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Discussion Starter · #1 ·
Just wondering for everyday street driving w/ 500-600hp, is the stock clutch O.K.? W/ maybe a very few trips to the track a year...

Is there anyone on here w/ a KB SC that's still on the stock clutch that doesn't feel the need to upgrade it yet?
 

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Snake Charmer
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If you beef up your clutch prepare for something else to break if your running DR's....ie input shaft or half shafts. If your tires aint slipping and your putting out monster torque somethings gonna give.
 

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stock clutch here.....

I still have the stock clutch with my modified cable, firewall adjuster and quadrant assembly which i feel is the reason the clutch is lasting behind my kb with 17 lbs. of boost.......feels great still !!:lol
 

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I have just a drop in K and N and do have some clutch slippage @WOT. I only have 3k on the car and am thinking the stock clutch may last to 8k if I am lucky.
 

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Some of this is not good to hear. Getting the KB soon, ordered yesterday, and my clutch currently is only good for one 1320' and thats it. Toasted it a while back during a burnout. I guess maybe replacing it with a stocker is the way to go......
 
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Good move..I dont have a KB...but using the stock is what Pete has said to me over and over...even when he was boosting his Eaton like I was....he always used a stock clutch.

Harry
 

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Speaking of stock clutch, where would be the cheapest place to buy one?
 

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Subscribing / Bump:D
I plan on going w/ a stock 03 unit b/c the 01 clutch doesnt work w/ the Fidanza flywheel.
 

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The Ubiquitous Jimmy V.
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The Spec 2 Clutch should be a little better then stock.My friend Joe has it with KB blower,,It feels like stock,,No Chatter at all..
 

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Discussion Starter · #10 ·
Hot Rod Harry said:
Good move..I dont have a KB...but using the stock is what Pete has said to me over and over...even when he was boosting his Eaton like I was....he always used a stock clutch.

Harry
Hot Rod,

What's the reason Pete told you to stick w/ the stocker? Easier on the drive train?
 
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doubleblack said:
Hot Rod,

What's the reason Pete told you to stick w/ the stocker? Easier on the drive train?
Yep.....if something needs to give at some time...better the clutch than the tranny or halfshafts. That stocker is fine for our modded 03 Cobra's. Hasnt given me any probs or any of the guys here that have KB's on their cars for quite some time now. Plus since the stock one is in there already with no probs....saves time and money at that point. And so far so good...about 1500 more miles on the black vert since the KB install and the whole setup is still just awesome!

Harry
www.HotRodHarrys.com
 

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I still used the stock clutch after the kb went on I am now using a autop but it held really well and I still have it no signs of real wear.
 

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kB and Stock Clutch

I still use my stock clutch, I have 10,000 miles on it with no problems so far. I have a KB with over 559 SAE RWHP.

AMB
 

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To answer your question, black, no. KB and stock clutch do not match up well at all.

The stock King Cobra 11.5" clutch does not have NEARLY the holding capacity to put all the torque of a KB 03 Cobra to the back tires.

If you look at some of the fastest 03's on manual transmission - most of them are using aftermarket clutches.

Jim D'Amore ran a low 10 in his convertible with a Ram full race clutch. And he did so on stock drivetrain and nothing has ever broken. He could not have come even remotely close to that quickness on the stock clutch.

Nitrous Pete took his stock tranny / clutch out as soon as he put the KB on the car and realized that it was slipping badly on the early dyno sessions. It just so happens that he chose automatic instead of manual tranny. But if he had stuck with the manual tranny, he'd have done a more race-oriented clutch or he would never have come even remotely close to 9's.

To the best of my knowlege, F8lbite's 10-second pass was with a Spec 3. I've never seen him post about it and it's not in his signature but I've been told by others. Also, I believe that he has broken a half-shaft and an input shaft.

In his new black car, D'Amore ran an 11.13 at Cordova FFW during TNT. His stock clutch was slipping very badly and so he sent Shaun back to NJ with the car to replace it. They put another stock 03 clutch in the car and it still slipped badly brand new.

My car is making good power. With the cooler September air that we've had lately, it feels like it has picked up another 100 RWHP. I've got 7500 miles on 640 RWHP and stock clutch. AS Hermann has posted, I use a firewall adjuster and quadrant. It's holding up great.

But I know that it's robbing lots of power and performance from the car. It's not very easy to detect because the slip is subtle and mostly on the top of each gear. It holds pretty good out of the hole in 1st and 2nd gear...at least enough to incinerate BFGs.

But it's not logical to put all of this time, money and effort into KB, tune and mods...and then have the stock clutch severely compromise the car's performance.

As for the slipping clutch protecting the drivetrain...well...I think that this is the wrong approach to alieveate a problem. My observations lead me to believe that broken drivetrain components are due to driving style more than anything else. If you're making pulleyed Eaton power and have an abrupt style on the clutch...you'll break if you hook. While a hard-gripping clutch will create a greater risk of drivetrain shock / damage, that's no reason to give up a half-second of ET or more...IMO.

I believe that 600-plus RWHP KB Terminators are quite capable of LOW LOW LOW 10-second passes - or better - in good weather...but no way with the stock clutch.

I bet that if JT and F8lbite had KBs and matching clutches...they just might dip into the 9's in September / October weather and on drag radials. I mention those two guys because we all know what talented animals they are behind the wheel. Can they do it repeatedly without breaking drivetrain components? I don't know..but I bet it's possible. We've seen many 1.5 short times without breakage. It's all in the clutch petal operation.

Now the trick is to get one of the FEW 'gray area' clutches....ones designed for big torque holding while maintaining street manners. Spec 2/3, Ram 900-series, Quarter Master Stampede Series, McLeod Twin Disc and Centerforce are the best candidates.

My friend Dustoff and I have just invested in identical Quarter Master Stampede 8.5" sintered iron clutches with sprung hubs. It's not going to be as easy to drive as the King Cobra 11.5", but I believe it can be mastered to maintain street manners with minimal to no chatter. And best of all? .5-.8 tenth improvement at the track and 3-5 MPH!

Will I break things? Probably. I drive like ass.

We'll be posting about it soon.
 

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I have no where near the expertise of some of you folks, but my stock clutch was slipping badly in the upper rpms with a upper/lower pullied Eaton. When we removed it, the disc wasn't all that worn, but there were a lot of hot spots on it.
Replaced with a Spec II and it's better, especially on the street, simply because the pedal is lighter.
 

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RaceRat, i hope your spec2 holds up, but nothing less than a spec3 was in the cards for me considering where i want to be.

i don't even think the stock clutch holds up to a pullied eaton. 535# TQ is really hard on the stock clutch.
 
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