Lets Talk Flywheels
Discussion
phazed said:
I just found the receipt for my forged aluminium flywheel that came from Abbey sports cars Ltd Which is V8 tuner.
As a few people who have driven my car will confirm, the engine acceleration is extremely rapid and spins up instantly but it is still a pussycat to drive.
There is a very minor amount of shunting at about 1500 to 1700 rpm If you really look for it, which may or may not be caused by the light flywheel, apart from that you would never know that the flywheel is so light.
How do you find throttle control when cruising at high speed? Does it cruise nicely and the revs stay settled? I guess I'm trying to ask if it's peaky whenever your pedal foot moves slightly. The mass of a heavy flywheel will store a lot more energy.As a few people who have driven my car will confirm, the engine acceleration is extremely rapid and spins up instantly but it is still a pussycat to drive.
There is a very minor amount of shunting at about 1500 to 1700 rpm If you really look for it, which may or may not be caused by the light flywheel, apart from that you would never know that the flywheel is so light.
TV8 said:
Hi Dave, some info here. Lots of other cars use the RV8 so the info could be out there somewhere re the 4lt with light flywheel
http://www.britishv8.org/Articles/Introduction-to-...
I would go for it personally.
Thanks, good article, actually I read it earlier today and its what lead me to conclude that 20lbs was about right for 'Ol Gasbag' and the power she makes.http://www.britishv8.org/Articles/Introduction-to-...
I would go for it personally.
I also spoke with the my friends at Lloyd Specialist Developments who like Simon have a 4.0 litre with the 15lbs flywheel.
Two opinions I respect they both said there are some downsides going this light.
I guess it all depends on what someone personally feels is acceptable, and without trying it that's something I'm left guessing on.
Its a tricky one for sure
Boosted LS1 said:
phazed said:
I just found the receipt for my forged aluminium flywheel that came from Abbey sports cars Ltd Which is V8 tuner.
As a few people who have driven my car will confirm, the engine acceleration is extremely rapid and spins up instantly but it is still a pussycat to drive.
There is a very minor amount of shunting at about 1500 to 1700 rpm If you really look for it, which may or may not be caused by the light flywheel, apart from that you would never know that the flywheel is so light.
How do you find throttle control when cruising at high speed? Does it cruise nicely and the revs stay settled? I guess I'm trying to ask if it's peaky whenever your pedal foot moves slightly. The mass of a heavy flywheel will store a lot more energy.As a few people who have driven my car will confirm, the engine acceleration is extremely rapid and spins up instantly but it is still a pussycat to drive.
There is a very minor amount of shunting at about 1500 to 1700 rpm If you really look for it, which may or may not be caused by the light flywheel, apart from that you would never know that the flywheel is so light.
The minor shunting I was referring to only occurs in first and second,
77racing said:
SILICONEKID345HP said:
There`s a nice aluminium one sat in Engineer1949 garage ,it came out of Nicks car .Can you remember the post ? 
I have that same style on the back of my Rover and it rev's up like a GSXR, 
awesome.I'm not!
As always I'm looking for the perfect compromise between a car that drives like a pussy cat around town yet picks up revs with controllable eagerness that delivers the best throttle response I can achieve.
Building a one trick pony is one thing, building a TVR that delivers both super smooth drivability and the performance characteristics we all yearn for is somewhat more of challenge.
It's what the likes of Porsche spend thousands of hours on the dyno trying to achieve, more challenging still is they are trying to achieve these goals while still hitting the very challenging Euro emission rules and fuel economy targets.
These super demanding and conflicting challenges is what interests me, they become my reference for the things I'm trying to achieve with my TVR.
A Chimaera is actually a super practical all rounder GT/sports car in the old school vein, as such it's my belief a Chimaera represents an excellent development platform to build the ultimate classic car.
I don't want a race car, I merely want a Chimaera where all it's already excellent traits of usability and performance are enhanced not removed.
Will I like the 15lbs flywheel?
Does it match my development "all things to all men" design brief?
Hard to say really without trying it
ChimpOnGas said:
Well I guess that's fantastic, but only if you're looking to build a TVR that revs like a GSXR.
I'm not!
As always I'm looking for the perfect compromise between a car that drives like a pussy cat around town yet picks up revs with controllable eagerness that delivers the best throttle response I can achieve.
Building a one trick pony is one thing, building a TVR that delivers both super smooth drivability and the performance characteristics we all yearn for is somewhat more of challenge.
It's what the likes of Porsche spend thousands of hours on the dyno trying to achieve, more challenging still is they are trying to achieve these goals while still hitting the very challenging Euro emission rules and fuel economy targets.
These super demanding and conflicting challenges is what interests me, they become my reference for the things I'm trying to achieve with my TVR.
A Chimaera is actually a super practical all rounder GT/sports car in the old school vein, as such it's my belief a Chimaera represents an excellent development platform to build the ultimate classic car.
I don't want a race car, I merely want a Chimaera where all it's already excellent traits of usability and performance are enhanced not removed.
Will I like the 15lbs flywheel?
Does it match my development "all things to all men" design brief?
Hard to say really without trying it
I have the 15lb v8tuner fly in my 4.6. It revs and feels just like my 400 with the lightened std fly, 23lbs. Very nice... in a 4 liter it would feel even zippier is my guess. I'm using the 500 AP clutch from John EalesI'm not!
As always I'm looking for the perfect compromise between a car that drives like a pussy cat around town yet picks up revs with controllable eagerness that delivers the best throttle response I can achieve.
Building a one trick pony is one thing, building a TVR that delivers both super smooth drivability and the performance characteristics we all yearn for is somewhat more of challenge.
It's what the likes of Porsche spend thousands of hours on the dyno trying to achieve, more challenging still is they are trying to achieve these goals while still hitting the very challenging Euro emission rules and fuel economy targets.
These super demanding and conflicting challenges is what interests me, they become my reference for the things I'm trying to achieve with my TVR.
A Chimaera is actually a super practical all rounder GT/sports car in the old school vein, as such it's my belief a Chimaera represents an excellent development platform to build the ultimate classic car.
I don't want a race car, I merely want a Chimaera where all it's already excellent traits of usability and performance are enhanced not removed.
Will I like the 15lbs flywheel?
Does it match my development "all things to all men" design brief?
Hard to say really without trying it
I could understand all this agonising if the rotating and reciprocating mass on the crank and crank-borne components was small. Then the differences between 19 or 15 pounds might have a really significant impact. That's just not the case however; the crank is massive, the damper is massive, the clutch is bloody massive too. All else being equal, if it wasn't for the need to have a ring gear for starting and a face for the clutch to drive off, I think the flywheel could be pretty much dispensed with 
77racing said:
SILICONEKID345HP said:
There`s a nice aluminium one sat in Engineer1949 garage ,it came out of Nicks car .Can you remember the post ?
I have that same style on the back of my Rover and it rev's up like a GSXR, awesome.http://ttvracing.com/engine-types/?manufacturers=r...
3.4kg!!!
Phil
Edited by Bassfiend229hp on Saturday 10th October 13:28
Pupp said:
I could understand all this agonising if the rotating and reciprocating mass on the crank and crank-borne components was small. Then the differences between 19 or 15 pounds might have a really significant impact. That's just not the case however; the crank is massive, the damper is massive, the clutch is bloody massive too. All else being equal, if it wasn't for the need to have a ring gear for starting and a face for the clutch to drive off, I think the flywheel could be prety much dispensed with
Great point Gary.Bassfiend229hp said:
I'm guessing that that one is this:
http://ttvracing.com/engine-types/?manufacturers=r...
3.4kg!!!
Phil
This one had to be removed ,it was undriveable on the road but great for track .http://ttvracing.com/engine-types/?manufacturers=r...
3.4kg!!!
Phil
Edited by Bassfiend229hp on Saturday 10th October 13:28
http://www.pistonheads.com/gassing/topic.asp?h=5&a...
Replaced for this one .
Edited by SILICONEKID345HP on Saturday 10th October 19:06
This is my 500 fly when I picked it up, that's 8.8kg on the scales. I had John Eales balance it neutrally so I could use it on my 4.0, it needed 8 holes drilling at 180 degrees to the existing 6 and was 8.7kg (19.1lbs) at the end. My advise would be to keep an eye out for a 500 version and factor in £120 for balancing and posting if your budget will stretch to it at the same time as the clutch.
SILICONEKID345HP said:
This one had to be removed ,it was undriveable on the road but great for track .
http://www.pistonheads.com/gassing/topic.asp?h=5&a...
Replaced for this one .
In that link he talks about going to a 12kg flywheel, that's around 26lbs so heavier than my 25lb one.http://www.pistonheads.com/gassing/topic.asp?h=5&a...
Replaced for this one .
Edited by SILICONEKID345HP on Saturday 10th October 19:06
I still feel 15lbs may be a step too far for what I want, 20lbs remains my target as something is telling me this would be the best compromise.
I wonder if I the solution is to have a 20kg one made, I think they are made to order anyway so the 15lb one with 5lbs more materialb left on the back of it should be spot on.
It would still be 5lbs lighter that what I have now and 2lbs lighter than a 5.0 litre one.
In theory it should also have less of a negative effect on drivability while still giving some engine responsiveness benefits I will feel.
Well that's the theory!
BoostedChim said:
This is my 500 fly when I picked it up, that's 8.8kg on the scales. I had John Eales balance it neutrally so I could use it on my 4.0, it needed 8 holes drilling at 180 degrees to the existing 6 and was 8.7kg (19.1lbs) at the end. My advise would be to keep an eye out for a 500 version and factor in £120 for balancing and posting if your budget will stretch to it at the same time as the clutch.
Very nice solution indeed, 19lbs is right smack in the middle of my 18-20lbs target range.
Gary (Pupp), will you sell me your spare 5litre flywheel?
ChimpOnGas said:
Gary (Pupp), will you sell me your spare 5litre flywheel?
Not impossible Dave, but not immediately - I picked it up a while ago in case the one on the car is fubarred - the clutch certainly is and will be being changed shortly. Plan is/was to use the new one as a straight replacement if needed - I'm not completely sure of its balance so was going to have it neutrally balanced but will hold off for now. I like the look of John's swiss cheese one if it's up for grabs but I suspect that might just be a tad fragile for a car doing some miles on the road Ok, all sorted girls and boys 
Before I explain I'd like to thank you all for listening to my agonizing over wanting something lighter than my current cast iron 25 pound flywheel, yet not quite as light as the 15 pound steel one on offer off the shelf
It was all solved in a highly educational 5 minute chat with the engineer himself.
As I've always said... it's the guy in the brown coat with a pencil behind his ear and a micrometer in his top pocket who really knows what's what!
The first lesson I was given was in inertia which lead to the following statement....
"I could make you 15lb flywheel that made your TVR drive like a tractor, it's not so much about the weight but where I choose to leave that weight when I make your steel flywheel"
Of course this lesson from the expert immediately made perfect sense to me so we chatted some more about what I have now (25lbs machined down SD1) and what I was trying to achieve as an improvement over it.
I made it clear I needed to keep just enough of that "pulling off the junction" and town driving flexibility to ensure the car remains nice and streetable.
Quite quickly the expert says....
"I get it, I know exactly what you want, if you're looking for throttle response improvements and quick revving engine characteristics over what you have now without going as far as the 15lb one I have ready on the shelf... I will simply make a 19lb one that does the trick perfectly".
The expert gave me so much confidence he knew exactly what I wanted I didn't bother to challenge him where he was leaving the additional weight, suffice to say he confidently ended our conversation by saying...
"I've been turning and balancing steel flywheels for everything under the sun for over 30 years, trust me, you will get the exact animal you want"
I think the real lesson here is... there's no substitute for knowledge and experience, a quick chat with the man himself left me 100% confident I've done the right thing and I'll get what I want".
Now that's what I call good old fashioned service, from a good old fashioned engineer
Before I explain I'd like to thank you all for listening to my agonizing over wanting something lighter than my current cast iron 25 pound flywheel, yet not quite as light as the 15 pound steel one on offer off the shelf
It was all solved in a highly educational 5 minute chat with the engineer himself.
As I've always said... it's the guy in the brown coat with a pencil behind his ear and a micrometer in his top pocket who really knows what's what!
The first lesson I was given was in inertia which lead to the following statement....
"I could make you 15lb flywheel that made your TVR drive like a tractor, it's not so much about the weight but where I choose to leave that weight when I make your steel flywheel"
Of course this lesson from the expert immediately made perfect sense to me so we chatted some more about what I have now (25lbs machined down SD1) and what I was trying to achieve as an improvement over it.
I made it clear I needed to keep just enough of that "pulling off the junction" and town driving flexibility to ensure the car remains nice and streetable.
Quite quickly the expert says....
"I get it, I know exactly what you want, if you're looking for throttle response improvements and quick revving engine characteristics over what you have now without going as far as the 15lb one I have ready on the shelf... I will simply make a 19lb one that does the trick perfectly".
The expert gave me so much confidence he knew exactly what I wanted I didn't bother to challenge him where he was leaving the additional weight, suffice to say he confidently ended our conversation by saying...
"I've been turning and balancing steel flywheels for everything under the sun for over 30 years, trust me, you will get the exact animal you want"
I think the real lesson here is... there's no substitute for knowledge and experience, a quick chat with the man himself left me 100% confident I've done the right thing and I'll get what I want".
Now that's what I call good old fashioned service, from a good old fashioned engineer
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