Chris Edwards

Curious if people are installing a gauge for each or if the instrument cluster warning signs are sufficient. Is there a sensor for both the trans and diff?

froggy47

The c5z has a DIC warning on tranny temp @ 274 or 276 F I forget which (from the factory stock), I got it once. If you run full syn fluid you should be ok. There is a "hack" to be able to display that on the dic. I have not done it so can't explain it. Requires wiring & etc.

For the diff, you would have to add a sensor & all that. IMO the diff should be ok also with full syn (I favor Redline for both).

If you are talking TT or WTW that's a whole other story.

I did just start messing around with some OBD2 bluetooth "dongles" that transmit to app's on a smartphone, so you might want to ck around on that & see if PID data (wiki it) is available at the obd2 port to show you what you want. Fun stuff.

Sox-Fan

Right hand guage is usually set to trans temp for the upper display

parsonsj

I've gotten trans temps on my C6 Z06 via OBDII connections (DashLogic and another custom pid app), but never diff temps.

I don't believe there is even a diff temp sensor... I think the diff temps are considered as part of the trans temps since they "share" a cooler.

Chris Edwards

I forgot to mention I will be doing HPDE, Froggy in your opinion do you still think I should be ok with just the synthetic fluids?

froggy47

Probably, mostly stock cars will see temps for coolant & oil go up before the tranny & diff get in danger zones.

What radiator & (if any) oil cooler do you have?

moespeeds

I heard all this talk about Trans and Diff coolers and when I was rebuilding my '00 FRC into a T1 car I considered adding coolers to both. Instead I decided to run gauges to both the trans and diff so I could monitor temps and decide if I really needed coolers. Call me a fast-ish HPDE guy, running a strong LS6 on coilovers and slicks. My trans rarely climbs above 200, but the diff will hit 300 fifteen minutes into a session. The gauge maxes at 320 and it will pin by the end of a 20 min session. To verify the readings I swapped sensor leads to confirm. I used sensors from summit racing, going into custom drain plugs in both the trans and diff. So IMO, the diff is what needs to be cooled first.

Watch the video below, skip towards the end. This is the second half of a 25 min session. You can see my two temp gauges, round with silver bezels, on the panel directly above my shifter. The right is Diff, Left is Trans. Both are 320 deg gauges/sensors. If you look closely you can see the trans hovers around 200, but the diff is maxed. This was Nov in NJ, probably around 60 degrees OAT.

mikeCsix

Moespeeds, thanks for posting. I run and A-6 on my GS and I can hit 240 fairly easily and have long suspected a diff cooler would help keep the temps down. The problem for dual duty cars (dd/hpde) is one of space to mount the cooler and for us A-6 drivers, modifying the diff itself for a cooler. Anyone know where we can buy the Z-06 differential pumps? I recall there is a vendor on CF that sells them, my bad for not bookmarking the website.

With dual duty cars and space considerations. I've been thinking about using a heat exchanger instead of a mini radiator. GM came out with the newer heat exchangers, using transmission oil to transfer the heat from the differential oil. With the A-6 already struggling with heat issues, this doesn't make sense to do. However, if the heat exchanger for the differential can be plumbed into the cooling system for the engine it might be a viable alternative especially if running an oversized/aftermarket engine radiator (I have a DeWitts).

Chris Edwards

So I'm guessing you ended up going with a diff cooler, the DRM?

Froggy, I am still using the stock radiator, but a good Setrab oil cooler with -12 fittings that Pumba sold me, in conjunction with an Improved Racing thermostat/ block adapter.

el es tu

c6s have trans temp as an option on the dic - I always switch to that while driving and run everything else on the hud

on a c5 you could have the car's tune set to have the warning come on at a temp you specify if you wanted a quick and easy way to monitor whats going on...

Chris Edwards

I have HP Tuners, I'd assume that's something I can change easily just like fan temp settings, etc? That's fantastic! What would be a safe limit for diff temps? I'll set the warning temp to something conservative until I have time to do the diff cooler.

I really wanted to take the car to the track as stock as possible to shake it down, but I keep reading about all the cooling problems these cars have, so I figure better safe than sorry.

froggy47

You should check out the screen setup I did for mine to keep all the street crap out of those nice clean units. It's on my channel & its very easy to do. Going to the track you just take it off. Get home just screw it back on.

My 04 stock radiator has plastic tanks, you sure yours is stock/original?

el es tu

When I hit the 220 - 230 range on my trans temp readout, I start slowing down just to be safe. Its really surprising that it took so long (C7) before these "sports" cars came with drysumps and cooling for all the fluids right from the factory...

Chris Edwards

Froggy, that picture was from when Pumba was advertising the cooler he sold me.

froggy47

Gotcha.

moespeeds

Redline told me the fluid I'm using in the trans and Diff are both perfectly fine up to 275. They don't recommend going beyond that. Ask Froggy what Redline products I'm using, I got the info from him and I can't remember off the top of my head. I change the Diff often, every 10-15 hrs. The C5 doesn't measure diff temp, just trans, and my diff runs a full 100 degrees hotter than the trans. Keep in mind I'm running a track only car, on slicks. Your mileage may vary with street tires.

C5Z06CE

I recently had a diff cooler and pump installed. My cooler is in the right rear brake duct area (tranny cooler in the left) with the turbowerx diff pump mounted on the center frame. Here is a pic and a link to the turbowerx pump.

http://turbowerx.com/Scavenge_Pumps/.../Exa-Pump.html

rithsleeper

Ive always wanted to cool my diff and draining that sucker with a pump is a pain. Was thinking of tapping out a drain plug and putting an old coolant sensor I had into the hole.

Why are these fluid pumps so much money? $400 to move a little oil? Isnt there anything around $100? I think even the smallest heat exchanger on a rear diff would make a huge difference seeing how it has nothing, even fins, right now on my c4.... I guess to monitor temps and pump I would need to tap 3 holes. Hope there isnt a clearance issue.

froggy47

I just bought a submersible water pump for my fountain for $30. I could see $100 but $400? A lot of "racing tax" on that little guy.

C5Z06CE

This is not a "racing tax". A pump for diff fluid needs to be able to handle hot oil up to 275F if you track the car. That water pump for your fountain and those Shurflo pumps commonly used for meth kits and soda machines have a rubber diaphragm inside to pump the fluid. How long do you think that will hold up to hot diff oil? Answer not long.... If your diff over heats and is damaged it's not cheap to replace.

If your car is a garage queen and occassionally auto crossed maybe you could get by with your diaphragm pump but any serious track use will require a pump that uses GEARS to pump oil. This motor is rated to 10,000hrs of use with the ability to be rebuilt and brushes are replaceable. I blew my diff on track at 100 mph and can tell you the extra $300 is worth it to me to not go through that again not to mention the expense and lost track time. It happened on lap #5 of my 1st session. I not only lost my $275 for track day, plus $175 towing, plus repair bills..... and Weeks in shop missing out driving my car, etc... Seems like cheap insurance to pay for durable quality product.

C5Z06CE

By the way here is a source to explain why gear motors are better. This guy is a bit arrogant and has a bit of a chip on his shoulders but if you filter through that he has some good stuff to teach.

http://www.rbracing-rsr.com/oilsystems.htm