JonH

along with a paddle-type Cusco clutch. However, the idling seems to fluctuate (sometimes) and occasionally, the car stalls when coasting to a stop light. (e.g. when I push the clutch in and engage neutral)

Is this something that is expected with a ultra lightweight flywheel? Also, considering that JUN offers either a 5.3kg version or a 4.6kg version, there must be a advantage/disadvantage of either for street purposes..

Could someone please help out? Before the install, I told the installers that it would not be acceptable if the car stalls; they will agree to change to a 5.3kg version once it comes in.. Will this solve my problems?

robski

Sounds about right to me from my experience (of a non scooby lightened flywheel.)

I think the problem is that due to the light weight (and therfore lack of momentum) the ECU cannot cope.

Should rev a bit nicer tho!?

I got used to it, you learn to blip the throttle, should be ok if you try this?

robski

SimonM

Okay.. so that is a disadvantage of having a lighter flywheel... what are the benifits?

SimonM

LanCat

Engine will rev more freely because there is a smaller lump of steel to get spinning.

MorayMackenzie

The car has less dynamic drivetrain load to deal with, so it will accelerate _and_brake_ better. It may require downshifts when climbing hills and the car may _feel_ less torquey.

robski

Yep.

Was told by a respected engine tuner that "internals" weight removal is 10 times better for power to weight than the equivalent weight lost on the car. e.g. 10KG off internals is worth 100KG elsewhere.
F1 teams look for a lighter engine so that they can move the weight elsewhere.

The flywheel isnt internal, but I would expect its still a lot better to loose it here than elsewhere.

Real world example, try to push an empty wheelbarrow, then a full one, which one do you get upto speed quicker?

robski

MorayMackenzie

robski,

Your wheelbarrow example demonstrates a change in static load... e.g. loosing 100kg from the car rather than 10kg of the flywheel.

Maybe it would work better if you filled the barrow's tyre with water for one run?

Moray

Craig H

How about you fit a lightened wheel? Should make it more responsive too
Heard something similar about the internals. But with the Scoob and things like strenghtened rods, does the weight increase, hence the power decreases.
Bit sad but I need to know!

Andy Banks

Hi Jon,

When GP club installed my Exedy twin plate clutch & lightened flywheel I had no idling or stalling problems whatsoever. The car revved much quicker, although the on/off clutch behaviour took some getting used to. It was a bit noisier...but got an email from Exedy of japan saying this was normal.

Now i've changed back to standard clutch and flywheel, I have the exedy twin plate & flywheel for sale. If this would be any use to you drop me an email...only used it for 2 weeks.

Long story why we changed back to stock clutch...basically the cluch/flywheel was fine but they'd misalligned the downpipe causing a clonking noise. Of course, only by trial and error did we find out that the noise was totally unrelated to the racing clutch, and instead caused by a poor installation :-(

BTW, where did u get the flywheel fitted?

Regards
Andy


[This message has been edited by Andy Banks (edited 21 August 2000).]

JonH

Andy,

Thanks for the offer - I was actually going to ask you if your twin plate was for sale but because I do a lot of hard launches (how can I resist with launch control installed??), I decided that it would probably break the transmission in no time.

I purchased the parts through Kayaba Motorsports Shop in Mong Kok; however, the install was performed by a very experienced mechanic in the New Territories area.

As a matter of fact, I didn't want to change the clutch yet but it was slipping so bad that the car couldn't even be driven normally. Additionally, there is a 1/4 mile challenge coming up which I plan to take part in so this was a necessary step.

BTW, how long do I need to "run in" the clutch before I can abuse it?

robski

Moray,

good point

I dont know, you try to help....

robski

JWKC

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by JonH:
<B>along with a paddle-type Cusco clutch. However, the idling seems to fluctuate (sometimes) and occasionally, the car stalls when coasting to a stop light. (e.g. when I push the clutch in and engage neutral)

Is this something that is expected with a ultra lightweight flywheel? Also, considering that JUN offers either a 5.3kg version or a 4.6kg version, there must be a advantage/disadvantage of either for street purposes..

Could someone please help out? Before the install, I told the installers that it would not be acceptable if the car stalls; they will agree to change to a 5.3kg version once it comes in.. Will this solve my problems?[/quote]
I Belive it is due from the installation Problem.An After market Clutch should not cause the Engine stall if you able to disengage the clutch.I belive For street use a 5.3 KG Version will be a better idea!But If you intend for race a lighter one will give your Engine Rev. up more Faster and Feel the turbo spool up faster. and get a better ET in 1/4 mile.But for daily driven car and the on off traffic in HK. <B>NO THANKS!</B>
By the way.The 1/4 mile Challenge in HK .Is it legitimate Already???

Thanks
JWKC

Mark Pattison

Jon, hows does your new flywheel feel compared to the old one ?

Are you sure we can't persuade you to buy the exedy ?

We managed 13.27 at the last 1/4mile day which easy saw off the F355 and 911 turbo's, even the evos couldn't keep up Any ideas when and where this years event will be ?

JWKC

13.27 in 1/4 miles and the Porsche 911 TT and Ferrari 355 can't keep up??Those driver must really baby sit their porsche and Ferrari already!!!!

Thanks
JWKC

Mark Pattison

hhaha its a lot harder than you think! both ferraris and porches where driven very aggresively (not afraid to spin the wheels). After all they didn't want to loose face to all the jap crap crowd

It was quite a sight to see a dambo SV light up the rears...but your dead right we're just amatures mucking about for a laugh. I can still clearly remember one guy in his M5, spinning in 2nd and being almost stationary!

JWKC

I belive the Porsche 993 turbo 's is quite easy to launch. Just rev. it up at 4000 rpm,easy to get mid to low 12sec for normal driver.A good Driver can do low 12 sec. easy!The Ferrari 355 if I remember correct.It should be around 6000 RPM.Just not too much Wheel Spin!!( 6 speed manual with Tubi exhaust) and we able to do 12.78
Diablo SV .Never Saw it in a Drag Strip. and I belive that 2WD Diable is hard to launch !
13.27 in 1/4 mile.for WRX STi???
I belive it can do low 12 sec!!
By the way What is your reaction time at 0-60 Ft time and 1/4 speed??
Last time My friends EVO 5 RS with downpipe ,Exhaust,intake and ECU and do 12.72.I belive the STI should be at that range also!

Thanks
JWKC

JonH

Mark,

The car definitely feels alot more eager to rev with the Cusco flywheel installed..
However, I'm still experiencing some problems with the flywheel in that the car still stalls sometimes with the A/C on..

13.27 is a pretty good time given horrible Hong Kong weather...

Actually, the 1/4 mie challenge I'm referring to is hosted by a new local tuning magazine called Top Mission... I don't have any further info yet but they are accepting entrants.. Apparently you have to beat 3 cars which include an Evo III, an Evo IV, and a third car which keeping tight-lipped about..

JWKC,

There are actually quite alot of factors involved in getting a good 1/4mile time/trap speed which I'm sure you are aware of.. I don't think a mildly modded STi can do low-mid 12's, in Hong Kong at least.. I think Bozz Speed's old STI Ver III (the blue car) with the 2.2l liter conversion + TD06-20G had a et of mid 12's as tested by Hyper Rev Magazine video vol.1..