When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Trying to learn more about my new to me 2003 Z06 track car. I bought a Edge CTS/2 monitor to use as a data logger. One of the features allows me to measure transmission temps. Doing 25 to 30 minute sessions I found the trans gets up to 251 degrees after the third session and seems to stay in that temp range even after the 4th session. The trans seems to have a heat soak effect compared to engine coolant and engine oil temps as the trans gets hotter with each session.
I don't have a way to read diff temps yet, but since both the trans and diff are connected, how much difference is there in temps between the two for those that have temp sensors in each? I'm wondering how much each has an effect on the other, especially after a 25 minute track session where the car then comes back to the pits and sits for about an hour.
My current track days have been in 80 degree and 65 degree temps...pretty cool. But 90 plus days are just around the corner and I'm trying to gather data on what's going on back there and if I'll be forced to run diff/trans coolers (something I'm trying to avoid for just an HPDE car).
The C5 diff has ~1/2 the fluid capacity of the diff and re-routes the torque 90 degrees so yes, the temp is a bit higher than the trans.
And yes, the hot diff casing will heat up the trans casing (and fluid).
The C5 diff has ~1/2 the fluid capacity of the diff and re-routes the torque 90 degrees so yes, the temp is a bit higher than the trans.
And yes, the hot diff casing will heat up the trans casing (and fluid).
I should have asked this before, but what is a safe "not to exceed" differential temperature?
I've read that the DIC will show a high temp warning at 270 degrees. What is the safe "not to exceed" temp for the transmission? Are transmission parts going to get damaged running hard for 25 minutes at 250 degrees?
The car has Redline fluids in both the diff and trans.
I have been looking for a way to scoop up some air from under the car to push around that area.
Also looking at wrapping the over the cradle exhaust to help with heat. Mine has never overheated but the effort to put the car in 4th gear progressively gets harder as the day goes on.
I have been looking for a way to scoop up some air from under the car to push around that area.
Also looking at wrapping the over the cradle exhaust to help with heat. Mine has never overheated but the effort to put the car in 4th gear progressively gets harder as the day goes on.
I've already done the DEI titanium header wrap from the X-pipe back over the cradle. In my first track day with no wrap I hit 250-ish degrees...Second track day with the wrap I hit 251 degrees, lol. At least I'm consistent. Both these temps were after the third session as I see the trans temp heat increase with each session.
I'm too am looking at trying some sort of scoop like my Viper uses to cool the rear diff. I'm going to mount it just under the trans and take readings to see if more air flow will help.
One "low rent" band aid may be to build some sort of low profile fan (like the radiator electric fans we have on our cars now) to slide under the vehicle after each session and blow air up to the trans/diff area. I have electric power from a generator at the track, so it would be interesting to see if just putting a fan under the rear end for about 45 minutes when between sessions would drop the temps down enough to keep the heat soak issue at bay. The trans/diff get hot and are pretty much in their own chamber and the heat has nowhere to go.
A Spal or Maradyne fan blowing upwards would be an interesting experiment.
I've already done the DEI titanium header wrap from the X-pipe back over the cradle. In my first track day with no wrap I hit 250-ish degrees...Second track day with the wrap I hit 251 degrees, lol. At least I'm consistent. Both these temps were after the third session as I see the trans temp heat increase with each session.
I'm too am looking at trying some sort of scoop like my Viper uses to cool the rear diff. I'm going to mount it just under the trans and take readings to see if more air flow will help.
One "low rent" band aid may be to build some sort of low profile fan (like the radiator electric fans we have on our cars now) to slide under the vehicle after each session and blow air up to the trans/diff area. I have electric power from a generator at the track, so it would be interesting to see if just putting a fan under the rear end for about 45 minutes when between sessions would drop the temps down enough to keep the heat soak issue at bay. The trans/diff get hot and are pretty much in their own chamber and the heat has nowhere to go.
A Spal or Maradyne fan blowing upwards would be an interesting experiment.
I had this same thought, I thought of backing the car onto ramps and letting a fan blow under the car.
I think the heat comes more from where the pipes turn up to go over. Wonder if heat shields would help there?
This area
Last edited by FASTFATBOY; 04-27-2016 at 10:16 PM.
I think trying to build some sort of heat shield may actually help impede more air flow and cause even more heat to stay in the area an not dissipate.
On my last track day I had the whole exhaust wrapped all the way over the hump. This was my first experiment with the wrap and the testing was more extreme than my first track day with no wrapping. This was a private track rental with two run groups so we were out for 25 minutes and back in for 35 minutes...very little cool down between sessions. What I'm seeing is about 220 degrees in the first session, 240 degrees in the second session and 251 degrees at the end of the third session (trans temps). It was a pretty cool 65 degree morning.
The ultimate solution is a real oil cooler system for the trans and diff....I just don't want add the expense and weight of that system without trying some low end ideas first. Not racing for a trophy, but I don't like equipment failures either.
At SEMA a few years ago I stood near a 20 amp Maradyne electric fan and was shocked at the amount of airflow and velocity it produced....it was actually uncomfortable to be near it and was blowing down other peoples displays. Maradyne did tell me that the only two manufacturers on the market that post truthful cfm figures is Spal and them. Just FYI if you go shopping for fans.
Just put a cooler and pump on the trans and never think about it... ever again. Yes there is a cost associated with this, but those of us that really use the cars never found a suitable "cheaper" alternative. We have all tried wrap on the exhaust, heat shielding, polished trans internals, etc. The only real fix is a trans cooler or diff cooler... you don't really need both.
DRM sells a good kit.
As for "safe" temps, most of us that have raced without the trans coolers usually hit the "Trans Hot" warning in about 20 mins. At that point you either start short shifting, skipping shifts, or ignore it. The latter wins coffee cups and Hoosier tires, LOL.
I don't know exactly how hot the trans or diff get but I've been through a few transmissions and had the "high trans temp warning" many times while on track.
I eventually bought LG's trans/diff coolers and haven't seen a light since. The hottest temperatures I've run in have been 95 degrees at Buttonwillow. The trans/diff temps didn't slow me down now that I have the coolers but engine oil and water were at about the max I was willing to risk. If it was 100 degrees or more I don't think I could have done a whole session. At least the trans and differential were still good.
LG has changed their kit a little since I bought mine, and its not cheap. Get an electric pump kit or the LG kit and never have to worry about it again.
The only time I'v ever seen the Trans Temp warning was on the autobahn traveling at 130 for 15min. But watch tomorrow it will pop up at the track, maybe I just don't push it that hard at the track. I believe that C5 sold in Europe came with a Trans cooler.
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
Our Diff/Trans cooler kit was setup for the racer in mind. Simple to use, no wiring, and no thinking. You don't have to think about turning the system on when you hit track, it is pumping as soon as the wheels are turning. No worry about a pump failing, or fuse blowing with an electric setup. For those of you that use it on a dual purpose car, it can not be heard inside the car even at 150 mph.
Compact install, no wiring, no switches, and quiet operation.
Most of my customer tell me a solid 50-75 degree drop in both diff and trans cooling with the setup on the cars and the coolers located in the rear fenders behind the Z06 cooler ducts.
We sell it a number of different ways, either with our brackets and lines or a 'do it your self' kit with just the fittings/pump/drive assembly and small hardware if you want to run your own coolers and lines.
Funny, seemed GM liked the idea so much they ran a similar setup on the C6Z's. Just not as efficient.
Had the same heating problems on my 03 Z06. Tried all the band-aid fixes of synthetic lube, header wrap on the exhaust, and a heat shield - none worked worth a crap. Save yourself time and $ and install a good cooler on both the tranny and diff, much cheaper than a replacement. The LG kit is gold standard, cools great and is priced accordingly. I used the DRM kits, much less expensive and saw about a 50 deg drop in temps. NO Problem running a 30 minute session ***** to the wall at VIR in August with 105 degree ambient temp.
Here is a post on the tranny cooler install that I did a couple of years ago.
Our Diff/Trans cooler kit was setup for the racer in mind. Simple to use, no wiring, and no thinking. You don't have to think about turning the system on when you hit track, it is pumping as soon as the wheels are turning. No worry about a pump failing, or fuse blowing with an electric setup. For those of you that use it on a dual purpose car, it can not be heard inside the car even at 150 mph.
Compact install, no wiring, no switches, and quiet operation.
Most of my customer tell me a solid 50-75 degree drop in both diff and trans cooling with the setup on the cars and the coolers located in the rear fenders behind the Z06 cooler ducts.
We sell it a number of different ways, either with our brackets and lines or a 'do it your self' kit with just the fittings/pump/drive assembly and small hardware if you want to run your own coolers and lines.
Funny, seemed GM liked the idea so much they ran a similar setup on the C6Z's. Just not as efficient.
Holy sh*tballs that's a nice kit. Too rich for my blood I'm betting though. My life has sucked pure sh*t since 2013...wtf.
04-27-2016, 12:54 PM
C5 Z06 Transmission track temps vs diff temps
Just not as efficient.
