2500M: lightened fly wheel great, good or indifferent?
Discussion
Guys, my car will be needing a new clutch fairly soon, and I'm wondering about two possibilities:
1) getting the stock flywheel lightened, when I do the clutch, or
2) replacing the stock flywheel with an performance, alumininum one, when I do the clutch
Any thoughts on this? Do you think it's a worthwhile performance upgrade, or largely not worthwhile?
If worthwhile, which would you do: lighten the stock one, or buy a performance replacement?
Ron
1) getting the stock flywheel lightened, when I do the clutch, or
2) replacing the stock flywheel with an performance, alumininum one, when I do the clutch
Any thoughts on this? Do you think it's a worthwhile performance upgrade, or largely not worthwhile?
If worthwhile, which would you do: lighten the stock one, or buy a performance replacement?
Ron
Renaldo said:
Guys, my car will be needing a new clutch fairly soon, and I'm wondering about two possibilities:
1) getting the stock flywheel lightened, when I do the clutch, or
2) replacing the stock flywheel with an performance, alumininum one, when I do the clutch
Any thoughts on this? Do you think it's a worthwhile performance upgrade, or largely not worthwhile?
If worthwhile, which would you do: lighten the stock one, or buy a performance replacement?
Ron
What else has the engine had done to it? if it is still a stromberg equipped smog spec engine then a lightened flywheel is the least of your worries.1) getting the stock flywheel lightened, when I do the clutch, or
2) replacing the stock flywheel with an performance, alumininum one, when I do the clutch
Any thoughts on this? Do you think it's a worthwhile performance upgrade, or largely not worthwhile?
If worthwhile, which would you do: lighten the stock one, or buy a performance replacement?
Ron
N.
N, it has a dual Mikuni carb conversion and a performance cam -- although exactly what specs the cam has are unknown to me. The last owner installed it, and he's long gone.
So, I guess you could say it's got some mild performance improvements...
I'm wondering if that flywheel option is just too costly for any improvement you might get.
Thoughts?
Ron
So, I guess you could say it's got some mild performance improvements...
I'm wondering if that flywheel option is just too costly for any improvement you might get.
Thoughts?
Ron
To be honest if you are using as a road car then i would leave flywheel well alone. You get better response at the expense of a rougher idle if you go too wild..and in real terms the performance improvements for a road car are just not worth it.
An extractor manifold and exhaust would be money better spent if the car hasn't one already.
N.
An extractor manifold and exhaust would be money better spent if the car hasn't one already.
N.
Neil, and my idle is already tough to smooth down, with the performance cam, which sometimes drives me to distraction.
I've got it idling pretty smoothly now, but it took a lot of tinkering and a higher idle than factory spec.
Some TR6 guys in the U.S seem to love the idea of lightening their own stock flywheels -- the aluminum replacement ones, not so much.
Ron
I've got it idling pretty smoothly now, but it took a lot of tinkering and a higher idle than factory spec.
Some TR6 guys in the U.S seem to love the idea of lightening their own stock flywheels -- the aluminum replacement ones, not so much.
Ron
I'm sure there will be info around on the web.
As I remember, lighter flywheel typically gives rougher idle, less low end torque deleivery, and makes it far easier to stall if you lift the clutch pedal quickly. It does give quicker acceleration in mid range.
On the basis you already have a hot cam with rough idle, I wouldn't do it....
I and friends with 2500 engines in kit cars typically used a 'mild road' cam, stage 1 flowed head, and 1.75 inch carbs (either Stromberg 175 or HS6 or HIF6 variants) and 6-2-1 manifold, but original flywheel and other bits.
The mild cam still gives good idle, and the bigger carbs gave noticeably better power, but economy still quite good.
As I remember, lighter flywheel typically gives rougher idle, less low end torque deleivery, and makes it far easier to stall if you lift the clutch pedal quickly. It does give quicker acceleration in mid range.
On the basis you already have a hot cam with rough idle, I wouldn't do it....
I and friends with 2500 engines in kit cars typically used a 'mild road' cam, stage 1 flowed head, and 1.75 inch carbs (either Stromberg 175 or HS6 or HIF6 variants) and 6-2-1 manifold, but original flywheel and other bits.
The mild cam still gives good idle, and the bigger carbs gave noticeably better power, but economy still quite good.
For one thing, adding performance will always carry a cost. For another, what degree of "discomfort" are you willing to put up with? My TR6 set-up was fairly hot, but as it's a straight six we're discussing here, was smoother than, say an equally prepared four. I had mine lightened, didn't have issues with stalling, no particular idling smoothness issues that annoyed me, and was happy to be rid of one more factory compromise in the wrong direction. I wish I had budgeted for an Alu flywheel, and had Glen Effinger or J.K. Jackson build me a real motor. There's nothing like the the sound of a hot six, to my ears. When they rev to 8, they scream like a banshee. Raw beauty.
What ever you end up with, just make sure that the compromises are the ones you want. $ always plays into it, and becomes part of the compromise.
I hope you enjoy it,which ever way you choose to go.
Best,
B.
What ever you end up with, just make sure that the compromises are the ones you want. $ always plays into it, and becomes part of the compromise.
I hope you enjoy it,which ever way you choose to go.
Best,
B.
Alloy flywheel is the only way to go...only problem is that you are fitting a hot street/ racing component to a largely stock lower end. This set up should be fitted at the time of a motor rebuild...meaning rods, crank, etc can also be lightened and balanced as a unit. Would save my money.
Cheers,
D.
Cheers,
D.
Renaldo said:
Sounds like it's not necessarily favoured as an isolated improvement, but one that should go hand-in-hand with other improvements, to get the most out of it?
Ron
Yes! You have a start on good bits in hand....save your pennies and buy special bits as you have the funds. Bernard and I have both been around these motors an know what can be done safely and street able.Ron
Cheers,
D.
That would be the very very last thing I would buy for a six pot triumph unit.
An alloy one would have to have hell freeze over before I would purchase for a road car..!!
Road cars should be built to perform reliably for many miles, not have everything lightened to prevent reliable use. Race cars are stripped / rebuilt and inspected regularly.
Flywheels are meant to give rotating inertia to facilitate the smooth running of engines. Manufacturers spend millions calculating optimum performance for intended use..Tuners spend a few bob making things go faster then more bobs strengthening other components that are compromised by the previous mod!
Strictly speaking if you are lightening anything on the reciprocating mass of the engine you should then balance the whole reciprocating mass dynamically.
Bang a new clutch in, spend as little time as possible with your car in bits then enjoy driving it..
N.
An alloy one would have to have hell freeze over before I would purchase for a road car..!!
Road cars should be built to perform reliably for many miles, not have everything lightened to prevent reliable use. Race cars are stripped / rebuilt and inspected regularly.
Flywheels are meant to give rotating inertia to facilitate the smooth running of engines. Manufacturers spend millions calculating optimum performance for intended use..Tuners spend a few bob making things go faster then more bobs strengthening other components that are compromised by the previous mod!
Strictly speaking if you are lightening anything on the reciprocating mass of the engine you should then balance the whole reciprocating mass dynamically.
Bang a new clutch in, spend as little time as possible with your car in bits then enjoy driving it..
N.
Guys, these discussions are always fascinating to me. Experts in their field (at least, you're experts compared to me)with varying opinions on some of these performance "improvements". Sometimes finding consensus isn't easy (nothing new there).
It looks like we can go all the way from some U.S. guys (on forums elsewhere) thinking the lightened flywheel for the TR6 engine, is the only way to go (raving about it, in fact!), to some of you who are less enthused.
I sure don't want to spend money on making my car less reliable, or on a questionable performance "improvement".
I live and learn.
If you were to do one performance improvement on my car (which as I mentioned), has a dual Mikuni carb conversion and a performance cam, but is otherwise stock, what might it be?
Best bang for the buck,and not breaking my bank account?
Ron
It looks like we can go all the way from some U.S. guys (on forums elsewhere) thinking the lightened flywheel for the TR6 engine, is the only way to go (raving about it, in fact!), to some of you who are less enthused.
I sure don't want to spend money on making my car less reliable, or on a questionable performance "improvement".
I live and learn.
If you were to do one performance improvement on my car (which as I mentioned), has a dual Mikuni carb conversion and a performance cam, but is otherwise stock, what might it be?
Best bang for the buck,and not breaking my bank account?
Ron
Renaldo said:
Guys, these discussions are always fascinating to me. Experts in their field (at least, you're experts compared to me)with varying opinions on some of these performance "improvements". Sometimes finding consensus isn't easy (nothing new there).
It looks like we can go all the way from some U.S. guys (on forums elsewhere) thinking the lightened flywheel for the TR6 engine, is the only way to go (raving about it, in fact!), to some of you who are less enthused.
I sure don't want to spend money on making my car less reliable, or on a questionable performance "improvement".
I live and learn.
If you were to do one performance improvement on my car (which as I mentioned), has a dual Mikuni carb conversion and a performance cam, but is otherwise stock, what might it be?
Best bang for the buck,and not breaking my bank account?
Ron
Thats easy:----- performance driving tuition. Comes with a lifetime guarantee and is transerable to every car you drive. Few people can drive their car on its limits.It looks like we can go all the way from some U.S. guys (on forums elsewhere) thinking the lightened flywheel for the TR6 engine, is the only way to go (raving about it, in fact!), to some of you who are less enthused.
I sure don't want to spend money on making my car less reliable, or on a questionable performance "improvement".
I live and learn.
If you were to do one performance improvement on my car (which as I mentioned), has a dual Mikuni carb conversion and a performance cam, but is otherwise stock, what might it be?
Best bang for the buck,and not breaking my bank account?
Ron
Without arguing with any of the above - it's down to what YOU want, and what YOUR driving style is.
The standard engine setup is for a road car, very tractable, quite smooth, wide range of torque, and good economy.
(at least for when it was designed).
IMHO, things which give more grunt without removing its tractability and range are 1) a gas flowed head, and 2) 6-2-1 exhaust. Perhaps you could also include bigger carbs and a flowed inlet manifold too.
Or go the whole way and go injection, but the original Lucas setup can be a complete nightmare, and is easily superceeded by an electronic setup nowadays.
Hot cams give more power, but always at the expense of low end torque, and often some smoothness too, and the 2.5 heads have a reputation for cracking (especially when gas flowed) as the gap between the valves is already a bit small. The hotter the cam, the worse the low end torque, but for more power available over a smaller range.
So if you mostly cruise on the road, stay conservative. if you rally or drive more aggressively, then it's worth looking at an engine in higher state of tune.
Often a specialist builder will know the secrets of how to keep as much low end torque as possible and still get a big power boost, but they obviously charge money for that knowledge !!
The standard engine setup is for a road car, very tractable, quite smooth, wide range of torque, and good economy.
(at least for when it was designed).
IMHO, things which give more grunt without removing its tractability and range are 1) a gas flowed head, and 2) 6-2-1 exhaust. Perhaps you could also include bigger carbs and a flowed inlet manifold too.
Or go the whole way and go injection, but the original Lucas setup can be a complete nightmare, and is easily superceeded by an electronic setup nowadays.
Hot cams give more power, but always at the expense of low end torque, and often some smoothness too, and the 2.5 heads have a reputation for cracking (especially when gas flowed) as the gap between the valves is already a bit small. The hotter the cam, the worse the low end torque, but for more power available over a smaller range.
So if you mostly cruise on the road, stay conservative. if you rally or drive more aggressively, then it's worth looking at an engine in higher state of tune.
Often a specialist builder will know the secrets of how to keep as much low end torque as possible and still get a big power boost, but they obviously charge money for that knowledge !!
I'm helping some frinds with a Eaton compressor and fuel injection setup on one of these engines (in a TR6), I'm the electric and software guy on the project, story and pictures to follow.
For your car I would definatly aim for a fulle electric ignition and perhaps Fuel injection (You can use a PI manifold and convert that to electric injectors) The operation will perhaps not add horsepower (in case you engine is in perfect trim) but it will ensure stability, driveability, and smooth power, and if you have idle problems that can be solved as well. One of the engines I've done EFI on is a rally TR8, with tuning aimed at max hp high up in the rev range with 300 degree cam, high compression and so on. And it idles smoothly at 800 rpm.
But to go ahead you self, a bit of electrical and software skill's is needed - as well as many hours avaliable to spend in front of google :-)
For your car I would definatly aim for a fulle electric ignition and perhaps Fuel injection (You can use a PI manifold and convert that to electric injectors) The operation will perhaps not add horsepower (in case you engine is in perfect trim) but it will ensure stability, driveability, and smooth power, and if you have idle problems that can be solved as well. One of the engines I've done EFI on is a rally TR8, with tuning aimed at max hp high up in the rev range with 300 degree cam, high compression and so on. And it idles smoothly at 800 rpm.
But to go ahead you self, a bit of electrical and software skill's is needed - as well as many hours avaliable to spend in front of google :-)
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