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.

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I always thought my 3:73s were optimum but I suppose 4:11s are better for where you need to be when you want to be there......................................
Depends on the variables.
For me it puts me just below redline in 3rd for several crucial corners on the tracks I run so, it's perfect.
With the blown 3 Valve I just ran 4th everywhere. It redlined much lower and had the torque to pull 4th/5th with ease.
The Coyote, not so much.
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
Thats the way to go me thinks...

for now these are the ratios that are typically available

Stock mt82
3.66​
2.43​
1.69​
1.32​
1​
0.61​
Stage 3
3.46​
2.29​
1.61​
1.26​
1​
0.65​
XL tall
2.97​
2.1​
1.46​
1​
0.8​
0.63​
XL close
2.66​
1.78​
1.3​
1​
0.74​
0.63​
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
I always thought my 3:73s were optimum but I suppose 4:11s are better for where you need to be when you want be there......................................
I think for the Mt82 in stock form and the 3.73 is a little bit short if you have lots of hp. The calimer stage three has beefier gears so its taller and 3.73 does well. The XL is even longer so I would thing at the very least a 3.73 or more likely a 4.10
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
The Kohr unit I purchased has the "Track Gears" with the close 4-5-6 shift from the 2.97 trans already installed.
I heard that they are all starting to ship that way now as that's a much better package but a quick trip to the Tremec site still shows the old ratios.
I'd want to be damn sure I got the right one personally.

Tremec:


Kohr:

However, truth be known, with the coyote I have never even used 5th gear as 7800 rpm with 4:10 gears and a 25.6 tall tire gets me 145 mph which is plenty for Laguna, Sonoma and Thunderhill.
T Hill has the highest top speed for me and I'm currently topping out at 142 mph. Not likely to go much faster than that around here.
Your mileage of course may vary....


I end up going upto 238km/hr in 5th which is 148mph at our main race track... And to be honest its my least favorite part. Imagination gets going and I think of all the things that could go wrong. But its a great place to pass the GT4 cars!
 

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I end up going upto 238km/hr in 5th which is 148mph at our main race track... And to be honest its my least favorite part. Imagination gets going and I think of all the things that could go wrong. But its a great place to pass the GT4 cars!
Sounds like 3:90 might be a good compromise. I’d try it with the 3:73 and see how the ratios work out on the tracks you run.
For me it’s all about 3rd gear.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Thats the way to go me thinks...

for now these are the ratios that are typically available

Stock mt82
3.66​
2.43​
1.69​
1.32​
1​
0.61​
Stage 3
3.46​
2.29​
1.61​
1.26​
1​
0.65​
XL tall
2.97​
2.1​
1.46​
1​
0.8​
0.63​
XL close
2.66​
1.78​
1.3​
1​
0.74​
0.63​
Tremec changed the OD clusters on the close ratio Magnum XL. They both have the .8 5th and .63 6th now. I finally got my close ratio model Wednesday night. I have 3:55 rear gears. The XL 1-4 is very close to the MT82 2-5, so I am going to try it as is to start with and then do a gear swap when I got to a Torsen this winter. Geoff at Mantic clutch ran me a bunch of comparisons between my current set up and the 2 versions of the XL with gear ratios up to 4:30. He didn't include the Calimer Stage 3 since I had already decided on not doing another MT82. I would post them here but not sure how to post a pdf file. If anyone wants copies I can email them.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
My close ratio Magnum XL came in Wednesday. I have the block plate, flywheel, clutch, and bell housing installed. I am having trouble getting the transmission in. I can get it to about a 1/4 inch from the bell housing. The alignment pins are starting in and then it stops. I don't see anything that is hitting anywhere. Does anyone have any idea what could be keeping it from going that last 1/4 inch?
 
1,161
2,116
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
My close ratio Magnum XL came in Wednesday. I have the block plate, flywheel, clutch, and bell housing installed. I am having trouble getting the transmission in. I can get it to about a 1/4 inch from the bell housing. The alignment pins are starting in and then it stops. I don't see anything that is hitting anywhere. Does anyone have any idea what could be keeping it from going that last 1/4 inch?
It’s the hydraulic slave cylinder. I’ve had the same issue and finally just cinched it together using the bolts, using small incremental turns on each one that you can get started. With each turn of a bolt, the slave cylinder would burp fluid out of the hydraulic line fitting. I know everything cautions to not pull together with the bolts, but I haven’t figured out any other way to overcome the slave cylinder that last little ways.
 

Fabman

Dances with Racecars
6,518
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
It’s the hydraulic slave cylinder. I’ve had the same issue and finally just cinched it together using the bolts, using small incremental turns on each one that you can get started. With each turn of a bolt, the slave cylinder would burp fluid out of the hydraulic line fitting. I know everything cautions to not pull together with the bolts, but I haven’t figured out any other way to overcome the slave cylinder that last little ways.
I must confess, that’s how we did it too.
 
898
544
Yes, I always have to use the bolts to draw in the Magnum and MT82 transmissions. Just make sure the transmission is engage with the clutch splines properly. One way to check is to put the transmission in gear after you stab it into the bell housing. It it has engage the clutch splines, you will not be able to rotate the transmission. Then, put it back in neutral, align the bolt holes and draw it in. If there is any type of resistance with the bolts, something is wrong. Draw the bolts up slowly and evenly around the bell housing.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Thanks guys but I found the problem. The input shaft passes through the disks but is not quite centered in the throw out bearing. It appears I was sent a 26 spline alignment tool for a GM not a Ford. The pilot end is .585 instead of .68. When I passed it through the disks into the pilot bearing the disks kept it from wiggling so I didn't realize it was not the right size. Well I am stripped back down to the clutch and need to get the correct alignment tool.
 
898
544
Its actually somewhat hard to locate the proper .68, 26 spline clutch alignment tool. In a pinch, you can wrap Gorilla tape around the input side of the tool to make it large enough in diameter (we've run into the same issue and that was our quick fix). Once aligned properly, you will still need to draw it in with the bolts. But, as said before, the bolts should turn very easily with a small wrench. Anything else, and the transmission is not aligned correctly.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
American Muscle has the precision steel ones in stock or I can drive across town and pick up a plastic one today. I missed Gingerman today and tomorrow so there isn't a big rush. I am trying to decide if having the steel one is worth it in the long run.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Well American Muscles idea of in stock receive via standard shipping in 3-10 days is actually drop ship from supplier with estimated shipping date of 8/29/22, than 3-10 days standard shipping. It took some doing but I finally got them to cancel the order. They insist it is in stock just not in their possession. I would not of ordered it from them if it wasn't listed as in stock. I order as little from them as possible because of things like this. Well I will drive across town tomorrow and pick up a plastic one from Silver Sport Transmissions.
 

TMO Supporting Vendors

Top