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-   -   Aasco and what? (http://986forum.com/forums/performance-technical-chat/41977-aasco-what.html)

Saw76 01-05-2013 03:25 PM

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

Eric G 01-05-2013 03:29 PM

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.

Saw76 01-05-2013 03:35 PM

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.

Jake Raby 01-05-2013 03:50 PM

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.

The Radium King 01-05-2013 04:21 PM

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.

Johnny Danger 01-05-2013 04:27 PM

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

thstone 01-05-2013 04:40 PM

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).

Jake Raby 01-05-2013 06:59 PM

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 ;-)

grubinski 01-06-2013 06:11 AM

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.

thstone 01-06-2013 06:36 AM

Quote:

Originally Posted by Jake Raby (Post 322108)
... I guess ignorance is bliss, ...

Yes, you are probably right. Peace brother.

stephen wilson 01-06-2013 07:00 AM

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

JFP in PA 01-06-2013 08:12 AM

Quote:

Originally Posted by stephen wilson (Post 322144)
Jake, why would it affect the ignition timing, is the crank position sensor off the flywheel?

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

jsceash 01-06-2013 08:23 AM

Quote:

Originally Posted by Jake Raby (Post 322108)
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 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.

Brucelee 01-06-2013 09:00 AM

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

Thanks

BL

Jake Raby 01-06-2013 09:55 AM

Quote:

Originally Posted by stephen wilson (Post 322144)
Jake, why would it affect the ignition timing, is the crank position sensor off the flywheel?

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.

stephen wilson 01-06-2013 10:51 AM

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.

Kenny Boxster 01-06-2013 11:22 AM

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.

AndyA6 01-07-2013 07:40 AM

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.....

BYprodriver 01-07-2013 09:07 AM

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.

stephen wilson 01-07-2013 10:14 AM

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


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