I'm about ready to take the plunge and purchase a Quaife LSD for my '03 MCS. The car is a daily driver and autocrossed frequently (1 to 3 events per month in season) in SM class. Pretty good amount of drivetrain and suspension mods.

Unfortunately, money IS an object. My questions are as follows:

While a lightweight flywheel isn't necessary, should I go this route when the tranny is out and open? Will the benefit be worth the extra money, especially in light of the frequent autocross use? Will an OEM clutch replacement kit work well with a lightweight flywheel?

If I keep the stock flywheel, and just replace the differential and clutch, will the tangible benefit be enough with those changes alone that I won't regret not changing the flywheel?

The Quaife is not cheap - anybody know of any really good deals on it or clutch and/or flywheels?

Any and all comments would be greatly appreciated.

Len

 

I looked into the lightened flywheel thing last month and came to the conclusion that the added trany noise was not worth it to me. I have the OEM LSD, but am upgrading the clutch to go turbo only, so that was my reasoning behind wondering about changing the flywheel too.

What clutch are you thinking about?

 

The Quaife is absolutely a must if you autocross, or track the car.

Regarding the lightweight flywheel, I personally like that, it makes the engine rev so much better,
and a good lightened flywheel will not add noise to the tranny.

The hard part is getting the proper clutch for the intended use, too many times I have seen people drive on a street with a full race clutch, not smart.

So there are a lot of choices for clutch, let me know if you need help with suggestions

Victor

 

I have the Spec stage 3/Quaife/Spec fw. I also campaign in SM. I love the combo for a number of reasons. The quaife is absolutely necissary to get max power down.

The Spec stage 3 I've had for about 16k miles of almost-exclusively stop and go in hilly western PA. It's just about toast. It's starting to slip, it engages at the very top of the pedal and I get a strange moaning sound in the lower gears. I have a Spec Stage 3+ sitting in the garage waiting for installation. It's supposed to be more street-friendly.

The fw is noisy. Imagine the rattle that a diesel pickup truck motor makes at idle and you'll be close. It only makes that noise when it's in idle and the clutch pedal is all the way up, though. Also, the combo of a grabby clutch and less rotational mass in the driveline makes launching at lower rpm's more difficult, espescialy on hills. I use the ebrake on big hills, otherwise the choice is bog or squeal.

The coolness of all of these together, quicker spool-up in autocrossing. Also, when you're at idle and blip the throttle, the rpms go up and down more quickly. Sounds awesome!

 

I'd get the flywheel and LSD, and leave the stock pressure plate in. It'll keep clutch engagement and pedal pressure easy to use for daily driving. If you did the clutch too, pedal pressure would go up and engagment would get very finnicky.

After researching I did just the LSD and flywheel and couldn't be happier.

 

There seems to be a lot misunderstanding out there about aftermarket clutches.

A good "fast road" or "high performance" clutch does not have to be noisy, or finnicky to operate.

there are a lot of clutches available, for different uses, you can have one for
- fast road
- drag racing
- road racing
single or twin disc.......
and in organic, bronze, kevlar or sintered iron

The hard part is getting the right one for the your use.

And all the bad press out there, is the people who got the one that was not intended for their use.

hope this helps

Victor

 

Len,

For the Quaife you can check around with the various vendors. Prices have gone up over the last 2 years and do vary a bit. Shop around.

I have a Quaife for my MCS but left the stock clutch and flywheel. Drives just like stock and seems durable enough after 34,000 miles and four years. Used for daily driving, monthly autocross and some track and driving schools.

As a daily driver you'll want to be careful about matching any upgrade and not going too far on the performance end. You'll need to make that clear to the vendor you deal with.

Being on a budget you'll have to consider the price and durability of the upgrades. Quaife is bullet proof, other upgrades may not be as durable but it will depend on your use. If you are hard on your clutch and drive alot of high speed track you'll get more wear and less life.

Labor prices for Quaife install varies alot. How much can you get it installed for. Low prices range from about $600-800 while in my area it goes in for about $1200+. Those who do the install alot will charge less, seek them out to save.

If I had to choose between lightweight flywheel and spec clutch vs the same $$$ for better R compound tires and lighter rims I'd choose the wheels and tires anyday.

 

I really disagree with the flywheel issue. Having been in several cars with light FW and clutch work they DO make more noise than stock.

 

Could the noise you are referring to,

have come only from the clutches???????

lightened flywheel= solid piece of aluminum with steel bolted inserts

clutch= multi piece disc ( including springs), with a multi piece pressure plate

 

The lightened flywheel causes the noise, but doesn't make it. The decreased rotaional mass means that there are pulsations in the gear train when the pistons fire causing gear lash when there is alternation between slack and tight. The heavy stock flywheel has enough mass to allow its inertia to keep the gear train tight constantly.

 

Thank you. Put it in technical terms a vendor should understand.

 

What are you talking about,

If you really need the mass of the flywheel to keep the gearbox quiet, then you have a gearbox problem.

We have installed a few lightened flywheels (10Lbs), with no noticeable increase in gearbox noise

victor

 

try turner motorsports . their prices seem reasonable

 

If you say so. There have been many flywheel threads on NAM. Almost everyone that actually has a lightened fw has the same noises.

This explains the phenomenon better than I can:

http://www.uucmotorwerks.com/flywheel/gear_rattle.htm

 

I'll second this!!
Steve

 

The thread was started because Len is installing an lsd. I agree the tire/wheels are > clutch/fw, but they can be added anytime. If he does the clutch/fw now, he'll save $600-800+ in labor over adding them later.

 

After reading all the info on the "noisy" lightened flywheels,

I understand now, why lightened flywheels have such a bad rep here.

I believe it has to do with people installing a lightened flywheel with the factory solid clutch disc. There is nothing to absorb the vibrations.

On all the cars that we installed a lightened flywheel, we also installed a "sprung hub " clutch disc, and synthetic gear lube.

The sprung dics minimizes the noise.

Hope this helps

Victor

 

My assesment too after much reading. Therefore I am gonna run the UUC sprung hub clutch/12.5 lbs FW. Reconsidered the FW issue after talking to UUC. They convinced me.

Best part is I picked up a brand new unit for $700 shipped

 

Cool. Let us know how it works out. That is the one I'm considering getting when my stock clutch goes.

 

Throw out bearing Noise mabye? my Ford focus had a spec stage 2 and Clutchmasters flywheel. id get a little more chatter at idle try depressing the clutch and releasing slowly so the throw out bearing can catch up. (As told by someone smarter than me)