O.k. been through every thread in search, still can't decide

I'm replacing my clutch. stage 1 street disk with 1800lb pressure plate - slightly better than stock.

Next.. the flywheel

My concern is driving in heavy traffic. Also, don't want my car to get worse when in 1/4 mile. I always like improvement, but not at cost of something else I might really need. Tuned, my tach goes up faster, just trying to understand this whole thing.

I read enough post about how great getting a lighter flywheel is, as some of you may reply with that.
What I'm looking for is bad feedback about lighter flywheel, not parts failure/rattling, but how it made your car drive/perform worse. For stock/all motor with street disk stage 1 1800lb pp

 

basically, it all goes back to simple physics.

A heavy flywheel that is spinning has a lot of momentum. When the clutch is depressed at a stoplight, the flywheel has spinning momentum from your idling engine and your clutch disc is floating at a rest in-between the pressure plate and the flywheel.

When you let off the clutch to go forward, the engine is spinning which moves the car forward. Also, the momentum of the flywheel assits in a smooth and easy takeoff since it's resistance to stopping(from the momentum) pulls the car forward more than the engine does alone. Basically, a heavy spinning flywheel has "more torque" behind it.

Now, consider a light flywheel. Sure, it takes less energy for the engine to spin it, so revving is much, much faster. The drawback is the lost momentum at idle. The light flywheel is more prone to beinging jerked to a stop by the resting clutch disc (which is connected to your not-spinning wheels). Bottom line, you need to rev the engine a little more while releasing the clutch to build up momentum in the flywheel in order to take off smoothly without stalling. Gotta ride the clutch a little.

Once you get off a stop, the car pulls like a banchee. Hondas love light flys. And you can get an AASCO aluminum flywheel, weighing an amazing 9 lbs at HEELTOE automotive!


[Modified by oldskool_rex, 10:28 PM 9/9/2002]

 

thanks for the help, couple other questions from that..

1. how much faster will my tach raise? like percentage wise, i just gotta feeling that 7lb and 9lb flywheel half the size of 15lb will go up like in neutral?

2. will lighter flywheel lower my shifting points.. lets say i would shift 1st to 2nd at 42mph, with same effort... will it be like 35mph?

3. and how much faster (if possible percentage wise) will it drop once I lay of the gas?

 

put it this way....if you drive around town & casually shift gears, you'll jerk the car because the revs have dropped farther than the matching needs to be. Shift fairly aggressive & it'll be smooth as silk. (I'm using the centerforce flywheel & stage 3 clutch = ~18,000 street & track miles so far).

 

o.k. i can adjust to changes with rolling from a stop or shifting faster to make the ride smoother... got that part clear..

but what about the following.. especially #2.. can anyone input on that?:

 

The weight of the flywheel has nothing to do with the gearing. You will shift at all the same points, and get to the same speed in all gears.

I have the 6.75 lb comptech Flywheel, and ACT HD/SS. There are NO drawbacks. I can shift the car smoothly at any RPM, or I can just side step the clutch and slam it if I want.

The RPM climb will be most noticible in lower gears. I could tell a difference in 1 - 3. I couldn't tell in 4th or 5th. In neutral, the car will rev quite a bit faster. How much faster? Tough to say. 50%? The RPM drop is also faster, again tough to quantify. Rev matching is MUCH easier with the flywheel.

Buy it up!

 

so.. if it doesn't affect the gearing, then the car must accelerate faster? or it creates an illusion of going faster by tach revving faster due to loss of torque?

 

There is no loss of torque, only a perceived loss from a standing start (something that I actually never felt, myself).

The car <U>is</U> faster because it revs faster. Your car makes more power at higher revs, so the quicker the engine gets to those higher revs the faster your car will be.

I can't give you a percentage on how much quicker the engine accelerates. What I can say is that the clutch/flywheel combo was the best mod I've ever made. I have absolutely zero problems with drivability, even in traffic. In fact, I think the car is easier to drive with the lightweight flywheel.

 

I like my AASCO.

 

Honest question: why pay $300 for an 9lb AASCO aluminum flywheel (never heard of it until yesterday, but is seems to be the heaviest aluminum flywheel out there, heavier than many chromoly ones) when I can get a proven 6.75 Comptech aluminuim one for $100 more? Given all the effort (or labour cost if you are not doing it yourself) of replacing a flywheel, $100 is not much - and 2.25 lbs is quite a bit of weight off a flywheel. Can they be found for $200 or something?

 

i have a cm stage3 w/ a cm flywheel (around 8 lbs).

 

Well I will sell you my clutchmasters flywheel for $200 shipped. You can see the flywheel here https://honda-tech.com/zerothread?id=272194

 

I run the Spoon flywheel only had is stall on my 3 times just because I bliped the throtal real lightly and it fell to fast to catch up but no biggie I love the way the car feels now

 

.....there is no downside to a lighter flywheel - get one already!

 

I paid nowhere near retail for a brand new unit.

It was cheap, available and lighter than the stock flywheel. Good enough for my daily driven beater.

 

or at 300, you can get a CM flywheel (7.5lbs)

go for it

 

quote:
I like my AASCO.

Me too. It was one of the best purchases I've made so far.

 

Consider the engine balancing properties of a flywheel. Lightening it is good, but recall all the controversy about crank pullies? A flywheel is going to have a similar effect of engine longevity (although this wear is going to be less extreme than that a pully might cause, since the transmission helps keep the crank inline).

Lightening a flywheel is definately an awesome upgrade, but 100 bucks difference for 2.25 lbs? Seems kinda raw to me. I mean, you are paying more for less material. There is such a thing as flywheels shattering too, keep that in mind.

I can get a comptech one too if you really want it, but I suggest AASCO, plus they are in stock. I am considering a group buy on them in the next few weeks.

 

The controversy over the lightweight pulley was not because it was lighter or not balanced, it was because it was a solid piece which did not have the OEM layer of stress absorbing material.

Careful with them apples and oranges......

John

 

As another person said: apples, oranges.

2.5 lbs from a flywheel is significant. People pay more than that to have their flywheel lightened.

This statement is so bizzarely strange I don't know what to say to it. Perhaps you should contact some Formula 1 one teams and tell them to stop paying $100k for carbon fibre bodywork because they could get a hell of a lot more steel for that money. And those poor dolts paying $2.5k for 11lb Mugen MF-10 wheels when they could get 20 lb steel ones for one tenth of the price....

A flywheel attached to a B18C5 shattering. Have not heard of a single reported case. And the Realtime Type-Rs have used Comptech's aluminum flywheels without failure for several seasons, standing starts and all.


[Modified by norice, 4:59 PM 9/10/2002]

 

thanks for all replies..

looks like i'll be replacing stock flywheel for aluminum one.

 

touche.

Look, I am all in favor of going with a lightened flywheel. Otherwise, I would not sell them. I, however, am not claiming to be a pro here (*not implying you are claiming to either, I am just saying). What I am typing here is not meant to discredit anyone, these are just my thoughts (I consider this a technical debate, not an arguement).

1) Yes, I know about the differences of crank pulley lightening and flywheel lightening. Regardless of that, one cannot deny that the lesser mass of an alunimum flywheel is going to effect the engine balance to a degree. A flywheel is really a big spinning weight on the end of the crank. If you don't think lightening it is going to effect anything, think again. The lighter the flywheel, the more extreme the effects could get. A crank pulley is a smaller spinning weight at the opposite end of the crank. The fact that it is harmonically balanced is only because it needs to absorb the torsional flexing of the crank through it's smaller mass. A flywheel is massive enough to absorb the flexing without needing a harmonic balancer. PLUS, the flywheel can transmit more engery from the crank through the clutch and transmission. While in one light, they are two different parts (apples to oranges), really, they do the same job (apples to apples).

2) I am not saying that 2.5 lbs is not going to make a difference. What I am saying is that there is not $100 worth more work that goes into a 6.5lb flywheel than there does in a 9 lb flywheel. They are both billet aluminum. A 6.5 fly actually should cost less. BTW, Comptech claims that their fly wheighs 7 lbs, not 6.5, or 6.75, or whatever. I personally think the extra $100 goes into a name.

3), No that reply is bizzarely strange. I was not comparing CF to steel, or forged aluminum to stamped steel....I was thinking about billet aluminim to billet aluminum. When you pay $300 for one aluminum fly, and pay $400 for another aluminum fly that weighs less, the only logical conclusion that can be drawn is that you paid more for less aluminum. You analogy is completely off. I sell sprung-center six puck clutches for $300 and solid-center 6-puck clutches for $275....guess why, they cost less in materials.

4) OK, well, I have not heard of any cases either, but I heard it does happen. Are you trying to tell me you think a sub-7 lb fly is going to hold up to more abuse than a 9 lb one? I will be honest, I don't know much about shattering and this comment by me was used a little frivolously.

Also, since Realtime Racing is no longer sponsored by Comptech (for a couple seasons now), I believe AASCO supplies their flywheels now.


Here are a couple pics of both, for viewing pleasure....
Comptech

AASCO

 

Let's keep it technical.

If the AASCO flywheel can be had for under its $300 MSRP and is proven reliable then it could prove a good choice. For me, the $100 difference between it and the Comptech (MSRP $450 but it can be had for $400) does not seem too significant given its increased weight and the overall cost/effort of installing a flywheel, but others may jump at the price.

Good luck with your business.

 

Thanks a lot! I still feel that while the difference of any Al fly and stock fly is going to be great, the difference between Al flys is going to be almost indecernable. Afterall, these are street cars we are talking about. The only reason I can see for spending more on one Al than another is bragging rights. I dunno, I guess I look at things from a budget-minded standpoint.

 

I also like the fact that the Comptech friction surface has 20 fasteners, all offset, where the AASCO only has 12. of those 12, there are 4 sets of 2 which are directly in line with each other. I'm not sure if I care for that set up.

Also keeping in mind, there are differences in how the piece is machined, and where the structural reinforcements are. A 9 lb flywheel can have less rotaional mass than another flywheel that weighs the same. It's also about how the weight is distributed.

Just some things to keep in mind.