Lightened flywall...pros? cons?

because it does not make a world of difference....
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I would disagree as well - made the world of difference on my Pinto esp as it now resides in the Westfield.

I drag raced a near identical Westfield who had 5bhp more than I did - his 0-60 and 1/4 mile times were 4.7s and 13.4 respectively and mine were 4.3s and 13.05. Flywheel was pretty much the only noticiable difference.
 
no way a flywheel is going to gain you nearly 4 10ths on the 1/4 mile. I would say the biggest difference between the 2 vehicles was the driver.
 
gurusan said:
no way a flywheel is going to gain you nearly 4 10ths on the 1/4 mile. I would say the biggest difference between the 2 vehicles was the driver.
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http://www.pumaracing.co.uk/FLYWHEEL.htm

"So in first and second gear this is a pretty important effect - I built an engine recently and managed to remove nearly 3 Kg from the outside of the standard flywheel - so that would be equivalent to lightening the car by over 100 Kg in 1st gear - not to be sneezed at in terms of acceleration from rest. "
 
Oh and if you still think it makes no difference, try driving a cavalier 2.5 V6. These has a massive flywheel to allow them to idle so low. They are massively unresponsive engines and you literally feel the engine trying to accelerate the flywheel.
 
hmm that is quite interesting. My civic did run a 1/4 mile of 14.9 which is not bad at for a b16 with bolt ons...perhaps that's some of the reason then.
 
gurusan said:
because it does not make a world of difference....
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The lighter the car, the more difference it makes. On something like a 7 it would significantly improve acceleration in the lower gears, but even on a heavier car the improvement would be noticeable. The example shown on the Puma Racing website shows 1kg removed from the OD of the flywheel of an "average" car is equivalent to 39kg removed from the body/chassis in 1st gear. You can see how an ultra-light steel flywheel that could save 5kg or so would make a huge difference.

Note that a lightened flywheel actually gives you more power at the wheels during acceleration (though obviously not under steady state conditions).
 
on my MR2 the orginal fly was 18lb, the new lightened fly is 11lb, there is definately a difference on how it now rev's. The idle is lumpy and sometimes it stalls, BUT that could be the flywheel and/or the engine internals as I uprated these at the same time

Check ebay for flywheels as you can ususally find a bargaim from USA suppliers, I got mine for £100 shipped
 
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I have a Fidanza lightened flywheel on my MR2 Turbo, absoloutely no ill effects to report on. Throttle response is better though, just requires slightly more throttle if you are not used to it when manouvering etc. Idle is perfectly smooth also.
 
no way a flywheel is going to gain you nearly 4 10ths on the 1/4 mile. I would say the biggest difference between the 2 vehicles was the driver.
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I'm glad to see a previous poster has already shot you down in flames. But to add, we did 5 runs in each others car as well and we both matched the others best time in this own car, so the driver was removed from the equation.
 
I put a lightened flywheel (8lbs, down from standard of ~17lbs) onto my Prelude.

Made no difference whatsoever to it's idling/low-speed manoeuvring, but it did "feel" slightly more rapid, especially in lower gears where it seemed to pick up revs more quickly.

By removing that much weight from the drivetrain it does make a nice difference, especially as it's before the gearbox.

I spent ~£50 on mine, so well worth that, but no way worth over £200 IMO!
 
One downside that is rarely mentioned, a missed gearchange is more likely to spell instant death to your engine with a very light flywheel.
 
I've driven a couple of cars with lightened flywheels - a 1.9 205 GTI that felt more like a fast 1.6 engine (anyone who's driven both will know what I mean by that) and a Suzuki Swift-engined Nova stage rally car.

I have to say I really liked the sensation it gave when driving.
 
its a pretty potent mod to some of the minis as well.

some of the flywheels (dual mass types) and clutches on new cars are insanely heavy.

unbolting one with the car in the air above you is now a extreme sport.
 
The wheels have proportionally more rotational inertia, so when you reach steady state the flywheel will be at a higher speed than if it was heavier.

Higher speed = more rpm. If you miss a downchange its more likely to throw a rod/piston valve contact.
 
I have quite a light flywheel on my Anglia, it flips the revs up and down nice and quickly with the lumpy cam and twin Webers which makes for nice quick gearchanges up and down. Also sounds awesome in traffic. It does have to idle a bit quicker though, not much because it's a pretty lairy cam in there anyway.

Note it's not a 'race' lightened flywheel. With this you WILL start to hate creeping around in traffic...

My dad had an ultra light flywheel and paddle clutch on his hotrod. Heavy 1930's car, 350hp V8 with a manual box and would stall easier than a 900cc Fiat Panda unless you gave it some revs, then it would roar up the revs, toast the clutch, fire you forwards or spin the tyres. It was just hard work and a nightmare on hill starts and parallel parking. When the clutch eventually needed replacing it was junked for a normal light flywheel and clutch. The car was then very driveable and no slower.

Think about that, because you can get your flywheel lightened for not too much and take a kilo or so off which will pep the engine up a bit but not make it a nightmare.
 
if you miss a gear? youre still loosing me

if you miss a gear and stamp on the throttle in neutral.. it will just go to the limiter


go from 5th to 2nd instead of 5th to 4th, itll die just as badly, standard or lightened flywheel
 
Matt82 said:
if you miss a gear? youre still loosing me

if you miss a gear and stamp on the throttle in neutral.. it will just go to the limiter
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With a lightened wheel you get there much faster and by the time the rev limiter acts you have more overshoot than a heavier wheel.
 
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