56 replies to this topic

[CHILL Gone DUTCH]

I think there are more factors than just fly wheel which effects engine braking

[drunknmunky]

Yes there are, I'm just trying to understand this one thats all.

[P11 COV]

Well your're all making me wonder if I have lightened flywheel or not as I have noticed no difference at all. Maybe it's because I went from a stage 1.5 to a 4 at the same time, but I do not notice any problems with day to day driving.

[mbes2]

Well your're all making me wonder if I have lightened flywheel or not as I have noticed no difference at all. Maybe it's because I went from a stage 1.5 to a 4 at the same time, but I do not notice any problems with day to day driving.

I've had one fitted for about 3 years. So paul is right. (I know I've got one. I fitted it) Just get it fitted while there.. love an upgrade. .

Edited by mbes2, 10 April 2014 - 10:56 AM.

[techieboy]

Maybe it's only noticeable on 2.2's then but there's no way you can miss the effect. Much quicker to rev but the second you lift off the throttle much quicker deceleration, especially noticeable at low rpm in slow moving traffic.

[mbes2]

Try to get a pax ride with someone of same spec.. see if you can feel it.

[Silent Steve]

It all sounds pretty horrible and undesirable, to be honest.

 

That's another one off my list.

[ghand]

Glad I wast going mad, mine had way less engine braking is all I know seems some think they get more engine braking due to revs matching faster as you change down but you actually don't maybe ? It was on high speed overrun I noticed it the most. You just kept rolling on Quote: Originally posted by FLY BY Z HFM, my findings coincide with yours. http://www.my350z.co....ywheel braking http://www.my350z.co....g&pagenumber=2 http://www.my350z.co....ywheel braking Wow Fly! Zzzya and your experiences are consistant with mine. I was reading that last thread and the discussion got a little heated. My experience concurs with yours. Here was my first impression. Note how I originally thought the car was slowing down quicker. I subsequently changed my mind after more time driving and found that engine braking was 30% to 40% less than stock. http://www.my350z.co....204#post473204 Add a lightweight pulley to that lightweight flywheel and the percentage is even higher. I would say engine braking is now 70% to 80% less than stock. What is amazing is how many people don't understand this experience. It is clear to me is that by reducing the rotational mass of these drivetrain components, acceleration is improved but engine braking is reduced. Your experience does coincide with mine. Thanks for your post.

Edited by ghand, 10 April 2014 - 11:58 AM.

[TheRealVXed]

Yes there are, I'm just trying to understand this one thats all.

 

 To be clear "engine" braking is the effect of all the resistance factors between the air intake and the wheels, the drive-train resistance, final drive ratio, the CR of the engine and weight of the fly wheel will all affect the overall "engine braking" effect.

 

The lighter the fly wheel the less rotational inertia it has the two effects being 1) It is easier to spin up in the first place and 2) it allows the engine revs to reduce more rapidly when off throttle

 

This will increase engine braking and reduce the amount of strain on the engine when accelerating allowing more of the energy created by the piston to be put through the drive train rather than wasted on turning the fly wheel.  The same priciple goes for the balancer shaft delete.

 

Overall I love the lightened flywheel in my NA.  Makes FA difference in traffic, and doesn't cause me any issues whatsoever.  I would not be put of by people talking of having to press the accelerator to move off... It's not that bad

[Horace]

Well that's cleared that up then! 

[Silent Steve]

Well that's cleared that up then! 

I think he just made that up.

 

Bloody bankers.

[ghand]

Yes there are, I'm just trying to understand this one thats all.

   To be clear "engine" braking is the effect of all the resistance factors between the air intake and the wheels, the drive-train resistance, final drive ratio, the CR of the engine and weight of the fly wheel will all affect the overall "engine braking" effect.   The lighter the fly wheel the less rotational inertia it has the two effects being 1) It is easier to spin up in the first place and 2) it allows the engine revs to reduce more rapidly when off throttle   This will increase engine braking and reduce the amount of strain on the engine when accelerating allowing more of the energy created by the piston to be put through the drive train rather than wasted on turning the fly wheel.  The same priciple goes for the balancer shaft delete.   Overall I love the lightened flywheel in my NA.  Makes FA difference in traffic, and doesn't cause me any issues whatsoever.  I would not be put of by people talking of having to press the accelerator to move off... It's not that bad

How do you explain all the comments from a lot of different sources including my experience that it reduces engine braking ? As above these guys all experienced less engine braking, I don't get it. Could it be the extra weight of drive train parts slows the car down more and without it the engine spins longer when off throttle, seemed that way on mine very much so in fact ? First drive home I followed a Z4M on a long fast overtake after the overtake I shut off and found I had to brake hard to stop running in the back of the thing, not much happened when I came off the gas, the lack of engine braking took a little time to get used to definitely on the brakes a lot more in it.

[Horace]

Sounds like expensive trouble to me.  Once you've spun the flywheel up, I guess the effect is reduced?  So you primarily experience the accelerative effect from standstill as you have less weight to initially spin up?  That is if you don't stall it when you drop the clutch!

[ghand]

Sounds like expensive trouble to me.  Once you've spun the flywheel up, I guess the effect is reduced?  So you primarily experience the accelerative effect from standstill as you have less weight to initially spin up?  That is if you don't stall it when you drop the clutch!

The one on my car was absolutely fine, no problem at all to drive and you would not know any difference to standard, it just spun up faster and had very little engine braking but clutch control, take off and gear change all superb.

[siztenboots]

I get more engine braking on mine , now the ecu map plays a big part , I noticed the quicker drop in revs means the gear changes happen quicker and minimal clutch (ttv flywheel) , so might be a F23 turbo ratios quirk

[CHILL Gone DUTCH]

Yes there are, I'm just trying to understand this one thats all.

   To be clear "engine" braking is the effect of all the resistance factors between the air intake and the wheels, the drive-train resistance, final drive ratio, the CR of the engine and weight of the fly wheel will all affect the overall "engine braking" effect.   The lighter the fly wheel the less rotational inertia it has the two effects being 1) It is easier to spin up in the first place and 2) it allows the engine revs to reduce more rapidly when off throttle   This will increase engine braking and reduce the amount of strain on the engine when accelerating allowing more of the energy created by the piston to be put through the drive train rather than wasted on turning the fly wheel.  The same priciple goes for the balancer shaft delete.   Overall I love the lightened flywheel in my NA.  Makes FA difference in traffic, and doesn't cause me any issues whatsoever.  I would not be put of by people talking of having to press the accelerator to move off... It's not that bad

How do you explain all the comments from a lot of different sources including my experience that it reduces engine braking ? As above these guys all experienced less engine braking, I don't get it. Could it be the extra weight of drive train parts slows the car down more and without it the engine spins longer when off throttle, seemed that way on mine very much so in fact ? First drive home I followed a Z4M on a long fast overtake after the overtake I shut off and found I had to brake hard to stop running in the back of the thing, not much happened when I came off the gas, the lack of engine braking took a little time to get used to definitely on the brakes a lot more in it.

When people change fly wheel is normally due to having gearbox off to do some work on engine and whilst they are there they may as we'll do the fly wheel, in my case I did it whilst changing engine with major updates , It could of been to do with any of the updated parts of removal of balance shafts or a combination of all of them , my whole setup deffo has less engine braking than standard setup

Edited by CHILL Gone DUTCH, 10 April 2014 - 02:00 PM.

[TheRealVXed]

Gordon, I experienced virtually no engine braking on the VXR (stage 2 lightened fly).  Must be to do with the turbo in some way, I don't know how though... 

 

What I was talking about is with the NA, so if you are comparing your VXR to your NA then that comparison is hopeless anyway as they are completely different beasts.

 

Chill I'm not sure, but you are SC are you not?  Cam timing, forced induction, CR will all have an effect one way or the other on the effect of engine braking

 

 

Basically if you change ONLY the flywheel then engine braking will be increased as the engine will be less willing to hold onto revs when off the throttle.

 

Ask Goose how my NA felt compared to his...

 

Edited by TheRealVXed, 10 April 2014 - 02:17 PM.

[Goosenka]

Gordon, I experienced virtually no engine braking on the VXR (stage 2 lightened fly).  Must be to do with the turbo in some way, I don't know how though...    What I was talking about is with the NA, so if you are comparing your VXR to your NA then that comparison is hopeless anyway as they are completely different beasts.   Chill I'm not sure, but you are SC are you not?  Cam timing, forced induction, CR will all have an effect one way or the other on the effect of engine braking     Basically if you change ONLY the flywheel then engine braking will be increased as the engine will be less willing to hold onto revs when off the throttle.   Ask Goose how my NA felt compared to his...  

Gutless?

[CHILL Gone DUTCH]

Gordon, I experienced virtually no engine braking on the VXR (stage 2 lightened fly).  Must be to do with the turbo in some way, I don't know how though...    What I was talking about is with the NA, so if you are comparing your VXR to your NA then that comparison is hopeless anyway as they are completely different beasts.   Chill I'm not sure, but you are SC are you not?  Cam timing, forced induction, CR will all have an effect one way or the other on the effect of engine braking     Basically if you change ONLY the flywheel then engine braking will be increased as the engine will be less willing to hold onto revs when off the throttle.   Ask Goose how my NA felt compared to his...  

Yes I am SC, I also changed engine to b207 forged internals low compression balancer removed so I couldn't tell you exactly what caused the lack of engine braking but it did stand out as soon as I started to use the new engine

[fezzasus]

Gordon, I experienced virtually no engine braking on the VXR (stage 2 lightened fly).  Must be to do with the turbo in some way, I don't know how though... 

 

Turbo will spool down slowly and therefore reduce engine braking (which is a function of the TB preventing air entering the cylinder and therefore creating a vacuum acting against piston motion)