Definative Flywheel Weight B17A- Here it is!

INFORMATION G2IC Archives
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Ok, I had these parts out of the vehicles, cleaned (new in the case of the ITR) and on a real scale (NOT a bathroom scale, either):

Gen2 B17A (GS-R) STOCK Flywheel: 19 lbs. 0 oz. (19.0 lbs.)
98 B18C5 Type-R (ITR) Stock Flywheel: 15 lbs. 8 oz. (15.5 lbs.)

If you want the Kilos, do the math on your own.

Soooo worth grabbing the ITR?

4 lbs from the FW is like driving a 100 lb. lighter car. SO: Is $225 to subtract 87.5 pounds of weight worth the extra loot? (ITR FW cost from ahmotor.com SHIPPED as of 2/22/02)?

HELL YEA! My STEREO weighs 30 pounds at least. More to come when it all gets installed!!!

–jay

[B]ARCHIVE THIS!

Noone here knew the weight of the flywheel and I even called Honda of North America. They were clueless as were at least 10 Acura dealer parts Dept’s.

I found the answer I needed by calling John Kauffmann @ KMS Engine Development in Georgia ( http://www.honda-performance.com/ ). This guy knows his sh#$![/B] check out his site!

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ARCHIVETHIS

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You da man. I say go for it. That is a good price for that much of a weight reduction.

-Steve

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what would be an even better deal is lightening your stock flywheel to 13lbs. With lightening and balancing it shouldn’t run ya more than $160.

oh, and thanks for the definitive weights! stuff like that is always helpful

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Lightened, balanced, resurfaced
This weighed in at 12lbs

shaved backside

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In the interest of all:
BUMP!

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sorry if this is a dumb question but how would losing 4 lbs be like losing 100lbs?

I was just told the other day that by getting a c/f hood(25lbs lighter) I wouldn’t gain anything. Why not?

anything else you can do to lose weight?(without messing with interior)

I want to make up for my 17" rims and stereo.

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Here’s your answer:

The engine turns the flywheel. The flywheel mounts to the clutch which, in turn, rotates your tranny, turning your wheels when engaged. Once it starts turning, the FW’s weight KEEPS it turning for a certain amount of time. This amount of time is dictated by gravity, friction and it’s own mass (weight).

Heavier FWs stay rotating longer on their own and, hence, the RPM’s don’t drop quickly BUT they take longer to get going, as your engine has to spin this thing at 500 to 8500 RPM (takes power to get a piece of metal spinning that fast. Lighter FWs don’t take as much energy to spin, but they don’t stay spinning as long b/c there’s less mass.

For example, try spinning an empty plastic cup on it’s bottom. Pretty easy, eh? Once the cup falls ofer, it stops pretty quickly from friction with the table or floor or whatever you are spinning the cup on. Now, fill the cup with water and try again. Not only would that make a mess, it take much more strength to spin a full cup than an empty one. If there was a top on the cup, you’d find that even after it falls over it still takes longer to stop moving b/c there is more mass.

The point:

Lighter FW gets your RMP’s up FAST FAST FAST keeping you running in your powerband on quickly on your way BACK to the powerband. Imagine how fast your car gets to 60 with just you in it, then compare that to you and a 200lb friend trying to get to 60. It takes longer with the additional weight. The concept is similar. The engine has to turn a 20 lb FW very fast and get it going quickly. If you lighten the weight, the engine can turn it more quickly b/c it takes less energy to make a 16 lb FW turn at 8000 RPM than it takes to get a 20lb FW turning at 8000 RPM.

Without geting into the exact math the difference translates to this:

For every 1 Lb you remove from the FW weight, the engine rev like it’s pushing 25 pounds less total car weight (up to a certain point, of course)

Remember that the engine routes power to the flywheel which turns the transmission. Power is greatest at the flywheel, which is why most cars rate their HP “at the flywheel” and not at the wheels.

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THANK YOU so much!!! You should archive this!!!

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ok…so how come Honda doesn’t put a lighter one on in the first place, there must be some sort of trade-off?

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Yes… the trade off was explained by Jay ^^^… Revs drop quicker, uphill battle might be a little tougher, low rpm shifts may cause engine to stall…

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Re: Definative Flywheel Weight B17A- Here it is!

Originally posted by Jay
[B]Ok, I had these parts out of the vehicles, cleaned (new in the case of the ITR) and on a real scale (NOT a bathroom scale, either):

Gen2 B17A (GS-R) STOCK Flywheel: 19 lbs. 0 oz. (19.0 lbs.)
98 B18C5 Type-R (ITR) Stock Flywheel: 15 lbs. 8 oz. (15.5 lbs.)

If you want the Kilos, do the math on your own.

Soooo worth grabbing the ITR?

4 lbs from the FW is like driving a 100 lb. lighter car. SO: Is $225 to subtract 87.5 pounds of weight worth the extra loot? (ITR FW cost from ahmotor.com SHIPPED as of 2/22/02)?

HELL YEA! My STEREO weighs 30 pounds at least. More to come when it all gets installed!!!

–jay

Once again the b18a is neglected :sad:

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Originally posted by NZTeg
ok…so how come Honda doesn’t put a lighter one on in the first place, there must be some sort of trade-off?

Cost, durability, & ease of use would be the reasons as far as I can see:)

Leif

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slprTeg: all b series flywheels except for the itr should weigh in at the same weight. So, your b18a1 flywheel is also 19lbs

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Originally posted by 91IntegGS
slprTeg: all b series flywheels except for the itr should weigh in at the same weight. So, your b18a1 flywheel is also 19lbs

You mean b18a2 :slight_smile:

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As far as I know, the B18 engines all (EXCEPT the B18C5, ITR model) have the same flywheel. I will double check.

–jay

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another thing to keep in mind…
when you add the pressure plate, which is about 8 lbs., i think, the difference isn’t that much - 27 lbs. vs. 22.5.

i put in a 9 lbs. flywheel, and it didn’t seem that much different… i mean, it’s one of my favorite mods, and very fun, but i can’t imagine you’d notice a difference of just 4.5 lbs.

but if you’re doing the clutch anyway, sure go for it.

jeff

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What are the durability issues with lightening a flywheel? What is the most you can shave off one?

Scott

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Durability issues:

Can’t resurface a lightened flywheel. It’s a good idea to resurface the FW every time you replace a clutch. You’d have to buy one with a replacable contact surface like the ClutchMasters FW.

In my case there are no issues, as I’m putting in the ITR fw, which is an Acura part. Hehehehe.

Hope that helped.

–jay

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Originally posted by Jay
[B]Durability issues:

Can’t resurface a lightened flywheel.
–jay [/B]

Who told you that? A lightened flywheel is shaven from the back of the flywheel and not on the front clutch contact side so yes you can still resurface a lightened flywheel. Lighter flywheels arent always good. You lose off the line torque like eric said. RPMs move quicker up and down but you DONT go faster. So for some people it can just be a waste of money.