"Rear Axle Differential Temp Increased, Decrease Speed" warning

[Optimum Performance]

FM is such a small percentage of the fill it is not going to effect how the oil cools.

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[EXP Jawa]

Not trying to highjack the thread but I think that if a easy and inexpensive solution could be found we would all be happy.

So Rick,
I have heard that due to the properties of FM that it doesn't dissipate heat very well (and this may be false). So if we don't run FM wouldn't the diff have a better opportunity to cool? Your thoughts?

I think you have it a little backwards - FM is thermally stable up to about 300 degrees F. Above that, it starts to cook out of the base oil. So, if the diff doesn't cool well, the FM is subject to breakdown.

I don't see how it would impede cooling. That which would impede cooling would be something that insulates the axle components from transferring heat to the oil, or transferring heat from the oil to the outer carrier or cooler. Unless the FM generates small air bubbles between the metal and the oil, it wouldn't make a difference. This is, incidentally, why Water Wetter works in a radiator system - it helps reduce the bubbles that insulate the heat transfer.

Anyway, if you knew what was going on inside the axle from a lube flow point of view, you'd see that a little FM couldn't possibly make a difference. Oil is being flung in every direction by the ring gear and pinion head, and there's very little actually sitting in the bottom of the carrier. If you have a vision of the oil sitting in a reservoir that the ring and diff happen to serenely dip through, well it couldn't be much farther from the truth. The ring is rotating at 7-800 RPM, depending on speed, and the oil is sprayed everywhere, becoming fairly aerated. If fact, the oil that gets into the diff gearing is little more than a mist. So, without a lot of volume to start with, and the exhaust running close by, there isn't a lot of opportunity for the oil to carry heat out regardless.

 

[Brent Dalton]

I have a hptuners nGauge. So I reached out to E-Motion, the maker of all nGauge's a while back about the diff temp sensor DMR/PID. They quickly got back with me and sent me a file to test out. It worked! I've been testing it the last couple of weeks and it has worked flawlessly. Today, they sent out the newest firmware 209 for BETA testing to me. As you can see...



The DMR has been added. Once the beta testing is complete, they will release the new firmware.

If you have an ngauge(I would assume this will work with Lund or hptuners) and would like to test the beta firmware so you can have the rear diff temp sensor(only works if you have a 16+ performance package or GT350), you can email support at e-motion. There is a disclaimer you need to be aware of though:

" It’s a BETA and very BETA at that. So, although we don’t expect any issues, there is the possibility it could brick on update or freeze or cause issues that may require it to be shipped back to us to rectify. I’d be really surprised if any of that was the case, but we really have to put the beta disclaimer on this build.

If you’re still comfortable with the prospect of using a beta build, go ahead and update your nGauge (put the firmware on your root directory of your SD card, and from within the nGauge go to Diagnostics>Settings>Update from SD). It should say it found v209 and ask if you want to update to it. Go ahead and update at that point and enjoy."

Also of note, I learned that the only cars with the diff temp sensor are the 3.73 cars(16+ performance package cars).

I've been dragging my feet on the rear diff cooler:

1. Because I haven't got the dash warning since switching to amsoil 75w110 and
2. Because I had no way to quantify changes

Now that I have some baseline data and a way to quantify changes, I'm going to start working on the diff cooler in the not too distant future.

I haven't done any track days with it yet, but I did drive an hour to the AutoX, did 4 runs, and drove an hour home. On the drive home(cruising on the interstate at about 75mph), the diff temp was 217 F. I didn't even think to look to see what the diff temp was during the AutoX unfortunately as it wasn't part of the main screen gauges until today(and I was still keeping an eye on my tune since I just went GT350 IM, TB, 47lb injectors, and E85 and got it dialed in the night before).

If anyone is wanting to pick up an nGauge to monitor diff temps(or any number of sensors/inputs), [MENTION=9374]Sock[/MENTION] on the forum sells them. It really is an awesome little unit.

 

[valentinoamoro]

Can one of our vendors make a simple aluminum finned differential cover with slightly more capacity than stock. Also, a scoop similar to the Ford performance pack transmission cooler to channel some underbody air to the diff?

This would be a simpler passive solution than running wiring, pumps, fans in the diff and be similar to the stuff you see under 'M' performance BMW's.

Between heat wrap, that and some higher temp diff fluid I think we should be good.

http://www.vrperformance.com/mt/DSC00724.JPG

Steeda had one for the S197 but it was same capacity I think as stock and no scoop...
http://www.americanmuscle.com/steeda-finned-88-diff-cover.html

 

[Brent Dalton]

It was discussed early on in the thread. It's a good idea. Someone had mentoned pricing one out and it was in the $500 range. It would have to be a cast piece and would require a large number to be put into production. I think most of us have come to the conclusion that a diff cooler is our cheapest and fastest solution. It will also be the most effective.

 

[valentinoamoro]

It was discussed early on in the thread. It's a good idea. Someone had mentoned pricing one out and it was in the $500 range. It would have to be a cast piece and would require a large number to be put into production. I think most of us have come to the conclusion that a diff cooler is our cheapest and fastest solution. It will also be the most effective.

Thanks. If its between 300-500, I'm in. Def not interested in pumps/fans and all that nonsense that will add weight and go bad. I just pinged Mishimoto - they specialize in cooling. I called out the fact that diff cooling is the most important cooling issue in the S550 Gt right now and asked them if they can look into it. I'd rather this than larger radiators, coolant tanks etc - no one had had a problem with any of thank on NA builds so far.

 

[Optimum Performance]

Thank you for your efforts Brent. My cover should be here this week, and I should have a working protoype for testing really soon. It runs a lot hotter on the street than I expected. I have to rethink some things now. I appreciate the insight.

 

[Brent Dalton]

It was 98-103 outside yesterday. I just drove about 60 miles round trip with it being 80 degrees outside at about 65mph. The temp was around 180-185. I wish I would have thought to look at the diff temp at the AutoX. I'mI'm kicking myself.

Look forward to what you come up with Tim.

 

[Kahboom]

Sub

 

[16s550]

Sub aswell

 

[Bahndvr]

I have a hptuners nGauge. So I reached out to E-Motion, the maker of all nGauge's a while back about the diff temp sensor DMR/PID. They quickly got back with me and sent me a file to test out. It worked! I've been testing it the last couple of weeks and it has worked flawlessly. Today, they sent out the newest firmware 209 for BETA testing to me. As you can see...



The DMR has been added. Once the beta testing is complete, they will release the new firmware.

If you have an ngauge(I would assume this will work with Lund or hptuners) and would like to test the beta firmware so you can have the rear diff temp sensor(only works if you have a 16+ performance package or GT350), you can email support at e-motion. There is a disclaimer you need to be aware of though:

" It’s a BETA and very BETA at that. So, although we don’t expect any issues, there is the possibility it could brick on update or freeze or cause issues that may require it to be shipped back to us to rectify. I’d be really surprised if any of that was the case, but we really have to put the beta disclaimer on this build.

If you’re still comfortable with the prospect of using a beta build, go ahead and update your nGauge (put the firmware on your root directory of your SD card, and from within the nGauge go to Diagnostics>Settings>Update from SD). It should say it found v209 and ask if you want to update to it. Go ahead and update at that point and enjoy."

Also of note, I learned that the only cars with the diff temp sensor are the 3.73 cars(16+ performance package cars).

I've been dragging my feet on the rear diff cooler:

1. Because I haven't got the dash warning since switching to amsoil 75w110 and
2. Because I had no way to quantify changes

Now that I have some baseline data and a way to quantify changes, I'm going to start working on the diff cooler in the not too distant future.

I haven't done any track days with it yet, but I did drive an hour to the AutoX, did 4 runs, and drove an hour home. On the drive home(cruising on the interstate at about 75mph), the diff temp was 217 F. I didn't even think to look to see what the diff temp was during the AutoX unfortunately as it wasn't part of the main screen gauges until today(and I was still keeping an eye on my tune since I just went GT350 IM, TB, 47lb injectors, and E85 and got it dialed in the night before).

If anyone is wanting to pick up an nGauge to monitor diff temps(or any number of sensors/inputs), @Sock on the forum sells them. It really is an awesome little unit.

So you're using the stock rear diff sensor, did you tap into it or disconnect it from the ECU?

 

[Brent Dalton]

So you're using the stock rear diff sensor, did you tap into it or disconnect it from the ECU?

No, it is pulled from the OBD II port through the nGauge. E-motion did all the work to figure out how to map the sensor. Very impressed with their customer service. I only wished I would have emailed them sooner. The more I play with the nGauge, the more I like it.

 

[Bahndvr]

No, it is pulled from the OBD II port through the nGauge. E-motion did all the work to figure out how to map the sensor. Very impressed with their customer service. I only wished I would have emailed them sooner. The more I play with the nGauge, the more I like it.

I know you said DMR but was just making sure.

*Oh forgot to ask, do you know if the nGauge can do the crank relearn?

 

[Brent Dalton]

Not sure if the ngauge can, hptuners can though(I am a hptuners user). I'll look around when I get a chance and check, but I don't think that would be something the ngauge could do. Who knows though, it might be something that could be stored on the SD card or added in newer firmware.

 

[Bahndvr]

The reason I ask is that I've heard that the SCT X4 can. I don't know all the details.

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