2018 GT PP2 Rear Differential Overheating Issue

[shogun32]

you are getting temp warning from the diff just bombing canyons?
Yes the FTB kit works fine. Or you can assemble the kit yourself from bespoke parts from Summit Racing. Steeda sent me their BoM for their race cars and it's very similar to the FTB kit. The only notable diffference is that Steeda mounts the cooler and pump in the trunk instead of exposing to nasty road salt and water spray.

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[mustang5o]

I've gone through the thread and seen the FTB kit mentioned a couple times without much follow up. Has anyone confirmed it actually works and solves all diff overheating issues?

Also has anyone swapped the diff cover by just loosening and supporting the diff instead of fully removing it from the car?

I'm not super enthused about having to pull the diff given that it would entail having to re-clock the bushings and re-align the car, all of which I literally just did.

This is becoming a little frustrating if I'm being honest. I bought a performance handling focused Mustang which I thought is built to carve canyons and I can't even do that.

I've been debating on trying to make a GT350 fit in my budget (I do have other hobbies ). The thought of this just reinforces that. I wonder if there's any good install write ups or video's to watch.

you are getting temp warning from the diff just bombing canyons?
Yes the FTB kit works fine. Or you can assemble the kit yourself from bespoke parts from Summit Racing. Steeda sent me their BoM for their race cars and it's very similar to the FTB kit. The only notable diffference is that Steeda mounts the cooler and pump in the trunk instead of exposing to nasty road salt and water spray.

I would like to see the data from Steeda.

If I don't get a GT350 (or maybe a Mach 1) I'll be considering a diff cooler next year as I'm hoping to get more track time in 2021 and beyond.

 

[wtb6mtv8rwd]

you are getting temp warning from the diff just bombing canyons?
Yes the FTB kit works fine. Or you can assemble the kit yourself from bespoke parts from Summit Racing. Steeda sent me their BoM for their race cars and it's very similar to the FTB kit. The only notable diffference is that Steeda mounts the cooler and pump in the trunk instead of exposing to nasty road salt and water spray.

I am although to be fair it's a quiet section of empty road I know well and can drive fairly hard on (edit: that would never happen with a Bimmer though!)

That's good to hear.

Tilton pump is ~200, Derale cooler/fan combo is 150-200. While I like the convenience of a complete kit it looks like there'd be substantial savings piecing your own.

BoM? Not familiar with that term.

Mounting in the trunk sounds great. There's plenty of room there actually.

 

[NeverSatisfied]

I've gone through the thread and seen the FTB kit mentioned a couple times without much follow up. Has anyone confirmed it actually works and solves all diff overheating issues?

Also has anyone swapped the diff cover by just loosening and supporting the diff instead of fully removing it from the car?

I'm not super enthused about having to pull the diff given that it would entail having to re-clock the bushings and re-align the car, all of which I literally just did.

This is becoming a little frustrating if I'm being honest. I bought a performance handling focused Mustang which I thought is built to carve canyons and I can't even do that.

I personally installed the ftbr kit and it fixed the problem. I could put into limp mode in 2-3 laps vs completely fixed the temps. Max temp was 235-240.

it just moves the weak link though to the engine coolant and engine oil cooling systems. You will probably be ok on the street. I’m impressed you can flag the diff on the street.

 

[shogun32]

BoM? Not familiar with that term.

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[fatbillybob]

FWIW I'm strapped into my racecar and it is difficult to exit because of all the gear and roll cage bars etc. Many many pro racers put the pump and even the radiator inside the trunk area. It makes servicing much easier than having to get the car on the lift and possible puncturing the radiator with rocks etc if under the car. I will say again the stock 350GT location is under the car away from rocks coming off the wheels.

If your racecar does not have an aftermarket bulkhead sealing off the rear trunk area I would not have the stuff inside the car with me. I don't want 300F oil spraying on me from a burst line or even the fire potential. I want all that stuff outside the cabin. Also without a bulk head the heat will increase in the cabin and help cook you. So the bulkhead also acts as a firewall. I also do not have batteries or AN fuel lines inside the car with me.

 

[racingandfishing]

All great points. I was thinking about mounting the radiator and pump in the rear wheel well, but I also have a rear seat delete that is even less of a barrier than the stock rear seats. Thinking it is going under the car and maybe finding a way to better protect it. Like you said, the GT350 has it mounted under a rear belly pan. Seems like it is going to have to be a compromise one way or the other as I don't want to fry myself!

 

[Champracerj]

All,

Here is an up date on my SUSA / AutoSport Diff Cooler. see post #296 and others.

I have now 4 track events and 9 days of tracking with this cooler. Weather was consistent at high 80's to low 90's

I am very pleased with the results. I can do unlimited lapping with the diff temp stabilizing at a max of 235F.

After the first 2 events and 5 track days, I sent the diff lube out for analysis to see how well the diff lube is holding up.

For my first 2 events with the cooler, I used Ford Motorcraft 74W-140 lube and the following is the lube analysis.

I'm thinking the excellent iron results could be due to in-line filter. Or I have a very good diff as I have taken good care of it changing the lube often.

For the other 2 events / 4 track days I'm using the Joe Gibbs Driven Racing Oil synthetic gear oil 75W-110 because it was developed to run cooler.
My experience on the highway at sustained 70mph it maybe running 5F to 10F cooler never getting above 185F. On track with continuous lapping the Max temps were the same at 235F

For now I have no other plans and will be running the system as is.

 

[racingandfishing]

Great information! Would be curious to see the oil results after running the Driven oil to see if there is any difference.

 

[1958cyclist]

Continued SUSA/AutoSport Diff cooler install
Mounting the pump.

I made a bracket to mount the pump. The bracket is ¼” alum plate mounted to the exhaust hangers. I used spacers between the exhaust hangers and the pump bracket to provide clearance for the from of the exhaust hangers and a wire harness. This allows the pump to be mounted at the level of the drain plug so it will never starve of fluid and destroy itself. The issue I see with it mounted to the under side of the trunk floor is that its higher than the fill plug.

Component placement and routing:
Once the placement of the filter, pump and cooler were determined I started to work on the hose routing. I wanted to keep every as compact as possible. I mounted the filter with spacer and 1” clamp between the pump and the cooler. The pump is on the cool return side to keep it cooler than on the hot side pumping hot oil. The Temp switch is on the fitting at the diff cover to get the best temp reading.

Fill procedure. I made a switch to jumper the relay so that I could run the pump to ensure the system is full of gear lube. I filled the cooler, pump and filter and connected the hoses. With the lower hose connected, and with the top hose to the diff disconnected, I filled the diff in the typical way. I also filled the top hose before connecting it. I ran the pump with the switch jumpering the relay. Then I removed the top hose connection to ensure the diff was full.

I'll be at Watkins Glen Aug 21-25 testing the system. In the mean time I will do some street driving to ensure everything is working without issues. I will monitor the diff temp with my dash gauge and AIM Solo.

Hi Jay, love following your solution for this issue. Unfortunately, I don't have the skill set to attempt the wiring, or a friendly shop to make the mounting bracket, so I guess I'll opt for the Full Tilt Boogie option as it is less expensive than the Ford Performance option, and seems to get the job done as a complete kit. Has anyone had any experience(s) with the FTBR unit?

 

[NeverSatisfied]

Hi Jay, love following your solution for this issue. Unfortunately, I don't have the skill set to attempt the wiring, or a friendly shop to make the mounting bracket, so I guess I'll opt for the Full Tilt Boogie option as it is less expensive than the Ford Performance option, and seems to get the job done as a complete kit. Has anyone had any experience(s) with the FTBR unit?

Yep went with FTBR. Stabilizes at ~235 also. I’d just skip the temp sensor switch that comes with it use a relayed switch. I put lots of track days on it and solved my differential overheat... just be prepared to find the next weak cooling system link on the PP2

 

[fatbillybob]

I do not see how a temp switch works because the temp switch measures oil sitting outside the diff usually inline on the way to the cooler. That oil isn't going to be an acurate temp. That's how most Tstats are wired in like champracer bove. If the Tstat is on the case then triggers the pump OK. That will work. I also do not think you can run the diff too cool on track. So if you just switched the diff pump on after the warmup laps I'm sure you would be fine and not need another failure point the Tstat. AS a racer I want stupid simple minimal failures. If the cooler is for a streetcar only you really don't need the cooler.

 

[MadDog]

I put on a lot of Heatshield on my exhaust pipes all around the differential cover and still had overheating issues at Buttonwillow. I recently ordered this finned differential cover and now waiting for Santa to deliver. I plan on using Amsoil Severe Gear 75W-140 and some Motorkote. I would also like to test the oil that comes out of the diff.

 

[Norm Peterson]

I do not see how a temp switch works because the temp switch measures oil sitting outside the diff usually inline on the way to the cooler. That oil isn't going to be an acurate temp. That's how most Tstats are wired in like champracer bove. If the Tstat is on the case then triggers the pump OK. That will work. I also do not think you can run the diff too cool on track. So if you just switched the diff pump on after the warmup laps I'm sure you would be fine and not need another failure point the Tstat. AS a racer I want stupid simple minimal failures. If the cooler is for a streetcar only you really don't need the cooler.

Stupid-simple sounds like the best way to arrange it even if you only need the cooler for the occasional canyon run on a hot summer day. Point being if you're going to play that hard, you should have your head in the game enough to make the necessary preparations first.


Norm

 

[1958cyclist]

Yep went with FTBR. Stabilizes at ~235 also. I’d just skip the temp sensor switch that comes with it use a relayed switch. I put lots of track days on it and solved my differential overheat... just be prepared to find the next weak cooling system link on the PP2

Have you begun to resolve that issue yet? Did you go the remote oil cooler route or larger radiator, or both?

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