Definative Flywheel Weight B17A- Here it is!

system · February 25, 2002, 5:45am

Originally posted by SlprTeg
[B]

You mean b18a2 [/B]

No, he meant B18A1. The only A2 I have seen was on a Turkish G2.

system · February 25, 2002, 6:22am

Well this is my ?. Is it worth doing to a lightly modified car? Here is a list of my mods that I am doing to my B16:

Firts gen B16
Stock bottom end
Type R valves, springs and retainers
Type R cams
Clutch…havent decided which one but am leaning towards Centerforce Dual Friction…suggestions would be great!
Possibly lightend flywheel…dont know is it worth 160 bucks?

system · February 25, 2002, 6:28am

Originally posted by Scooter

Possibly lightend flywheel…dont know is it worth 160 bucks?

hey scott, is that how much it costs to get your flywheel lightened?

system · February 25, 2002, 6:59am

Dont know for sure I was just going off of what 91IntegGS said, but I am going to look into it more tomorrow. I know a great machine shop that can possibly hook me up!

system · February 25, 2002, 7:03am

Originally posted by Scooter
Dont know for sure I was just going off of what 91IntegGS said, but I am going to look into it more tomorrow. I know a great machine shop that can possibly hook me up!

cool… if you get it done let me know on their quality. i’m thinking about doing this sometime. i’m probably just going to find a used b-series flywheel so my car doesn’t have to be out of commision while i do it… and i don’t really want to get the 7.5 lb flywheel (to light for me)

system · February 25, 2002, 7:29am

Friend did mine if you guys are interested, let me know. much cheaper than 160.

system · February 25, 2002, 7:32am

To achieve the greatest increase in performance a lighter flywheel must lower the moment of inertia characteristics of the engine by lessening it’s own weight. Put in simpler terms, we must reduce the amount of horsepower needed to turn the flywheel so that horsepower can be used to turn the wheels.

Dave Coleman’s term… taken from Sport Compact Car

Effective weight = 1/ 2(FWweight)((FWradius)(GearRatio)(FinalGearRatio
)/TireRadius)^2

For example 92-93 GS-R

gear ratio
1 3.307
2 2.105
3 1.458
4 1.107
5 0.875
F 4.400

GS-R FW weight = about 19lbs
Type-R FW weight = about 15.5llbs
tire radius for stock rims(Michelin 195/60R14 85V) = 11.6"
FW radius = about 5.625"

effective weight for GS-R in 1st gear
=0.5*(19)((5.6253.307*4.4)/11.6)^2
=472.96 round to 473

effective weight for GS-R with Type-R FW in 1st gear
=0.5*(19)((5.6253.307*4.4)/11.6)^2
=385.83 round to 386

therefore… 473-386 = about 87 lbs

So…

With the Type-R flywheel, 92-93 GS-R engine is able to spin like it pushing 87.5 lbs less than otherwise.(in first (1st) gear) saving 24.85714286
pounds total per pound at the flywheel.

system · February 25, 2002, 7:48am

Originally posted by Ray
[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. [/B]

Here’s the thing… if you shave it to a certain point (7.5 lbs for example), you may not WANT to have it resurfaced. Resurfacing removes metal = even lighter weight. The part becomes unstable at some point, hence scatter guards. I figure lightening it until it shatters, eating your engine or tranny at the same time isn’t worth finding out about.

RATHER than lighten it, get one with a replacable surface or something.

You’re right, you don’t go “strait-line” faster but I guarantee you’ll see a difference if you were doing Auto Cross. AutoCross is more like daily driving for some of us (but definately not all).

More usable power = faster lap times.

Shoot, everyone who’s played Gran Turismo knows that one!!!

system · February 25, 2002, 7:55am

Originally posted by Jay
[B]

Here’s the thing… if you shave it to a certain point (7.5 lbs for example), [/B]

b-series flywheels should only be lightened to ~12-13lbs safely.

system · February 25, 2002, 11:47am

I agree. You can only shave a flywheel SO much. Nice taillights. You gotta tell me how you did that.

–jay

system · February 25, 2002, 5:04pm

Originally posted by B17A
[B]

No, he meant B18A1. The only A2 I have seen was on a Turkish G2. [/B]

grr, I thought 90-91 were b18a1’s and 92-93 were b182’s???

system · February 25, 2002, 5:33pm

So would you recommend swapping an itr flywheel in or a clutchmasters?

system · February 25, 2002, 6:30pm

Ask me in two weeks when I have the CM Stage 1 clutch and the ITR FW installed and I’ll be more in a position to answer that one.

–jay