hardcore4sure

Going H/C soon and obviously going to have to replace the clutch. I've already decided to go with the LS7 clutch and know it's heavy so I want to offset the weight so started looking into aluminum flywheels/lightweight FWs. So Scoggin Dickey sells the LS7 with a RAM for a great price $559 but at 19.5lbs it seems to be the heaviest aluminum FW out there and only offsets the added weight of the LS7 50lbs total to the same as the LS6 assembly. I've found the SPEC is 13lbs $367, the Fidanza is 13lbs $426, and ACT Prolite is 15lbs and appears to be steel that has material removed to achieve the weight almost like it's vented for $281. Any experiences on which ones are better or worth the extra$$$. I kinda like the ACT cuz looks like it's vented and wonder if that helps it stay cooler. It would be nice to free up some HP but want to make sure everything will work well together and be reliable.
Thanks Matt

ISeeRed

I don't know how soon you have to do this, but Katech just developed the LS9X Twin disk clutch system with an aluminum flywheel for the C5. My car is the prototype and they plan on having these available by late summer. The system is awesome without any noise and it holds like crazy.

Here is a link from a Katech post about it:

http://www.ls1tech.com/forums/manual...clutch-c5.html

Toque

I am going to try the Fidenza Aluminum Flywheel with the LS7 Clutch... in the next month or so. I stil have my stock LS6 setup now. A few guys in the post below answered some of my questions I was worried about.

http://forums.corvetteforum.com/c5-t...-flywheel.html

The rotating mass of my stock LS6 set up is 50lbs
The rotating mass of a LS7 clutch and FW is 60lbs...
The rotating mass of a LS7 clutch with a RAM Aluminum Flywheel is 50lbs.
The rotating mass of a LS7 clutch with a Finanza Aluminum Flywheel is 43lbs.

Toque

hardcore4sure

Yea I read your thread that's what sparked me looking into other options. The Fidanza is the priciest and was interested to know what real advantage there is over the Spec 13lbs also or the ACT Prolite 15lbs both are quite a bit cheeper in price but appear to be high quality. My H/C/I is pretty close in size and will hopefully make similar power to yours. When are you putting your clutch in?

jpandes

When I was having my LS7 Clutch & FW installed, I spoke with two reputable local tuners and got two completely different answers.

One tuner suggested the Fidanza to oftset the heavy LS7 Set-up
and the other shop said NOT to go with a lightened FW, because they have had customers experience issues where they couldn't get the car out of gear at times.

I ended up just having the LS2/LS7 FW since I had already purchased it and didn't want to deal with trying to sell it, etc...

Toque

I got a bunch of things at work right now driving me crazy. Hopefully in June sometime when I can put everything together. I'm also having my tranny rebuilt at the same time... that's why I'm doing the clutch too.

Toque

Chicago1

I had a F1 racing/Spec3 combo and th3 flywheel was 16lbs. It Had chatter but no issues taking off from a dead stop or barely cruising from a low idle. Seemed to rev quicker but did drop off in revs if you don't shift quick enough. I didn't notice a big like OMG you can tell you have a lightweight flywheel in here. I have a Mcleod twin disk and steel flywheel and I really can't tell the difference from the two flywheels.

hardcore4sure

I think I'll do more research into the ACT prolite then, it's not aluminum and at 15lbs it's right in-between the RAM 19.5lbs and the Fidanza or Spec 13lbs. Not to mention it looks like it's vented and would stay cooler, and it's only $300 shipped. I guess it's a compromise. Thanks guys,Keep the input coming!

zeevette

A couple of pounds must make a big difference in FW performance. I've got a steel FW in my new RPS twin carbon clutch, and it's supposed to be only 17.5 lbs. It doesn't make any noise, and feels like stock, except for the engagement point, which isn't a factor of the FW.

Toque

Is the ACT compatible with the LS7 clutch ?

Toque

LS1 REDBIRD

Depends on what type of driving you are doing. For drag racing I would want the heavier flywheel since it will have more rotating mass. Lighter flywheel will be more suited road course since it will rev quicker.

Toque

Real interesting read on a C5 Z06 with light weight flywheel I found.

http://www.vetteweb.com/tech/0407vet...ion/index.html

Notice the "time" it takes to reach max HP over stock.
Scroll down to the bottom for the Dyno charts.

They went a little extreme in shaving 24lbs off the clutch and flywheel. Our results will not be as dramatic, but we should see small gains on the dyno, and feel gains in how the car accelerates. What I see on the dyno charts more than just a peak HP/TQ gain is that the entire chart moves to the left.

Toque

ISeeRed

Katech's system uses their own design aluminum flywheel, but it's cut by Fidanza for them......

Pfadt Racing

We run a Katech street package in our LS7 5th Gen Camaro... had excellent luck with it so far. We haven't been able to really get the car on a road course yet, but it's held up to several Autox and a few thousand street miles very well.

It's a little too aggressive for the scope of this thread, but we now offer a 8.5" Twin Disk setup from Quartermaster geared towards our Road Race users. It uses an 11lb steel flywheel and the entire assembly tips the scales at about 25lbs... it's pretty responsive.

We've had really good success with this clutch for club racers and weekend warriors. Katech and Quartermaster both seem to have great options for street users looking to put good power down.

hardcore4sure

There was a chart that showed vehicles that it fit on, and both c6 vettes 6.0,6.3,7.0 and 05-06 GTO were listed.of course I would call to confirm this before ordering. It's made of Chrome-moly steel and actually weights 14.7 lbs.

Toque I think I saw that article to but thanks for reposting it, It seemed more clear in the actual article then when was copy/pasted in a thread. After reading that again it seems that by cutting the rotating mass almost in half they gained an average of about 10hp/15tq between the 2 cars. As I expect to be at similar power levels to the second test, but not having reduced as much weight one can only conclude that the gains will only be a fraction.
So even with the lightest flywheel coming in at a total weight of 43 lbs , and a total weight saving from stock of 7lbs that is only roughly 1/3 of the combo in the test. I don't think we can only expect 1/3 the results,as I think the initial weight reduction may show the majority of the difference and at a certain point you will see diminishing returns from additional reductions. But I would guess that maybe 1/2 the gains could be achieved. Similar to having a 25% underdrive pulley netting 8rwhp , but would you see 16rwhp with 50% underdrive? I doubt it.
It seems dollar to HP isn't that great but 5 here 10 there adds up, when the engine parts are gonna do what they do you gotta trim the fat to squeeze a little more out I guess.

hardcore4sure

I have no doubt that many of the high end clutch/flywheel combo would easily out perform the LS7 but at this point it's a matter of cost for me, even looking for a flywheel outside the $443 for the complete LS7 kit is gonna cut into the install budget. Although I would love to have any of the super badd *** set ups,remember this is a street car so do need to keep some of the ease of take off from stoplights and especially on hills of which there are many in S.F. The objective here is to achieve a increase in holding capacity for the added power while maintaining stock like manners,pedal feel and longevity. So if it's possible to steal a little extra HP that's a bonus.[/B]

TmillerC5

I just put the the LS7 with the Fidanza flywheel on about a month ago. Went to Heartland Park last weekend for a Audi HPDE. I really could feel a difference pulling out of corners and it really seem to have a quicker throttle responce. I am very happy with this set up for the road racing type stuff I do. It really has a nice feel to it.

Toque

Exactly what I want too !

Not that were adding HP... were actually allowing more of the engine's HP to reach the back tires.

I also don't think we will see much more than 4rwhp on the dyno. We likely will "feel" an improvement around town though.

I just don't want to "feel" a loss in power anywhere. I bet I would if I went to the LS7 clutch and flywheel...

Toque

ISeeRed

Not sure about pricing yet on the Katech, but I can tell you that it's manners are 100% stock with the exception of a slightly stiffer pedal feel. It's a twin disk and will hold 800 ft/lbs of torque.....I know I won't be testing the limits of it.......

ISeeRed

Not sure about pricing yet on the Katech LS9X, but I can tell you that it's manners are 100% stock with the exception of a slightly stiffer pedal feel. After all it is the ZR1 clutch and it's a twin disk and will hold 800 ft/lbs of torque and 800 rear wheel horsepower.....I know I won't be testing the limits of it.......