Clutch recomendations

[The_bald_eagle_machine]

Hey Everyone,

Looking for clutch recommendations... I have a LS3/M6 car currently making 430rwhp with mods in my description. Currently on stock clutch setup. I definitely hurt the clutch a bit early in my ownership being a dummy. I am currently waiting on my intercooler setup to be delivered but the car will be getting the centrifugal supercharger treatment and I estimate the car will make around 600ish RWHP. Can the stock SS clutch handle this kinda duty just fine for street use?

Otherwise I am leaning towards Mcleod RST vs RXT dilemma. Remember, the car is not seeing any road course, auto cross, and very limited drag strip use. For example It may see a few passes here and there once or twice a year. Car is 95% street use.

Lastly, who has the best tax sale deals on clutch kits?

Thanks for your input everyone!

[The_bald_eagle_machine]

Preferably looking to hear from someone who has experience with the stock clutch around that power level or with someone who has installed one of the two Mcleod clutches and has feedback on how the clutch handles. Alot of feedback is mixed on both clutches.

[acammer]

If it's not getting drag raced regularly, then the RST is a good driving clutch with good power handling for the money. The RXT is substantially more aggressive with a segmented face, ceramic material, and an unsprung hub. Yes, more power handling, but a sharper engagement and highly propensity for chatter. If you' were gonna hit the drag strip regularly and really put some aggressive heat cycles into the clutch, then I'd lean toward the RXT, but for your setup RST sounds like the way to go. It has a power rating to cover your goal with the future setup.

We're usually competitively priced at GPI - but no sales going on at the moment. If it turns out I can help you get a package together for the clutch, slave, support, and all the other parts for a complete start, you can feel free to message me here, or e-mail andrew@gwatneyperformance.com.

[acammer]

Originally Posted by The_bald_eagle_machine

Preferably looking to hear from someone who has experience with the stock clutch around that power level or with someone who has installed one of the two Mcleod clutches and has feedback on how the clutch handles. Alot of feedback is mixed on both clutches.

I'll build out on this more. I have experience with all three, stock, RST, and RXT. You won't beat the stock clutch driveability, but the RST is very, very close. Not enough difference that most people would know otherwise unless you told them. The RST will tolerate abuse pretty well, but it is an organic, full faced, sprung twin disk, and so if you hit it with enough heat (ie repeated slip-heavy drag launches) you'll get it unhappy. You'll also wear it faster with abuse for the same reason, the material is not up to the task of major heat and abuse. Power handling is around 675whp/800bhp.

The RXT is noticeably sharper on engagement. It has segmented ceramic disks, and an unsprung hub. All that translates to better power handling and heat resistance, and the cost of some driveability. It's not hard to slip, but it happens over a narrower band. For drag racing, these cars need the clutch slipped, a lot, and having more clutch than you need for a given power level will make it more challenging to slip, and the RXT will live up to that reputation. It will also give you chatter occasionally on a normal driving take off (no sprung hub to help with dampening). Nothing dramatic, but you'll remember it's not a stock clutch. Power handling is around 850whp/1000bhp.

I have probably 20,000 miles on the RXT setup in my personal car. I forget that it's there 90% of the time, it drives easily. I have a Tilton slave, which makes the pedal effort a bit heavier, but that doesn't bother me either. I will get that occasional chatter on take-off, but it's not common, and not a big deal when it does. I've got a big, aggressive cam in my car, and it's no problem. I have a driveability video I can share with you with some data traces so you can see my clutch pedal positions and get an idea what it's like if you're interested:

[acammer]

3m57s is a good example of how the RXT will bite and be aggressive with just a touch too much travel in the early part of the release.

[The_bald_eagle_machine]

Originally Posted by acammer

I'll build out on this more. I have experience with all three, stock, RST, and RXT. You won't beat the stock clutch driveability, but the RST is very, very close. Not enough difference that most people would know otherwise unless you told them. The RST will tolerate abuse pretty well, but it is an organic, full faced, sprung twin disk, and so if you hit it with enough heat (ie repeated slip-heavy drag launches) you'll get it unhappy. You'll also wear it faster with abuse for the same reason, the material is not up to the task of major heat and abuse. Power handling is around 675whp/800bhp.

The RXT is noticeably sharper on engagement. It has segmented ceramic disks, and an unsprung hub. All that translates to better power handling and heat resistance, and the cost of some driveability. It's not hard to slip, but it happens over a narrower band. For drag racing, these cars need the clutch slipped, a lot, and having more clutch than you need for a given power level will make it more challenging to slip, and the RXT will live up to that reputation. It will also give you chatter occasionally on a normal driving take off (no sprung hub to help with dampening). Nothing dramatic, but you'll remember it's not a stock clutch. Power handling is around 850whp/1000bhp.

I have probably 20,000 miles on the RXT setup in my personal car. I forget that it's there 90% of the time, it drives easily. I have a Tilton slave, which makes the pedal effort a bit heavier, but that doesn't bother me either. I will get that occasional chatter on take-off, but it's not common, and not a big deal when it does. I've got a big, aggressive cam in my car, and it's no problem. I have a driveability video I can share with you with some data traces so you can see my clutch pedal positions and get an idea what it's like if you're interested:

With my stock clutch I have ALOT of chatter. I also have low rpm bucking, which I THINK is related to the factory flywheel material? I wanted to go steel flywheel for this reason. Car will be basically daily driven on highways and backroads, with the ocassional track visit where it will not be heat cycled aggressively. I have seen all of your videos and was hoping someone like you would weigh in and give an opinion.

Do you carry clutch setups at GPI that I might be able to purchase from you directly?

[acammer]

Originally Posted by The_bald_eagle_machine

With my stock clutch I have ALOT of chatter. I also have low rpm bucking, which I THINK is related to the factory flywheel material? I wanted to go steel flywheel for this reason. Car will be basically daily driven on highways and backroads, with the ocassional track visit where it will not be heat cycled aggressively. I have seen all of your videos and was hoping someone like you would weigh in and give an opinion.

So, I wouldn't expect a stock clutch to chatter much unless it's been beat pretty bad and has some warping - which is certainly possible. I agree with steel for the flywheel. It's true, lighter aluminum will accelerate faster, but it also makes the car more challenging to drive, and harder to launch. IMO, at the drag strip the benefits the steel flywheel has in storing more energy for the launch outweighs the benefits of acceleration down track. Long term wear resistance is a consideration as well.

Low RPM bucking may be a function of the cam you have, but even a big cam (like the Max Package cam in my car) can be made to drive pretty well with the right attention to detail and time invested in the driveability tuning. Not sure who does your tuning, but it might be worth a conversation with them about your concerns. I noticed after I posted that you don't have a cam. You are probably experiencing the parking lot speed bucking inherent to these cars. That's hard to get rid of - it's a consequence of all the parts in the car with lash - and there are LOTS of them. Clutch, Trans, Driveshaft, Rear End, Axles, Suspension bushings - all play a role in creating that slop that is really noticeable under 10mph or so.

Do you carry clutch setups at GPI that I might be able to purchase from you directly?

We do. We carry Mcleod and Monster. Feel free to reach out directly if you want to work out a package with all the parts for the install - you wanna do the salve (with a billet support) while you've got it apart, and there is never a better/easier time to add a remote speed bleeder and make that job 1,000x easier. Flywheel bolts, pilot bearing, all little bits of hardware that should be replaced while it's apart. Andrew@gwatneyperformance.com

[The_bald_eagle_machine]

I am embarrassed to say that I think I heavily damaged the clutch trying to do a burnout. I pushed thr traction control button once and proceeded to attempt to do a burnout 3 or 4 times, on the 4th attempt what I though was tire smoke was actually clutch.... so I think it's a stock clutch that has seen some improper use and abuse from yours truly.

Howard at Redline motorsports did my tuning and to my knowledge he is a 5th gen wizard when it comes to tuning. So I doubt it's tune related. I have already upgraded to 1 piece driveshaft, poly diff and cradle bushings. BMR camber arms, control arms and caster arms in the rear. The clutch has always had that low speed buck. 1st gear is not friendly in these cars lol.
Email sent regarding the clutch setup. Hoping we can work something out.

[CamaroDreams76]

I think Howard will recommend a McLeod RXT. After the cam and heads I made 513hp and 463tq. My stock clutch lasted 2 launches and only a handful of highway pulls. Howard recommend an RXT. So far so good. He said this clutch will be good for 1000hp.

I launched my car hard and for about 60ft, i outlaunched a FBO 10R80 Mustang then i thought i was spinning, slammed 2nd, my car immediately hits redline and i smelled nothing but clutch. My symptoms after that were that all the gears became super notchy and I couldn't get the car into reverse without me nearly breaking the shifter. But initially the car blew straight through the clutch during that launch. My car is 99% street use.

My stock clutch never chattered. So that's definitely odd. Acammer hit the nail on the head with the RXT. I have no experience with the RST. But the RXT you definitely know it's an aftermarket clutch. It bites fast and without a good bit of RPM imput it will chatter at low rpm. But going through the gears is smoother than stock. Just that stop/go and low speed rpm stuff not really super friendly. Just takes a little learning.

If your over the other coast hit me up, I'll let you drive.

[The_bald_eagle_machine]

Originally Posted by CamaroDreams76

I think Howard will recommend a McLeod RXT. After the cam and heads I made 513hp and 463tq. My stock clutch lasted 2 launches and only a handful of highway pulls. Howard recommend an RXT. So far so good. He said this clutch will be good for 1000hp.

I launched my car hard and for about 60ft, i outlaunched a FBO 10R80 Mustang then i thought i was spinning, slammed 2nd, my car immediately hits redline and i smelled nothing but clutch. My symptoms after that were that all the gears became super notchy and I couldn't get the car into reverse without me nearly breaking the shifter. But initially the car blew straight through the clutch during that launch. My car is 99% street use.

My stock clutch never chattered. So that's definitely odd. Acammer hit the nail on the head with the RXT. I have no experience with the RST. But the RXT you definitely know it's an aftermarket clutch. It bites fast and without a good bit of RPM imput it will chatter at low rpm. But going through the gears is smoother than stock. Just that stop/go and low speed rpm stuff not really super friendly. Just takes a little learning.

If your over the other coast hit me up, I'll let you drive.

I don't want to lose too much driveability. I am actually moving out to the Florida countryside in the next few weeks, so I probably wont see too much stop and go driving. Maybe I should consider the RXT...

[acammer]

Originally Posted by The_bald_eagle_machine

I am embarrassed to say that I think I heavily damaged the clutch trying to do a burnout. I pushed thr traction control button once and proceeded to attempt to do a burnout 3 or 4 times, on the 4th attempt what I though was tire smoke was actually clutch.... so I think it's a stock clutch that has seen some improper use and abuse from yours truly.

Howard at Redline motorsports did my tuning and to my knowledge he is a 5th gen wizard when it comes to tuning. So I doubt it's tune related. I have already upgraded to 1 piece driveshaft, poly diff and cradle bushings. BMR camber arms, control arms and caster arms in the rear. The clutch has always had that low speed buck. 1st gear is not friendly in these cars lol.
Email sent regarding the clutch setup. Hoping we can work something out.

Got and responded to your e-mail.

You're experience with the stock clutch and burnout is not an unheard of scenario. Basically, the stock clutch is enough power handling capability - but only so long as it stays relatively cool. Once it has some heat in it that holding capacity goes away, and it's very easy to blow through it on a shift or a launch. I drag raced a good bit on my stock clutch and have had those experiences where it hangs the pedal, or slips on the 1-2 shift, ect. All that heat will make quick work of that factory throwout bearing support as well - definitely have turned those into soup before!

As far as RST vs RXT, that really comes down to how you use the car. The RXT is definitely the more aggressive clutch with higher power handling and better abuse tolerance. I'm not hearing that you're looking to go out drag racing routinely, and the RST is still a substantial upgrade from the factory clutch, with more power holding and more durability. From a driveability perspective it's no contest, the RST is about like stock, an the RXT is noticeably different. I think either would be ok, but I think the RST fits how you've described you use the car. If you think you might end up doing more drag racing, or pushing the power up further, then getting the RXT in there now isn't a bad approach as long as you don't mind the driveability trade offs. A Monster triple disk is a consideration as well - those drive awesome and hold power great - but they are $$$$.

[SS_Dave]

Monster S should probably be a consideration here.

[CamaroDreams76]

Originally Posted by The_bald_eagle_machine

I don't want to lose too much driveability. I am actually moving out to the Florida countryside in the next few weeks, so I probably wont see too much stop and go driving. Maybe I should consider the RXT...

It's really not a bad clutch. Once you learn how to drive the car with the new clutch, you don't think about it. I wanted a clutch that would hold the power and be good for my next power level with the twin turbos.

[fz4k98]

The stock clutch works for driving but will not handle the power for long if you have any traction. I have about 600 rwhp and have had a stock clutch, mcleod twin disk, mantic twin disk and am now using a spec 3+.

The spec 3+ drives like stock and handles the power. It is a single disk clutch. It has been in for 2 summers and has been to the dragstrip and track day at road course with no issues,