ACT Twin didn't work so well, video
01-29-2011, 12:47 AM
#1
Le Mans Master
Thread Starter
ACT Twin didn't work so well, video
Last week, I had the ACT twin disk installed. I did a couple hundred break in miles, mostly city, then took it to the track. First pass, I thought I forgot to take off traction control since I did stall in the pits/ then after the burnout. I thought the clutch stuck to the floor, but wasn't positive since I think traction control was kicking in.
Second pass, I ran a 10.6, clutch was fine but did smell. Drove the car pretty easy this week with about another 50-80 city miles.
Tonight, I do a burnout, and the clutch just melts down to the floor on launch like the stock ls7 did. It actually shifted to second, but not third. My car, hours later and 70+miles later, smells like campfire. The clutch burning smell is so strong.
You can see the smoke from the clutch on the launch. Any ideas what is going on? Thanks!
BTW, fluid is clean and I have a remote bleeder. Not giving the clutch the knock quite yet, but not very impressed.
Second pass, I ran a 10.6, clutch was fine but did smell. Drove the car pretty easy this week with about another 50-80 city miles.
Tonight, I do a burnout, and the clutch just melts down to the floor on launch like the stock ls7 did. It actually shifted to second, but not third. My car, hours later and 70+miles later, smells like campfire. The clutch burning smell is so strong.
You can see the smoke from the clutch on the launch. Any ideas what is going on? Thanks!
BTW, fluid is clean and I have a remote bleeder. Not giving the clutch the knock quite yet, but not very impressed.
Last edited by winters97gt; 01-29-2011 at 12:51 AM.
01-29-2011, 02:34 AM
#3
Le Mans Master
Thread Starter
Have you ever really launched your car with a big second gear burnout and this clutch? Not that my burnout was that big, or that I launched that hard, but just trying to see. If this clutch doesn't work, I'm going with my bud from monster, Chris and their Stage 3-5.
I don't mind breaking parts, as I've been through rear end parts left and right in the last 18 months in my last car, since that is racing. I get annoyed at stuff like this, though.
01-29-2011, 02:42 AM
#4
Burning Brakes
Member Since: Jun 2009
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St. Jude Donor '10
The ACT is a full faced organic disc right? Once organic discs get heated up/slipped a lot they have a tendency to glaze over which will lower the coefficient of friction, often resulting in it continuing to slip more.
It could be a result of your driving habits. If you drove in lots of stop and go traffic and heated it up, weren't used to it and overslipped it, or just have a habit of slipping the clutch too much around town you could have glazed it over (many organic/kevlar/etc friction compounds like those used on many full faced clutch discs are very susceptible to glazing during break in) and exacerbated the issue when you took it to the drag strip.
It simply may have needed more break-in time. I know my Spec twin had a distinctly different feel for the first ~800-850mi compared to what it has now. I went with a puck design with ceramic/metallic material because I drag race a lot, and while that material makes it slightly more difficult to modulate its unlikely to glaze over slipping out of the hole and bites harder when it gets hotter (to a point). I also don't like racing on a street clutch with under 1000mi to make sure its properly heat cycled.
If it were me, I'd take it very easy on the car for another 4-500mi and see if it it can clean its self off, otherwise you may have to pull it back out. Slip the clutch minimally even if it means being a little rougher, don't put a lot of heat in it, don't beat on it which doesn't only mean don't run out 1-3 but also includes WOT in high gears at lower RPM, and hope that you didn't cook it too bad already.
Worst case scenario, you'll need to resurface the flywheel, pressure plate and float plate and reline the clutch discs. If it slipped bad enough to boil clutch fluid its almost definitely got hot spots already.
It could be a result of your driving habits. If you drove in lots of stop and go traffic and heated it up, weren't used to it and overslipped it, or just have a habit of slipping the clutch too much around town you could have glazed it over (many organic/kevlar/etc friction compounds like those used on many full faced clutch discs are very susceptible to glazing during break in) and exacerbated the issue when you took it to the drag strip.
It simply may have needed more break-in time. I know my Spec twin had a distinctly different feel for the first ~800-850mi compared to what it has now. I went with a puck design with ceramic/metallic material because I drag race a lot, and while that material makes it slightly more difficult to modulate its unlikely to glaze over slipping out of the hole and bites harder when it gets hotter (to a point). I also don't like racing on a street clutch with under 1000mi to make sure its properly heat cycled.
If it were me, I'd take it very easy on the car for another 4-500mi and see if it it can clean its self off, otherwise you may have to pull it back out. Slip the clutch minimally even if it means being a little rougher, don't put a lot of heat in it, don't beat on it which doesn't only mean don't run out 1-3 but also includes WOT in high gears at lower RPM, and hope that you didn't cook it too bad already.
Worst case scenario, you'll need to resurface the flywheel, pressure plate and float plate and reline the clutch discs. If it slipped bad enough to boil clutch fluid its almost definitely got hot spots already.
Last edited by mAydAy121; 01-29-2011 at 02:45 AM.
01-29-2011, 02:53 AM
#5
Le Mans Master
Thread Starter
The ACT is a full faced organic disc right? Once organic discs get heated up/slipped a lot they have a tendency to glaze over which will lower the coefficient of friction, often resulting in it continuing to slip more.
It could be a result of your driving habits. If you drove in lots of stop and go traffic and heated it up, weren't used to it and overslipped it, or just have a habit of slipping the clutch too much around town you could have glazed it over (many organic/kevlar/etc friction compounds used on full faced discs are very susceptible to glazing during break in) and exacerbated the issue when you took it to the drag strip.
It simply may have needed more break-in time. I know my Spec twin had a distinctly different feel for the first ~800-850mi compared to what it has now. I went with a puck design with ceramic/metallic material because I drag race a lot, and while that material is harder to launch its unlikely to glaze over slipping out of the hole. I also don't like racing on a street clutch with under 1000mi to make sure its properly heat cycled.
If it were me, I'd take it very easy on the car for another 4-500mi and see if it it can clean its self off, otherwise you may have to pull it back out. Slip the clutch minimally even if it means being a little rougher, don't put a lot of heat in it, don't beat on it which doesn't only mean don't run out 1-3 but also includes WOT in high gears at lower RPM, and hope that you didn't cook it too bad already.
Worst case scenario, you'll need to resurface the flywheel, pressure plate and float plate and reline the clutch discs. If it slipped bad enough to boil clutch fluid its almost definitely got hot spots already.
It could be a result of your driving habits. If you drove in lots of stop and go traffic and heated it up, weren't used to it and overslipped it, or just have a habit of slipping the clutch too much around town you could have glazed it over (many organic/kevlar/etc friction compounds used on full faced discs are very susceptible to glazing during break in) and exacerbated the issue when you took it to the drag strip.
It simply may have needed more break-in time. I know my Spec twin had a distinctly different feel for the first ~800-850mi compared to what it has now. I went with a puck design with ceramic/metallic material because I drag race a lot, and while that material is harder to launch its unlikely to glaze over slipping out of the hole. I also don't like racing on a street clutch with under 1000mi to make sure its properly heat cycled.
If it were me, I'd take it very easy on the car for another 4-500mi and see if it it can clean its self off, otherwise you may have to pull it back out. Slip the clutch minimally even if it means being a little rougher, don't put a lot of heat in it, don't beat on it which doesn't only mean don't run out 1-3 but also includes WOT in high gears at lower RPM, and hope that you didn't cook it too bad already.
Worst case scenario, you'll need to resurface the flywheel, pressure plate and float plate and reline the clutch discs. If it slipped bad enough to boil clutch fluid its almost definitely got hot spots already.
I didn't overslip the clutch on the initial break in. I really let the car bog on the stop lights, if anything, especially for the first 100-150 miles. After that, I started to drive normal. I went with the ACT recommended break in on their clutches.
As mentioned, I hope I have not developed "hot spots" in the clutch as you mentioned. They were very obvious in the ls7 when we pulled it. I am use to putting in a clutch(spec-corvette, king cobra-mustangs) driving them a few hundred miles like the manual says, and then being able to beat on them.
I already planned on driving it 100+ miles tomorrow(today) to have dinner on the coast with the significant other, then doing another 50+ miles to see if it would clean itself off. Maybe making a pass on Sunday. Might wait another 2 weeks for another 200-300 miles on it.
Just really surprised that 600rwhp can do this to a clutch so fast with a proper break in with such a good reputation.
01-29-2011, 03:15 AM
#6
Burning Brakes
Member Since: Jun 2009
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St. Jude Donor '10
Outstanding post!
I didn't overslip the clutch on the initial break in. I really let the car bog on the stop lights, if anything, especially for the first 100-150 miles. After that, I started to drive normal. I went with the ACT recommended break in on their clutches.
As mentioned, I hope I have not developed "hot spots" in the clutch as you mentioned. They were very obvious in the ls7 when we pulled it. I am use to putting in a clutch(spec-corvette, king cobra-mustangs) driving them a few hundred miles like the manual says, and then being able to beat on them.
I already planned on driving it 100+ miles tomorrow(today) to have dinner on the coast with the significant other, then doing another 50+ miles to see if it would clean itself off. Maybe making a pass on Sunday. Might wait another 2 weeks for another 200-300 miles on it.
Just really surprised that 600rwhp can do this to a clutch so fast with a proper break in with such a good reputation.
I didn't overslip the clutch on the initial break in. I really let the car bog on the stop lights, if anything, especially for the first 100-150 miles. After that, I started to drive normal. I went with the ACT recommended break in on their clutches.
As mentioned, I hope I have not developed "hot spots" in the clutch as you mentioned. They were very obvious in the ls7 when we pulled it. I am use to putting in a clutch(spec-corvette, king cobra-mustangs) driving them a few hundred miles like the manual says, and then being able to beat on them.
I already planned on driving it 100+ miles tomorrow(today) to have dinner on the coast with the significant other, then doing another 50+ miles to see if it would clean itself off. Maybe making a pass on Sunday. Might wait another 2 weeks for another 200-300 miles on it.
Just really surprised that 600rwhp can do this to a clutch so fast with a proper break in with such a good reputation.
The binding resin in a friction material, when heated up beyond a certain point will outgas releasing some compounds trapped in the friction material (that's what the grooves in brake pads and clutches are for), and they do much more so and at a lower temperature before they are bedded in because the binding resin hasn't cured/matured yet. The outgassed material can then reattach to the surface creating the glaze.
In addition, when the clutch is first being bedded in to the flywheel, there are very very small gaps between the friction material and the metal surface due to the machining processes. A full faced disc (and also a twin) is going to be lighter on the surface, its very possible that it just didn't get a chance to bed in fully. Its also possible being that its a twin that perhaps it never got hot enough to outgas (here I go flip flopping!!) until you took it to the drag strip at which time it got heated up too much. Whatever happened, it shouldn't have (or they should have provided different instructions for break-in)
Make sure the clutch is fully disengaging also, I know I've heard of people with the Spec twins having issues with that -- some need to use the shim they send out and some find the clutch doesn't disengage fully when using the shim. That'd be a quick way to fry any clutch.
Last edited by mAydAy121; 01-29-2011 at 03:17 AM.
01-29-2011, 10:28 AM
#7
Le Mans Master
I've launched mine at the track 8 or 10 times but no big burnouts before those, just cleaning off the tires. Last weekend I did put some street tires on it and practice my burnouts and last night I was pracaticing my 0-60's and it's been fine. I also changed my clutch fluid (via remote bleeder) last weekend too, which was dark and the pedal is back to how light it was when it was new. But no signs of slipping.
It's hard to say with a twin, especially with a strapped floater plate. If it was not adjusted right from the factory. There are stand offs that the floater plate bumps up against to keep it centered between the disks when disengaged. I could see if that were misadjusted it could keep one of the disks from clamping completely. I donno how feasible that is, just looking for reasons.
Good advice above. If its drivable take it easy on it for a little while and see if it corrects.
Still disappointing though...
It's hard to say with a twin, especially with a strapped floater plate. If it was not adjusted right from the factory. There are stand offs that the floater plate bumps up against to keep it centered between the disks when disengaged. I could see if that were misadjusted it could keep one of the disks from clamping completely. I donno how feasible that is, just looking for reasons.
Good advice above. If its drivable take it easy on it for a little while and see if it corrects.
Still disappointing though...
01-30-2011, 03:28 AM
#8
Le Mans Master
Thread Starter
I've launched mine at the track 8 or 10 times but no big burnouts before those, just cleaning off the tires. Last weekend I did put some street tires on it and practice my burnouts and last night I was pracaticing my 0-60's and it's been fine. I also changed my clutch fluid (via remote bleeder) last weekend too, which was dark and the pedal is back to how light it was when it was new. But no signs of slipping.
It's hard to say with a twin, especially with a strapped floater plate. If it was not adjusted right from the factory. There are stand offs that the floater plate bumps up against to keep it centered between the disks when disengaged. I could see if that were misadjusted it could keep one of the disks from clamping completely. I donno how feasible that is, just looking for reasons.
Good advice above. If its drivable take it easy on it for a little while and see if it corrects.
Still disappointing though...
It's hard to say with a twin, especially with a strapped floater plate. If it was not adjusted right from the factory. There are stand offs that the floater plate bumps up against to keep it centered between the disks when disengaged. I could see if that were misadjusted it could keep one of the disks from clamping completely. I donno how feasible that is, just looking for reasons.
Good advice above. If its drivable take it easy on it for a little while and see if it corrects.
Still disappointing though...
Today, I drove about 50 miles in the city running errands. I plan to put another couple hundred on it this week. Do you guys think 300 miles of easy driving is good enough before I run it again? The car still smells from last night, but not as strong.
Might sound dumb, but one thing that I did notice, is that the window did fog up from the burnout last night, even when leaving one window half way down. Today, the window was fogging up as well. This is directly in the middle of the window where it comes down an meets the hood. I'm guessing the clutch is directly under that. Not sure if the clutch or exhaust would cause this, but I have not experienced that in this car during a burnout. Makes me think something was really cooking down there during the burnout to cause the cab to heat up like that. I always keep my windows down before I run, and one cracked so that I don't fog up during the burnout.
01-31-2011, 04:49 AM
#9
Le Mans Master
Thread Starter
I contacted ACT this morning with a link to this thread. Not to throw them under the bus, since their product has proved very well for many guys in our application. Hoping that they can help me out so that I don't have to go with another brand. I have the SFI card in front of me.
01-31-2011, 10:49 AM
#10
Former Vendor
ACT is a class act in the clutch business and we use them on the severest of applications without issues. Give them the facts and they will work with you. BTW, when the clutch sticks to the floor it's generally hydraulic related.
As for not wanting to throw them under the bus - you already did that.
As for not wanting to throw them under the bus - you already did that.
I contacted ACT this morning with a link to this thread. Not to throw them under the bus, since their product has proved very well for many guys in our application. Hoping that they can help me out so that I don't have to go with another brand. I have the SFI card in front of me.
01-31-2011, 01:47 PM
#11
Safety Car
02-03-2011, 04:25 AM
#15
Le Mans Master
Thread Starter
I'm going to try and have another 700+miles on the car before the next track visit. After about 200 miles, it already feels better. It is stiffer and I did a few WOT pulls today and it feels good. I am also going to install a line lock on the car, so that it might not put as much heat in the clutch during a burnout. Completely change the fluid as well, probably to Amsoil 600.
If that doesn't work, I will be pulling it out and having my shop look at it.
If that doesn't work, I will be pulling it out and having my shop look at it.
Last edited by winters97gt; 02-03-2011 at 04:40 AM.
02-04-2011, 01:49 AM
#16
Burning Brakes
When you were breaking it in did it buck in first gear on initial take offs? Mine is doing that but it seems to be getting a little better every time I drive it.
02-04-2011, 02:26 AM
#17
Le Mans Master
Thread Starter
Hey Troy!
I wouldn't say it "bucked", but it made a slight chatter(car shake, low RPM's). The chatter is pretty much gone now. I would guess that the car has 750 miles, with mostly stop light to stop light, so lots of city driving.
Mine feels great on the street. Hopefully, if it glazed over, a little extra break in might clean it off, and I'll change fluid, add a line lock, and this thread will be history! Keep me updated on how it goes up there, and stay warm! We're getting snow/sleet so tomorrow, our track will be closed. If I get a couple hundred more on it, I will run it next Friday.
I wouldn't say it "bucked", but it made a slight chatter(car shake, low RPM's). The chatter is pretty much gone now. I would guess that the car has 750 miles, with mostly stop light to stop light, so lots of city driving.
Mine feels great on the street. Hopefully, if it glazed over, a little extra break in might clean it off, and I'll change fluid, add a line lock, and this thread will be history! Keep me updated on how it goes up there, and stay warm! We're getting snow/sleet so tomorrow, our track will be closed. If I get a couple hundred more on it, I will run it next Friday.
02-04-2011, 02:43 AM
#18
Burning Brakes
Nice to know. Mine is doing that right now but I just picked it up today. I think I have put 30 miles on it so far. So the break in should get rid of all that? Seems to shift really smooth now might switch over to the c6 shift *** soon. Yeah it's still really cold here and seems to be messing with my A&A order. My intercooler seems to be stuck in Tx somewhere right now and it shipped on the 28th of last month. I might be heading home to SA and letting Lethal Performance do my install soon I'll have to come check out your car if that happens.
02-04-2011, 03:03 AM
#19
Le Mans Master
Thread Starter
Nice to know. Mine is doing that right now but I just picked it up today. I think I have put 30 miles on it so far. So the break in should get rid of all that? Seems to shift really smooth now might switch over to the c6 shift *** soon. Yeah it's still really cold here and seems to be messing with my A&A order. My intercooler seems to be stuck in Tx somewhere right now and it shipped on the 28th of last month. I might be heading home to SA and letting Lethal Performance do my install soon I'll have to come check out your car if that happens.
