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Pictures and Comparison
I'm just throwing this page together rather quickly to get some pics up of the recent clutch problems I've been having. ARGGH!!! :-)
These pictures came about due to my 2nd high performance clutch failing in well under a year with normal driving conditions. Sure, I get on it once in a while but only go to the track once or twice a year and then launch on street tires at under 1500 rpm. I'll show you pictures of a Star Stage III Kevlar setup, a LT4 pressure plate and clutchnet.com disk combo, and the stock pressure plate and disk that came out of the car. It's also important to note the stock clutch lasted in this car around 65k miles with 50k of those miles being with the car at around 450hp at the crank. I'm having trouble getting these high performance clutches to last more than 5,000 (sometimes less) before they completely go bad... doesn't seem to make a lot of sense? The stocker finally let go after doing a few additional mods to the old SS and me taking it to the track. It just couldn't take anymore but still ran a 12.8 at 110 mph slipping away (not bad though... didn't completely fail until the next run).
I've been in contact with Star about the problems I'm having with their Stage III clutch. I must say their customer service is top notch and I would not hesitate to purchase another product from them. They have several LT1 Z28s out there with more horse power than myself and who are dumping the clutch at 5k rpm and don't have problems. Currently the clutch is in route to Star to be tested and have the Kevlar material replaced with Carbon. Star said the Kevlar seems to be a bit inconsistent... meaning, in some cases it works great but in others it doesn't seem to work at all? Not sure if it's the Kevlar material itself that is inconsist or if it is just very finicky in its application. Either way and even though Star knows this car is not stock and a modified SS, they are more than willing to fix this for me and get things running right for me. So far, a big thumbs up for Star in my book.
|Here is the pressure plate side of a Star Stage III Kevlar disk. It has less than 10k miles on it but as you can see, appears to be worn pretty good.|
|This is the flywheel side of the Star Stage III Kevlar disk. Much more "damage" it appears on this side.|
|Star pressure plate. Only a couple hot spots on it and it even still has the swirl marks in it from when it was made! Not much use on this at all|
|Here is the flywheel used on the above setup.|
|Here we were taking a look at how much space there is
between the pressure plate just resting on the disk and flywheel as compared to when it is
installed and the pressure plate is bolted onto the flywheel. My mechanic bud said
this is not as much as most clutches. We only had about 1/8th an inch and he said
normally he sees almost 1/4 of an inch. But, after taking with Star about this, they
said 125/1000th is about normal (which is 1/8th :) so this isn't an issue.
The bottom picture compares the difference between the Star setup and the LT4 pressure plate and clutchnet.com disk combo. Oh, both flywheels have been ground once and have had 20 thousandths taken off then in these pics. The clutchnet.com disk and LT4 pressure plate combo was supposed to have been good for 600 hp but started slipping a few months after I installed it. This clutch had ZERO track time. ARRGHH!!! :)
|Picture of the disk in place on the flywheel.|
|On the upper left is the Star setup and the lower right is the LT4 pressure plate setup. These two pressure plates look identical and even share the same numbers on both the housing and "fingers."|
|On the left is the flywheel I just removed. On the right is the flywheel that was used with the LT4 PP and clutchnet disk. They look about the same don't they?|
|This is the failed clutchnet.com Kevlar disk
supposedly good for 600hp. Not sure why this combo didn't work for me because I know
it has worked for 500rwhp guys??? Very confusing. I think a lot of this is leading
back to my conversation with Star in that this Kevlar stuff just isn't consistent or
predictable. I will not have (or at least pay for!) another Kevlar clutch...
Here is a close-up picture of the flywheel used with this combo and how it looked after being removed.
|In the lower right is a brand new never installed stock LT1 pressure plate. Notice the difference between the fingers as compared to the LT4 pressure plate next to it.|
|There's a couple bucks here :) On the left is the Star Stage III setup, in the middle the LT4 pressure plate and clutchnet.com disk, and on the right is the stock pressure plate and stock disk (many miles and very toasted!).|
|Here is just a close-up comparison of the three (two?) different pressure plates I have. The top is the stocker, middle is the LT4 pressure plate (part number 10222083 and costs about $215 from a discounted online GM parts dealer) and the bottom is the Star pressure plate. Again I think the LT4 and Star pressure plates are identical.|
|Shown here is the pressure plate side of the stock
disk, the clutchnet Kevlar disk, and the Star Kevlar disk.
My mechanic buddy (builds transmission too) pointed out some things he liked about both the clutchnet and Star. On the clutchnet disk he said the hub area of the disk looked very strong but the "fingers" that go out between the center portion and the Kevlar portion is normally what will fail in high hp applications. On the star he commented on how it was one solid unit and therefore you wouldn't have the problems with the "fingers" breaking.
|Same disks as above but you are now seeing the flywheel side. Looks a lot more burnt up on this side, eh?|
|Pressure plate faces for a brand new stocker, the LT4, and the Star.|
|And here is one last picture of everything before it goes back in the garage. Also pictured here but not above is the old/original stock pressure plate... yeah, the one that is all black :)|