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Do you have any idea how your ACT pressure plate compares to the RPS Maxx pressure plate? I don't know what the lb rating on the RPS pressure plate is but if it's similar I would just throw it back in with your old disc or buy a new OEM one. The RPS Maxx street clutch has already been proven to hold a great deal of torque. It was holding everything Matt could throw at it with his DR-750s.
both are rated at about 30% more clamp load than stock. The RPS is rated at slightly more torque (580 vs 540). Since they both use the same disk the plates should be similar if not the same. The ratings may be different because the RPS plate is a couple percent heavier or one or the other may rate things differently.Quote:
Originally Posted by TurboSinceBirth
I think Matt m is running the 6 puck rps disc right now.
The 6 puck act disc is rated at 690 or 150 ft/lbs more than the street disk.
Adam, do you slip on street tires and slicks? I've always dumped on street tires because I know I'll spin, so that avoids shock loading the drivetrain. It's been good to me on good tracks, consistent 1.6x 60's all day, but consistent smoke shows on a shit track or if I don't hit up the burnout box first. But I've never ran slicks and I've seen trannies pop when the tires grab.
I will be using a Clutchmasters 700+ series on my build.
You still shock loaded the drivetrain in order to break traction, didn't you? It's still all wheel drive and making all 4 tires break loose requires a pretty significant amount of torque.Quote:
Originally Posted by lawdogg
Others have described the way I launch as a slip-dump. I don't use a 2-step or anything... I just go WOT and come out on the clutch in the ~5K range. As the clutch engages, I slow down my foot a bit, and once the car begins to roll I come all the way out. It all happens in a fraction of a second. I've only been to the track once with the slicks and tried to baby it out of the hole and broke a stock rear axle.
Definitely, but far less than putting that much torque into something with 4 tires worth of full traction! Who knows what the coeff of friction of a spinning tire is ... I'm sure there's data out there. But like anything there are a thousand ways to skin this cat, I just wonder what the pros and cons are of the slip-dump method. Your method probably takes more skill. The couple times I've tried it, I've just roasted the clutch. :(Quote:
Originally Posted by AdamVR4
well like a lot of things it looks like I'm going to be running a mutt clutch. ACT HD pressure plate with the southbend FE clutch disk. Assuming that they like almost all of our clutch people build their pressure plates off the same blanks and basic size it should work just fine.
Should be good for 700 ft/lbs or so and the price was less than half that of the whole southbend kit. MTC was able to get one for me.
I'm going to take some measurements of the stock disk and the fe disk to verify their thickness is in the same ball park. Not a definitive test since the feramic disk may need more air space when released to not drag, but it'll make me feel better.
If it doesn't drive right I'll pursue other options. Should be a beast. The act plate is really good, balanced and SFI approved.
Would anyone suggest methods for prepping the pressure plate? I was thinking of hitting it lightly with a medium scotchbright type disk on my die grinder just to knock off the old clutch material, but I'm not sure if that is more harmful than just letting the new more aggressive disk do that itself.
It is probably a waste of time, I'm sure the first couple starts will have the old material abraded away.
The flywheel is getting resurfaced today at auto tire and parts. Their machine shop has been good. We have one of the biggest auto tire and parts stores here in cape and I believe it is the founding store. Very fast turnaround, same day and I didn't ask for any type of rush.
here is some info for your guys. ACT would not tell me what the pressure plate load in lbs is, but they said that the MB019 pressure plate is a 30% increase over stock.
Stock pressure plate clamp load in lbs is 2072 lbs. Adding the .30 increase from act puts the act plate at 2693.6. I believe RPS rates their plate at 2900. I do not know what southbend rates theirs at now, but I read in the past that it was 2750 lbs.
Should be a good match. FYI that puts the act plate at about 8% less clamp load than the RPS. Even if the 750 ft/lbs rating of the southbend clutch is with a 2900 lb press plate that should still put my mutt clutch's torque capacty at about 690, which will certainly be plenty for all but the absolutely max effort DR750 setup.
Quote:
Originally Posted by Forest Gump
If you've got brand new surfaces, simply use brake cleaner to ensure there's no grease or oil on the flywheel or pressure plate surfaces and let 'er rip...
That's how I've always installed clutches on my car and locals' cars. If reusing a pressure plate, yeah, hit it with sand paper or potentially a scotchbright pad. I've only had one cluth fail -- I tried to reuse an RPS pressure plate by having it resurfaced for a 6 puck. I destroyed that clutch the first time I took it to the track, heh... There were sparks flying out from beneath the bottom of my car. Resurfacing the pressure plate reduces the clamp force. I don't recall how much the machine shop removed, but I immediately called RPS and they said that should be OK. Guess not.
The pressure plate has a couple thousand on it, but it looks practically new. No warps, scores, or hotspots. I'll probably go over it really lightly just to get some of the old clutch material off.Quote:
Originally Posted by AdamVR4
Like you I'm reluctant to have any machining done to the plate, but it should not be needed.
Machine shop called and they were concerned that there is apparently no spec for how thick the flywheel needs to be from the clutch surface to the bolt hole surface, but I had them cut it anyway. They knew exactly what the step height should be. When I get it back I'm going to make sure that there is a little bit of a step where the friction surface meets the casting. RRE says that as long as you have a step there it is ok to resurface.
They shouldn't have had to take off much, you could still see the maching marks from the last time this flywheel was cut.