Hey guys, I was dead set on going with an ls7 clutch in my c5 Z06. I am running 383rwhp, and will be running around 410rwhp after I go with a baby cam. I have searched clutches to death, here and ls1tech. I was set on the ls7 because of the stock feel, and I've heard it is not near as harsh on the drivetrain like a monster or spec clutch, but will slip a bit and lessen the likelihood of breakage.

However, It seems that the ls7 clutch assembly is a lot heavier, not allowing the car to rev as quickly? In reality, what loss is this going to give me in ET and MPH at the track on a car with my hp level? Any guesses? Should I just go with a spec 2+or 3 and ease the car out of the hole? Price range is 500-600.

Mark

 

Spec II with an aluminum flywheel will free up some power (just the opposite of the LS7 set-up), and drive like stock. If you don't plan on any power adders down the road you should be fine. If you had a little more to spend I would recommend an RPS unit but at that price point and your power level the Spec combo would be fine.

Don't let the Internet sway you from the aluminum wheel assuming you can swing it financially. It will actually soften the "hit" a little which will enhance parts reliability and give you a little extra zing when you stab the gas. It drive fine and you wont have to "rev it up a bunch" (typical Internet misnomer) to get going from a light....not to mention you have more displacement anyway making a lighter assembly even more forgiving.

I ran that set-up in my 346 and was very pleased with the stock like drivability and extra holding power. As things progressed for me power wise though I eventually had to move into something else and sold it before I turned it into a worthless pile of metal by pushing it past its limits.

Hope this helps....

Tony

 

agree with the above, i have used fidanza aluminum on everything from small block chevys to 9,000rpm b18c hondas. the friction material has the greatest impact on street manners, not the flywheel. the only discs i dislike for the street are metal. anything copper, sintered iron etc is like an on/off switch. organic, ceramic or kevlar are much more forgiving. the exedy hyper comes as a package with a chromoly flywheel for around $1300. they also have a twin disc for $400 more but it's really overkill unless you have one seriously insane engine or drive around on R compounds dropping the clutch often. i'd compare this with the above suggestion and find which you prefer after reading up. normally anytime you can reduce weight on a car that spins, pound for pound it's preferable to just loosing weight. loosing 10lbs of wheel weight will always create a quicker lap than 10lbs of seat weight for example.

 

Hey man!

I have been looking for a clutch too. I just ordered a Grip Force F1 flywheel that came recommended by a few forum members: http://gripforce.com/store/index.php...roducts_id=409

The holes on the flywheel sold me on it rather than the weight, but the weight savings is great too. The holes help cool the assembly down and as you know heat is an issue with our clutches.

As for a clutch I am going with a 12" centerforce DFX. I have researched them up and down and have not heard anything but good. I seriously have not read one bad post about them. They are good for 675 rwtq I believe and have a slight increase in pedal feel. I will be throwing it in asap.

Good luck
Matt

 

You can use the LS2 fidanza aluminum flywheel with the LS7. The clutch is still a little heavy but its what I'm using until it goes.

 

We also have a RAM aluminum flywheel for the LS2/LS7 if you are budget oriented. We have the LS7 kit grouped with this aluminum flywheel and new ARP bolts for the flywheels and the pressure plate for $559

 

nice combo SDPC.

 

That sounds great! I will be in touch in the next couple weeks.

Tony, thanks for the thorough response. The Spec 2-3 was what I was leaning towards when I left the house for the day. I am just worried about breaking parts, but it seems that the aluminum flywheel might help ease the shock. Unfortunately, the spec with aluminum flywheel is going to be out of my price range. It sounds like a good setup though. I have to factor in labor, and a new slave cylinder as well. I've got a quote from a reputable shop in San Antonio that will be doing the install for 500. So all in all, I should get it all done for around $1200.

Racebum, I would love to go with a more expensive setup like what you mentioned, however, I just don't want to drop that much money right now. Plus, the other half keeps tabs on what I am up to, and I'll have to take her on a major shopping spree if she finds out I spent $2000 on a clutch!

Gleds, thanks for the post and the message. I'm in San Antonio every other month to float. My family has a place north of town on the River in Spring Branch. I'll let you know when I'm headed that way!

MattB, how does the setup sound? Is there a lot of rattle with the aluminum flywheel? How does the car launch? I'm running MT 305/35/18's and was cutting high 1.7's to low 1.8's. I'm looking to run 11.70-11.80's at 383rwhp. I figure that low to mid 1.7 60 fts should put me in the 11's with a decent DA.

Thanks for the replies, keep them coming, as I do change my mind quite a bit.

Mark

 

Does this kit need any balancing?

 

No, they are zero balanced

 

I need to get an LS7 Clutch and LS2 flywheel installed that bought a while ago fropm Gene Culley while on sale.

I was just told by reputable tuner local to me, NOT to go with the Aluminum Flywheel because it can cause problems disengaging at high RPM's... I'm so confused.

 

HOW can the material a flywheel is constructed of possibly cause disengagement problems?

Its a flat friction surface the clutch disc is sandwiched against. It has very little to do with actual clutch engagement.

Don't forget all the aluminum wheels have a steel plate inserted in them that the clutch friction material actually rides on....its experiencing nothing different and could care less whether the rest of the flywheel is constructed of steel or aluminum.

A flywheel's two major functions are to facilitate starting your car (via the ring gear around the perimeter) and to provide mass to get your car moving from a stand still a bit easier (but always consider the total mass of the clutch/pressure plate/and flywheel combo). Once your car is already under power all that mass becomes a liability that has to be accelerated and robs some of the power available to the rear wheels. That's where the delicate balance of the total combination's mass becomes important. You want/need enough mass to get the car moving easily but nothing more in an ideal scenario. For me, the weight of a low/mid 30 pound assembly is just about right.

An LS7 or Spec clutch with an aluminum flywheel still weighs 40+ pounds as a whole which provides more than adequate inertia for stoplight to stoplight type driving.

You do not need or want a 45+ pound assembly in a street performance vehicle (assuming you are modding it in search of even more performance). It reduces engine responsiveness and power output.

One of the inherent problems with message boards and the Internet as a whole, is some of the advice dispensed by "experts" really isn't as solid as you would hope (unfortunately). Likely they are experts in one aspect of the hobby however....the key is to weed thru and determine who's opinions are more valid in the area you are researching. For the average Joe not devoting his life to this hobby (that knows a little or enough to be dangerous), thats not as easy as it sounds, usually requiring spending additional time and digging deeper on controversial issues and being naturally intuitive (on whose opinion you ultimately subscribe to) doesn't hurt either. In short....how good is your BS meter??.....LOL

The larger the magnitude of the mod your considering, the more research you should invest before pulling the trigger.

OK....rant off....LOL

-Tony

 

I agree. The aluminum flywheel option in the heavier kits is not as taboo as it's made out to be, simply because the overall weight is still relatively high and provides plenty of inertia.

The only variance I have is nothing but personal preference. I prefer a slightly heavier setup in a street car than he does for a well mannered street car, but we all have different ideas of what is considered well mannered and different preferences. We are in total agreement though that even with an aluminum flywheel, the heavier setups like the LS7 are still easily heavy enough for decent mannered street driving.