New Product: 928 Aluminum Lightweight Flywheel
 

As Promised:

Porsche 928 Lightweight Hi-Performance Aluminum Flywheel

>> Bolt-on installation to the 928 crank with no special tools or fasteners
>> The friction insert is made out of a hi-strength alloy steel comparable in hardness to the OEM flywheel
>> The friction insert can be replaced at the track or shop - easily and inexpensively - no need to send the flywheel out.
>> This flywheel will last indefinately - unlike the OEM flywheel that can only be ground once or twice and is worn out.
>> ...and this flywheel is less than half the weight!

We took to making this part for you because there was no lightweight flywheel for the Porsche 928 available anywhere. The entire aluminum alloy carrier (flywheel) is turned from a single, one-piece billet.

Question: How many more HP will I get with a lightweight flywheel?

Answer: None. The HP output of the engine does not change when you add a lightweight flywheel.


Question: So what is the benefit to installing a lightweight flywheel?

Answer: There is a delay when you accelerate the engine as the engine winds up. This is caused by the engine torque being consumed just overcoming the resistance to polar itertia in all the rotating parts. If we lighten the rotating mass of the engine, the engine winds up much faster, and the torque becomes available to the rear wheels sooner as a result.

Bonus: If you are supercharged or turbocharged, a lighter flywheel allows you to get into your power band sooner, and hit your shift points sooner.

New Item - Special Warranty: This is a brand new part and does not have a lot of road miles on it just yet. However, we designed and built this item following learned aluminum flywheel do's-and-don'ts from a number of other applications, and we had it machined for us by a shop that has years of experience making aluminum flywheels for the Porsche 944 Turbo.

We have every confidence that you will not have any problem with this flywheel. But - because it is so new - we are offering this special warranty on this item: if this flywheel fails for any reason other than clutch wear within one year of use, we will replace it, repair it, or refund your money at YOUR option. Racing does NOT void this offer - that's what we built it for!

I am pricing it at $529.00 for now, the replacement steel insert is $179.
I do not have it on our website yet - it is brand new - but it is in our eBay store at this time.

Out of respect for the Rennlist, I will not put a link to eBay in the post.

Just wanted you guys to know it is finally real.

And this works for any year 928?

Yes, what model year are we talking about?

Hi Carl:

Do you expect any stalling issues? One of the big problems with the 911 variants (964 especially)
is that the lightened flywheel accelerates quicker but also decellerates guicker. Some of the vehicles will not maintain the momemtum of the engine when coming back down to idle and the engine stalls.

Curious if you have seen any issues. I've deleted my AC, air pump and pulley driven fan and there is a huge difference in the accerleration of the engine. I used to race snowmobiles and the old rule of thumb was the 1 pound of rotating weight was equal to 7 pounds of regular weight in the dynamics of the sled.

Best regards,

Ken

I have not heard of a stalling problem on the 944 and 951's that have an aluminum flywheel like this, and we patterned our flywheel after the most successful design I could find for them.

Also - in my experience as a mechanic - rapid decel stalling problems were always linked to failed electric idle pots, bad idle speed or idle throttle stop adjustments, vacuum bleeds, and other various problems. A well-tuned motor should not stall under sudden lift from the throttle pedal - and if it did, I would not add mass to the flywheel to fix it.

Yes, it accelerates AND decelerates quicker - that's a good thing - as anybody downshifting to get into a corner will tell you. We want them to decel promptly too. Your brakes have a big enough load on them already without the rotating mass of the engine contributing to the problem.

This is the flywheel for the twin-disk setup.... I can make a aluminum flywheel for the single-disk setup if there is a demand for it, but I made this one first as the twin disk clutch is more widely used by the racers that I am aiming this product at. Even those later 86-and-up 928s with the single disk clutch often retrofit their clutches to the twin-disk setup for racing.

Why? More contact surface area, higher clamping force, and a lower moment of polar inertia than the single disk setup. Just like the aluminum flywheel - it revs and decels faster than the larger diameter single disk clutch.

BTW - I ahve a pressure plate modified to match this flywheel - will post it tomorrow... 2200 lbs of clamping force instead of the normal 1200 lbs... and matching solid plate clutch disks to complete the setup.

Hi there.

Is it a Fidanza unit? Also, woudn't it have been more beneficial to make it for the latter unit instead seeing as how it uses a larger disc and is heavier? It is neat, I just would like to hear about what you think the drivability is like. Also is it 6061 or 2024?

Thanks

does it come with the timing ring or do we need to find our own?
Thanks
Tom
midlman@rennlist.net

Ditto Tom's question. Where's the teeth?

would you say this is a streetable unit?

I'm presuming this only works with the non euro cars? If I have a Euro car with a twin disc setup, which I do, I presume it wont work with that as it cant send the signal to the manegtic pickup?

yes, where are the timing teeth?? looks nice, BTW. if it had been last month i would have had one but the machine shop is just in the middle of making my hybrid flywheel now.

Carl. I have wanted to retrograde my 89GT clutch to the twin disc setup. This seems like a great solution. My clutch was rebuilt in '98 and they used the "updated type" release parts. What I would like to do is get a complete kit from you, including your special flywheel.

So the question is, can you supply all the parts necessary to do the retrograde? and of course, how much is this gonna hurt my wallet.

hi carl,
can you tell me more about the solid discs for the clutch? didn't realize you had those or i would have gotten them as well.

Thank you for all of your timing gear questions. As I tend to specialize in the early cars, I designed this for the 78-84 L-Jet and K-Jet systems that do not need/use timing gear. This would be a direct fit for 80-84 cars now, and the 78/79 cars need to upgrade to the intermediate plate and release fork for the 81-83 cars to use it.

The 78/79 cars need this upgrade anyway - those years have the lightest/lowest clamping force of any pressure plate in the system. My first year with my supercharged 928, I went thru 4 of them. I could be going 60 MPH and put my foot into it and spin that clutch. There is a video on our website of me racing that year and you can hear the Revs climb everytime I accelerate. I had to feather the throttle pedal like a mad man that year...

This is a bit of a learning curve for me on the LH (later) cars. I am working with Mark Anderson right now to get educated and we will see if we can come up with a flywheel with timing gear boss for the later cars. I do not see any reason why we can't.

Shaark89 - I did not tell you about the solid plate clutch disks because I do not HAVE them in my hands. We will not advertise somthing that we do not physically have in our hands.

Here is what I know about our design so far - we are making the solid-disk clutches for the twin-disk setup. I have a 3-puck clutch in my race car now, but we are looking at a 4-puck design instead. The 3-puck clutches are very agressive and grabby - harder to drive, while the 4-puck designs tend to have better driveability, and the clamping force is the same between the 2 designs.
I have attached a picture of my old 3-puck clutch below for your reference - this is NOT the one we are developing, but will give you a point of reference.

I should have them available within a month if nothing bizarre comes up.

My goal - when this is all said-and-done is a complete packaged kit.... aluminum flywheel, hi-clamping force pressure plate (I DO have now and hope to post about it today) and solid clutch disks.

forgot the picture...