I have been told by a repitable company that lightend flywheels, on turbo applications for the street is not a good idea. Stock weighted flywheels for the street, is better for street applications. Supposidly it takes more RPM to get the car moving with 9 lb flywheels verses the stock weighted flywheels. Some of you street racers, give me some good info.

 

For launching, a heavier flywheel will make things easier. This is because flywheels do not waste energy, they store it due to thier rotational inertia. So once you get them spinning, they hold thier rpm better.

With that being said, you can also launch at a higher rpm to compensate. A lighter flywheel means that the engine is easier to spin up and easier to slow down. When you let off the pedal, the rpm will drop quicker than with a heavier wheel. If you are road racing and need to rev match for downshifts a lot, the lighter unit will really be nice. It will also make for getting the engine speed up more quickly. On this car, I have yet to hear anyone that has bought a light flywheel complain one bit.

But with that said... dont take my reply as me being a street racer I race on a track... and one with turns at that :D

 

Meh straight line

 

i would think the car might build boost quicker and easier with a heavier flywheel cause of the extra load on the engine. make sense?

 

with a turbo charger you build boost at a certain rpm. and a supercharger boost is based on rpms. If you can reach an RPM faster with a lighter flywheel. You can do the math.

 

do you have a turbo? what your saying sounds good but i really don't think it's true. ever heard of brake boosting? it's the same idea, your putting more load on the engine which allows boost to build quicker.

i have never had a turbo but i know that turbo's don't work like superchargers, you won't always build the same boost with a turbo. it can vary a bit.

another example: if you're going up a hill with a turbo car it will build boost easier than going down a hill cause there is more load on the engine.

 

^^I see where he's coming from and I agree with him. However, and this is one of my favorite movies quotes, I don't think the Juice would be worth the squeez. The lighter flywheels advantages would outweight those of a heavier fly wheel i think.

 

a lighter flywheel means less rotational mass which means faster revving rpms.

this is good because the faster your car revs, the faster you hit boost, with both turbo or supercharging.

i have a lightweight flywheel, but i'm not boosted yet, and the only problem is that the car is alot easier to stall when moving away from a stop because the flywheel slows down alot faster when you engage the clutch than it did with the stock heavier flywheel, but it is no big deal, i just have to adjust my timing with the clutch and throttle pedals.

i haven't launched the car hard yet since putting on the flywheel, but on the road, the car has noticibly more pull especially at lower rpms because of the reduction in rotating mass. and it is still extremely drivable.

oh, and i have the competition clutch 9.5 pound flywheel from www.dezod.com

 

I have an automatic. Will the flywheel make it accelerate faster?

 

you don't have a flywheel.

 

i heard lighter flywheel will make the throttle response faster on a manual. does anyone know by how much faster if let's say.. i went from stock ( what is stock anyways?) to a 9lb? what about a 12lb?

 

Did you read the thread?

Yes, it will make the car rev faster. I dont know what you mean by how much... I doubt anyone has pulled out a stopwatch and timed it

 

yea i read the thread. almost the either thing was talking about accelerating faster between a NA vs. a turbo. That means, how quickly the RPM needle rises AFTER it has began to respond to input from the pedal. I was not referring to the speed of the RPM, I was referring to the throttle response, which means the time from the moment you step on the gas to the moment the needle begins to move. you accused me of not reading the thread when you actually did not even read my question, so shut your hole

 

uh... ok kid. Whatever you say.

so given your definition of throttle response, which is half the equation, the question is the same. I dont think anyone has broken out the dual channel o-scope to measure the difference in tenths of a second.

 

if you havent noticed, there's a great deal of complaint regarding the throttle delay on the TC. some say it's due to the drive by wire, others say it's the heavy flywheel. the difference is much more than a 1/10th of a second. why don't u go drive a car with a cable throttle to experience the difference.

the question is the same? if that is so, then why would people upgrade to a lighter flywheel for cars with cable throttle when there's no delay at all to begin with? your ignorant response is what makes us look bad in the car community, no difference from a ricer. it doesn't help anyone to offer your lame excuse of an answer for the sake of raising your chin. if you have nothing to contribute, don't and with that, please don't post anymore.

 

I thought people get lighter flywheel to accelerate or rev faster and compensate for throttle delay due to drive by wire on a tc.. People with cable throttle (less delay) get lighter flywheel to reduce rotational mass and rev faster. So even with cable throttle certain delay is present but on the flywheels side being heavy..

So,

drive by wire= throttle delay = add lighter flywheel = faster increase/decrease rpm (throttle delay still exist due to drive by wire)

cable throttle= less delay = add lighter flywheel - faster increase/decreas rpm (still with better response than drive by wire)

So delay due to flywheel (wheel side having to deal with rotational mass) is different from throttle delay (deals with how fast the pedal communicates with the engine to increase rpm)

I could be wrong on this, but this is how i understand it..

 

even thought it did not answer my question, you addressed the same concern as I have and stayed on topic. Thanks Ace83.

for the record:
even though i have a lighter flywheel on my integra, it accelerates faster, but the throttle response is the same as before the mod.

 

to try and asnwer your question tekstyle, it doesn't make the car rev noticibly faster when in neutral up to redline.

all cars should rev up extremely quick in neutral because there is no load on the engine, all your asking it to do is rev up. if the engine is designed to move a 2900 pound car plus a driver, a couple of pounds off the weight of the flywheel doesn't mean that the car is going to just rev through the roof at the slightest touch of the gas.

the plus side is that the engine does respond faster, not a quick as a cable throttle, but the delay has been reduced, i notice this because my usual timing is no longer as smooth as it used to be because without the delay that i was used to, i'm actually over revving a few rpms and kinda getting a shift surge when i engage the clutch. but i'm fine tuning it out.

oh, and btw, enginifineer contributes A LOT to this forum because he knows a great deal about cars, so stay on his good side should something go wrong with your car and you don't know what it is.

 

Wow.. you are a wealth of reading comprehension. I have probably driven more types of cars than you have sit in.


I will avoid spelling it out for you completely, but the point made is that 99% of that "delay" people talk about is actually the slower response of a heavier rotating mass... hence people buying a flywheel and saying "wow! the delay is gone!!". not that adding the ecu to the mix in the throttle control doesnt add SOME delay, but my point (I cant believe I have to spell this out to you.. since I have said it clearly) is that most of what you call delay is due to rotational mass. Thus, people with a throttle cable.... yet with slow response. buy a lighter flywheel to fix the issue. Unfortunately an auto doesnt have this option.

Most throttle delay (The part of it that actually exists) is designed into a drive by wire system on purpose, to avoid jerky operation.

You can call me names all you want kid, because you dont like my answers, but maybe if you read and comprehend a bit more you will learn something. And it has nothing to do with me knowing anything special.. it is just basic automotive tech and physics.

But in any case, any delay that is there will be a few tenths of a second tops.. if it were more it would be so bad that toyota would have already been working on it, as it would have been a safety issue. A few tenths of a second is an eternity when you look at what you brain is able to interpret. But again, you dont comprehend well, since you are talking more that 1/10th of a second when I clearly said

which to the rest of us implies more than one tenth.

And by the way, you mentioned

to another person.... actually answering your questions are totally off topic since the thread was about the effects of lighter flywheels on performance, not the dbw throttle delay

Regarding the flywheel having less effect in neutral, it should actually be more noticeable in neutral, as the effect of the difference in rotational mass is a larger percentage of the overall picture with the rest of the drivetrain out of the picture. One very large improvement that people who road race a car will notice is in rev matching for downshifts. The rpm will be quicker to change, thus making for better rev matches.

 

i don't notice a throttle delay on mine.