KY 4+ Clutch
 

Hey all,

Over memorial day weekend, I installed all new hydraulics, a LuK OE replacement flywheel and KY's stage 4+ "full faced" clutch. Clutch is supposed to be rated for 550 lb/ft of torque, so we'll see.

https://cimg0.ibsrv.net/gimg/www.cob...02e3beb731.jpg

After 76K miles, the factory stocker had had enough :lol:

https://cimg9.ibsrv.net/gimg/www.cob...9ac705bef7.jpg

I bought the car with 66k miles and it was bone stock. This clutch survived 10K hard miles (tuned, tuned with ethanol and bolt ons, K04R with ethanol and then WR-3 with E) after who knows what kind of driving it encountered with the previous owner. Quite the testament to the factory clutch! :lol:

It finally started to slip on me after my race with a turbo charged LSx truck. The WR3 was the one to do it in. And you can see from the picture above, it was well past time. Also, there was an even larger pile of clutch material under the car versus what's in the picture above.

Plan is to drive 1000 miles in total (as much stop and go as I can but I drive for a living, so no choice on not driving on the HWY). I'll keep everyone posted. After about 140 miles of stop and go driving, the clutch is getting more and more firm. Engagement improves noticeably each and every time I drive it. Has definitely taken some getting use to, no doubt about it.

Stay tuned :cssNET:

Sweet, keep this updated. Would love to see how the LuK likes a clutch with more bite vs my GMPP.

Nice. Hope you have good luck with it.

*UPDATE*

After putting just over 600 stop and go miles on the clutch (driving Mrs. Daisy mind you...), the pedal has definitely stiffened up and it feels good. The release point changed as well as it use to be more mid-pedal and now it's right at the top. Not too fond of the new release point but it definitely allows for a little slip to take place. Engagement improved every 50-100 miles and it's really evident that she's grabbing well now.

I'm going to put another 3-400 stop and go miles on the clutch before I decide to drop the hammer but I am now starting to drive the vehicle like I normally would and finally getting out of vacuum.

Stay tuned

I always assumed that the clutch was more worn out the farther it engaged off the floor, or the least pressure it had. I would be concerned if I were you about it being at the top. That's just me.

That was always my thoughts/experiences as well, except some trucks where that just seemed to always be the case. I know when my stocker was near the end it was higher up, and the GMPP went from right on the floor to about 1/4 after breaking in. Still there after almost 10k since install.

I don't know about concerned, but I'd just keep an eye on it. Who knows T-Man, maybe that's just how it is, I've never had a KY to compare.

Zero concern just yet as it's identical to the KY S3 that I drove. I know it's apples to oranges but my brothers 04 Cobra was the same way with his McLeod twin disc.

See and my stocker didn't change at all. It stayed right in the middle but that sucker was toast! :lol:

Honestly though, I'm not sure and it's quite possible it's just how the PP was setup. To my knowledge, it's no different than the S3 PP, just modified further for more clamping pressure.

Appreciate the input fellas! I'll keep you posted when I finally drop the hammer.

Clutch doesn't hold

​​​​​​ after 930 miles of stop and go city driving, I finally got on it last night and it held second gear. Pulled third and immediately bounced off the limiter.

Now mind you, this is turned down even more than my stock clutch tune I was running. I'm honestly really disappointed because the drivability is great. Now since trying a few more times, thinking maybe it glazed a little, it's slipped even harder and is now locking me out of gears during normal acceleration.

Details and screenshots when I get home... I will be contacting KY tomorrow.

That is shitty

Well that sucks

Didn't someone else on here just have issues with theirs? And put a Frankenstein setup together. Sounds like it's best to steer clear of the 4-4+ kentuckys.

Yeah hopefully they do right by tman as well

That blows man, it really does. I'm sure KY will do you right with replacing it, but the lost time still sucks.

As promised,

Here's a log to show not only was it rather tame but the fact that it just plain doesn't hold. As I indicated, this is the same tune I was running with the 76K mile stock clutch I.E neutered and very much ramped to keep it from slipping further. 18 degrees of timing and less than 22lbs of boost. :lol:


https://cimg0.ibsrv.net/gimg/www.cob...ceecb02831.png

Really seems like its hit or miss with KY. Mine has been great (i have a 9" stage 3) and i didnt wait nearly as long to go wot with it.

I don't hear of many issues with the 3, but when you up the power and go with a 4 it's seems they don't hold as well as a 3? Sounds like they need to do something with the pressure plates they use. You shouldn't have to install one twice. Personally I would never use one, I like to do things once.
Omiotec says he has had good luck with spec 3+ even on efr's.

The 3 is rated for 475lb-ft... not many people on here are making that kind of torque.

Called and was unable to reach anyone. Sent them an email and will call again tomorrow.

I'm way past being disappointed now. I can't even drive the car due to the pressure plate. It's locking me in and out of gears. Not only that but I get a rattle from the trans area unless I depress the clutch.

This to me screams a faulty pressure plate. This would also explain the strange tip top engagement

The stage 3+ is rated at 550, and is also a full face vs the pucked 3. Sadly it also cost a bit more.



Yeah, something definitely was weak and let go on you. Like I said earlier, the worst part is all the lost time, having to replace it and drive it more before even getting back to turning the power up. On one hand I was gonna say hope they do right by you and replace it at no cost, but the other hand is do you even want to put another in and potentially have the same issue occur again?

Here's the knocking/clicking noise I was talking about. With the clutch pedal pushed in you'll hear a scratching/metal clanking noise. What's funny is my wife heard this the other day before I went WOT and mentioned it to me but I didn't catch it....

I'm the one who returned the other stage 4+ and they built me a custom setup with a stage 5 pressure plate and 6 puck ceramic disk. There is not enough clamping force on a full face clutch to hold the torque. Plus my disk only made about half contact on the flywheel side on the 4+, I'll say it was a bad pressure plate imho. But they took care of me and I'm sure they will with t-man. KY is a standup company.

The frankenclutch feels just like the old stage 3 did, but with stiffer pedal and lower engagement point. It drives fine. I think this new one is a winner as it's got about 100 miles on it now and it's very very grippy,.

that clicking noise is your throw out bearing. Mine did that for years on the stage 3, it's just a not that great shape TOB, mine was fine though it's just annoying. If you press and release the pedal a few times you'll notice sometimes it finds a "spot" where it's quiet when the pedal is released.


TLDR; you need a pucked clutch for torque capacity. We both learned a valuable lesson. TOB is the clicking.

Spoke with Chris at KY today and he is going to build me another clutch. Suggested that we might look into the stage 5 pressure plate and a "full faced" puck design clutch disc. It looks similar to what Southbend uses in their stage 4+

Really great to hear that they're standing behind their product

Told ya he would take care of it. Hes a very nice guy and very knowledgeable. I know a lot of folks bash KY clutch sometimes, but sh*t happens with making parts and sometimes they fail, it happens to everyone. I'm just glad they stand up to their products and are willing to make custom setups for us at no charge to keep up happy. Can't say I've had that kind of service from many folks.

I will be a returning customer solely from the wonderful support that Chris at KY has given me.




That sounds like their stage 5 setup, looks like the southbend disk, I think 8 "pucks" but a sort of full face look.

https://cimg2.ibsrv.net/gimg/www.cob...fd9cde138c.png


i guess he went pucked on mine bc I told him it better hold 500+ ftlb lol

https://cimg6.ibsrv.net/gimg/www.cob...ea5549c6b7.jpgStage 5 frankenclutch
https://cimg7.ibsrv.net/gimg/www.cob...c751491680.jpgStage 4+ that failed


mine gets better each day, it engages at the perfect height now just like stock, and is slippable.

So with multiple failed setups requiring a lot of effort to change, is he going to make long term changes? In my opinion, if they were great, they wouldn't send a substandard setup to you to begin with, or am I off base. I would kiss your ass too if the setup I sent you didn't work, and I was trying to keep my name unblemished in the marketplace. I like to do things once because my time is valuable. I don't play games of -it should work, and if it doesn't we will make it right. Not everyone can do clutch jobs themselves and that could be expensive for someone who had to pay a shop to do it again. Don't get me wrong, it's nice that they rectified it but it should have been right to begin with. Not like you guys are the first couple customers with over 400whp. Just sayin.