Cadillac Owners Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Ride of the Month Challenge!
1 - 20 of 28 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
**I know this isn't new to anyone but I though I would post this up for the ones on the edge.**
**Posted this over on LS1tech.com so sorry if its a repeat for some!**

Just finished up an install of a C6 Corvette flywheel, clutch disc and pressure plate along with the the slave cylinder on a first generation V.

Easy enough install (Cadillac technician by day), installed a urethane differential bushing as well since this one was toasted(which was also cake thanks to Kent Moore and their overpriced tools I don't have to pay for) and went for a MILD test drive since this isn't my personal car.

WOW.

If anyone wants to keep the stock apply pressure of their clutch, doesn't need any more holding power and wants to improve the drive ability of the first gen V, this is THE clutch to do. Even if you don't need a clutch yet I think it would be money worth spending.

I have driven V's with aluminum flywheels and higher capacity clutches and while those have their place this was pretty damn hot for someone who just wants to increase their driving pleasure in these cars.

If you have any questions about the install just ask!
 

·
Registered
Joined
·
37,297 Posts
Several guys here have done it. It's a great mod. I think it makes the car a little more prone to stalling though.
 

·
Registered
2007 CTS-V
Joined
·
435 Posts
Several guys here have done it. It's a great mod. I think it makes the car a little more prone to stalling though.
I found that its easier to control the LS7 clutch then the stock. A lot easier to rev match, and slipping the clutch is cake with the LS7. Might just be me though. Prior to owning the V, which I switched out the clutch in the first 6 months, I hadn't driven a manual in about 10 yrs, so for me I love the LS7.
 

·
Registered
Cadillac CTS V
Joined
·
196 Posts
Is everything a direct swap?
 

·
Registered
2006 CTS-V
Joined
·
897 Posts
This is something that I'll be saving up to do for sure. I've looked around and done some price shopping and I have a pretty good idea what's up.
One thing I'd be curious about is the flywheel. OP - did you install it with the OEM ('vette) flywheel, or a lightweight fly? I'm under the impression that most of the differences you feel with the LS7 clutch is from a lighter flywheel rather than the clutch disc and assembly itself.
One of the kits I was looking at HERE includes an "upgraded" 19.5 Lb flywheel, which I'm not sure other kits come with. I have read that the LS7 flywheel is still pretty heavy, so do most kits (IE Luke's kit) come with a different one?

EDIT: I *think* I came across an answer to how heavy the LS7 fly is ... 24Lbs. Think the 4.5 Lb difference is worth it?
 

·
Registered
Joined
·
37,297 Posts
yeah, that's what I meant. Most who swap out for the Ls7 clutch, use the lighter flywheel too. I was planning on this mod too, before I sold my V. Never got around to it. But my V was a toy. I don't think I would do it if it was my daily driver. The reason the V has such a heavy flywheel, is it is such a heavy car. Ask anyone who has installed a lightweight flywheel. It's a blast to drive, and revs up fast, which is great on a track. But it's a challenge to keep the car from stalling in traffic.
 

·
Registered
2006 CTS-V
Joined
·
897 Posts
Jimmy, the OP (and others) didn't mention that the lighter fly affected drivability. Maybe because they used the oem ls7 fly, but even that is half the weight of the OEM V fly so you would think that they would report this issue too. Anyone else have any input on this?
 

·
Premium Member
2005 CTS-V
Joined
·
8,362 Posts
There are many previous threads on whether conversion to a lighter flywheel affects drivabilty. Based on my own experience I do not believe going to a lighter flywheel creates any drivability issures.

I found that launching the car was essentiially unaffected because the amount of foot pressure required on the gas pedal remained constant. This is because the same foot pressure with the lightweight flywheel produces more rpm and than with the OEM dual mass flywheel which offets the fact that the lighter flywheel needs more rpm to launch. If you an keep your eyes off of the tachometer you can't tell which flywheel you have. Once you floor it first gear though - you will feel the difference - a lightweight flywheel will get at least one full car length over the OEM flywheel before the 1-2 shift..

Also, the stock tune works just fine with a lighter flywheel, but if you start modding the engine - cams and such - the lighter flywheel does become a factor your tuner needs to be aware of.
 

·
Registered
05 maggied CTS-V, 2017 NSX Whoo Hoo!
Joined
·
8,804 Posts
Jimmy, the OP (and others) didn't mention that the lighter fly affected drivability. Maybe because they used the oem ls7 fly, but even that is half the weight of the OEM V fly so you would think that they would report this issue too. Anyone else have any input on this?
Flywheel is only part of the story.

I use a Monster, and what ever weight savings from the lighter flywheel was almost used up in the heavier pressure plate.

The biggest noticeable difference is probably the elimination of the dual mass.
 

·
Registered
Joined
·
37,297 Posts
Jimmy, the OP (and others) didn't mention that the lighter fly affected drivability. Maybe because they used the oem ls7 fly, but even that is half the weight of the OEM V fly so you would think that they would report this issue too. Anyone else have any input on this?
some people have an issue, others don't. Quite a few guys on this forum have mentioned it, so I felt it incumbent on me to report it. Alot of people who do mods they are not completely happy with are not going to admit it. My only experience in the V is with a stock clutch/flywheel. But my point stands as to why GM used such a heavy flywheel with this car.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #13 ·
The stock CTS V flywheel weights 47lbs.
The stock flywheel weights just about the same as the LS7 flywheel, clutch disc and pressure plate. Weight savings was around 27lbs. This is the OEM C6 Corvette flywheel, clutch disc and pressure plate, along with the OEM Corvette slave cylinder. You can guy this from ANY GM dealer.

This makes the V MORE driveable. You can slip the clutch with more precision, the engagement is more intuitive and smoother than the stock V clutch and you get a hp gain from the reduced mass.

Some light aluminum flywheels may make the V a little less driveable because of the faster the engine gains and drops revs but this doesn't isn't on that scale and I have driven some aluminum flywheeled V's that aren't the easiest(but more fun I think) to drive. Revs do build and drop faster but I think at the perfect amount. Downshifting is perfectly easy.

The dual mass flywheel was not added to the V because of its weight. Cars that weight 1000lbs less have dual mass flywheels(BMW roadsters, Porsche's and the Ford Focus to name a few) Dual mass flywheels are there to separate vibrations between the engine and the transmission during no load conditions. Some engines will transmit vibrations into the transmission and cause "gear rattle" between speed gears. The dual mass flywheel is used mainly as a "comfort" item to reduce noise.

I would recommend this to ANYONE who wants more performance and a better driving car.
 

·
Registered
2006 CTS-V
Joined
·
897 Posts
Thanks for the input everyone. Reason I'm so interested in drivability changes is because as it is already I can rarely shift from 1-2 (and even 2-3) smoothly. It always "bounces" a bit on clutch engagement, unless I'm trying really hard to be super smooth. I've never driven a car that's so tough to shift smoothly when granny driving.

Does anyone notice more vibrations and/or noise after eliminating the dual mass?
 

·
Registered
05 CTS-V, 04 Armada, 11 STi Hatch
Joined
·
247 Posts
I have done this conversion as well. The lighter flywheel has not effected driveability at all. The dual-mass flywheels are put in on "luxury" cars to help eliminate vibrations and to also allow for easier shifting because the heavier flywheel keeps the engine rotating when shifting whereas a lighter one will allow the rpms to drop more.

I deal in the subie world and in 2005 they put in a dual mass on the "luxury" Legacy GT. This similar to the V had the issue of a heavy flywheel and the inevitable loosening of the 2nd mass. We've done this conversion on the subies as well.

On the V when I did mine we added a SS braided line for the clutch bleeder right up to the engine bay which is great for bleeding the clutch!

-mike
 

·
Registered
Joined
·
37,297 Posts
The dual-mass flywheels are put in on "luxury" cars to help eliminate vibrations and to also allow for easier shifting because the heavier flywheel keeps the engine rotating when shifting whereas a lighter one will allow the rpms to drop more.
That's exactly my point. This is great if your car is a toy, and makes driving more fun when you are into it. But if your V is your DD, especially if you spend time in traffic, the lighter flywheel is going to make shifting tiresome. This is something folks need to consider before making the swap.
 

·
Registered
07 TG V1
Joined
·
89 Posts
The OE heavy flywheel on our cars is strictly for EVERYONE's driveability. It is a compromise so that anyone can drive these cars. Having an LS7 clutch can only be a huge benefit and if one has driven a ZO6 it will feel the same. I don't see any reason not to install this if you can afford it. You may need to pay a little more attention until you get used to it. Don't teach your kids to drive in this car.
 

·
Registered
2006 CTS-V
Joined
·
897 Posts
Hopefully lots of you guys are with me here ... I have a hell of a time driving my car smoothly. 1-2 and even 2-3 shifts are often "herky jerky" unless I really concentrate on not letting the clutch out too quickly. Would those of you with the LS7 clutch/lighter flywheel say that this herky jerky 'issue' is exacerbated by the lighter fly/clutch assembly, or is it actually improved? Or, maybe, this whole issue I'm experiencing is actually an effect from something that's wrong with my car...?
 
1 - 20 of 28 Posts
Top