Group Buy Possible group buy feeler thread: Tilton Engineering Flywheel

In an effort to encourage potential new vendors but also avoid persons trying to get around vendor registration rules, I am posting this feeler thread on behalf of a Prime member who is considering becoming a vendor. I am not involved other than to post this thread to allow the member to determine if there is enough of an interest in the product to seek vendor status. I advised him I would post in my name to avoid other sellers coming on Prime, posting a feeler thread like this, and then using PMs to avoid being a registered vendor like our other vendors since members would know who to contact privately.

If there is interest in this product, please post here and then the member will decide if it is worth it to him to become a vendor. If not enough show initial interest, there would be no group buy.

Tilton Engineering Flywheel for Acura NSX with the Dual spline main shaft

- weighs 7.25lbs lightest flywheel for the NSX
- 100% chromoly steel for the lowest MOI
- Uses an OEM style clutch
- 8-10 weeks lead time
- $800 total cost, $400 non-refundable deposit
- Discontinued part made available again for this run, may not be made available in the future
- 5 speed trans (or six speeds that have had the dual spline mainshaft installed)

Good solution here Bob. I'm in.

The best NSX flywheel revived from the dead! Nice!

Does dual spline main shaft mean it is only for the 5-speed transmission and dual-disc clutch?

With respect to any questions like above, please be patient and allow the member to answer through me and I will post on his behalf immediately upon receiving the info.

It's only for the 5 speed OR if you have a 6 spd you can convert to the Type R input shaft. Someone please confirm this for me.

Let me help spread my $0.02 for some folks who might be on the fence or have recently just joined the NSX community.

Back in the day, this was a fantastic option to have for the NSX, especially if you plan to keep the stock 5spd clutch (which is already a good twin disc clutch). There are only 3 LWFWs (light weight flywheel) that I know about. Tilton (lightest), Jun (also good), and Fidanza (no experience). I don't even know if they make the Fidanza anymore. These were/are the only three flywheels that were made for the stock NSX twin disc clutch. Mark at Dali use to provide this and it was him who commissioned for this to be made. However, Tilton requires a BIG minimum production run and as far as I know.. no new batches have been made in many years.

This option provides you with a free revving engine due to the LWFW while still maintaining the OEM driveability and engagement. If I had a 5spd NA car and was looking to do a clutch job soon i'd be all over this. I'm buying one just to have because someday I might go back to NA and retire my car from track duty. Cost wise, yes, it's expensive but still competitive with the other 2 options out there - and this is American made and Tilton is a well respected company. If I was looking to replace a worn out OEM clutch i'd just buy the clutch plates (About $500-600 IIRC), add this Tilton LWFW, and possibly reuse the pressure plate (not the best idea) or buy a new one. You're not really spending that much more if you don't buy the whole OEM clutch kit from Honda.

The feeling of a hyper revving NSX engine is amazing. NA2 6spd guys are especially hindered with that boat anchor of a flywheel setup.

BTW.. this isn't my group buy. I'm just glad someone with connections inside Tilton was able to make this happen.

I can also put in my .02 in the ring for feedback. I have the Fidanza flywheel on my NSX. A LWFW totally changes the response of the engine rev's. In a good way. I could not see ever going back to an OEM one.

jwmelvin said:

Does dual spline main shaft mean it is only for the 5-speed transmission and dual-disc clutch?

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"you CAN install it in a 6- speed if you have converted it to run the twin disc clutch (which requires the dual spline mainshaft)"

- - - Updated - - -

From the potential vendor:

"A LWFW is one of the most rewarding mods to awaken any engine, especially true in regards to a high revving engine like in the NSX. In the case of the fidanza flywheel it is an aluminum base with steel friction surface plates riveted on and a steel ring gear for the starter. There isn't anything wrong with the Fidanza design, however using a single piece full steel flywheel (as in the JUN and Tilton units) allows for a much lower Movement of Inertia (MOI) which is hugely beneficial when you consider the flywheel turns incredibly fast and any weight that can be kept closer to the centerline of the crankshaft (thereby making it quicker to rev up and down)."

I'm interested.

I'm getting quite a few PM's on this GB but i'm not the one putting it on so I don't have any detail on the product itself or the GB. Please feel free to ask your questions here. I'd assume Bob will cut it off at some point but for now i'd encourage you guys to ask away.

RYU said:

I'm getting quite a few PM's on this GB but i'm not the one putting it on so I don't have any detail on the product itself or the GB. Please feel free to ask your questions here. I'd assume Bob will cut it off at some point but for now i'd encourage you guys to ask away.

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Yes, please post questions here and I will provide answers as I receive them.

Once again, this is a "test" thread to try to encourage new vendors without them going to the time and expense of becoming a vendor before they even know if there is interest in their product/s. My design is to avoid naming the potential vendor so that the marketplace then becomes all behind the scenes in pm's thereby avoiding the protections afforded by requiring vendor registration in the first instance.

All questions should be asked, and will be answered, publicly in this thread. That is the only way we will know if this has potential.

I have advised the member that the thread will be kept open at least 2 weeks but no longer than 4 weeks. If there is enough interest prior to that time, he will be advised to go through vendor registration and then all contact will be through him. If not enough interest, I will state that in this thread and it will be locked.

I'm interested in one. I'll keep a look out on this thread.

Count me in...

BTW.. Weight vs MOI is different guys. This tilton has the lowest MOI last I checked.

If they are making a run of these, could they not make one to fit the stock 6 spd tranny without that shaft or is that a stupid question?

NRG TRADR said:

If they are making a run of these, could they not make one to fit the stock 6 spd tranny without that shaft or is that a stupid question?

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"The two clutches are two completely different animals. I do knot know of any LWFW for the six speed.

This isn't a new product, but a rerunning of an old discontinued part."

Interested...

Bob- the potential vendor and others have laid out the benefits of the LWFW, that’s great and based on that alone it sounds like a must-have item.

I suggest that it might help spur interest if people -especially those unfamiliar with the purpose and function of a flywheel- also knew roughly what install entails...what will my shop need to do?

I see hints here and there, but could someone take a shot at a brief "flywheel upgrade 101" so folks can decide if this is for them?

Thanks!
Fuji

Mr. Fuji said:

Bob- the potential vendor and others have laid out the benefits of the LWFW, that’s great and based on that alone it sounds like a must-have item.

I suggest that it might help spur interest if people -especially those unfamiliar with the purpose and function of a flywheel- also knew roughly what install entails...what will my shop need to do?

I see hints here and there, but could someone take a shot at a brief "flywheel upgrade 101" so folks can decide if this is for them?

Thanks!
Fuji

Click to expand...

The member/potential vendor does follow this thread as I requested and he pm's me answers to all questions after which I post like above. I trust he will see yours and I will be exchanging pm's with him to provide the best info "I" can asap.

On behalf of "my alter ego", thanks for the interest guys!

- - - Updated - - -

"A flywheel is the item with which your engine and transmission connect (along with a clutch). The flywheel is attached to the crank pulley on the transmission side and it spins with the engine. Normally manufacturers put a moderately heavy flywheel on their cars from the factory to help with driveability. A heavier flywheel will take more time to rev up, but also longer to rev down allowing the driver more time to disengage the clutch properly. Anything that the engine has to turn, push, pull, stop, etc takes power away from the end destination (wheels) a LWFW frees up the weight that the crankshaft has to spin through the rev range. The only notable downside to a LWFW is driveability, as the engine revs up and down much faster than with an OEM flywheel the window at which you need to engage and disengage the clutch without stalling becomes smaller.

I would like to quote another prime member in his explanation of moment of inertia from an old thread on Prime:

Rotating mass takes energy to spin it from one RPM to another. Therefore, it takes power from the engine that could otherwise be used to accelerate the vehicle.

The significant measure of rotating mass is called the mass moment of inertia. To keep it simple, weight is bad, but weight farther from the center-of-rotation is much worse. The mass moment of inertia is measured by the mass (weight) multiplied by the distance between the weight and center of rotation squared. For instance if you had a weight of 10 pounds mass, 5 inches from the center of rotation, its' mass moment of inertia would be 10 lb x 5 in x 5 in = 250 lb in^2. That same 10 pounds only one inch from the center of rotation would only have a mass moment of inertia of 10 lb in^2 (96% less). This is why lower diameter flywheels are an issue and heavy larger wheels can have an effect.

When you were a child you may remember playing on hand pushed marry-go-rounds. Kids would stand on them and other children push to get them spinning. You may also remember that it was much harder to push when there were more kids on the marry-go-round and they stood near the edges.

Now for the NSX stock flywheel. I am told the NSX stock flywheel has a mass moment of inertia of 280 lb in^2 and I used this value in these calculations. Let me warn, the effect of rotating mass is not constant for RPM or road speed. In other words, the effect in 1st gear is different than second, and in any gear the effect changes with speed. This is why, if anybody quotes a given horsepower savings measured on a dyno, it is not accurate because chassis dynos DO NOT simulate accurate transients. They measure horsepower at the wheels just fine, but they can not measure the effect of a lightened flywheel, tires, or wheels. They will measure a difference, it just isn't accurate. But it is easy to calculate the difference.

From simple calculations the stock NSX flywheel (280 lb in^2) takes 10-20 HP to spin it while accelerating in 1st gear. In second gear it takes about 5 HP. In 3rd gear it takes 2-3 HP. Therefore, if your lightweight flywheel had half the stock flywheel mass moment of inertia, you could save half the above values. To me, this would be more significant in a 1/4 mile run where the launch and 1st gear is very important. On a road course, not as important.

As stated above, not only does the weight of a flywheel have a large effect on the engine's ability to rev up and down (and how much horsepower it takes to rev up and down) but WHERE the weight is located is almost as important of a factor. The Fidanza flywheel weighs about the same as the Tilton unit I am trying to get made. A causal observer of the Fidanza unit will see it is comprised mostly of aluminum, a very lightweight material, looking closer you'll find that the friction surface is steel (to deal with the friction plates of the clutch) as is the ring gear on the outer most edge of the flywheel (attached with bolts IIRC) so having the heaviest parts of the flywheel on the furthest point away from the crankshaft centerline requires more HP to spin the unit up and down.

This is where the Tilton flywheel really shines, being a single piece flywheel made from one billet piece of steel. Some Primers here might be ready to reply "steel is heavier than aluminum", which of course it is (can't argue that). However, Tilton Engineering designed this flywheel is as little as possible material to achieve the incredibly low weight of 7.25lbs. Where did they take the "unnecessary" material from? The outer most edges right next to the ring gear. This puts the majority of the weight closer to the center of the flywheel and crankshaft (which, if you read the above quoted post...is a very good thing) freeing up even more power and increasing the benefits of your choice in switching to a LWFW.

What is entailed in the installation of a Flywheel? It is the same as installing clutch, transmission has to come out removal of the clutch and OEM flywheel and reverse the process. Your Flywheel is a wear item, no getting around that. Anytime you replace a clutch you are recommended to replace your flywheel. If you plan on having an upgraded clutch installed in your NSX it is the perfect time to install a LWFW as there shouldn't be any addition labor costs. Eventually all of our cars will need a clutch as some point or another so having your flywheel of choice ready to install may be worth it for some owners.

This potential group buy of Tilton Engineering flywheels may be the last time these are offered so I wanted anyone whoever felt like they missed their chance to own a very special, incredibly high quality part for their NSX to have the ability to participate in this (potential) group buy."

I'm interested ....

I would be interested also, contact me by pm when and if this happens.

Roger59 said:

I would be interested also, contact me by pm when and if this happens.

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If there is enough interest at the end of this "feeler" period, the member will become a Registered Vendor and will post a new official Group Buy thread.

My head would explode if the vendor was tomaske.....:tongue:

docjohn said:

My head would explode if the vendor was tomaske.....:tongue:

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He STILL emails me begging to be let back in to play our reindeer games.........

lol............:biggrin:

Maybe a running total of how many interested would help?

If my math is right...7 so far +me is 8 total...