ACT 2900: Old style vs new?

[MindBlowin03]

Im not at all interested in the disks so Im just asking about the pressure plates. I know the newer style pressure plates have the 'strengthening humps' in the fingers. Here are my questions...

1) Were the humps an answer to broken fingers? Upon searching I have seen broken fingers with both old and new style fingers.
2) Does anyone know if the pedal pressure was changed/lightened with this revision?

Old style

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New style

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The main reason I ask these questions is because I am searching for a 2900 pressure plate and I dont know if I should stay away from an old style or if it really even matters.

 

[We're on Boost]

Nick, I was just noticing how good that dyno curve looks in your dyno thread posted back in 2010. I've got a couple more questions about your wmi setup. We had already talked about it some back in 2010. Should I fire away here, or post it back in the 2010 thread?

 

[leepen]

My old style cracked, I just put the new style in and the pedal pressure feels the same

 

[FirstCarIsA GSX]

I'm curious also about the results between the two because i also just ordered the new style.

 

[MindBlowin03]

My old style cracked, I just put the new style in and the pedal pressure feels the same

Can you compare the pedal pressure to a 2600?

 

[My1GLaser]

I've had both and the 2900 is a little bit lighter. After a little while in bumper to bumper traffic, you won't be able to tell if it's lighter or not cause they all make your leg tired! I actually have the new 2900 in there right now. I've had the 3200 also, and it felt about the same as the 2900.

 

[MindBlowin03]

That's exactly what I was hoping to hear. Thank you!

 

[bastarddsm]

I'm running a 2600, but I'm in the market for a 2900. I currently have an old style 2600 with the thick fiingers. The one thing I have noticed is they have a tendency to have centrifugal assist. Meaning as the RPM's come up the fingers come out, clamping the disc tighter. This also eats up some of your release travel, leading to release problems. It gets worse as the disc wears.

This was with a new in box (but old) 2600pp, ACT 4 puck and new ACT streetlite.

Off topic, but I just got my GGSX ripping, and I re-experienced launchin on a street disc, and it's so much easier than a 4/6 puck. I want to try the old school shep, 3200 street disc combo.

 

[We're on Boost]

..... Meaning as the RPM's come up the fingers come out, clamping the disc tighter. This also eats up some of your release travel, leading to release problems. It gets worse as the disc wears.

What kind of rpms are you talking about, where it gets nasty towards shifting?

 

[bastarddsm]

you can see it in this picture. By 7500 it's causing problems. I have worked around it, but it still sucks. The cheap china XTD clutches worked better.

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[We're on Boost]

That's a pretty cool log. Let me see if I'm looking at it right:
Shift out of 1st at a little over 9000 rpm
out of 2nd at about 9000 rpm
out of 3rd at about 8500 rpm

Forward accelerations of about 0.4 g or a little less - Oops, more like 40 ft/sec^2 in 1st and 2nd gear?
Shifts taking about half a second

Is there anything wrong in there? I can't see anything wrong.

 

[bastarddsm]

I shift at 9600, 9000, 8600. Look at the purple clutch trace. See how it rises with rpm. That is throwout bearing position.

 

[We're on Boost]

Oh yeah, then over to the right from about 12 seconds on, where your rpm's have come down, the TO bearing is riding where it should be.
Cool! I mean, bummer!

I currently have an old style 2600 with the thick fiingers.

Old style 2600 with the thick fingers - would that be like the one in this picture?
This is a screen shot from a Tom's Turbo Garage video, the one where he is replacing his ~5 year old ACT 2600 with a new ACT twin disk.

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[School Boy]

I shift at 9600, 9000, 8600. Look at the purple clutch trace. See how it rises with rpm. That is throwout bearing position.

I think i might've asked you this before but what is done to your transmission? And how is your clutch pedal assembly holding up with the 2600?