Ok, sorry I did not finish, I had to go play tennis. Went through three sets of strings in 45 min then ran out of rackets
Ashaman wrote:Not to poop on this party, but I question some of this stuff....
Don't tell that to Dave_M or Costas, Dave has the same flywheel and Costas used the same line of thinking when he made his.
http://www.lotuselancentral.com/forum/v ... ht=fidanzahttp://www.lotuselancentral.com/forum/v ... &start=200Here is the deal, F=MA. With all cars the concept is that you have mass and you want to move it, the acceleration is the rate at which you "move it" or change its state of motion. The motor also follows this same principle (F=MA), there is a lot of mass within the motor that you have to "move" or accelerate in order to eventually accelerate the car, the greater the mass you are moving within the motor, the more force that has to be used to "moved" or accelerated it at high rates. If your force is limited and you want to get more acceleration then the only variable you can change to get the results you want is the mass! The mass of the car, or as in the case, the mass of the components within the motor. The motor has pistons, connecting rods, valves, springs, crankshaft, camshaft, gears, belts, and a
flywheel. If you decrease the mass of these components, the motor will have less internal inertia and will have greater acceleration. Simple physics. I would disagree with any statement that anyone would ever claim where they state that a lighter flywheel gives you MORE horse power, false, it frees up horse power so the motor (and car) can accelerate quicker, but most people have a hard time understanding that concept.

Ashaman wrote:Secondly, while a lighter flywheel can definitely make an engine more free-revving, I seriously doubt those numbers are proven on a dyno.
For starters, it really depends on what your goal is. Mine is to increase the rate of acceleration between 1 - 2 -3 gears. I want more "zip" in my life

Now, as for the flywheel, less mass = greater acceleration and yes the results are proven, look at Costas dynos just for kicks but the math speaks for its self. Also, keep in mind that I am using a stock pressure plate so in reality I am not cutting the total weight on the crankshaft in half but maybe less by a third. Philbo talks about this in several of his threads.
http://www.informatica.zen.co.uk/elan/Stages.htmhttp://www.lotuselancentral.com/forum/v ... a+flywheelAs for the valve springs and their price, part of the price is for the titanium valve retainers, again, less mass to accelerate. I am also thinking about the titanium intake valves but at $100 a pop this might get too expensive but I am still thinking about it.
Ashaman wrote:Stronger valve springs are typically done to compensate for engines running increased RPMs.
Very true, and if a cared about valve floating I would throw out my hydraulic lifters and use solid lifters but this is not why I am using stronger valve springs. My Elan is a forced air injected (turbo) motor and therefor, under boost air is being forced into the intake at pressures above the normal atmospheric pressure and then into the combustion chamber. Unlike a normally aspirated engine, pressurized air is pushing on the back side of the valves causing the valve to "want to" open. The greater the boost pressure, the more air that there is pushing on the backside of the valve causing it to open. My mechanic showed me a really cool demonstration, he had rigged a head from a motor so it could be pressurized at about 14 psi you could just start to hear and feel the air leaking around the valves. He then told me that the springs were rated at 40 lb. Now, the air may not be enough to push the valve all the way open but only because the spring must follow Hooks law of F=kX and as the valve spring becomes compressed it pushes back with more and more force. I do not want my valves opening even the smallest amount at all! I want to run 1.2 ~ 1.5 Atm of boost and the stock valve springs are only 45 lb., we have calculated that I need around 60 lb. just to be safe in order to make sure the valve does not open at all from the backside pressure.
Ashaman wrote:Now, given that boost can only occur on the compression stroke, this means the valves are already closed. If this is the case, how do stronger springs help? Am I missing something (entirely possible)?
I think you are missing on this one.

If you are under boost, every part of the intake including each valve, closed or open, is feeling the pressure (so to say). Under boost the turbo is pushing air through the system, not just when the pistons are on their compression stroke. The intake directs the air but does not tell the air what cylinder and when, that is the job of the valves and the camshaft. Under boost, the valves are now at the mercy of the valve spring to make sure they do not open prematurely. I am using a stronger spring to make sure the valves stay closed when they are suppose to be closed