The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Has anyone done the Magnum XL swap and regretted it?

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Happy to help. Good luck this weekend.
Great news! The Mustang is back together and the clutch seems to be working better than the previous two, by far. There might still be some air trapped in the clutch slave cylinder, but it's actually pleasant to drive. The clutch action is very smooth, and there's a good bit of travel from where it first begins to grab and where it's solid. It begins to engage about 3 inches off the floor and takes 2-3 inches to completely engage. It's so easy to modulate. The previous two clutches (a McLeod RXT and an Exedy Stage 3) were both ceramic and felt more like on/off switches. Pulling away from a stop or using reverse was an abrupt, chattering mess. This one is nice and smooth. I wonder how well this one will handle the power? I'm going to follow the instructions and go easy for the first 800 miles or so.

Oh, and I used the Tremec fluid this time, because that's what Tremec recommends, now. They keep changing their mind. And the Tremec fluid took 4 months, was on back order... Seems to shift very nicely, not notchy at all. But I'm keeping it below 4k RPM, for now.

Thanks everyone, for your help, especially Eric. I would never have gotten to this point without the input from the group.
 
Last edited:

Fabman

Dances with Racecars
6,587
8,259
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Great news! The Mustang is back together and the clutch seems to be working better than the previous two, by far. There might still be some air trapped in the clutch slave cylinder, but it's actually pleasant to drive. The clutch action is very smooth, and there's a good bit of travel from where it first begins to grab and where it's solid. It begins to engage about 3 inches off the floor and takes 2-3 inches to completely engage. It's so easy to modulate. The previous two clutches (a McLeod RXT and an Exedy Stage 3) were both ceramic and felt more like on/off switches. Pulling away from a stop or using reverse was an abrupt, chattering mess. This one is nice and smooth. I wonder how well this one will handle the power? I'm going to follow the instructions and go easy for the first 800 miles or so.

Oh, and I used the Tremec fluid this time, because that's what Tremec recommends. Seems to shift very nicely, not notchy at all. But I'm keeping it below 4k RPM, for now.

Thanks everyone, for your help, especially Eric. I would never have gotten to this point without the input from the group.
The TREMEC fluid is no good for high rpm shifting. I have had much better luck with amsoil. It’s a night and day difference.
 
The TREMEC fluid is no good for high rpm shifting. I have had much better luck with amsoil. It’s a night and day difference.
That damn saleen supercharger makes a TON of heat at high RPMs. When I'm at an HPDE day, I usually shift about 5,500 or so and rarely go to 6,000. Is that below what you would call "high rpm" shifting? I know these days everyone running around with a coyote hitting 7,500... I'm still milking the old school 4.6 3V....
 
1,212
1,213
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Great news! The Mustang is back together and the clutch seems to be working better than the previous two, by far. There might still be some air trapped in the clutch slave cylinder, but it's actually pleasant to drive. The clutch action is very smooth, and there's a good bit of travel from where it first begins to grab and where it's solid. It begins to engage about 3 inches off the floor and takes 2-3 inches to completely engage. It's so easy to modulate. The previous two clutches (a McLeod RXT and an Exedy Stage 3) were both ceramic and felt more like on/off switches. Pulling away from a stop or using reverse was an abrupt, chattering mess. This one is nice and smooth. I wonder how well this one will handle the power? I'm going to follow the instructions and go easy for the first 800 miles or so.

Oh, and I used the Tremec fluid this time, because that's what Tremec recommends, now. They keep changing their mind. And the Tremec fluid took 4 months, was on back order... Seems to shift very nicely, not notchy at all. But I'm keeping it below 4k RPM, for now.

Thanks everyone, for your help, especially Eric. I would never have gotten to this point without the input from the group.
Good to hear that you have it back on the road.

The engagement point and the feel are more a product of how the clutch is designed than the disk material. the way it was explained to me was that the engagement point and feel are the result of the fingers and the amount of cushion in the disks. The disks are not solid and have some give before they bottom out against each other. The Mantic that I had behind my MT82 engaged very high on the stroke and was an on/off switch. Geoff said they had a batch of disks that didn't have enough cushion in them resulting in the behavior. He thought they had weeded them all out, but it sounded like the set I got were at the tight end of the spec. He picked me a couple of disks with more cushion in them when I switched to the Tremec and needed 26 spline disks. The engagement is completely different and much more stock like. I went with the cerametallic over the organic based on Mantic's recommendation. My car doesn't see much street use anymore and I was told that the cerametallic would handle the heat from the track better.

As far has fluid goes, I am running the Amsoil that Modern Drive Line recommended when I bought the Tremec. I don't have enough use on it yet to know how it is going to work out long term.

If you have air trapped in it still you should probably do a vacuum bleed. It beats pumping the clutch pedal a million times to get it to self bleed.
 

Fabman

Dances with Racecars
6,587
8,259
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
That damn saleen supercharger makes a TON of heat at high RPMs. When I'm at an HPDE day, I usually shift about 5,500 or so and rarely go to 6,000. Is that below what you would call "high rpm" shifting? I know these days everyone running around with a coyote hitting 7,500... I'm still milking the old school 4.6 3V....
I would think you’d be ok at that rpm.
 

Mad Hatter

Gotta go Faster
5,289
4,292
Santiago, Chile
I am preparing the road to a Tremec migration in the future. Does anyone have the part number handy for the 26 spline Clutch disc for the Exedy Hyper single?
 
After some slow driving last evening, I stopped to get gas and when starting the car it made an unusual noise. Almost like one or two spark plugs were removed, or the starter gear was missing a tooth. I'll jack it back up after work and see if something is loose. Maybe I didn't torque all three bolts down that hold the starter? Could there be something inherently different about Mantic dual disk clutch that just sound different at start-up? Hmmmmmm.
 

xr7

TMO Addict?
725
847
Exp. Type
Autocross
Exp. Level
10-20 Years
Minnesota
Dual disk clutches with free floating center plates can be noisy on start up. You can isolate this possibility by temporarily defeating the clutch switch so you can start the car without having to depress the clutch. Now you can easily start the car with clutch engaged or disengaged. If the noise is there regardless of clutch engaged or not, something else is the issue. Lastly, if you try this method make damn sure you put the clutch interlock switch back into operation. These switches can save you from some bad stuff.
 
Dual disk clutches with free floating center plates can be noisy on start up. You can isolate this possibility by temporarily defeating the clutch switch so you can start the car without having to depress the clutch. Now you can easily start the car with clutch engaged or disengaged. If the noise is there regardless of clutch engaged or not, something else is the issue. Lastly, if you try this method make damn sure you put the clutch interlock switch back into operation. These switches can save you from some bad stuff.
Wow, that's a really good idea. I'll try it this weekend. Thanks!
 
1,212
1,213
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
After some slow driving last evening, I stopped to get gas and when starting the car it made an unusual noise. Almost like one or two spark plugs were removed, or the starter gear was missing a tooth. I'll jack it back up after work and see if something is loose. Maybe I didn't torque all three bolts down that hold the starter? Could there be something inherently different about Mantic dual disk clutch that just sound different at start-up? Hmmmmmm.
I haven't driven mine in a month or so, but I don't remember it making any weird noises at start up. I will get it off the lift and give it a try. I would start with xr7's advice and disable the switch and start it in neutral without depressing the clutch pedal to see if it sounds any different. If it doesn't the starter would be where i would start. I am not sure about the starter on the 4.6 but the starter bolts on the coyote are a pain in the but. You can't see them and have to tighten completely by feel.
 
1,212
1,213
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
I got my car back out today. I don't have any unusual noise on start up. There is a little rattle from the twin disks at idle with the clutch pedal pushed in, but it is barely noticeable. Defeating the switch for testing does not have to be elaborate or difficult. You can kneel down next to the car and reach under the clutch pedal with your left and to depress the switch as you turn the key with your right hand. Just make sure the car is in neutral and wheels are chocked or parking brake is engaged.
 
I jumped the clutch over-ride switch and started the car with the clutch out (engaged) and the transmission in neutral. There was a little different noise (something extra spinning, the input shaft, maybe?), but the same sound was still there. I guess it's just that the new clutch sounds different than the last three... That's funny now that I write it down.

The car is running better as I break in the clutch, so I'm going to call this one closed. I appreciate everyone's help.
 
1
2
Exp. Type
HPDE
Exp. Level
10-20 Years
San Antonio
FYI, the magnum XL is not bullet proof either. I grenaded mine at COTA a couple years ago. Apparently under hard and long acceleration like road course the oil sloshes to back of transmission and the input shaft bearing and gear overheat. This is what what happened to mine, and the input shaft gear stripped, while running in 3rd. I have swapped to the tick performance upgrade, although mine is an earlier version with an electric pump.

 
220
186
Exp. Type
W2W Racing
Exp. Level
3-5 Years
Columbia, TN
Found this and gotta imagine it's a great upgrade! I'm still on the fence about rebuilding my MT-82 and sourcing the good parts from somewhere or just taking the plunge.



I was cruising through the latest PRI magazine Nov 2023 issue and found this:

20231101_103609.jpg
 

Mad Hatter

Gotta go Faster
5,289
4,292
Santiago, Chile
Found this and gotta imagine it's a great upgrade! I'm still on the fence about rebuilding my MT-82 and sourcing the good parts from somewhere or just taking the plunge.



I was cruising through the latest PRI magazine Nov 2023 issue and found this:

View attachment 91021
Hmmm... so that would be around US$2700 in parts plus shipping.
 
Edit MT82 is about 20lbs lighter if not more.

I have a Calimer stage 1 MT82 for a few years now.. beat the snot out of it for about 10-15k miles including race track visits no issues at all. Maybe its got to do with a light weight clutch? i've got a 38lb setup including flywheel from Spec (the stage 2+ with billet internals). When i upgrade it will be to the 26lb street carbon twin from RPS.
 
I would love to go for the Calimer XL with dog gears.... but that will have to wait a bit. Getting a quote for parts from Calimer now, and then sit down with a calculator. At least I can sell the one I have if its in working order.
Do you know if you have to get the 26 spline or 'should' get the 26 spline setup with this straight cut version? Alternately, i think there is a g-force gearbox as well to go 'up' from the tremek.
 

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel
Top