lightweight flywheel with boost or no?
 

Currently building a 300 crank HP D16Y7 SOHC VTEC engine
I got my act clutch kit yesterday
some people say that a lightweight flywheel is no good for turbo'ed cars


is it beneficial or not worth it?

Re: lightweight flywheel with boost or no? (Civic Racer X 7)
 

Personally, I don't think it's worth it. A have a VW, but I can speak from experience.

With my G60 motor, I had a 9lb flywheel and it was fun, despite spinning through 1st and 2nd whenever I would punch the throttle. With a VR6 Turbo, it's even worse. A friend of mine has a VR6 Turbo (~300whp) and a lightened flywheel. It's just a pain in the ass to drive on the street. Highway, different story, but the revs go up so fast, he ends up spinning til redline most of the time.

For that reason, I kept my stock flywheel, so that I don't have that problem. It'll make a difference, but not anything you wouldn't be happy about. I say keep the stock one on there, with that much power.

aside from the cost is it worth the performance gain?

Re: (Civic Racer X 7)
 

For a stock motor or even an all-motor setup, I'd say yes, but if you're going to be making 300whp+, personally, I don't think it even matters.

Like I said before, my friend has one and his car spins tires worse than mine. The driveability is definitely worse, from experience, with a 300whp+ car.

Re: lightweight flywheel with boost or no? (Civic Racer X 7)
 

From the technobable section of the current Sport Compact Car:
"Accelerating a pound of flywheel weight is like trying to accelerate 30 pounds on your chassis"

Re: lightweight flywheel with boost or no? (Civic Racer X 7)
 

it really depends the most on what your planning to do with the car. drag racing (where your only accelerating straigh forward only for a 1/4 mile) no, deffinatly not lighter, and if might even be beneficial to go slightly heavier if you can find one (you want the momentum for the launch, it will give you much better 60 foots with the right suspension and tires). road racing/autocrossing (where your revs are constantly up and down) a lighter one will help you if you can get the power to the ground, cause you need to constantly change RPMs quickly. if its just a street car that see's only occasional track use (whatever it is) keep it stock, its probably the perfect weight for what your gonna use it for on the street, heavy enough to still be driveable off the line, and light enough to accelerate easily on the highway.

Re: lightweight flywheel with boost or no? (TiresmokinHONDA)
 

1. This dead horse has been beaten about 50 times now

2. Lighter is always better

lighter = better
highway races own

I've got a fidanza 7lb on my sc61 ls turbo.It's not that bad of the line b/c it's takes my turbo a while to spool.I say get one.

Re: (lsturbocivic4do)
 

the difference is here... with less moment of inertia your car will be harder to get going smoothly from a stop. It will require that you slip the clutch a bit more.

The plus is... once you get your clutch engaged your engine will rev quicker...and put more power to the ground. since lightened flywheel=more whp... and more whp= https://honda-tech.com/forums/images...s/emsmileo.gif then lightened flywheel= lots of https://honda-tech.com/forums/images...s/emsmileo.gif

Re: (RTErnie)
 

Light flywheels don't affect you launch if you are a good driver. Basically, with the heavier flywheel, you have a rather large RPM window for a decent launch. With the light flywheel, the window is very small - you have to really know your engine and have a perfect feel for the clutch to keep from bogging/spinning you tires.

<U>stock</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;----------------launch-------------------&lt;&lt;&lt;&lt;&lt;&lt;spin&gt;

<U>with light flywheel</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt ;------launch------&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&l t;spin&gt;

yeah, i love my lightweight flywheel.

i basically got it for free (did work for somebody), and i would probably save my money if it were up to me, but i am glad i have one. dont know if it's worth the money or not.

at a road course, it really really helps rev-matching though, blip the throttle, and the rpms are there. its great.

Re: (EnzoSpeed)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">Light flywheels don't affect you launch if you are a good driver. Basically, with the heavier flywheel, you have a rather large RPM window for a decent launch. With the light flywheel, the window is very small - you have to really know your engine and have a perfect feel for the clutch to keep from bogging/spinning you tires.

<U>stock</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;----------------launch-------------------&lt;&lt;&lt;&lt;&lt;&lt;spin&gt;

<U>with light flywheel</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt ;------launch------&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&l t;spin&gt;</TD></TR></TABLE>

essentially what I just said...without going into the details. Rotational Inertia... thats really all you need to thing about. Think about the extra weight and the conservation of momentum, then think about torque and how rotational weight affect the ability to rotate something...rotational inertia. it will all make sense.

Re: (RTErnie)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTErnie &raquo;</TD></TR><TR><TD CLASS="quote">
essentially what I just said...</TD></TR></TABLE>

I know, I was in agreement with you https://honda-tech.com/forums/images/smilies/emthup.gif . I just wanted to second that before everyone jumps on the "you'll suffer off the line" bandwagon.

Re: (EnzoSpeed)
 

haha. https://honda-tech.com/forums/images/smilies/emthup.gif

bandwagons...make the world go 'round https://honda-tech.com/forums/images/smilies/emsad.gif

Re: (RTErnie)
 

what about on a LS tranny?? in the 300-350 hp range.

Re: (RTErnie)
 

i just put a 7lb on .. i am only running about 225 whp but it definately helps once its engaged. its gonna take some learning but i think it will be worth it...especially on the highway. https://honda-tech.com/forums/images/smilies/emthup.gif

i can say this...before from a roll i didnt spin second...now with the flywheel i do.

Re: (00IntegrAllmotoR)
 

in any app its good. I run a 3.55 tranny in my neon...basically a LS tranny... ITR 4.4 tranny~3.94 ACR tranny. Still doesn't change the fact that lighter flywheels will benefit the car...still rely's upon good ole' physics. https://honda-tech.com/forums/images/smilies/emwink.gif

Re: (EnzoSpeed)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">Light flywheels don't affect you launch if you are a good driver. Basically, with the heavier flywheel, you have a rather large RPM window for a decent launch. With the light flywheel, the window is very small - you have to really know your engine and have a perfect feel for the clutch to keep from bogging/spinning you tires.

<U>stock</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;----------------launch-------------------&lt;&lt;&lt;&lt;&lt;&lt;spin&gt;

<U>with light flywheel</U>
&lt;bog&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt;&gt ;------launch------&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&l t;spin&gt;</TD></TR></TABLE>
https://honda-tech.com/forums/images/smilies/emthup.gif

I got my fidanza 7lb on a gsr tranny and traction problems aren't that bad.You just gotta learn you car off the line.

I had a lightweight flywheel on my turbo S2000 and went back to stock. Turbo clutches tend to be very grippy and a bit more unforgiving. Couple this to a light flywheel and you have a recipie for horrible drivability.

Tim

Re: (timg)
 

^^My daily driver has a prolite flywheel, 6-puck clutch, and JimFab motor mounts https://honda-tech.com/forums/images...es/emdgust.gif

At first, it seemed insane and I thought I'd never be able to drive it on the street. Now, after two years, it feels normal. I just have to have the radio turned up 24/7 to drown out the God awful noises coming from the drivetrain.

Re: (EnzoSpeed)
 

Well here's the answer to my EX tranny problem. I hate the way 3rd pulls in my turbo Z6. I was going to go for a higher final drive and get a DX or LX 5th gear.

Looks like a lightweight flywheel is in store for my next build.

Re: (EnzoSpeed)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnzoSpeed &raquo;</TD></TR><TR><TD CLASS="quote">^^My daily driver has a prolite flywheel, 6-puck clutch, and JimFab motor mounts https://honda-tech.com/forums/images...es/emdgust.gif

At first, it seemed insane and I thought I'd never be able to drive it on the street. Now, after two years, it feels normal. I just have to have the radio turned up 24/7 to drown out the God awful noises coming from the drivetrain.</TD></TR></TABLE>

Very insightfull, Ill keep my stock flywheel


Another thing to note is that your boost will fall off quicker when changing gears because the flywheel is the main inertia in the engine, So keep the stock flywheel.

Re: (dc4g)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dc4g &raquo;</TD></TR><TR><TD CLASS="quote">your boost will fall off quicker when changing gears</TD></TR></TABLE>


No! That's just bandwagon talk. Lightweight flywheels don't make the RPMs rise/fall much faster compared to stock. It's not like you suddenly have an F1 engine.

There is no chance of falling out of boost with a light flywheel. That myth needs to stop. Even with my Prolite wheel, the revs don't fall fast enough - when I shift, the clutch still has to snap the revs down to match the next gear.