nukblazi

Ok, I dyno'd today... Here they are, I am happy... The is the stock MAX compared to the w/flywheel MAX




The w/KLEEMANN flywheel modification stand alone.



The numbers from the max dyno run...



The same correction factor was used for the baseline and todays dyno's. I didn't bother with A/F today as I didn't change anything that would affect it.

So, to place a conclusion to this stuff...

Not only did I gain so much in feel, shift, and launches, I gained 9.8 ft/lbs of torque, and 5.7 HP at the wheels with the KLEEMANN flywheel/clutch/pressure plate mod. Not bad for just removing some wieght.

This is just about awesome in my opinion. It is a very worth while modification in my opinion.


Thomas

nukblazi

Is anyone having trouble seeing the pics?

Wheens

Pixs fine. So what was the $/hp expense, i.e., How much to gain 5.7 hp or an increase of 3.4% ??

nukblazi

Depends on how you look at it.

If this modification was being mass marketed, it was speculated that it would cost approx. $1700.00, which is comparable to similar race units for the Audi S4.

Beyond the HP gain, the Torque gain is significant.
The feel is awesome compared to stock. It is a 6-puck vs. a solid clutch disk. Launches, shifts, and downshifting is significantly improved. The new flywheel is 22lbs. lighter, and a S4 pressure plate was modified to work with the coupe and the spring rate was increased.

Beyond that, and most importantly. I had heated the stock unit several times to the point it no longer could maintain friction. So the clutch just slipped and slipped and slipped. This unit will not suffer from the same issue. Now I can move on to more substancial modifications without the fear of not having the clutch there when I need it. This unit should be good to 400 HP easily.

vadim

This just doesn't make any sense... All this tells me is that the dyno is fairly inacurate to show a significant - 9.8 ft*lbs - discrepancy, as there has been nothing done to this engine yet to increase its power output. A flywheel is just a mechanical capacitor - it doesn't dissipate any energy. It will certainly affect the engine's dynamics, but not the power output (which we clearly see on these two graphs).

Lynn

If what you say is correct, there is no point in lightening anything in the drive train. I guess all the money racers spend on lightweight con rods, titanium valves, carbon fiber driveshafts, magnesium wheels, etc is just wasted.

vadim, it consumes more horsepower to accelerate a heavy flywheel and clutch than a lighter one. Nukbazi's set up consumes less power and that shows up at the wheels.

hobie

vad> Look at it from a converse point of view at the extreme. If you had 300 kilos of lead stuffed in your drive shaft would your chassis dyno numbers change?

nuk> Can you run through the gears on the dyno? t.p. thread was sweet, thanks for the r&d, dyno $, and autoX feedbacK.

vadim

Lynn, spooling up a heavier flywheel to a certain speed (or accelerating any other heavier drivetrain component) does require more work. However, the peak power output of an engine is not affected by this, as it reflects a stationary (or, rather, quasi-stationary) condition of being able to move the vehicle with a near-constant speed overcoming forces of resistance (the flywheel not being in the picture). Light flywheel or heavy, the same car will have the same max speed, as it races against the drag at a constant speed. This is what is to be expected from a dyno result. A lighter flywheel will undoubtedly change the dynamic characteristics of a car, as there is less mass to accelerate - more of the engine's power will reach the wheels. This will be reflected in the power/torque graphs by higher curves in the lower RPM range. No arguing here. A side note: more vibrations will be transfered both from the engine to the rest of the drivetrain and vice versa - anyone familiar with electrodynamics would know that replacing a capacitor connected in parallel (=flywheel) with one of lower capacity (=lighter flywheel) would increase voltage pulsations in the circuit.

Steve Clark

inertial dyno:it measures how quickly the tested vehicle's drivetrain can accelerate the dyno's drums.Anything that affects the inertia in the drivetrain will shift the dyno results.If you mount lighter wheels/tires/a flywheel/driveshaft or whatever,the car will yield bigger torque numbers. Conversely,larger (and heavier) tire/wheel packages have an opposite effect.

nukblazi

Excellent posts guys...

Tying a 10 lbs. wieght to the end of a string and spinning it in a circle is not as easy as spinning a 5 lbs. wieght at the same speed.

The 10 lbs. wieght also takes longer to get up to speed, and stop.

This Dyno is extremely accurate. The correction factor was identical between the baseline and todays dyno's, I used the same 93 octane gas from the same gas station, and I used the same dyno, and dyno operator.

As Steve explicitly stated, and stated quite well, the lightening of components in the drivetrain will be represented at the wheels on an inertia dyno. No, the crankshalf HP has not changed, we are just losing less of it on it's way to the wheels. This is why racing wheels are lighwieght and racing clutch/flywheel assemblies are lightwieght, and lightwieght driveshalfts are used, etc... This is also why the conversion from the wheels to the crank is a best guess more then an exact formula.

Vadim, as you stated, there are vibrations felt with in the car now. They are controlable with RPM management and gear selection speed and timing for road driving. At speed and in the upper RPM band you can't feel it. The same gearbox vibrations were there before, they were just dampened by the dual mass +22 lbs. heavier flywheel.


Hobie- We did a run in third gear but I forgot to ask for a print out. The dyno operated mentioned again how consistant the car was.

I will be going back so I can have them printed for me. All four of today's runs on a single graph, and the third gear run. All of today's runs only varied by a few tenths n.8, n.5. One run was 173.n max HP


Next up is the pulley install. Hopefully I can keep everyone entertained for a little while...

nukblazi

I just thought this was funny, this morning I had six hundred and sixty six miles on the new flywheel...


666 muhahahahahaha I made it through the day though