benimpreza

Hello

Can anybody help me I am after a lightened flywheel but dont know which one to go for I dont do any track days or drag strips but a lot of country lane driving so which weight would everybody recomened

p.s I do about 12 k a year so it needs to be drivieable still

Thanks

Ben

RB5_245

Lots of choice, lightest I found was helix 4kgs but prob too light for you. TEG sport do a lightened steel one probably a good deal for a road car and cheap too click

There are better things to spend money on though unless you really need a new flywheel.

Dave

sideways scooby

ive just had one from api ( advertised on top of page ) 7kg, got it as part of a group buy, give them a ring

martyrobertsdj

iTrader: (1)

I got one from API at the same time as a new clutch. Just though I'd take advantage of the gearbox being out, but also do away with the chance of an old flywheel damaging the new clutch.

I was advised not to go lighter than about 8Kg. The API one is IIRC 7Kg.

To be honest, I haven't noticed a massive difference, but then I was driving about with a slipping clutch for about 4 months, so the car felt faster as soon as I got in it with the new clutch.

All advice I took seemed to suggest that a lightened flywheel was a good thing to do, but not on it's own. Too much money, time and effort for the benefit. Do it at the same time as the clutch and you've made a sensible choice I think.

Kondor

I've got a Fidanza flywheel, it's 4,5 kg. I got it fitted together with an AP Racing clutch, and the difference is big, the engine revs a lot quicker.

harvey

iTrader: (48)

The engine will only rev noticably quicker when sat blipping the throttle in neutral. The mod is only cost effective if you already have the engine or gearbox out for other work.
O/E lightened are available from API, AS Performance and others and are relatively cost effective. TEG do a nice aftermarket flywheel. There is little point spending mega money on an after market flywheel as there are better gains per £ spent elsewhere.
Going much below 8kg, eg 4 or 5kg will require a very precise launch technique if you do drag starts.

alloy

I have a 4.6 kilo flywheel on my Bug STi along with a new clutch and the car is so much more responsive!! The best mod i've done IMO

Tripple'O G

Agree with the lads here.........I had a new gearbox and clutch from API so I decided to get the flywheel......other than that, there's not much point....

Aztec Performance Ltd

iTrader: (234)

From what people have said on these threads in the past - they have noticed very little difference, if any on getting a lightened OE one (8kgs).

My personal view is that its worth spending a little more on a proper lightweight flywheel and you WILL notice the difference.

I find launches very good and consistant once you get the hang of it. The only compromise I feel is in with medium speed take offs when driving locally.

I run a 4.2kg flywheel.

Agreed with Harvey, that its not really worthwhile unless you have the gearbox/engine out anyway.


Bob

alloy

Yeah once the launches have been sussed there is no end!! It is an animal off the line, and with the 4.2/4.6 i'm not 100% which one i got, i have found that it just goes and picks up much more freely and on command than with the stock flywheel

APIDavid

iTrader: (4)

We probably fit 5 out of 5 light flywheels [ @ 7.5 Kg's ] on clutch replacement, customers ask for it, as a known, good, mod. We offer it on rebuilds, together with ported headers and MOST customers opt for it. I'd have to say it's one of our most popular lines and the feedback from our customers is that the car is definitely more responsive [ on either - not necessarily both together ] and they are glad to have it done. I would not offer it as a stand alone fitment, it isn't worth the cost of stripping out the box just to change a flywheel

WE can also supply a billet steel flywheel at £300.00 should it be necessary, strictly speaking you only really need a billet steel, if you run a ceramic clutch. [ Non organic ]

The Fidanza is, in my opinion, too light for road use and will interrupt the harmonic balance of the crank and front pulley assembly. You REALLY SHOULD lighten the crank pulley at the same time as fitting a Fidanza and also rebalance the whole crank, pulley, flywheel and clutch assembly to be safe.

David APi Engines / APi Impreza
www.apiengines.com

BVM

Sorry I am a little late to the game. What year and spec scooby do you have? You have to be careful with 02-03 WRX because too light a flywheel combined with a light crank pulley will most likely trip a CEL code for misfire. '02's are especially prone to this even w/o any mods! Search for "phantom misfire" or P0301, P0302, P0303, P0304 CEL codes on NASIOC.

As for lightened flywheels they can be a bit of a double edged sword. Why? Well, a heavy flywheel uses the rotational mass (kinetic energy) as a means of improving standing starts on cars with less torque, ie turbo cars, or engines with small displacement. If you lighten the flywheel too much, you will have to rev higher to get an equally smooth start as the stock weight flywheel. This means more clutch wear and its also hard to rev match when up or down shifting. You will notice it the most in those situations. This is not as important on large displacement engines such as a 7.4 liter big block chevy! Lighter would be better in this situation to help reduce all that rotational mass (heavy crank, pistons, rods ETC). Also, sometimes the Idle air control motor (IAC) can not react quick enough and you can stall when pulling up to a stop. How embarrassing!
If you were upgrading the clutch in your car, many uprated clutches are actually heavier than their stock replacement counterparts.

For example:
Stock '02 WRX clutch = 14.3 pounds
Stock '02 WRX flywheel = 24 pounds
total 38.3 pounds

ACT HD organic clutch rated to 411lbft = 17 pounds (notice the difference in weight right here!)
matching billet steel lightweight flywheel = 13.9 pounds (most shops agree this is the lightest you want to go)
total 30.9

Total reduction over the stock setup is 7.4 pounds or about the equivalent of about 15hp!

So if you were to install the uprated clutch but use the stock flywheel you would be adding 2.7 pounds or rotation mass! That adds up. I don't know the exact amount it translates into but thats like loosing about 10 hp (or more)!

Before I forget to mention, aluminum flywheels are usually formed with an aluminum outer ring with a steel friction plate bolted or otherwise fastened together. Obviously they have very different thermal expansion rates and over time will work themselves loose. Aluminum flywheels also transmit a lot more harmonics and vibration through your drive train. You will notice this on the over run and it can be quite annoying! Billet steel flywheels seem to transmit far less and are often as quiet as the stock parts! My friend Ali replaced his gear box, and rear diff chasing a noise and if he would have listened to me, he could of saved a lot of money... the noise was the aluminum flywheel!

Anyway, I hope this helps and is somewhat coherent, I had dental surgery and the pain killers are working their magic!

RaymondH

Does a lightened flywheel affect the boost curve in any way? I'm wondering if fitting a 7kg one when I change the clutch will mean that I don't reach full boost until later. I've just had a remap and don't want another one

APIDavid

iTrader: (4)

Not in so many words, but of course if the car is able to start spooling faster because of less effort required to get it all moving then it is probable that the boost curve will start from a lower point in the rev range. It ought to follow the same shape of curve just start from a lower engine speed.

The boost curve itself is controlled by either your ecu or the boost control solenoid - OR the dreaded Dawes...........

David APi

Aztec Performance Ltd

iTrader: (234)

Why the dreaded?

Danny Boy

iTrader: (2)

I have one of the API 7kg lightened OEM flywheels fitted and i have seen a nice improvement.
One of the first things i thought when i drove the standard turbo 2000 was that the flywheel seemed too heavy as when pressing on and trying to make fast gear changes the revs never fell fast enough inbetween changes to make a nice fast shift. The mass of the flywheel encouraged a more leisurely gear change approach.

Now with the new flywheel fitted the revs drop a bit quicker inbetween changes giving a much smoother 'fast shift' which seems to suit my driving style more. We will see on sunday wether this improvement translates into better times at elvington.

Dan.

RB5_245

The V2 dawes device controls boost as well as any perfectly set up stupidly expensive EBC or better than a badly setup stupidly expensive one.

People dont like them because they are simple, don't have flashing lights and don't cost a fortune.

Engine failures have been wrongly blamed on dawes devices as they are easy to just turn up the boost to anything you like.

Only downsides are you can't have throttle progressive boost control (don't think even the best of ebc's can do this either) and you can't hold your boost target all the way to the red line (which imo you shouldn't do anyway unless you don't care about engine life).

Dave

tfl55

OK Ben

Have you been enlightened or not? So many answers.

APIDavid

iTrader: (4)

RB5 245 has said or before I did. In irresponsible hands they are a ticking bomb.

David APi

Aztec Performance Ltd

iTrader: (234)

as is any other form of user adjustable boost control

RB5_245

That's the point I was getting at

Aztec Performance Ltd

iTrader: (234)