[Z06] Horsepower limit question???
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 9,883
Likes: 518
From: Bergen County NJ
Horsepower limit question???
Hey guys, what's the most rwhp the LS6 clutch can take before we should start to have probems. I thought I read somewhere around 460rwhp???
Le Mans Master
Joined: Feb 1999
Posts: 7,121
Likes: 0
From: Vilano Beach FL
Howdy!
I know folks with moderate H/C setups (420-440rwhp) that don't do a lot of drag racing, but drive the car hard around town and do a few (4-5) DE's a year and have done well with the stock setup.
From what I've read, the LS7 clutch is the next best thing to a stock setup in terms of drivability and sounds like it adds a little "insurance" at that ~440-ish HP levels, and holds pretty well up to ~475 or so.
With a clutch (and especially if you're running LT's which adds a extra PITA factor to a clutch swap) I'd build in a good 75+ HP buffer so I wouldn't have to worry as much.
So if I was putting together a targeted 450rwhp buildup, I'd go ahead and budget in a clutch that would hold 500-525, so I could grow my setup, add a little shot, etc.
Nothing is worse than underbuying a clutch!
I'm thinking about a OZ700 for my next setup - that will allow me to grow from a 375HP car upwards to a 700HP and maintain a decent amount of "streetability" - the only downside is a little firmer pedal and about 3X the cost of a stock setup (but think of all the time/$$$ if you have to replace a stocker premature!)
Seeya!
I know folks with moderate H/C setups (420-440rwhp) that don't do a lot of drag racing, but drive the car hard around town and do a few (4-5) DE's a year and have done well with the stock setup.
From what I've read, the LS7 clutch is the next best thing to a stock setup in terms of drivability and sounds like it adds a little "insurance" at that ~440-ish HP levels, and holds pretty well up to ~475 or so.
With a clutch (and especially if you're running LT's which adds a extra PITA factor to a clutch swap) I'd build in a good 75+ HP buffer so I wouldn't have to worry as much.
So if I was putting together a targeted 450rwhp buildup, I'd go ahead and budget in a clutch that would hold 500-525, so I could grow my setup, add a little shot, etc.
Nothing is worse than underbuying a clutch!
I'm thinking about a OZ700 for my next setup - that will allow me to grow from a 375HP car upwards to a 700HP and maintain a decent amount of "streetability" - the only downside is a little firmer pedal and about 3X the cost of a stock setup (but think of all the time/$$$ if you have to replace a stocker premature!)
Seeya!
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 9,883
Likes: 518
From: Bergen County NJ
Well I have a stock LS6 clutch and in a few weeks getting the Vararam, American racing headers, and custom ECS cam and with that set-up alot of people make from 430-445rwhp. Just wondering if I'll be ok for awhile till I can afforde a new clucth and maybe some trickflow heads. Thanks for the well thought out reply!!
Le Mans Master
Joined: Feb 1999
Posts: 7,121
Likes: 0
From: Vilano Beach FL
Well I have a stock LS6 clutch and in a few weeks getting the Vararam, American racing headers, and custom ECS cam and with that set-up alot of people make from 430-445rwhp. Just wondering if I'll be ok for awhile till I can afforde a new clucth and maybe some trickflow heads. Thanks for the well thought out reply!!
I think a big factor in how a clutch survives is how it's used - I had a Supra with BIG numbers, and managed to blow out a couple of dual plate setups doing serious slip and high RPM dumps on a strip. (These were $1000+ setups). Later I switched to an RPS disk and used the OEM pressure plate and that lasted for like 2 years with the same HP levels (and even a couple of road track events).
Sounds like your plans will take you to a point where you should start considering one of the beefier aftermarket setups (like the OZ700 I mentioned). As I plan my setup I'm spending alot of attention on the clutch and supporting driveline mods (like a DTE brake, possible a slightly built rear, likely at least 300M shafts).
Good luck!
DT
Thread Starter
Le Mans Master
Joined: Feb 2002
Posts: 9,883
Likes: 518
From: Bergen County NJ
Nice sounds like it's going to be a killer setup! The TFS heads have been generating some great numbers too.
I think a big factor in how a clutch survives is how it's used - I had a Supra with BIG numbers, and managed to blow out a couple of dual plate setups doing serious slip and high RPM dumps on a strip. (These were $1000+ setups). Later I switched to an RPS disk and used the OEM pressure plate and that lasted for like 2 years with the same HP levels (and even a couple of road track events).
Sounds like your plans will take you to a point where you should start considering one of the beefier aftermarket setups (like the OZ700 I mentioned). As I plan my setup I'm spending alot of attention on the clutch and supporting driveline mods (like a DTE brake, possible a slightly built rear, likely at least 300M shafts).
Good luck!
DT
I think a big factor in how a clutch survives is how it's used - I had a Supra with BIG numbers, and managed to blow out a couple of dual plate setups doing serious slip and high RPM dumps on a strip. (These were $1000+ setups). Later I switched to an RPS disk and used the OEM pressure plate and that lasted for like 2 years with the same HP levels (and even a couple of road track events).
Sounds like your plans will take you to a point where you should start considering one of the beefier aftermarket setups (like the OZ700 I mentioned). As I plan my setup I'm spending alot of attention on the clutch and supporting driveline mods (like a DTE brake, possible a slightly built rear, likely at least 300M shafts).
Good luck!
DT
Thanks DT!! Yea man I love Supras also. Yea I guess I'll take it pretty easy on this set-up and when I save up some more cash I'll get a better clucth from ECS when they install the trickflow heads. Thanks man
Chris
Drifting
Joined: Mar 2005
Posts: 1,542
Likes: 76
From: Houston TX
Right now I am at 486hp/503tq on the juice. The LS6 clutch is holding but the hydralics are not. After a run on the juice the peddle will go away and have to be pumped a few times. I do not get any clutch slipage just a mushy peddle. Off the spray I have no problems at all 383hp.
Race Director
Joined: Aug 2004
Posts: 14,639
Likes: 39
From: Winston-Salem North Carolina
St. Jude Donor '08-'09
I have the ls7 and so far so good at 430rwhp. I don't drag, but I have launched at 5k and it gets a little soft, back it down to 3k-3.5k and it seems to hold fine. It also holds on the road course shifting almost at rev limit, downshifting/heel toe, no problems last season. I blew an rps clutch with less hp(383) after about 10k hard street miles, and about 400-500 road course miles, seems like it just didn't want to be slipped at street lights.
Racer
Joined: Nov 2002
Posts: 397
Likes: 0
From: Auburn AL
When you are looking at buying a clutch it's the flywheel torque you have to keep in mind. The torque is what will give you a more accurate estimate of what clutch you will need. I have a Spec Stage II and using my 425 rwtq I estimate that I have about 490 ft-lbs at the flywheel. If I remember correctly the clutch is rated for 525 ft-lbs. I only have about a 35 ft-lb buffer but I have never had the clutch slip. When my car was put on the dyno after my H/C setup my stock clutch slipped badly. I ended up leaving my car with Vengeance and they had to tear the car back apart to install the Spec clutch.
If you are going to have the motor out I would not leave the LS6 clutch in and take a chance because if it slips you will be pissed that you have to take the car back apart.
Good Luck
If you are going to have the motor out I would not leave the LS6 clutch in and take a chance because if it slips you will be pissed that you have to take the car back apart.
Good Luck
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Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
Driving habits set the threshold for a clutch. Driven hard and subjected to launches without a lot of intentional slip, the LS6 clutch will hold 380-390 without issue. That assumes good following of the clutch fluid swap protocol.
If an owner doesn't launch the car or hammer high-rpm shifts, an LS6 clutch will support 450 rwhp or so.
But the LS7 clutch...oh my.
It will break your heart, if you drive the car like you did a bone-stock C5Z06. It will glaze on a launch above 3600 and will simply not accept a launch with 10 feet of slip even at a measely 3000 rpm.
So I'd suggest anyone that intends to launch a Corvette to stay far away from the LS7 clutch.
Ranger
If an owner doesn't launch the car or hammer high-rpm shifts, an LS6 clutch will support 450 rwhp or so.
But the LS7 clutch...oh my.
It will break your heart, if you drive the car like you did a bone-stock C5Z06. It will glaze on a launch above 3600 and will simply not accept a launch with 10 feet of slip even at a measely 3000 rpm.
So I'd suggest anyone that intends to launch a Corvette to stay far away from the LS7 clutch.
Ranger
Safety Car
Joined: Jun 2006
Posts: 4,007
Likes: 1,488
From: Ashland, OH
Driving habits set the threshold for a clutch. Driven hard and subjected to launches without a lot of intentional slip, the LS6 clutch will hold 380-390 without issue. That assumes good following of the clutch fluid swap protocol.
If an owner doesn't launch the car or hammer high-rpm shifts, an LS6 clutch will support 450 rwhp or so.
But the LS7 clutch...oh my.
It will break your heart, if you drive the car like you did a bone-stock C5Z06. It will glaze on a launch above 3600 and will simply not accept a launch with 10 feet of slip even at a measely 3000 rpm.
So I'd suggest anyone that intends to launch a Corvette to stay far away from the LS7 clutch.
Ranger
If an owner doesn't launch the car or hammer high-rpm shifts, an LS6 clutch will support 450 rwhp or so.
But the LS7 clutch...oh my.
It will break your heart, if you drive the car like you did a bone-stock C5Z06. It will glaze on a launch above 3600 and will simply not accept a launch with 10 feet of slip even at a measely 3000 rpm.
So I'd suggest anyone that intends to launch a Corvette to stay far away from the LS7 clutch.
Ranger
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
That doesn't become an issue unless the car is launched or subjected to high rpm shifts. But an LS6 clutch would take it in a C5Z at stock horsepower. And because of that, it is a logical expectation that the LS7 would be stronger and better and would take it too in a stock C6Z.
Unfortunately, the logic fails in reality. The LS7 clutch lacks the stoutness one expects. So an owner of one must adjust launch procedures to the limitation of the LS7 clutch. That mean accepting that the car will bog, because the launch rpm cannot be raised appropriately without glazing the clutch. That is at stock C6Z rwhp level of about 450.
Ranger
Last edited by Ranger; Feb 26, 2007 at 10:08 AM.
Racer
Joined: Feb 2007
Posts: 333
Likes: 1
From: ronkonkoma new york
just bought a 2001 zo6 with a procharger and some other mods and its making over 550 rwhp on stock clutch. like i said i just got and havent got on it to bad yet, and i guess i better not either. any ideas on a good clutch setup and how much they cost installed, my car also has long tubes on it. ty
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
just bought a 2001 zo6 with a procharger and some other mods and its making over 550 rwhp on stock clutch. like i said i just got and havent got on it to bad yet, and i guess i better not either. any ideas on a good clutch setup and how much they cost installed, my car also has long tubes on it. ty
And then, when the current clutch is worn out, look seriously at the Cartek clutch or the textralia brand. You'll need to choose the model based on your particular driving style.
Everything the car does, depends on the clutch. So it's not an area to skimp. Also choose your installer with special care. Too many reports of botched installs leading to vibrations.
Ranger
Melting Slicks
Joined: Feb 2005
Posts: 2,087
Likes: 4
From: granville mass
I've read the balance or don't balance a flywheel threads here before.
What were you referring to you talk about a "botched" install causing a vibration? Some clutch and flywheel packages come balanced together. With the exception of that, what could cause vibration when doing an install?
From you LS6 days, did you ever change the flywheel and not change out the rest of the clutch? Do you zero balance flywheels?
thanks,
mike
Burning Brakes
Joined: Mar 2003
Posts: 824
Likes: 5
From: Chicago Illinois
I have 442rwhp, 410rwtq on a stock Z06 clutch with 6,676 miles on it. As Ranger stated, if you don't launch insane or powershift/bang shifts all the time it WILL hold up. I was very surprised and pleased that my stock LS6 clutch lasted all last season (though it is on it's way out the door...I still don't feel it slipping but I know it's coming!). I went to the track about 3 times last year and cruise/drive hard about once or twice a week during the spring/summer. It shoud last for a bit then!
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
Ranger -
I've read the balance or don't balance a flywheel threads here before.
What were you referring to you talk about a "botched" install causing a vibration? Some clutch and flywheel packages come balanced together. With the exception of that, what could cause vibration when doing an install?
From you LS6 days, did you ever change the flywheel and not change out the rest of the clutch? Do you zero balance flywheels?
thanks,
mike
I've read the balance or don't balance a flywheel threads here before.
What were you referring to you talk about a "botched" install causing a vibration? Some clutch and flywheel packages come balanced together. With the exception of that, what could cause vibration when doing an install?
From you LS6 days, did you ever change the flywheel and not change out the rest of the clutch? Do you zero balance flywheels?
thanks,
mike
Also if the clutch needs replacing, it is worth replacing all the component parts, not just most of them. That includes the hydraulics.
Finally, find an installer who's done a lot of C5/C6 clutches and has a good reputation. The install is only good if the tech is meticulous.
Ranger
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
^ Actually you should match your new clutch to the old one comming out. Many times GM purposly installs an off-balanced clutch assembly to make up for any off-balance motors at final testing.
Early service manuals specifically state to swap all flywheel balance weights, later ones do not. C4C5specialist of www.corvettemechanic.com says to transfer on all installs. However most aftermarket assemblies do not have the provisions (holes) in the back of the flywheel in which to transfer the weights.
Take your new equipment and the old to a machine shop to have them match balanced... this is the only way to verify you will not have a new vibration when changing clutches.
Ask me how I know.
Early service manuals specifically state to swap all flywheel balance weights, later ones do not. C4C5specialist of www.corvettemechanic.com says to transfer on all installs. However most aftermarket assemblies do not have the provisions (holes) in the back of the flywheel in which to transfer the weights.
Take your new equipment and the old to a machine shop to have them match balanced... this is the only way to verify you will not have a new vibration when changing clutches.
Ask me how I know.
Last edited by Cobra4B; Feb 26, 2007 at 03:11 PM.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
^ Actually you should match your new clutch to the old one comming out. Many times GM purposly installs an off-balanced clutch assembly to make up for any off-balance motors at final testing.
Early service manuals specifically state to swap all flywheel balance weights, later ones do not. C4C5specialist of www.corvettemechanic.com says to transfer on all installs. However most aftermarket assemblies do not have to provisions (holes) in the back of the flywheel in which to transfer the weights.
Take your new equipment and the old to a machine shop to have them match balanced... this is the only way to verify you will not have a new vibration when changing clutches.
Ask me how I know.
Early service manuals specifically state to swap all flywheel balance weights, later ones do not. C4C5specialist of www.corvettemechanic.com says to transfer on all installs. However most aftermarket assemblies do not have to provisions (holes) in the back of the flywheel in which to transfer the weights.
Take your new equipment and the old to a machine shop to have them match balanced... this is the only way to verify you will not have a new vibration when changing clutches.
Ask me how I know.
My 02 did not.
The GM procedure that dealer techs follow changed in 2003.
What Cobra is poining out is why I never change a clutch unless necessary and I carefully maintain my clutch fluid.
Ranger
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
^ Yep... it's a nightmare. But now that I know the match balance routine I'll spend the $90 at the machine shop everytime.
Or... you could just build a new motor and have it zero'd perfectly
I'd hope that the hand built LS7's don't have the balance issues that the production lines LS1/LS6s have/had.
Or... you could just build a new motor and have it zero'd perfectly
I'd hope that the hand built LS7's don't have the balance issues that the production lines LS1/LS6s have/had.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
I'd rather have heart surgery that my clutch replaced....Well, almost.
Ranger