Road course temps

[PRE-Z06]

On a performance package GT, does the oil or transmission cause limp mode first?

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[NvrFinished]

On a performance package GT, does the oil or transmission cause limp mode first?

Neither. It's the rear differential that gets hot first. If you have a 2016 or newer you will get a temp warning light, but no limp mode.

 

[CTH621]

Neither. It's the rear differential that gets hot first. If you have a 2016 or newer you will get a temp warning light, but no limp mode.

So with 2015 model year vehicles, there's no temp warning light, and limp mode will just suddenly kick in?

I'm curious because I do time attack with my 2015 GT 6r80 with 3.15 final drive. The cylinder head temp and oil temps go dangerously hot after 8 to 10 mins, but I never had limp mode kick in. No cooling mods.

 

[PRE-Z06]

Neither. It's the rear differential that gets hot first. If you have a 2016 or newer you will get a temp warning light, but no limp mode.

Didn't realize they had a temp sensor in the diff, thought the complaint on the gt350 was from the trans and the diff was brought into the mix just because on the R it has a cooler too. Imagine the 2018 5.0 with its 2 additional quarts and the 10-speed with its 2 additional quarts will help.

 

[racingandfishing]

I have a '15 manual (which means cast iron diff) with no sensor. Curious of those with '16 and up if there is any more frequency with the warnings between the aluminum auto vs the cast iron manual?

I know you would have to have same car, driver and conditions - but maybe a couple of folks were on the track on the same day with auto vs. manual. Would normally think the aluminum would dispel heat better, but there may be other factors.

 

[ddozier]

I have a '15 manual (which means cast iron diff) with no sensor. Curious of those with '16 and up if there is any more frequency with the warnings between the aluminum auto vs the cast iron manual?

I know you would have to have same car, driver and conditions - but maybe a couple of folks were on the track on the same day with auto vs. manual. Would normally think the aluminum would dispel heat better, but there may be other factors.

I have a 15 manual with cast iron diff, so no sensor. I have always limited myself to 25 min or less with at least 2 session off for cool down. I have moved to a 85w140 full synthetic gear lube and change it after every 3 track weekends. Under these conditions the fluid is not burnt and comes out fairly clean but is not as clear as when it went in.

I am adding trans and diff coolers to all my builds as another layer of protection. I do not see how the aluminum housing could hurt but I do not see it as being enough to allow for much longer runs or double stints on track. Really the time and expense to change the rear diff housing vs adding the cooler would make the cooler slightly more expensive than the other work, but the coolers would solve the problem completely and allow for the option to do some endurance racing or for the car to be shared between 2 drivers for 2 sessions back to back at an HPDE.

The next big issue to tackle in order to double stint the car or extend past the 25min window is a dedicated oil cooler and remove the oil to coolant cooler in the GT. Separating the two systems will allow for much better control over the coolant and oil temps. Right now they are tied together and the oil cooler adds a lot of heat load on the coolant system and is marginal at cooling the oil. It is nice to have the two tied together to aid in bringing the oil up to temp quicker for a daily driver but for a track car it is a liability.

Dave

 

[wildcatgoal]

Anyone know if I can tap the 16+ diff temp sensor and send that signal to a gauge that actually displays temp? (This versus installing another sensor in the diff.)

I've tracked my car like 12 times. I've gotten 1 engine oil warning which quickly went away when I toned it down and that was my first track day on 5W20 oil. Since going to 5W40 Liqui Moly, I never saw that again. I get the diff temp warning during summer track days, but BG fluid and wrapping my exhaust with heat tape helped avoid that mostly. I will be installing a diff cooler sometime this year as that is f'ing annoying - usually happens right when I get into a groove.

 

[ddozier]

Anyone know if I can tap the 16+ diff temp sensor and send that signal to a gauge that actually displays temp? (This versus installing another sensor in the diff.)

I've tracked my car like 12 times. I've gotten 1 engine oil warning which quickly went away when I toned it down and that was my first track day on 5W20 oil. Since going to 5W40 Liqui Moly, I never saw that again. I get the diff temp warning during summer track days, but BG fluid and wrapping my exhaust with heat tape helped avoid that mostly. I will be installing a diff cooler sometime this year as that is f'ing annoying - usually happens right when I get into a groove.

It is a 0-5vdc sensor, I would not tap the sensor voltage lead for fear of causing an issue with what the ECU is seeing. I believe you can see the rear diff temp with a scan tool but I have not tried it yet. If you have a tuner or OBD2 scanner that can read Fords protocol I would try that first. Other wise I would keep it simple and add another sensor when you add your cooler. You can add a sensor and gauge very easily in the fitting you use to attache the cooler hoses to the diff. We plan to add idiot lights instead of a gauge, 2 lights would be needed one for min temp reached(green) and a second for over temp(red with buzzer).

Dave

 

[PRE-Z06]

I have a '15 manual (which means cast iron diff) with no sensor. Curious of those with '16 and up if there is any more frequency with the warnings between the aluminum auto vs the cast iron manual?

I know you would have to have same car, driver and conditions - but maybe a couple of folks were on the track on the same day with auto vs. manual. Would normally think the aluminum would dispel heat better, but there may be other factors.

Haven't had an IRS mustang since my 2000 GT which had a unit from '01 Cobra under it, so not up to speed on all the recent changes though trying to get caught up since I'm considering an '18. Interesting they put two different housings in the car I guess to save weight with the auto which should have less drivetrain shock? Would be a nice comparison and you're in the same state so know then the climate would be similar atleast. Correct me if I'm wrong, but none of the cars have an actual numeric value assigned to engine oil temp right?

Btw like your screename as they're my two favorite hobbies!

 

[wildcatgoal]

It is a 0-5vdc sensor, I would not tap the sensor voltage lead for fear of causing an issue with what the ECU is seeing. I believe you can see the rear diff temp with a scan tool but I have not tried it yet. If you have a tuner or OBD2 scanner that can read Fords protocol I would try that first. Other wise I would keep it simple and add another sensor when you add your cooler. You can add a sensor and gauge very easily in the fitting you use to attache the cooler hoses to the diff. We plan to add idiot lights instead of a gauge, 2 lights would be needed one for min temp reached(green) and a second for over temp(red with buzzer).

Dave

Interesting. I plan to add a sensor to the drain hole and when the diff cooler goes in, I'll adjust accordingly. Already have the associated fitting, so why not. I'd like to actually know what temp the diff is when the warning kicks on. Idiot lights seem like a great idea. I was just going to use a white out pen to mark targets and excessive temps.

 

[PRE-Z06]

Interesting. I plan to add a sensor to the drain hole and when the diff cooler goes in, I'll adjust accordingly. Already have the associated fitting, so why not. I'd like to actually know what temp the diff is when the warning kicks on. Idiot lights seem like a great idea. I was just going to use a white out pen to mark targets and excessive temps.

Would like to know as well, please share results!

 

[NvrFinished]

I get the diff temp warning during summer track days, but BG fluid and wrapping my exhaust with heat tape helped avoid that mostly.

The BG 75w-140 fluid plus exhaust wrap near the differential definitely made a difference for me.

 

[PRE-Z06]

The BG 75w-140 fluid plus exhaust wrap near the differential definitely made a difference for me.

I run 85w140 in the c5 diff as precaution since there's no temp sensor and easily see 300* engine oil temps in 20 minute sessions with 7.5 qts of 15w50 in 80*+. I want to keep the car in stock class for autocross, but have something that is going to better on the road course than c5 otherwise I think the c6 GS may be better option.

 

[JohnD]

I have OBDLink MX bluetooth and with Forscan on my phone I can see the diff temp reading, plus so much other stuff I've never gotten through it all.

Do not buy a cheap OBD reader, they will only see the OBDII stuff and none of the stuff specific to the car maker on the Canbus, and that's where the diff temp resides.

Also using the BG 75W140 fluid.

 

[Competition Orange]

I run 85w140 in the c5 diff as precaution since there's no temp sensor and easily see 300* engine oil temps in 20 minute sessions with 7.5 qts of 15w50 in 80*+. I want to keep the car in stock class for autocross, but have something that is going to better on the road course than c5 otherwise I think the c6 GS may be better option.

A c5 with a BBK should have no problem pulling away from a mustang with similar prep.

I don't fit in corvettes or I'd already have one.

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