Installed a Tremec Magnum XL in my S550

db252

Equinsu Ocha
Joined
Jan 1, 2016
Messages
1,464
Reaction score
836
Location
Bay Area, CA
Vehicle(s)
16 GT Premium/PP/Nav
Took on a new project and thought I’d share it. Never thought I’d go this route but but just saying that doesn’t really surprise me.

Backstory: The car is a 16 PP so it has the 3:73 rear gears and is pretty heavily modified. Like most of us, I ran the MT82 with an MGW and had no real issue especially after adding that shifter. I didn’t break anything in my stock transmission and it worked the same from the day I bought till the day I took it out. For 28k miles I ran the stock clutch with it and I was fairly quick to add a Whipple and shortly after that E85. I was amazed at how well the stock clutch handled it. I do occasional road course days, and as some forum members can attest to from riding shotgun, I push the car hard and play with the line of limit. The 3:73 differential made 1st and 2nd gear pretty useless at my power level and considered changing diffs but didn’t want to ditch my Torsen. I don’t do 1/4 mile runs and for the most part I daily drive the car which includes commuting to work in traffic. The car is literally 95% street with casual manners and 5% track/canyon carving/hurt the feelings of another car brand/owner that unwisely has challenged.

I bring up this info because it has a factor in making choices in parts and gear selection. Also, my baseline is can my wife take the car out and drive it ‘normally’ without it being annoying/difficult to operate and that applies to me as well.

This is what I ended up buying and most of this comes in a kit which is the route I went:

Tremec Magnum XL transmission (duh)
First gear choice of 2.66 and opted for the 5th and 6th OD gears of the 2.97 trans which gives me in order of 1st to 6th, 2.66/1.78/1.30/1.00/.80/.63

Quick Time steel sfi bell housing

QA1 carbon fiber driveshaft with sfi (upgrade)

Bowler all-in-one harness for electronic connections

Rest of the kit included fluids, transmission mount, cross brace and mounting hardware

Also added the MGW shifter since I really appreciated what it did for the MT82


The clutch was a difficult and time consuming process and there is a endless amount of choices out there. Everyone has their preferred brand or special purpose for what their plans are for their car but this is also the reason I gave the back story above because it applies here. I would love to try all brands and models that I narrowed it down to (probably 5) but I’m not sponsored, a company that works in the industry nor someone with unlimited funds. My personal requirements were something near stock weight for stored energy, sprung hub and organic. I was open to single and dual disc setups knowing the inherent differences. Ultimately I went with the Ram Pro Series twin disc organic with steel flywheel.

Like I said, plenty of great choices to go with and I even tried for a short period, which was completely non cost effective for me, a Mantic 9000 organic series clutch which I will say was awesome with my MT82 the short time I had it. I could have easily just switched to 26 spline clutch discs but the light weight would have been an issue I feared so I did what I did.


Here’s some pics cuz that’s all most care about....

22B49E1B-D50F-436C-8D25-BF15FB08BE02.jpeg

6F75DE80-E680-4CFC-A1B1-79D7614C8285.jpeg
4EEB91A5-CB7B-46BF-AC05-FD2E63C79518.jpeg
5316F36B-7B02-4B19-85D2-746393F7A482.jpeg
28D8580D-70AB-4442-8B8B-6D04C3C7D196.jpeg
6D8013D6-5E5C-4CF1-B8EC-9732C8F707FB.jpeg
2A732B9A-D5B2-42D9-ADDD-71EAA031D3A8.jpeg
44345936-FA41-4B18-8A90-4EF865C8DB32.jpeg
FDF58B3C-984D-48CC-929C-8A8EC1A031B2.jpeg
48AC3E88-F9B9-4B38-BFFD-0125387C2188.jpeg
AF199552-9E96-4436-AB2F-DD5381D69DF9.jpeg
0E141C3E-4926-4F70-9BF8-C8BFF73D100A.jpeg
D755A471-DCA2-4C02-ABB4-32806973BAC0.jpeg
5178D562-26E9-4DBD-AA2F-D5730049969D.jpeg
8AA3B291-D17F-44E3-8577-D37B1B34F706.jpeg


At current writing, I’m around 300 miles on the break in. At first, and at around only 25 miles I thought I made a mistake with clutch choice. First gear start off from a stop had significant chatter but that has quickly become better and better and I’m sure will continue to get better as smooth slipping start off has become an easy thing to do now. Recently took the wife out to mess around with first gear in a parking lot and she did great but could notice the current difference. If you’re already moving, this clutch is just perfect. Clutch pedal effort is less than stock, initial grab and capture is well within the throw of the clutch pedal; not quick off the floor grab or late grab near the top. I’m 90% happier with the clutch than my first quick to judge impression.

I cannot say enough about the transmission. I absolutely LOVE the gears I chose granted I’m in the break in phase and not shifting over 4000 rpm for the most part but again, this is how the car will be driven most of the time. First and second gear are so much more useful and enjoyable to use. Fourth gear (1.30) in the MT82 was one of my most favorite gears to play in and also was a factor in choosing the magnum gear selection I did because third gear in this set is also 1.30 which made it perfect. 4th is now the 1:1 gear which I like and the two OD gears are gapped perfectly unlike our 5th to 6th is in the 15-17 MT82. I will say it is weird downshifting to 1st gear around corners in residential/commercial zones but it’s easy, called for and works like any other gear you’d be used to using normally. Hell, I’m still learning what gear to be in based on muscle memory of where the shifter used to be. I really couldn’t be happier with how this all works together and with the stock 3:73.

The driveshaft is awesome and the second QA1 I have owned and also part of the not a wise investment in regards to how long I had it in the car before switching to the Tremec. I’m sure it’s not the last time I’ll do that.

One other thing when I first got it on the road and getting a feel for it. There was a small vibration/drone in the car that came in around 3200 rpm and went out around 3800 rpm. Believe me I thought of every possible scenario and incorporated lots of others thoughts to the mix so before you start throwing out ideas, it was figured out. There is a reverse lockout solenoid that is on the drivers side tail section of the transmission and it was touching the body lightly. The idea of what to do was easy but the process of doing it wasn’t quite so easy especially without removing things. It took a small hydraulic ram to push, which happens to be a much stronger and stiffer section than I expected, the body panel away which now looks like this, totally fixed the issue and might as well be a mile away compared to what was before.

40801D28-C54B-49BF-A636-203E29CABFD4.jpeg


This is the electronic harness that was included with the kit and sold from Bowler. It incorporates all electrical connections and really made everything work easily and its adjustable for things such as tire size, OOS pulse calibration and reverse lockout parameters to make to your liking (speed at which lockout engages or deactivates). Reverse switch is a no brainer. Literally soldering 5 total wires to the original trans harness to make everything connect; the two reverse wires and reverse camera and light work like stock. Positive, ground and oss wire.....done. You download an app to your iPhone or android and and it Bluetooth connects when ever you want for changing parameters. Without going into too much detail, just go with it’s easy and works great. All connectors to the sensors on the trans are OE style and weather sealed.

429687FE-49C6-4C87-BA46-9CD49225392E.jpeg


In regards to the actual install, it’s no more difficult than changing a clutch if you’re comfortable with it. I really liked the separate bell housing.

That’s all I got for now. Still have miles to go before it all gets more aggressive testing but I have no doubts.
Advertisement

 
Last edited:

whatsup62

Well-Known Member
Joined
Sep 16, 2015
Messages
2,046
Reaction score
510
Location
Jupiter
Vehicle(s)
2015 Mustang GT PP (Gone but not forgotten).
Great write up! Ive had mine for 8000 miles now. Im more of a straight line guy and opted for the 2.97. IMO the 3.73s are just barely enough. I went ahead and went with 4.09s. Ive always said after the change out it just feels right in the car. Ford should have saved us the trouble.
 
OP
OP

db252

Equinsu Ocha
Joined
Jan 1, 2016
Messages
1,464
Reaction score
836
Location
Bay Area, CA
Vehicle(s)
16 GT Premium/PP/Nav
Thanks and I would recommmend the 2.97 for someone like yourself looking for a better hole shot. Even changing the diff gears like you did. Always loved the car but it’s a new found lust with this new setup.
 

2morrow

DesignR/DriveR/RiceEatR
Joined
Nov 15, 2015
Messages
5,183
Reaction score
4,156
Location
NorCal Bay Area
First Name
Todd
Vehicle(s)
'16 Mustang GTPP
Another amazing project in the books! Thanks for the insightful write up and install notes. I can't wait to get a ride in it!
 

aleccolin

Well-Known Member
Joined
Jun 7, 2017
Messages
693
Reaction score
225
Location
VA
Website
www.CarClubVT.com
First Name
Colin
Vehicle(s)
2016 GT PP
Did you order this as a package from Bowler? What's your total cost (for parts)?
 
OP
OP

db252

Equinsu Ocha
Joined
Jan 1, 2016
Messages
1,464
Reaction score
836
Location
Bay Area, CA
Vehicle(s)
16 GT Premium/PP/Nav
Did you order this as a package from Bowler? What's your total cost (for parts)?
No, ordered from Modern Driveline as they were the only ones able to order the QA1 driveshaft which was a significant up-charge and something I specifically wanted. QA1 wouldn’t even let me order it on my own for some reason not very clear other than ‘we don’t offer it’. The Bowler harness is just included as part of their kit.
Price was right around $5800 for everything not including the clutch.
 

aleccolin

Well-Known Member
Joined
Jun 7, 2017
Messages
693
Reaction score
225
Location
VA
Website
www.CarClubVT.com
First Name
Colin
Vehicle(s)
2016 GT PP
I’m guessing the CF driveshaft was somewhere around a $1500-2000 uptick? Pretty spendy but they are really damn nice.
 

aleccolin

Well-Known Member
Joined
Jun 7, 2017
Messages
693
Reaction score
225
Location
VA
Website
www.CarClubVT.com
First Name
Colin
Vehicle(s)
2016 GT PP
Would you recommend any specific sales rep at MDL? I’m leaning hard toward doing this before bolting on a blower.
 
OP
OP

db252

Equinsu Ocha
Joined
Jan 1, 2016
Messages
1,464
Reaction score
836
Location
Bay Area, CA
Vehicle(s)
16 GT Premium/PP/Nav
Paul Coffey is the one that helped me and he or whom ever answers the phone (it may just be two of them) will easily take care of you. Feel free to reach out to me if anything comes up.
 

aleccolin

Well-Known Member
Joined
Jun 7, 2017
Messages
693
Reaction score
225
Location
VA
Website
www.CarClubVT.com
First Name
Colin
Vehicle(s)
2016 GT PP
So you've got the 2.66 first with a 3.73 rear, right? Do you even have to shift to second doing 0-60?
 
OP
OP

db252

Equinsu Ocha
Joined
Jan 1, 2016
Messages
1,464
Reaction score
836
Location
Bay Area, CA
Vehicle(s)
16 GT Premium/PP/Nav
Yes to your question. 1st gear can get to 60 at 7500 rpm. 3000 rpm is basically 25 mph.
 
Advertisement

 
63 - Late Model Restoration - 2
Advertisement
Top