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QM twin disc questions

bob92vr4

Well-known member
Joined
Dec 24, 2003
Messages
258
Location
littleton colorado
Ok so I bought a used QM twin disc and Im getting ready to install this thing and just curious if anyone with experience with these can tell me if i should install the isuzu slave and a pedal stop. I have search this subject and cant find any info on it also if anyone know's where to find dsm/gvr4 specific install info I.E how much material and where it needs to be removed from the stock clutch fork that would be great too thanks.
 

4thStroke

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Joined
Oct 22, 2007
Messages
1,864
Location
Vancouver, WA
If I recall correctly, the Isuzu lave and clutch stop are needed for the PTT twin, not the QM.

The 2g accumulator and slave can be used to help out the driveability, and help a ton. As far as trimming the fork, Im not sure how much needs to be trimmed, you may just need to test it out and see.
 

brisvr4

Well-known member
Joined
Feb 13, 2004
Messages
955
Location
brisbane australia
I used the stock slave and no pedal stop with mine.
I set the clutch up on a bench and assembled the fork and throwout bearing then laid the fork on the clutch housing to see where the bolts would hit and ground away that area only.
Took a decent amount of time till I could rotate the fork all the way round the clutch housing without it hitting any of the bolts.
That seemed to be the easiest way to do it without having the motor out so you could test fit everything easily.
I was a bit paranoid about it hitting though!
 

Here are some pics of the fork.


1638294_600.jpg

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1638297_600.jpg

1638298_600.jpg

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curtis

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Joined
May 4, 2003
Messages
11,892
Location
Clarksville TN
Ok since this is used you need to check it first. It may be fine but you don't want to install it and a month later smoke two disks that are about 220 to replace plus the time and effort to pull it again.

first you need a slab of marble or something known to be dead flat. Thick mirror etc. Set the flywheel face down and measure the inside of the friction area and do the outside with a feller gauge do the same to the pressure plate disk friction surface. I can't remember the specs on it but I'm sure a quick call to QM or PTT will get the specs they cup from heat. Its steel under tremendous load and heat and will cup do all the way around it. Now for the disks measure the thickness all around and get an average thickness also get the specs for it. The disks are only allowed like .008 total loss or something like that so It might look perfect and plenty of material left but may be junk. When my thrust went out I was about 70 miles from home and kept trying to adjust the clutch and nothing help so I limped it home. I had worn off like .070 total on both disks and Steve (I think that's his name) at PTT couldn't believe I got home.

As for the isuzu slave. I used it on mine and didn't build a stop because I never slab it to the floor and never over extend it anyway so just a waste for me but a stop would be easy enough to build. I found my slave out in the shop other day and some how one of the new bolt holes I drilled broke off so I'll have to get another or just have a stock one bored out and the piston from the izuzu installed in it. Alot has to be cut off the ears for the mitsubishi bolt holes to line up but a hack saw and a drill will only take a few minutes. Measure and mark 4 times cut once.
 

turbowop

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Joined
Apr 29, 2001
Messages
11,971
Location
Yakima, WA
I bought my setup used from a buddy that put maybe 700 miles on it and installed it using the stock slave cylinder and put a bolt in the lower clutch switch location to create a pedal stop. Mine came with a clutch fork that was already clearanced. Works fine, but the clutch is very on/off. I recently purchased a 2gDSM AWD slave and accumulator that I will be installing with a new transmission this spring. I will also be removing the pedal stop. BrianAWD has had good luck using this combo on his setup.
 

4thStroke

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Joined
Oct 22, 2007
Messages
1,864
Location
Vancouver, WA
I drove Brians car when he had just the accumulator installed. It was very, very manageable, not much more aggressive than my 2600/6 puck setup.

When my QM goes in, Im going to strictly swap the clutches, then later add the accumulator and 2g slave just to see how each piece affects the clutch on my setup.
 

cobrajetguy

Well-known member
Joined
Aug 2, 2004
Messages
407
Location
Fort Collins, CO
I have a PTT in my GVR4, I used a bolt in the stock clutch switch location to make a pedal stop and I couldn't ever get the isuzu slave to bleed perfect so I put a stock slave back on it and it was fine. I didn't clearance the clutch fork but it will definitely hit if the stop is not set perfect which makes it pretty close to the floor on engagement. I already chewed through a set of metallic discs street driving the car and am trying a set of organics next and will clearance the fork while it's apart.

Peter
 

curtis

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Joined
May 4, 2003
Messages
11,892
Location
Clarksville TN
So whats the bore dia. on the 2nd gen slave and also whats the dia of the master on a second gen. I have one of there masters in the shop somewhere to go on mine because it comes with a remote mount fluid tank. If no one knows right off hand I'll dig it out and measure.
 

1941Galant

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Joined
Aug 21, 2004
Messages
1,909
Location
Charles Town, WV
Quoting cobrajetguy:
I have a PTT in my GVR4, I used a bolt in the stock clutch switch location to make a pedal stop and I couldn't ever get the isuzu slave to bleed perfect so I put a stock slave back on it and it was fine. I didn't clearance the clutch fork but it will definitely hit if the stop is not set perfect which makes it pretty close to the floor on engagement. I already chewed through a set of metallic discs street driving the car and am trying a set of organics next and will clearance the fork while it's apart.

Peter



You don't have to clearance the fork when using the PTT twin disk. I don't use the clutch stop with my twin disk, I make sure the clutch disengages just before the clutch pedal hits the floor, and I test it every time I fire the car up. I also use the 2g fwd slave w/ the clutch line accumulator.
 

bob92vr4

Well-known member
Joined
Dec 24, 2003
Messages
258
Location
littleton colorado
ok so i went to jnz they dont have a accumulator listed does anybody have the part #'s? and are both the slave and accumulator from the fwd and not awd?
 

1941Galant

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Joined
Aug 21, 2004
Messages
1,909
Location
Charles Town, WV
Here are the part #'s that were posted in another thread, they were apparently taken off of the link forums. I believe the accumulators came on both FWD and AWD 2g DSMs.

Accumulator - 2ga - MD746400
Accumulator - 2gb - MD749915
Long hard line - MD746084
Short hard line - MD745644
 
Last edited:

1qkfwd

Well-known member
Joined
Sep 29, 2009
Messages
209
Location
Sun Valley, NV
I run the QM on my talon. I love it. I have the 2G slave and accumalator, I can slowly the pedal out and inch the car forward as needed. I probably couldnt do that without the accumalator. No stop yet I run the pedal a little low. I talk to shep about the stop he said over time it can over extend the fingers on the pressure plate, and cause some stuff to warp. I like the idea of installing a stop where the switch is. I looked right over that.
 

GSTwithPSI

Well-known member
Joined
Jan 1, 2012
Messages
3,442
Location
SoCal
Bringing this back thanks to Andrew's suggestion. Ordered the accumulator to try and further tame my QM clutch, so I'll report back in 2 years when I actually feel like wrenching on the car.
 

turbowop

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Joined
Apr 29, 2001
Messages
11,971
Location
Yakima, WA
I had to find mine at a junkyard. Of course I never got around to installing it and went back to a single disk because I don't give a sh*t about racing anymore. Sold it to somebody. Don't remember who. /ubbthreads/images/graemlins/dunno.gif
 

thecman02

Well-known member
Joined
Nov 3, 2007
Messages
913
Location
Kalamazoo,MI
You sold the QM to me. I ended up putting "street" friction disks with Tim Zimmer's Gear Drive setup. It worked great. You also sent me the accumulator and I didn't want/need it. I ended up selling it for a case of top shelf beer haha.
 
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