Nick Forza Lightweight Flywheel / Clutch

Nice thread, I've been looking at the flywheel myself. Before next summer I’m also going to order a few parts from Nick, mainly the cooler radiator, although I don't have over heating problems now, AZ heat is a strain on anything, the cooler the better.

Can’t wait to see your Dyno numbers…I hate threads like this-all they make me do is spend money

 

If you're installing this clutch, here's a couple of tips:
1) Don't trust the installation literature that comes with it. It's general Quartermaster Installation & is a tad confusing.
2) The Pressure Plate/clutch stack bolts to nuts inserted into the flywheel with what appeared to be grade 8 fine thread 1/4" bolts. The QM literature says to torque the bolts securing the PP/clutch stack to 100 ft-lb!! I took one look at the bolts & said 'no way'. Called Nick & he said 'Just torque them until they're "tight"'. Tossed a coin, coated the threads w/red loctite & torqued them to as high as I dared go: 40 ft-lb.
3) The PP & clutch stack housing come tie-wrapped together. This appears to be because they were balanced together in that relationship. I loosley attached the PP/housing to the flywheel with 3 of the bolts, before I cut the tie-wraps. Probablyshould have painted alignment marks on the PP & housing so if anyone ever takes the clutch apart will notice the need for alignment.
4) One of the diaphram wedge springs was painted white. Nick said this was just the factory marking things while balancing the PP.

It's no biggie if you're fairly experienced, but IMHO, better & 308 specific instructions are really needed for the novice who's doing something like this for the 1st time.

 

Hey Steven,

Good to see you, glad it all got accomplished, even if you guys finished at 4 AM!

I understand your need for a beefier clutch for supercharging, but I don't see how a new clutch is going to change your driveline loss and therefore your power to the wheels. I mean, unless the old clutch was slipping.

Birdman

 

Since horsepower is a measurement of movement of weight over a specific time, the lighter flywheel will improve horsepower because there is less weight to move. Hey... does anyone sell an aluminum crankshaft?

Gene

 

It doesn't change the torque the engine is actually producing and on a break dyno neither the hp or torque will be improved.

What does change in the energy being stored in the flywheel, lighter flywheel, less energy stored, means more gets to the wheels during acceleration. An acceleration dyno (dynojet) will show a torque and hp increase with a lighter flywheel, lighter wheels, lighter rotors, ect.

I'm honestly surprised it's a noticeably change. I did a light clutch, but left the flywheel heavy and all I notice was the clutch problem was fixed....of course since I can't open the throttle in first or second without the wheels spinning anyway, I guess there is no way I could have notice a change in the low gears


And what about pictures of this way cool set-up?????

 

I agree with Mike, a lighter flywheel and or clutch will not change the engines ability to create torque or hp at a fixed rpm, (as in dyno). what it will do is allow the engine to get that energy to the rear wheels more quickly, since it doesn't have to twist up as much mass before it will get to the rear wheels. It makes the engine noticeably more throttle responsive - a very good thing.

I had my stock 308 wheel reduced from about 16 pounds to about 8 and the difference in ACCELERATION was noticeable but not that great.

It was much more noticeable with a 4 cylinder engine with a relatively heavy wheel, as in Toyota 4 cyl 24 lb to 12 flywheel and Porsche 914 clutch & pp 34-18 lb.

but still worth while

best,
chris

 

That is a great looking set-up, and I'm sure it will be bullet proof.

The AF is much better, but you're lean now. There's still another 5-10hp on the table getting the mixture into the 13.0-13.2 range. It's tough tuning with CIS, but I guess it can be done. Maybe Scott will chime in...I'd just type +10% across the board and 20% for 5000-5750 range and be done with it...ahhh the beauty of EFI.

If you're going to add one of Scotts (now Nicks I guess) blowers, I don't know how much time you want to spend getting it perfect now though.

When you do the blower, you'll still make the most hp at about 13 and it will be really really temping to set it there, but that's playing with fire. I'd aim for more like 11-11.5 with that set-up and live with whatever the hp is....the flame rings on a QV head gasket are sensative to detonation and can fracture and come flying out the export, although head gasket still won't leak and the engine will run fine (ask me how I know).

 

i can't remember if steve's setup is K-basic or not since he has the euro model. in any case the only way to richen up the AFR is to mess with the WUR. but i'd caution against that as it will screw with the rest of the range. a properly functioning WUR will automaticly adjust for the increase in airflow.

my AFR dips into the 11 range at WOT above 5K. the WUR that was spec'd for the 308's & Mondi's is a turbo vacuum/boost one for lack of a technical term. without that WUR it is not possible to compensate for the increase in air like a EFI system.

Larry was telling me last yr about a guy working on a mappable WUR for FI setups like the turbo's and now our new crop of superchargers. how long before production and availabilty? don't know. but that would really help dial in the AFR.

 

there is a roundy round when setting the idle, it can be a real pain! the WSM lays it out pretty well.

from memory here so double check the WSM!

close the thumb screw all the way down.
attach a vacumm gauge to the EGR port on the TB
idle engine
adjust screw under TB that opens throttle not the thumbscrew!

adjust CO to read in specs

rinse repeat....

is the vacumm reading and idle speed can not be ajdusted to spec with the above then you can start to open the thumbscrew bypass.

rinse repeat...

it can take some time to get it dialed in, feel and paying attention to what is changing helps alot. i would set aside at least an hour to get it dialed in. and the other wrench is the electromotive allows for instant change of the curve at idle, so it's another round of adjustments. i'd pick an initial timing point and adjust for that. if it feels like more advance is needed then you'll have to repeat the above see if it really is different.

ain't tuning these cars fun!!!!

my AFR at idle is around 14.6~15:1, off idle it drops right to 13 and slowly dips into the 11 range above 5k at WOT.

 

Steven,
In the absence of other guidance, I used the WSM clutch setup procedure, & by the time we got the pedal stop made it was far too far into the wee hours of the next AM to try tweaking it.

Who at KTR did the clutch adj?
Did he say how he changed the settings?

I'd like to learn how he changed it for future reference.

BTW, keep an eye on the bracket the pedal stop bumps up against. Check it before & after your 1st track run to make sure it isn't bending.

I think It's strong enough to take the pressure since it supports the cable pulley, but better to keep an eye on it until you're certain.

 

smg2,
Steven's car is a Euro, It is K-basic, ie: doesn't have the lambda feedback system that fights tweaking the mixture. So you have more adjustability than US spec systems.

Steven,
I think smg2's right, the key to sorting out your idle is the throttle plate adjustment he mentions.

The procedure is in the MondialQV WSM, but isn't very widely known about since about the only time it's ever needed is when the throttle body or K-jet distributor is replaced, or the butterfly plate is removed from the shaft. Once it's setup it seldom needs further changing unless someone messes with it.

 

I just thought I’d offer a quantifiable explanation for the “increase in power”.

Effective inertia at the wheels is found by the square of the gear ratio. That’s why you notice the effect so much in 1st gear, and it seems to taper as you go up in gears.

The Euro QV gear ratios found here: http://www.ferrarichat.com/forum/showpost.php?p=135362464&postcount=7

1st: 13.072
2nd: 8.996
3rd: 6.473
4th: 4.756
5th: 3.514

So.. for example. If you lost 1lb at 6” from the center of the flywheel, it would be effectively like losing overall weight from the car:

1st: 83 lbs
2nd: 40 lbs
3rd: 21 lbs
4th: 12 lbs
5th: 7 lbs

[ratio]^2 * [mass] * [distance from crank axis]
--------------------------------------------- + [actual mass lost]
[radius of tire]

Steven definitely lost more than 1lb on the flywheel / clutch setup, and his new clutch has its mass closer to the crank than a stock size clutch.

-Chris

 

the large screw with the hex head is the thumbscrew, that screw is a air bypass and will cause problems for your idle if you haven't set the throttle plate right. i have to step out for few hrs, i'll scan the WSM later today.

 

The FORZA clutch & flywheel packages weigh 14 & 15 lbs respectively. The unit that Steve is using weighs 15 lbs. The difference in weight of one lb between the 2 packages is, the new version which Steve has comes with timing marks for PM 1-4 & 5-8 & timing pins for the OEM Digiplex ignition systems, they will work on all 308’s & 328’s which makes it a more sellable item & we can now install pins for other custom engine management systems such as MoTec etc.

It could not be done with the original flywheel design, as there was not enough material to install the pins for the Digiplexes.

As to the different in weight, I just weighed a used 308 QV clutch & flywheel, it came in at 33 lbs! That is a big difference!

Pic of the other design on Paul Sloan's car.
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Chris, I'm having trouble with this, there don't seem to be anywhere enough terms in it.....an aproximation?

Generally the flywheel inertai is I=(massxradius)^2/2
Then the total I needs to be calculated for the whole car and driveline, and then the acceleration, no?

In the extreme, a car weighting 1 million pounds with either a 100lb flywheel or a 1 lb flywheel would have the same acceleration for all practical purposes. What matters is the % change in total inertia, no?

 

Mark,

First of all.. thanks for questioning, I definitely missed a square in there.

NOTE: EQUATION IN MY FIRST POST IS WRONG
This should be the corrected equation:

[ratio]^2 * [mass] * [distance from crank axis]^2
------------------------------------------------ + [actual mass lost]
[radius of tire]^2

With the proper calculations for equivalent weight: If you lost 1lb at 6” from the center of the flywheel, it would be effectively like losing overall weight from the car:

1st: 40 lbs
2nd: 20 lbs
3rd: 11 lbs
4th: 6 lbs
5th: 4 lbs

I used: I=m*r^2 for inertia; T=I*α; F=m*a; a=r*α; T=F*d; Ieffective=I*[gear ratio]^2. Please correct me if I missed anything.

You’re right, what matters is % change in total inertia. It seems car enthusiasts rarely talk about total inertia probably because it is not easily found. I’m pretty sure the calculations are complete and show the actual equivalent stationary weight loss on the car.. meaning: regardless of the actual % change, dropping 200lbs worth of passenger will have the same effect (in first gear) as dropping 5lbs 6” from the center of the crank on a QV.. etc.

-Chris