Aasco and what?
 

So I have a 2000 Boxster normal. Im about to embark on some much needed maintenance. Hopefully you guys can lead me in the right direction. I'm about to do The IMS, new light-weight flywheel and clutch. Ive read and searched on here and other forums but cant seem to find the best parts to match up with this Aasco flywheel. So I'm asking here. What clutch or kit do you recommend for the least chatter and best performance and reliability. Part number and links are appreciated also. Thank you guys for always being here with your opinions and input.
Saw

The light weight flywheel has inherent risks to your motor. The heavier flywheel is designed to counterbalance the M96 motor. If you plan on keeping this car as a daily driver for the long haul, you are asking for problems. You are not going to gain any appreciable power by going with this modification.

I keep hearing this Eric, I've even had back and forth Private messages with Jake Raby. Im really starting to think maybe you guys are all right. Maybe I shouldn't get the fly. Thanks Eric.

I see no benefits from them and in the history of my engine program we have utilized them only on 3 occasions.. I have removed dozens of them from existing engines, however.

less rotating mass so revs faster, but no addnl power once spinning. lightens car by a few pounds. good for track applications where your engine is always one bad shift away from the grave, but hard to rationalise the risk/benefit ratio for street use.

Yes on the IMSB retrofit. A big no on the light weight fly wheel.

I have put over 30,000 miles on my LWFW with no problems. Maybe I'm just lucky, I don't really know, but it is what it is. Car is my daily driver and it sees 25+ track days a year. Engine runs perfect with 120,000 miles. I'm not making a recommendation because I am not an expert, just relaying my personal experience. Your mileage (and luck?) may vary.

To answer the OP's question, I used the Sachs sport clutch for use with the LWFW:
Pelican Parts - Product Information: 88-1861-000-017-M410

(orig post said 20K miles, sorry for the typo, actual is over 30,000 miles).

What you don't know is the ignition timing that you are losing... I guess ignorance is bliss, because you never thought about it till now ;-)

I have used several LWFW in various cars of mine over the past 25 years. Never an issue.

I don't believe the argument that the FW is used to balance the engine ... a flat six like this has perfect primary and secondary balance, that's why they're so smooth. The cars I used LWFW on were inline 4's, and there were no balance or engine longevity issues.

As far as the "no power gain" argument, the car will rev faster IN GEAR in the lower gears, markedly so. I did some calculations before fitting one to my previous car, a Supercharged MR2, and in second gear (think autocross) the lighter flywheel I installed was good for a 6 HP gain. First gear would have been more than that, because the car revs faster in first gear. This was borne out after install by the noticeably improved performance of the car.

Additionally, the car just feels more responsive when the engine responds more eagerly, in gear or out.

All that said, I will not be installing one in my Boxster. I have no plans to autox this car. With the stock flywheel, this is a very easy car to drive, and I have hopes of teaching my wife to (finally) drive a stick shift. The LWFW would make that a pain, they *do* take a little getting used to.

Yes, you are probably right. Peace brother.

Jake, why would it affect the ignition timing, is the crank position sensor off the flywheel?

Yes...................

I don't understand how this would effect engine timing. The fingers the sensor picks up are mounted to motor side of both styles. The fixed portion is then bolted on the crank. The crank to pick up timing can't vary. The spring deadened portion of the DMFW is the friction side. The dynamics of this really looks like they are using the weight to stop gear clatter in the transmission. So like Thstone says using a sprung clutch put the back lash back at bay to some extent. The big difference form an engineering stand point is that the clutch can't supply as much force to the gears so like every video I've heard with an aasco installed there is an increased gear noise at idle and low RPM.

Jake, let's play nice. There is no need to push back quite so hard.

Thanks

BL

Thats the reason why you guys don't realize how these LWFW units impact the M96 in so many ways. The same goes for non OEM engine and tranny mounts. Couple these mounts with a LWFW and you have just created a huge compromise.

Anything else I'll say will be intense and strong willed and would be perceived as "pushing back too hard". I'll not say anymore.

FWIW the M96 isn't like most other cars or engines that many have owned or experienced. Treating this engine like it is something else is the first mistake that people make. Thats why they can't learn and make mistakes that they'd never expect. This is the reason why my engine classes are filled with 40 year Porsche veterans that have their asses kicked by these engines and lose their shirt on jobs all the time.

Jake, I appreciate you're frustrations, but there are people here who would like to learn. A brief explanation of LWFW-related timing and mount issues would be appreciated.

I may have an explanation for the ill effects of the DMF:

Boxster has no harmonic dampener on crank pulley. The Dual-Mass fly wheel serves as a harmonic balancer. By removing the dual mass flywheel and replacing with a single mass, the crankshaft is not harmonically balanced and has excessive vibrations as a result. Even with spring centric hub clutch to mitigate vibrations, it is not as effective as the original application.

I imagine timing could be affected with the system parameters originally designed for the heavy flywheel; all of a sudden compromised be a very light flywheel. I can see why the DMF is controversial - the concerns have merit, but there's no need for such vitriol on these forums.

Hmmmm, so many discussions regarding the LWFW.....

In my '90 Carrera 2 I had an RS flywheel which -if I remember correctly- was no dual mass and way lighter, super fun to drive. I guess in those engines it is not a problem.

On the other hand, if someone wants to kill an engine rapidly try a LWFW in an inline 6 like BMW, no bueno!

Not gonna lie, I'd like to use a LWFW in my car but these discussion make me think twice.....

A 4-cycle engine only makes power during 1 of it's cycles, until the next ignition during the next power cycle the engine is slowing down. The flywheel mass helps to maintain momentum until the next ignition firing accelerates the crankshaft faster. The flywheel inertia smooths these variations in rotational speed of the crankshaft. The knock sensors can detect excessive variations in this rotational speed & interpret it as "knock" & signal the DME to retard ignition timing. The "low mass" LWFW is not heavy enough to prevent this from occurring.
I believe this is what Jake Raby was alluding to.

Thanks Pro , that gives me some information that make sense, instead of vague references.

i thought knock sensors were piezo, ie, they actually listen for a knock sound which will trigger them ... ?

I had heard of instances where the LWFW can be made to work if you tore the engine down and balanced the crankshaft with the intended fly wheel. I am not sure how you would account for all harmonics this way. Was not aware that the knock sensor used crank speed....wow

Way back when I first got my S, I was I interested in a LWFW to reduce the huge cantilever load on the crankshaft....being worried about the RMS and crank carrier loads ....live and learn

They detect excessive vibration which is why stiffer than stock mounts can be interpreted as detonation also.

sound = vibration. i can't help but think ecu's are sophisticated enough to figure all that out, otherwise that death metal i'm always playing would be messing with my timing. i'm no expert on this, but a quick google tells me that the ecu reads two signals - average and peak, and only declares knock when the difference between the two exceeds a certain threshold in order to ensure that it isn't reacting to background noise. they are also frequency specific; ie. designed to 'hear' knock specifically and not just any bang or rattle. so, you would have to overcome at least two checks before a lightweight flywheel or bad engine mount will read as knock.

further, the guys who would notice the effects of pulled timing the most - cup cars, etc., are all running factory GT3 RS lightweight flywheels and, while i am sure they have go-fast ecu maps, i doubt they run different/more advanced knock protocols.

AASCO and Tilton! Kidding of course but this is a custom option from AASCO for the Boxster S.

http://i1089.photobucket.com/albums/...m/cae3f28f.jpg


I do actually have a different ECU and knock control on the car the Tilton is on. It also has semi-solid trans and engine mounts and data logs on knock readings that don't seem to be a problem. However, I ran the Boxster spec AASCO flywheel and clutch package just like the dozens of other cars on track every weekend with stock ECUs. At least we could all be ignorant and easy to beat together and enjoy the same koolaid afterwards.

Either way, I just got myself a Boxster for every day driving and the first time the trans is pulled the Spec clutch package will go in. If for nothing else, the car is more enjoyable to drive with quicker rev matching. People enjoy driving and their cars for different reasons so the right answer may not be the same for everyone...

As a somewhat non-related data point. I was told to worry about all the things that are being discussed in the thread when I chose to install a solid flywheel in my GF's MCS. While not a light weight unit per say, it is not as heavy as the stock DMF. I guess that I was luck as none of the horror that was predicted came to pass... It works beautifully. I only have about 10K on the install, but so far so good...