JohnVallo
1 5 4 8 3 7 2 6
- Joined
- Feb 9, 2015
- Threads
- 49
- Messages
- 360
- Reaction score
- 596
- Location
- Venice, FL
- Website
- racersreunion.com
- First Name
- John
- Vehicle(s)
- '16 GT350, Shadow Black, Whipple Supercharged
- Thread starter
- #1
· When I bought my 2016 GT350 in Dec. 2015 I was very aware that If I was thinking about tracking this car, I would definitely need the Track Pack option w/coolers. So, in my case I was not going to track it, and was very happy that I saved money on the Base model. (It suited my particular need perfectly, -option wise-).
Speaking of tracking it, I spent over 39 years racing late model stock-cars on Midwest oval tracks, as a summer hobby.
You can check my accomplishments here: http://racersreunion.com/john-vallo/gallery/all/p=1
So for me, after 2008, it was time to retire from my Racing/Driving career, and move to Florida. Then in 2013 to retire from my Day Job: (F idelity, B ravery, I ntegrity), -Tampa Field Office-
After changing rear-ends and gear ratios several times in my GT350 I really learned to like the new ‘Super 8.8’ IRS design in the S550, but I did have some concern in a couple of areas. The main concern was: Shouldn’t this rear-end hold more fluid ? (Even if Cooler equipped, the fluid capacity was minimal)
This minimal fluid capacity in the rear axle puzzled me. Ford raised the performance engine-oil capacity to 10qts, but reduced the performance rear axle capacity???
After all, there is about 3 ½” of clearance between the back of the cast IRS housing and the Sub-Frame. Plenty of room for a larger rear cover that could hold more fluid..
I waited and figured surely some third-party vendor would come out with a finned rear cover, or a finned rear cover that held more fluid. Didn’t happen… maybe mainly because Ford started putting rear-end coolers on all GT350’s in the 2017+ model years.
This issue bothered me for some time. Two main areas of concern I had with the new Mustang ‘Super 8.8’ IRS rear-end:
1. Minimal air flow to the rear-end housing, as well as exhaust very close to housing.
2. Not enough fluid capacity. (Cooler (69 oz.), or No Cooler, (61 oz.) of gear oil is just too minimal, in my opinion)
I thought about this for awhile before deciding on my approach of designing something myself.
I had read many ideas, (Other than a Cooler Kit), some seemed more helpful than others. (Wrapping the exhaust, so as to reduce heat. Redirecting more air flow to the housing. A finned rear cover. A cover offering larger fluid capacity.)
My approach was to combine 2 of these ideas. A finned aluminum cover that holds more fluid.
Some 2015+ Ford F150 (trucks) also utilize a ‘Super 8.8’ rear end. One problem, the truck rear end is not IRS, it is solid axle. The good thing is that almost all internal parts, as well as the rear cover bolt pattern are the same. I found a company (actually 3 companies), that produces an extra capacity, finned, aluminum cover for the truck. So far so good, but what about the rear mounting, which is on the cover itself for the mustang ‘Super 8.8’ IRS rear end, and two other concerns?
1. No rear mounting on cover.
2. No vent system, (Built into the Mustang cover, and not in the truck cover).
3. (OEM) Temp sending unit/Cooler Line accommodation needed.
From the start I had two plans in mind:
PLAN A was to somehow incorporate the stock Mustang rear cover with a higher capacity finned aluminum cover (from the F-150).
PLAN B was to buy the higher capacity finned aluminum cover (from the F-150), modify it as needed, and design and make my own steel mounting brackets for the rear mustang IRS mounting (not using an additional modified stock cover).
I looked at all 3 finned aluminum covers I found for the truck
1. B&M – This cover was high-quality, and expensive, also had differential cap supports built into the cover (for ring gear and bearing cap deflection), which I didn’t think were necessary for the IRS. Also, the way the fins were cast into the cover, it would require a lot of machine work to allow for any brackets to attach to the back of it. Also, every bolt hole was recessed, which would require washers or machining to get a flat surface on the back of the cover.
2. Mag-Hytec – this cover incorporated a built-in dip-stick, also had large casting supports between the bolt holes that would need to be addressed.
3. PML – this cover seemed best suited for the conversion, it had a lower cost, was flat on the rear (except 3 bolt holes), no fin/casting interference, and held ¾ qt. or (24 oz.) more fluid than stock.
So, I contacted PML and offered them my idea and ask if they would work with me on this project.
My idea was to send them a stock mustang rear cover, they would machine it into just a bracket (with the diff mounts still attached, and this would be fitted to their finned cover.
The PMLTruck cover compared to the OEM Mustang Cover
At first, PML thought I wanted the two pieces machined and welded together to form the new cover. (While this may still be a worthy consideration), I told them: -No welding-, just machining the stock cover so it would clamp or sandwich their cover into place using 8 of the 12 bolts.
The OEM Mustang cover would get machined, then fit to the PML Truck cover
PML's Tech dept. really showed interest, as we went back and forth several times on the details, then suddenly they backed out. Something about: “Since the cover is part of the mustang suspension, we cannot go forward with this effort”.
NOW to PLAN B
I went ahead and purchased the PML rear cover. When it arrived, I studied it and began my design for the steel diff carrier mounting bracket that would attach to the rear of the cover. I also had to figure out a venting system for it and it needed a thicker area for the Ford OEM temp-sending unit. The cover had a unmachined boss cast in it for an old-style temp sending unit about ¾” thick, but the Ford OEM unit doesn’t go all the way thru to the oil, and needed 1 ¼” of thickness. So, about ½” more alum thickness was needed on the boss, as well as the proper sized hole and threads cut for the sending unit.
Ford has a very nice venting system for the OEM Mustang cover, I tried to duplicate this on the PML Truck cover, I call this a "Worm Trail", as the diff fluid cannot directly contact the vent tube.
I also wanted to place the top vent tube in the same relative position as to use the OEM Rubber Vent Tube Connection.
FLUID DYNAMICS:
The PML cover follows the shape of the ring gear pretty close, except at the bottom.
I took a page from Gale Banks theory, and tried to make the fluid flow smoothly around the back of the cover, as to keep the fluid from foaming and help the horsepower/cooling loss of a deep cover, so I added this lower aluminum piece to smoothly redirect the oil flow.
The rear axle temp sending unit installation required welding a small dimple on the inside of the PML cover to replicate what Ford did with the OEM Mustang cover. Additional aluminum material was also welded on the outside of the boss area to allow the Stock Ford temp sending unit to be used.
If I wanted to retain the correct geometry, I would need to make a jig so the new bracket and diff carrier mounting holes would line up in the Exact proper position.
Starting the bracket Jig
Finishing the bracket Jig.
After being satisfied with the new jig, I began the construction of the steel bracket. 3/16” steel I believed would be adequate as I intended to triangulate the bracket design as needed for strength.
For the threads, I bought (2) steel 14mm coupling nuts. They are 2” long and seemed to be a perfect start. I also wanted some thick mounting face pads, so I purchased (2) steel ¼” thick 9/16” ID x 1 ½” OD washers. The rest I fabricated from 3/16” steel plate.
Starting the steel bracket fabrication
Finishing the steel bracket
Finally, after checking everything and final assembly, 85 oz. of BG 75W 140 LS Gear Oil was added, and the unit was ready to be installed. -The original 3.73 unit was used as to have the best baseline for temp comparison, etc.-
Side by side with an OEM carrier, The finished project looked really good as I also replaced the inverted torx headed bolts with hardened flanged cap screws.
No problems with Installation, everything fit perfectly
UPDATE: Recently I also got some time to experiment with these two Vibration Dampers, attached to the top 2 rear bolts. I decided to drill-out the threads on the rear mounts to 9/16", as to allow using longer thru-bolts on the rear mounting. This allowed the longer bolts to go in from the front, and allow room for the attachment of the dampers at the rear. The longer bolts would not go in from the back, because of the clearance needed due to the spare tire pan, (Unless of course you dropped down the entire cradle, which I didn't want to do)
Summary:
After driving with this configuration over 5000 miles, some comments:
The rear axle fluid temps are definitely reduced, not by much, but somewhat.
The rear axle temp used to run between 10 to 15 degrees less than the transmission temps.
Now, the rear axle temps are running 20-30 degrees less than the transmission. Fully warmed up extended driving in 90-95 degree weather, on Florida Interstate (road-surface temps well over 100 degrees F) , rear axle temp running between 205-210 degrees, where the temps were previously 225-240.
Speaking of tracking it, I spent over 39 years racing late model stock-cars on Midwest oval tracks, as a summer hobby.
You can check my accomplishments here: http://racersreunion.com/john-vallo/gallery/all/p=1
So for me, after 2008, it was time to retire from my Racing/Driving career, and move to Florida. Then in 2013 to retire from my Day Job: (F idelity, B ravery, I ntegrity), -Tampa Field Office-
After changing rear-ends and gear ratios several times in my GT350 I really learned to like the new ‘Super 8.8’ IRS design in the S550, but I did have some concern in a couple of areas. The main concern was: Shouldn’t this rear-end hold more fluid ? (Even if Cooler equipped, the fluid capacity was minimal)
This minimal fluid capacity in the rear axle puzzled me. Ford raised the performance engine-oil capacity to 10qts, but reduced the performance rear axle capacity???
After all, there is about 3 ½” of clearance between the back of the cast IRS housing and the Sub-Frame. Plenty of room for a larger rear cover that could hold more fluid..
I waited and figured surely some third-party vendor would come out with a finned rear cover, or a finned rear cover that held more fluid. Didn’t happen… maybe mainly because Ford started putting rear-end coolers on all GT350’s in the 2017+ model years.
This issue bothered me for some time. Two main areas of concern I had with the new Mustang ‘Super 8.8’ IRS rear-end:
1. Minimal air flow to the rear-end housing, as well as exhaust very close to housing.
2. Not enough fluid capacity. (Cooler (69 oz.), or No Cooler, (61 oz.) of gear oil is just too minimal, in my opinion)
I thought about this for awhile before deciding on my approach of designing something myself.
I had read many ideas, (Other than a Cooler Kit), some seemed more helpful than others. (Wrapping the exhaust, so as to reduce heat. Redirecting more air flow to the housing. A finned rear cover. A cover offering larger fluid capacity.)
My approach was to combine 2 of these ideas. A finned aluminum cover that holds more fluid.
Some 2015+ Ford F150 (trucks) also utilize a ‘Super 8.8’ rear end. One problem, the truck rear end is not IRS, it is solid axle. The good thing is that almost all internal parts, as well as the rear cover bolt pattern are the same. I found a company (actually 3 companies), that produces an extra capacity, finned, aluminum cover for the truck. So far so good, but what about the rear mounting, which is on the cover itself for the mustang ‘Super 8.8’ IRS rear end, and two other concerns?
1. No rear mounting on cover.
2. No vent system, (Built into the Mustang cover, and not in the truck cover).
3. (OEM) Temp sending unit/Cooler Line accommodation needed.
From the start I had two plans in mind:
PLAN A was to somehow incorporate the stock Mustang rear cover with a higher capacity finned aluminum cover (from the F-150).
PLAN B was to buy the higher capacity finned aluminum cover (from the F-150), modify it as needed, and design and make my own steel mounting brackets for the rear mustang IRS mounting (not using an additional modified stock cover).
I looked at all 3 finned aluminum covers I found for the truck
1. B&M – This cover was high-quality, and expensive, also had differential cap supports built into the cover (for ring gear and bearing cap deflection), which I didn’t think were necessary for the IRS. Also, the way the fins were cast into the cover, it would require a lot of machine work to allow for any brackets to attach to the back of it. Also, every bolt hole was recessed, which would require washers or machining to get a flat surface on the back of the cover.
2. Mag-Hytec – this cover incorporated a built-in dip-stick, also had large casting supports between the bolt holes that would need to be addressed.
3. PML – this cover seemed best suited for the conversion, it had a lower cost, was flat on the rear (except 3 bolt holes), no fin/casting interference, and held ¾ qt. or (24 oz.) more fluid than stock.
So, I contacted PML and offered them my idea and ask if they would work with me on this project.
My idea was to send them a stock mustang rear cover, they would machine it into just a bracket (with the diff mounts still attached, and this would be fitted to their finned cover.
The PMLTruck cover compared to the OEM Mustang Cover
At first, PML thought I wanted the two pieces machined and welded together to form the new cover. (While this may still be a worthy consideration), I told them: -No welding-, just machining the stock cover so it would clamp or sandwich their cover into place using 8 of the 12 bolts.
The OEM Mustang cover would get machined, then fit to the PML Truck cover
PML's Tech dept. really showed interest, as we went back and forth several times on the details, then suddenly they backed out. Something about: “Since the cover is part of the mustang suspension, we cannot go forward with this effort”.
NOW to PLAN B
I went ahead and purchased the PML rear cover. When it arrived, I studied it and began my design for the steel diff carrier mounting bracket that would attach to the rear of the cover. I also had to figure out a venting system for it and it needed a thicker area for the Ford OEM temp-sending unit. The cover had a unmachined boss cast in it for an old-style temp sending unit about ¾” thick, but the Ford OEM unit doesn’t go all the way thru to the oil, and needed 1 ¼” of thickness. So, about ½” more alum thickness was needed on the boss, as well as the proper sized hole and threads cut for the sending unit.
Ford has a very nice venting system for the OEM Mustang cover, I tried to duplicate this on the PML Truck cover, I call this a "Worm Trail", as the diff fluid cannot directly contact the vent tube.
I also wanted to place the top vent tube in the same relative position as to use the OEM Rubber Vent Tube Connection.
FLUID DYNAMICS:
The PML cover follows the shape of the ring gear pretty close, except at the bottom.
I took a page from Gale Banks theory, and tried to make the fluid flow smoothly around the back of the cover, as to keep the fluid from foaming and help the horsepower/cooling loss of a deep cover, so I added this lower aluminum piece to smoothly redirect the oil flow.
The rear axle temp sending unit installation required welding a small dimple on the inside of the PML cover to replicate what Ford did with the OEM Mustang cover. Additional aluminum material was also welded on the outside of the boss area to allow the Stock Ford temp sending unit to be used.
If I wanted to retain the correct geometry, I would need to make a jig so the new bracket and diff carrier mounting holes would line up in the Exact proper position.
Starting the bracket Jig
Finishing the bracket Jig.
After being satisfied with the new jig, I began the construction of the steel bracket. 3/16” steel I believed would be adequate as I intended to triangulate the bracket design as needed for strength.
For the threads, I bought (2) steel 14mm coupling nuts. They are 2” long and seemed to be a perfect start. I also wanted some thick mounting face pads, so I purchased (2) steel ¼” thick 9/16” ID x 1 ½” OD washers. The rest I fabricated from 3/16” steel plate.
Starting the steel bracket fabrication
Finishing the steel bracket
Finally, after checking everything and final assembly, 85 oz. of BG 75W 140 LS Gear Oil was added, and the unit was ready to be installed. -The original 3.73 unit was used as to have the best baseline for temp comparison, etc.-
Side by side with an OEM carrier, The finished project looked really good as I also replaced the inverted torx headed bolts with hardened flanged cap screws.
No problems with Installation, everything fit perfectly
UPDATE: Recently I also got some time to experiment with these two Vibration Dampers, attached to the top 2 rear bolts. I decided to drill-out the threads on the rear mounts to 9/16", as to allow using longer thru-bolts on the rear mounting. This allowed the longer bolts to go in from the front, and allow room for the attachment of the dampers at the rear. The longer bolts would not go in from the back, because of the clearance needed due to the spare tire pan, (Unless of course you dropped down the entire cradle, which I didn't want to do)
Summary:
After driving with this configuration over 5000 miles, some comments:
The rear axle fluid temps are definitely reduced, not by much, but somewhat.
The rear axle temp used to run between 10 to 15 degrees less than the transmission temps.
Now, the rear axle temps are running 20-30 degrees less than the transmission. Fully warmed up extended driving in 90-95 degree weather, on Florida Interstate (road-surface temps well over 100 degrees F) , rear axle temp running between 205-210 degrees, where the temps were previously 225-240.
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