Should I get a lightened flywheel....

[G50trim92]

I took the stock clutch out last night and am now wondering if I should get a lightened flywheel or not. The only one I would consider getting is the one from RRE. I can't afford a fidenza. I have done alot of reading about this and some people are totally against it because it makes your car hard to launch and it has a chance of blowing apart. On the other hand some people are all for it, quicker revs, less rotating mass.
I will be doing mainly drag racing with my car.

I was also wondering if I should go ahead and upgrade my center diff while the tranny is out of the car. I plan on doing some hard launches with the 2600 while going for 11's. I don't know how long the stock one will put up with it. What kind of diff's does everyone use, and or recommend. I am on a budget so the quaffe(think that's how you spell it)
is not an option.
I would really like to get some responses from people who have personally delt with lightened flywheels and center diffs, but all responses are appreciated.
Thanks,

 

[HighPsi91]

Ive used lightened factory flywheels and currently use a Fidanza. The lightened stockers really dont make that noticeable of a difference in my opinion. You can notice a difference but it is minimal. The Fidanza made a very noticeable difference on the other hand. Idle becomes a bit more finicky especially with cams, hacked mas, etc. Launching is a bit more challenging, too low an rpm and the chance of bogging is increased. It does pull through the first two gears a bit quicker though. All in all I would have to say that I would recommend staying with a stock unlightened flywheel especially if your goal is only high 11's. I dont think even the fidanza would shave a 1/10th in the 1/4. The gains are minimal in relation to cost and 60ft times may actually suffer unless you are setup to be able to launch at a higher RPM. Traction, clutch, two-step, etc, if you have the right parts then a fidanza would be a decent mod. This is just my opinion though, I am sure others may disagree. I just feel its money better spent elsewhere, unless you are at the point where you are trying to find every last HP.

As far as diffs go, I have broken my fair share. I now use a welded center diff. I used to use a welded viscous coupler but still managed to shatter the spider gears in the diff. Locking the center diff in any way will result in a car that doesnt turn for **** in parking lots. Tight manuevering is tough. It is also very hard on u-joints on the driveshaft. If you plan on driving the car on the street often I would recommend the 4 spider gear upgrade. You could use your fidanza money

 

[dsmnate]

I got a RRE lighted flywheel and I noticed a difference. The RPM's definatly go up faster. It is lightened to about 14 lbs. I didn't have the money for a Fidenza and can't imagine how the RPM's would shoot up with one of those. It would be like riding a motorcycle.

 

[Dylan]

hmm, i didnt know they made that big of a diff. like how much time could one lose in the 1/4. how expensive is that cheaper one? and how long will it last.

 

[JeffreyS]

I would have to agree with HighPSI91...

I just had a Fidanza installed (with a new RPS stage 3) in my 91 tsi, and though the response does seem faster, it's not necessarily going to give you anything better with respect to HP figures, it's just going to make pedal response crisper. I still haven't gone and done too much yet (still in the 500MI break in), and still fighting lingering issues with non-max acceleration - (see my other post..)

 

[kilurv8]

I tend to disagree with those of you who claim no gain. I put a clutchmasters flywheel in my car and I noticed a huge difference. The car revs like a dirt bike motor now. I get spool on my turbo so much faster than with out. If you base it on theory, then you will see increased horse power. Let me explain it like this. If your motor makes 500 HP (not crank or wheel) just talking theory here. And you have a lot of rotating mass (pistons, rods, crank, flywheel, accesories, crank pulley), each causes some sort of power loss. Based on moments of inertia, the more weight farther away from the center of rotation, causes even more of a higher moment of inertia causing even more power loss. So if you lighten your flywheel, lighten and decrease the size of your crank pully, get a lightened and balanced crankshaft, then each of these frees up horse power. It does not create more, but does free up horsepower that is being robbed by the mechanics of your engine. And either way, when the motor revs faster, you get more exhaust coming out faster which inturns spools your turbo faster. I know I rambled on and on here but if you sort out my thoughts, you will understand the concepts that I am talking about. Dont take my word as rule, but there are some pretty basic physics concepts that back me up.

 

[Awdboost]

It will make a difference when your on the highway and draging.. My idle never change and it didn't make my car feel any faster. But the weird thing is that I do see my revs rev out faster.. Go figure. getting a lighten flywheel from road race if you don't want to spend all that money on a Jun or what ever. Your going to have to get you flywheel cut anyways so just spend a little extra and get the lighten flywheel.

 

[kilurv8]

I again have to disagree with AWDboost on the RRE one. I would not take the risk of having it explode on you and destroy your entire tranny. The stock flywheel was made a certain weight due to strength of material used. If you remove some of that material, you are removing some of its strength. I say if you go with a lightened flywheel, save your pennies until you can get a Fidanza or clutchmasters. I know 2 people who have had lightened flywheels come apart on them and it is not pretty of what it does to your engine compartment, tranny, hood, block, well you get the idea.

 

[Dylan]

how much $$$$$?????

 

[kilurv8]

You can usually get an aluminum flywheel for somewhere around 360 to 400 bucks brand new with a new surface. Sometimes you can find used ones for 150 and buy a new seating surface for 75 bucks. I would really only get an aluminum flywheel if you are going to autocross a lot or if you have a BIG turbo, otherwise you wont notice much of a difference.

 

[Awdboost]

Originally posted by kilurv8
You can usually get an aluminum flywheel for somewhere around 360 to 400 bucks brand new with a new surface. Sometimes you can find used ones for 150 and buy a new seating surface for 75 bucks. I would really only get an aluminum flywheel if you are going to autocross a lot or if you have a BIG turbo, otherwise you wont notice much of a difference.

Don't get aluminum, it could shater on you.. Be careful. that Why Jun is like momocromieo what ever..

 

[kilurv8]

I have never ever heard of a Fidanza/clutchmasters flywheel ever shattering in my life. On any car no matter how much horsepower. But if you want to believe that, feel free.

 

[Awdboost]

Originally posted by kilurv8
I have never ever heard of a Fidanza/clutchmasters flywheel ever shattering in my life. On any car no matter how much horsepower. But if you want to believe that, feel free.

Are you sure they are aluminum or Momocromin what ever

 

[kilurv8]

Fidanza makes anodized aluminum flywheels with replaceable surfaces. I have actually heard more horror stories about the JUN flywheels rather than Fidanza. I have heard that Fidanza has a slight quality control problem and has also had some dowl pins fall out of the flywheel if not locktighted in. That is all I know.

 

[DMS-WhiteGSX]

Go for it! RRE will do fine..

 

[HighPsi91]

This is a good example of the benefits of lightened flywheels. KillurV8 contradicts himself in posts 6 and 10. Post 6 you go into the theory why lighter is better (and I agree with all the theory you cited). Then in post 10 you said unless you road race or have a big turbo you wont really notice a difference. This is what I mean... on paper lightened flywheels sound good. Once you bolt one on most of the gains are all in your head. Your car will not suddenly drop 2/10ths with a lightened flywheel. Thats why I say the money is better spent elsewhere unless you are after every last hp. Heck just turn your boost up one more pound and you will make more hp and go quicker than a flywheel will.

If you must have a lightened flywheel I feel either way you go has pros and cons. RRE bad - the possibility of an explosion will always be in the back of your mind. RRE good - cheaper, dowels dont shoot out, step height is able to be set properly. Fidanza bad - step heights vary greatly, new surface isnt cheap, dowels can come shooting out (in some cases putting holes in your bellhousing). Fidanza good - really light, its pretty, likely will never shatter.

Its almost a toss up.

 

[G50trim92]

WOW! Thanks for all the replies. I think I am going to just get the stocker resurfaced and stick with it till fidenza makes a flywheel that's a little heavier: )

The next thing I am debating on are center diff's. From what I hear the welded diff is great for drag racing but sucks on the street. The speed design 4 sypder diff is still kind of pricey at $475 from TRE, but is supposed to be good on the streets. I did see a VCE eliminator that looks appealing though. You can put it in for drag racing and dyno tuning, and take it out for street use in around 30min with basic hand tools. Costs $150 from TRE. Is the VCE eliminator just as strong as having your center diff welded?
With the VCE eliminator you can run fwd for a dyno, but can you run on the street with only FWD, or will this mess up your rear end with the tires rolling?(not that I would do this

Thanks again guys!

 

[HighPsi91]

The VCE replaces the viscous coupler. This will lock up your center diff. Then to dyno as a FWD you will either have to jack up the back of the car and put it on jackstands or remove the transfer case. In order to drive around as a fwd you would also have to remove the driveshaft. This is a situation where spending the extra money on the 4 spider setup is well worth it. Who wants to drop their tranny fluid and pull their side tranny case everytime you want to switch.

And yes, you can still break the center diff even though you have a locked viscous coupler. It is alot harder to however. I shattered my spider gears with a welded viscous coupler during a hard launch, of course I am making more than average power.

 

[Blitz]

BM Tranny has their own 4 spider center diff. for $400 with core.
http://bmtranny.com/Products.htm

 

[JET]

The BM is a reworked stock shaft, right? The Speed Design is a new shaft and is supposed to be stronger than a reworked stocker.

 

[boostineklipz]

MY Jun flywheel was like $400

 

[JET]

Jun flywheels are chromemoly. Is is light and stong, but does not hold up to heat well and tends to crack and get hot spots. Good for rollcage, bad for flywheel. I don't know who told that guy that Fidanza's can shatter, but that isn't very feasible. Aluminum is pretty maleable and bends rather than breaks. This is all to a point of course.

 

[G50trim92]

Any opinions of what to do with my center diff? Does anyone have a "spool" diff from TRE? They look pretty good. I want some feedback before I order anything.

Thanks!

 

[Blitz]

Originally posted by JET
The BM is a reworked stock shaft, right? The Speed Design is a new shaft and is supposed to be stronger than a reworked stocker.

The BM Tranny center diff. does have a stock shaft, but has so far had a zero failure rate and is running in alot of street driven and race cars.

 

[klipzedgsx]

hey guys ill start off by telling u i did a search and only found alot of fidenza reviews. my ? is should i get a new flywheel or should i stay stock. my reason to get one is takes less weight off witch lets the engine rev better and faster good for spool on my agp 50 trim, but i heard u cant hold boost between shifts. this with the fidenza. now im not sure the actually weight on the act but i know its like 11 pounds, will this be better or what, yes this is on a street/drag car. thanks guys