Honda D Series Forum banner

1 - 9 of 9 Posts

·
DIY Guru
96 Ranger-stock
Joined
·
637 Posts
Discussion Starter #1
How to lighten a stock cast iron flywheel



Start with your stock flywheel, In my case, 2.3L Turbo Ford



Its weighs in at 20.5Lbs

Lets see how much weight can be cut off….



Next is to remove the clutch plate alignment pins….



A slide hammer works well



Mount the flywheel upside down, on the flywheel grinder



Start buy cutting the excess cast iron down to the ring gear..


Once that was flush, I weighed the flywheel again, that reduced the weight by .75 lbs (12 oz) now 19.75 lbs

Time to thin the fat from behind the ring gear…



each pass, this machine cuts only .005-.008 off…




the final weight is now 17.75 Lbs

I removed a total of 2.75lbs…. This should help the engine rev a bit faster, with out giving up too much torque..
 

·
DIY Guru
96 Ranger-stock
Joined
·
637 Posts
Discussion Starter #3
If it is what I am thinking, just holes thu the clutch disc mating surface of the flywheel. I am not much for them. It lessens the surface contact area. so you loose contact area and can slip the clutch easier.

I am sure there is an equation that would allow you to calculate just how much surface area is needed to hold torque and HP


Now add into the strength of cast iron and how brittle it is when compared to a street lite moly flywheel or an aluminum flywheel and it becomes a hazard from the weaking of a cast iron flywheel coming apart at a given RPM
 

·
Premium Member
2005 Legacy GT
Joined
·
1,754 Posts
If it is what I am thinking, just holes thu the clutch disc mating surface of the flywheel. I am not much for them. It lessens the surface contact area. so you loose contact area and can slip the clutch easier.

I am sure there is an equation that would allow you to calculate just how much surface area is needed to hold torque and HP


Now add into the strength of cast iron and how brittle it is when compared to a street lite moly flywheel or an aluminum flywheel and it becomes a hazard from the weaking of a cast iron flywheel coming apart at a given RPM
What about speed dimples? If you were to start holes (on the side that the clutch doesn't mate to) and not go all the way through would that be useful? I was just kinda thinking that one might not want to make the flywheel too thin overall, so could you (in theory) make the dimples once you reached a certain thickness that you didn't want to go under, without compromising the structural integrity too much? You could keep a full face on the the clutch side to maintain the grip surface an potentially get a few more ounces off.
 

·
DIY Guru
96 Ranger-stock
Joined
·
637 Posts
Discussion Starter #5
Yes you could do something like that. But with how affordable moly and aluminum flywhees are the question comes to why?

Even with all that work you will still be heavier than a moly street lite flywheel.

If it a case of DIY bragging rights, Ok I can get that too.

But I would not want to pay a shop to do all that work, good chance is overall is you would spend more cash than just buying a new moly flywheel.

The only case I could see investing this much time and money in a stock cast iron flywheel is for some sort of "Stock appearing" class racing.
 

·
Retired From Hondas
Joined
·
2,796 Posts
No one is checking flywheels at a track last time I checked. But fidanzas can be found pretty cheap.


I could see this beneficial for a model of car which has little aftermarket support.
 

·
Registered
Joined
·
71 Posts
I wouldn't want to take to much from directly behind the clutch surface because of heat sink capacity. Its like having drilled rotors. may work for some but not for others. Now I like me a turbo ford....... had a 85 turbo coupe. what was left of it at least. but it had the 7.5 rear with the 9inch brakes with the quad shocks....
 

·
Premium Member
2005 Legacy GT
Joined
·
1,754 Posts
Yes you could do something like that. But with how affordable moly and aluminum flywhees are the question comes to why?

Even with all that work you will still be heavier than a moly street lite flywheel.

If it a case of DIY bragging rights, Ok I can get that too.

But I would not want to pay a shop to do all that work, good chance is overall is you would spend more cash than just buying a new moly flywheel.

The only case I could see investing this much time and money in a stock cast iron flywheel is for some sort of "Stock appearing" class racing.
I was speaking in a more general sense of flywheel lightening than directly to this specific example.
 

·
DIY Guru
96 Ranger-stock
Joined
·
637 Posts
Discussion Starter #9
I get where you are going, I would have to say it would be a rare instance where the aftermarket did not have one.

I do some old school machining from time to time just because I can

This was one of those times
 
1 - 9 of 9 Posts
Top