

Anyone with experience with JDM flywheels? I have a JDM flywheel that appears to look exactly like a US spec flywheel on the clutch side, the steps are vented. However on the other side it does not have that weight ring. I'm considering having it resurfaced and using it since it weighs a few pounds less.

 

[NosLaser]

...What you said about load is partially correct.. I definitely feel that the load that the engine operates on creates the exhaust gas to spool any turbo; however, every engine has a specific displacement (i.e. 2.0L/122 cubic inches), compression ratio, bore/stroke, cam duration/lift, runner size, etc that will make the amount of exhaust gas it creates EQUAL as long as intake air volume & CFM stays the same. At WOT, an engine will not create MORE exhaust gas simply because it is going up a hill. Engines are more about air CFM than they are load. More air + more spark + more fuel (and timing, for that matter) = power = exhaust energy. So if you have a 16G that flows 505CFM, your engine will not receive any more than that, and thus your exhaust flow will not be any more that that. Exhaust gas volume and CFM is basically what spools any turbo, and a flywheel will do nothing to change that; an engine can only work so hard at full load if it's only given a certain amount of air volume....

I commend you for trying to make an intelligent argument, but this is what happens when people who have read too many books try to apply their knowledge to the real world. If weight/going up a hill/etc. does NOT affect engine load, then explain to me why your car doesn't build boost when you free rev the motor in neutral, but has no problem building 20+ pounds of boost while you are in a higher gear? Why do turbo cars typically build less boost in the first 2 gears? Why do cars dyno in 3rd-4th-5th? The answer is engine load. You better believe it DOES affect exhaust gas energy.

Regards,

 

[Kingdom]

I just recieved my SSG 9pound flywheel.

I dont really care about consistency launching since I will probably never visit the track. But I would like to know if it will increase the power to the wheels.

Has anybody done a back to back run on dyno with the stock flywheel and then a lighter one.

any gains with Torque?

 

[SPEEDY]

If I'm not mistaken, for every pound of a rotational mass that is removed from a car, such as a flywheel, wheel and tire combo etc. is equivalent to about 8 pounds being removed else where from the car.

 

[dolemite]

Originally posted by NosLaser

I commend you for trying to make an intelligent argument, but this is what happens when people who have read too many books try to apply their knowledge to the real world. If weight/going up a hill/etc. does NOT affect engine load, then explain to me why your car doesn't build boost when you free rev the motor in neutral, but has no problem building 20+ pounds of boost while you are in a higher gear? Why do turbo cars typically build less boost in the first 2 gears? Why do cars dyno in 3rd-4th-5th? The answer is engine load. You better believe it DOES affect exhaust gas energy.
Regards,

Read too many books, huh? Like I said, I agreed with you for the most part about load. You mistake me for an idiot when you give me the "rev it in neutral and you don't make any boost" argument that I understood before I was like 5. You didn't read fully what I said about CFM - and that is what happens all the time on boards like this - someone thinks they are an expert and they have nothing but theories and guesswork and then everyone immediately assumes that what they said is true. On the other hand, I choose to believe what either makes more sense to me from a mechanical standpoint or what I know to be true based on hard facts.

Again, I'm not disagreeing with you. I don't pretend to be an authority on the matter, I just offered my opinion - an opinion that I mentioned before was backed up by some pretty substantial gurus. For example, I called several motorsports engineering professors at my school (UNCC) and also talked with a few students about it.. most of them work on the project drag car (1G AWD) as well as the legend cars and they've all had experience and understand all aspects of physics, metallurgy, and so on. I don't have any real world proof, but before I decided to purchase my chromoly flywheel I also spoke with David Buschur, Jon at TRE, a few people at RRE, and most importantly several guys over at Extreme including Sean himself. Everyone had a different viewpoint on the matter, but all that I spoke to entirely disagreed that an aftermarket flywheel will alter spool up time. All of them agreed that there will be more power to the wheels, faster RPM spin up, and obviously most agreed that launching and shifting the car will be entirely different because of the lack of rotational inertia held within the flywheel while free revving before engaging the clutch.

An engine can only produce so much power from so much air. All I was saying is that I disagree with your very first post/argument that a turbo will spool slower with a lightened/aluminum/chromoly flywheel. LOAD comes from the engine having to move the weight of the car. You will naturally experience more load on the engine when going up a hill because of gravity; however, I can almost guarantee that no matter what your incline is (downhill/uphill/flat) if you go WOT your turbo should spool about the same, regardless of flywheel weight. I am simply saying that a different flywheel will not increase NOR decrease your spool up time IF you go WOT. Now, under partial throttle conditions, I think the engine will experience more load going up a hill MUCH faster and must pull in more air quicker than if the car was on flat ground BECAUSE there is, like you said, more load. Again, less weight on the flywheel means that the engine experiences less load, but it doesn't mean that it pulls in less air that would in turn make the turbo spool slower - it simply means the engine doesn't have to work as hard to create the SAME amount of exhaust gas as it did before, period.

As for why people dyno in 3rd, 4th, 5th, that has more to do with capabilities of the actual dynamometer and the computer/system reading/analyzing information. Most moderately powered cars on a 2-wheel dyno will spin first and sometimes second or even third - I have seen this tried at a customers request. Most dynos need time to read and analyze inputs from the sensors that measure speed, rpm, hp/tq, wideband O2, etc.

To sum up, I don't think flywheels change spool up times at all.. if they do, it's either negligible or unmeasurable. They simply hold less rotational inertia making it harder to launch and shift consistently, but at the same time you're losing a lot of weight that the engine must spin and thus increasing hp/tq to the wheels by a reasonable amount.

Just my $0.02 - and remember, it's only opinion. That's why these boards are here, for people to share their ideas. If someone thinks what I said makes sense and they choose to apply that to their existing knowledge base then so be it.

Anyway, my chromoly flywheel is on the way and I will let everyone who is considering an aftermarket flywheel know what the results are before and after.. the ballbearing turbo I have now makes 20psi somewhere around 3700 in third. If that changes when I put in the chromoly, I will definitely let you know... but I think it will be a substantial increase in power, and I will most likely measure these results on the dyno (before/after).

 

[umiami80]

How about a review from someone who has one? First off I don't believe that a FF should get one, as launching would be a BICTH as you would and have too increase the revs to get off the and with no traction you would just spin, but that is my opinion.


I juts put on a BRAND NEW Fidanza (8pounds) and a Sprung Six puck, also a GVR4 1st gear, all at the same time. I gave about a week for break in (really do not need a break in on a six puck, but the chatter got considerably less with each pasiing day, and finally dissappered after about a week, so I asumed a break in period).

Yes you have to rev higher, especially with a tealler 1st gear. Spoolup has INCREASED, by a lot. 20PSI in full at 3500 rpms as opposed to a lil past 4000RPM'S. Car has more pull in WOT from a roll, just feels faster. You let off the gas to shift rpms do drop faster, BUT for racing this is good as if you shift fast enough, they drop to 5000 rpms, right at the beginning of the powerband once again, and the turbo spools back up instantly, it does drop to 15PSI or so.

I love it, car is way easier to drive, puts more pwer to the wheels, and car just feels overall faster plus an extra 500 RPMs of power band, hell for normal driving I can shift earlier cuz the car picks up speed so much more quickly with minor pedal effort. The turbo is SO willing to spool as well.

Again I do not recommend this flywheel for a FF unless you do highway racing, they your 3-4 gear pulls will be faster, you may lose overall topend but my AWD keeps speed nicely well past 100MPH so I may be wrong. I reccomend one for ANY AWD, they are simply great, no drivability issues, just more speed, and the throttle IS more touchy, but you get used to it.

Take this info for what it is worth, but is what I have experienced and is fact.

 

[GRNDSM]

>I love it, car is way easier to drive

This is funny, after being used to driving DSMs, I am hating the first gear in my GVR4 with stock FW (I have been driving for last couple of weeks). I keep bouging the darn thing off the line, just driving it around… I can't even imagine how bad it would be with a light FW.

I guess it all comes down to a personal preference

Leon
RR

 

[BlitzMR2]

In the MR2 community we've argued this point for years. Some have honestly called it the best mod they've ever done, while others refuse to even consider one. I happen to think that there are very few people who'd go through the trouble of paying $400 for a LWFW, install it, and have the balls to say it sucked, or at the very least was a partially good/partially bad mod.

Why are cars dyno'd in 3rd or 4th? Load. In first, especially BFT cars, run out of revs before boost can build as well as it does in 4th, etc. The earlier boost builds, it builds on itself -more power, more exhaust gas, and so on. On a NA car I see the benefit, but on a turbo car I think OE weights are often good. It also depends on what your OE weight is -IINM a MR2T flywheel is aorund 15 lbs, while a Starion ESi-R is around 40! Obviously, a Starion could use a lighter flywheel -light and heavy being relative terms.

I don't care much about launching -it's something I rarely do, and when I do I'll learn to launch a LWFW car, but everywhere else I honestly don't see it. It looks like a compromise, and I simply don't want the engine outrevving the turbo. I know the car will still reach full boost, but IMHO the extra load a OE flywheel (again, depending on weight) places on the engine and turbo is a good thing.

I'd love to see a neutral party do a back to back comparison with no other changes, and give subjective and objective reactions back.

 

[->PrOjEcTGS<-]

I am sorry to bring an old post back to life but I think that I might have some words to say about this whole topic.

First off, when I first got introduced to performance parts on cars I learned for myself that for every benefit there is a drawback that goes along with it. This also pertains to a lightened flywheels.

Now for what I believe the pro's and con's to a lightened flywheel are.

Pro's:
1. Faster Spoolup not in RPM's but in TIME.
2. Faster Rev up and down
3. More Torque at mid-higher RPM

Con's:
1. Less Lower end torque
that's about it.

WHY????

First of all let's start with the launching. Let's leave boost out of the picture right now. Just think of this car I am talking about as a NT AWD car. Yes, a heavier flywheel is better for lauching because of the energy it can store up and be put to use when the clutch is dropped and the car is put into motion. As for a lighter flywheel cannot store up as much energy. Therfore launching will be a bi***.

Now let's add boost. I agree with you that LOAD creates boost BUT not speed. PERIOD. But that's all that I agree with. Because let's take for example that you have a stock GSX and you are in fourth gear with the cruise control on set at 45mph going up a hill with just you in the car, it makes about 5lbs of boost and get's up the hill. Now let's just say you have a heavy set freind that weighs 300lbs and you have about 400lbs of luggage in the back!! That's going to be a more of a LOAD you still have the cruise set at 45mph and going up this same hill it makes about 15lbs of boost. All because of load. Cool huh? NOT!!! You just wasted 10lbs of boost you could be using more wisely. A case of too much load. So if you took the guy out and the luggage you eliminated the NEED for more boost. That is essentially what you are doing with a lightened fly. Now you can make more power with the boost that you do actually make. Thus increasing your torque while you are in boost. So all the heavier flywheel is good for, is getting you out of the hole, with a little boost.

Ok now as for spoolup, take that same stock GSX and go from a roll in third gear. Bogg it down pretty low to about 2,000 rpm's and time it in seconds till you hit full boost. I don't know exactly how much time this would take but I can garauntee that it took a while, even though there was a lot of LOAD on the engine. Now take the car home, put a lightened flywheel in and do the same test I will bet any of you that the time it took in seconds to "SPOOL" up to full boost was shortened by a lot of TIME. Now race these two vechicles against each other from a roll. Who will win? The one with the lightened flywheel. WHY? Because he got into boost FASTER.

This is one contributing factor as to why a stock GS-T's trap speed will ALWAYS be higher at the same ET as a GSX. Because of their weight, powertrain loss and ETC...

My final 2 cents on this whole thing is: I already know that my TSi will come out of the hole pretty hard at that, it's getting the damn thing going after that, that's what I'm concerned about and since a lightened fly can help my mid-top end powerband, then I'm all for it. For example my stock TSi ran a 14.6 @88 mph. I only gained 14mph from the 1/8mile to the 1/4mile mark. I figure that's where I need the improvement.

Thank you and Sorry for the long ASS post.

~Kletke~