: Rear Diff Cooler ?s, report back especially track guys



spearfish25
05-22-13, 08:59 AM
Have any of you guys installed the rear diff cooler? Did you get the OEM GM version or the D3 kit?

For anyone who tracks/autoXs without a cooler, how is your rear diff holding up?

I tracked my Nissan 370Z quite a bit and the stock LSD quickly became an open diff without a cooler. I'm reluctant to do much with my V until I get a cooler installed unless I hear it holds up well without one.

the blur
05-24-13, 02:07 AM
I think, you don't really need one, unless your racing. I tracked my car about 300 track miles so far. Never had the light go on. I was not running 10/10's, maybe 8/10's, on OEM tires.

spearfish25
05-24-13, 07:40 AM
Nice to hear it holds up ok for you. Also good to know there is a temp light if its overheating. My Z just turned into an open diff with one wheel peels during auto cross events. Frustrating and disappointing it just died.

Random84
05-25-13, 11:05 PM
I haven't raced mine yet, but the major complaints (besides no cooler and getting the too hot/reduced power thing) is that the fluid volume is only 1.5L.

The upside is that it's relatively cheap to replace it often, so if you're tracking the car it's cheap insurance to replace the fluid more frequently.

spearfish25
05-25-13, 11:24 PM
Another benefit I just discovered is that I can fill and drain the diff without jacking up the car. Just a little shimmy underneath and both screws are accessible. While my dealer said they checked all the fluid levels including the rear diff, they clearly didn't. I added another 300-400ml to my diff when I checked the level tonight.

Somefun
05-26-13, 08:57 AM
If you drive hard you need one for sure.....I can only get about 10 to 13 laps in at Watkins Glenn and just a few more at Lime Rock until the the car says no more. So if your going to really track the car you should get one.

the blur
05-26-13, 09:08 AM
13 laps is a session at WGI. So it's time to come in anyway. Or just short shift 1 lap, then get back on it. Think about all the years cars did not have diff sensors, and they ran just fine on track. Now we know too much, and start worrying too early. Even the old Corvettes ran fine at WGI without a diff cooler, simply because we weren't watching diff temperatures.

spearfish25
05-26-13, 11:36 AM
I agree that ignorance was bliss. My Nissan 370Z that I traded for my Vagon didn't have any diff sensors and I tracked it often. But by year 4 of ownership, the rear LSD was toast. I'd autocross the car and I pretty much just had an open diff. Before I start tracking the V, I'm going to add the diff cooler and trans cooler upgrades. Hopefully it will prolong their lives. 556HP is plenty for me so I'm planning to just focus on making her more robust for lapping and longevity.

Most-wanted
05-26-13, 05:35 PM
13 laps is a session at WGI. So it's time to come in anyway. Or just short shift 1 lap, then get back on it. Think about all the years cars did not have diff sensors, and they ran just fine on track. Now we know too much, and start worrying too early. Even the old Corvettes ran fine at WGI without a diff cooler, simply because we weren't watching diff temperatures.

One cool down lap wont do it. And its not knowing too much. There is no airflow under the car and thats why it gets so HOT. Other cars without sensors are not getting that hot as they have better airflow to that area. If they did overheat you would smell it in a minute like you do on the V. It absolutely needs a diff cooler if you are tracking it in my opinion.

soon to V
05-26-13, 11:11 PM
I've run about 10 track days with the second gen V and diff overheating is pretty likely to happen through the hot of summer. The first session is never a problem. After the diff gets heat soaked through the day, you start getting the warning. At first I would run a big house fan under it after every run, but that gets old and still can't keep up. After the mods I have (about 600 HP at wheels) its much harder to keep it cool. Sure, driving style makes a difference, track layout makes a difference, and location etc, but its still hits the 300 mark sooner or later. I haven't seen a cooler I would want to put on my car, so I've designed my own and have run it for a year and a half now. I've designed it for track days only, not full races, and so far no problems. I've been doing data recording and looking at heat slopes so I hope to offer it to others soon. Its completely hidden and lower in cost since its a lighter duty application.

spearfish25
05-26-13, 11:27 PM
That's great you made your own cooler kit. The D3 kit is a nice and slightly cheaper alternative to the true GM kit, but both are priced very very high. Parts wise, you could put a kit together for $500. But I've been there, done that with an oil cooler on my previous car. The amount of time spent piecing it all together is far more expensive than the overpriced, pre-packaged kits. Still, I'd like to see your setup.

I suppose a poor man's alternative is to spray the diff with a yard sprayer full of water after each session. But that doesn't exactly protect the hardware.

the blur
05-26-13, 11:35 PM
300 degrees doesn't worry me. It's not a crankshaft running fine bearing clearances. The synthetic oil should handle it.

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And I love that splitter. Mine is destroyed from parking lot curbs.

Low_ET
05-26-13, 11:41 PM
I was at Sebring today. I got the differential temperature warning each session. I am going to have to instal a differential cooler to continue to track the CTS-V.

I'm driving pretty hard. I boiled my ATE Super Blue brake fluid yesterday. Larger brake cooling ducts are high on my list too.

the blur
05-26-13, 11:47 PM
I was at Sebring today. I got the differential temperature warning each session. I am going to have to instal a differential cooler to continue to track the CTS-V. I'm driving pretty hard. I boiled my ATE Super Blue brake fluid yesterday. Larger brake cooling ducts are high on my list too.

I have never boiled ATE, not even in my race car. Was it fresh?? Did you test it with the fancy hydro meter ? like most clubs are doing now. I even have opened 2 year old ATE in the metal can, that reads good on the meter.

Low_ET
05-26-13, 11:55 PM
It was fresh for this event. I boiled it after only four 30-minute sessions as my calipers turned from silver to gold. After I bled out the not-so-fresh looking fluid, the pedal went back to normal for the next four sessions. I will bleed it again in the next couple of days just to be safe.

USAFRET
05-27-13, 08:53 AM
If you drive hard you need one for sure.....I can only get about 10 to 13 laps in at Watkins Glenn and just a few more at Lime Rock until the the car says no more. So if your going to really track the car you should get one.

All the HSDE's I've attended usually limit you to about 7 laps. My last event was at Road America in Wis hosted by the Mid-West F-Body Association with my bone stock Z06 and we were limited to 7 lap sessions. To be honest anything more than that would be trouble. Fluids, brakes, tires and even the driver were getting overheated. Of course if not running all out then of course you could run more laps.

thebigjimsho
05-27-13, 09:25 AM
I was at Sebring today. I got the differential temperature warning each session. I am going to have to instal a differential cooler to continue to track the CTS-V.

I'm driving pretty hard. I boiled my ATE Super Blue brake fluid yesterday. Larger brake cooling ducts are high on my list too.

I think a very intensely driven V has the ability to boil fresh ATE fluid. I did it on a hot day at VIR Grand East in my V1 with track pads and slicks. So on the much heavier V2, I'd always use Motul 600, or higher...

spearfish25
05-27-13, 08:17 PM
Agree. The weight is a real issue. I spoke and rode with a guy who owns a Radical SR8LM and he hasn't swapped brake pads in 2 years. He also buys new tires due to heat cycling rather than tread wear. Thats the beauty of a superlight car. While I'd love to have a V that is an end all track car, it needs some serious upgrades and investment to do so. It may ultimately be cheaper to buy a used track toy than to bulletproof and maintain a V for heavy track work.

Doc GTO
05-27-13, 10:21 PM
I was at Sebring today. I got the differential temperature warning each session. I am going to have to instal a differential cooler to continue to track the CTS-V.

I'm driving pretty hard. I boiled my ATE Super Blue brake fluid yesterday. Larger brake cooling ducts are high on my list too.


For a heavy car like the V you need ProSpeed 683. You will not boil that. ATE is only 530 degrees.

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Agree. The weight is a real issue. I spoke and rode with a guy who owns a Radical SR8LM and he hasn't swapped brake pads in 2 years. He also buys new tires due to heat cycling rather than tread wear. Thats the beauty of a superlight car. While I'd love to have a V that is an end all track car, it needs some serious upgrades and investment to do so. It may ultimately be cheaper to buy a used track toy than to bulletproof and maintain a V for heavy track work.

Yep. I have a 2002 E46 M3 track car. Lightweight, slicks, and downforce does the trick! v is for DD and drag strip fun.

baabootoo
05-28-13, 01:18 AM
Have any of you guys installed the rear diff cooler? Did you get the OEM GM version or the D3 kit?

For anyone who tracks/autoXs without a cooler, how is your rear diff holding up?

I tracked my Nissan 370Z quite a bit and the stock LSD quickly became an open diff without a cooler. I'm reluctant to do much with my V until I get a cooler installed unless I hear it holds up well without one.

Get a laser temp gun and make sure of them. I think some sensors are bad. I "may" have had one "high heat" warning, but it went out right away. This was on the Milwaukee Mile, the oval part, on an 80s day. I've been out in the 100s and not a wimper. Unless I get it regularly, I'll skip the cooler and watch the temps.

sshu
06-10-13, 03:03 PM
I remember somebody saying before that during a cadillac event, they were placing fans under the diff to cool it off between sessions. Assuming you can power the fans, would this be a easier solution? I wouldn't want to put my warranty in jeopardy with mods.

spearfish25
06-10-13, 06:04 PM
Using fans under the car doesn't make the diff stay cool so you can stay on track longer. It also doesn't protect the diff from overtemp issues.

The diff cooler install looks pretty easy. If I ever had an issue, I'd just take it off before going to the dealer. It's just an inlet and outlet hose, pump and a cooler with fan. Simple install.

soon to V
06-11-13, 10:37 PM
Using fans under the car doesn't make the diff stay cool so you can stay on track longer. It also doesn't protect the diff from overtemp issues.

The diff cooler install looks pretty easy. If I ever had an issue, I'd just take it off before going to the dealer. It's just an inlet and outlet hose, pump and a cooler with fan. Simple install.

Year before last, I used a big house fan (powered from a powerpack) between runs to test the ability to keep diff temps down before the run. Suffice it to say, it gave me like one more run before the heat soaked diff just couldn't be cooled down to keep up. That was with stock HP. I'm running more HP now. More HP, means more heat being put through the diff. This is why I just designed my own lighter duty cooler for Track Days. I just ran Mid Ohio yesterday and another V was there. It had Diff overheat warnings - mine did not. 7 some events now, and no overheating. I plan to offer it for sale here soon. Agree with spearfish about just taking off the cooler before taking it to dealer if you're concerned about warranty (but not running one and overheating puts your diff at more risk). I've designed mine to be very simple to take on and off and no one would know. V2VDesigns.net

spearfish25
06-11-13, 10:59 PM
Looking forward to seeing your design. What temp triggers the OEM high temp alarm in the diff?

soon to V
06-11-13, 11:07 PM
Looking forward to seeing your design. What temp triggers the OEM high temp alarm in the diff?

300 degrees. Design done and perfected. Just finishing all the other business stuff et al. Yuck! Stay tuned.

Rule12b
06-12-13, 10:23 PM
I run the D3 diff cooler. I've only overheated my diff twice since then, both on track days exceeding 100 degrees ambient. Other than that, it's kept it cool. Before installing I overheated on a heavy track day when temps were low 80's, that was enough for me to invest. I run 25 minute sessions and I don't take laps off if I can avoid it.

soon to V
06-12-13, 11:08 PM
I run the D3 diff cooler. I've only overheated my diff twice since then, both on track days exceeding 100 degrees ambient. Other than that, it's kept it cool. Before installing I overheated on a heavy track day when temps were low 80's, that was enough for me to invest. I run 25 minute sessions and I don't take laps off if I can avoid it.

Thanks. This is good info. How much Horsepower you running? My design goals are up to 30 minutes, 100 degrees ambient, 600 Wheel HP.

hlantin
06-13-13, 12:19 PM
I've got a modified D3 cooler and 600+ rwhp. Last track day was at Willow Springs and 100+ by noon. Never got the diff warning message. It was about the only thing that kept my temps in check...everthing else ran HOT!

spearfish25
06-13-13, 01:55 PM
Modified how?

Rule12b
06-13-13, 02:41 PM
Thanks. This is good info. How much Horsepower you running? My design goals are up to 30 minutes, 100 degrees ambient, 600 Wheel HP.

Running 110, I'm running about 660 rwhp. On 91, about 600. The D3 cooler should do the trick although I have an AT. The MT's seem to heat up a bit faster.

hlantin
06-13-13, 02:55 PM
Running 110, I'm running about 660 rwhp. On 91, about 600. The D3 cooler should do the trick although I have an AT. The MT's seem to heat up a bit faster.

+1..mines is a manual. I like to overdo things..so I ran bigger lines.

You'll be fine w/ the D3 cooler. Rule12b's car is a testament to their durability and efficiency..he's been tracking his car since the Cad Challenge started..

jb_bgg
06-13-13, 03:02 PM
FYI - There is a new grill mounted HX kit available. Doubles OEM diff oil capacity, no fans required, and nothing hanging beneath the car creating ground clearance issues. During four days of track testing (16 sessions total) in 85-90 ambients, 10 lap sessions, return oil temperatures monitored post-HX averaged 170*. PM for details.

Dr. Design
06-13-13, 04:10 PM
Hello,

We have a fairly decent amount of track time with the Cadillacs. We've had dozens installed on a majority of the Cadillac V-Series Academy cars over the years as well as sold a bunch to Pratt & Miller. We developed our differential cooling kits based off of information we learned on the racetrack racing over the course of a year. I think that you will find our systems extremely beneficial in terms of keeping the differential fluid cool and keeping that pesky "reduce speed diff overheat" light off. For all of the cars running the Cadillac Challenge it's pretty much a must to run a diff cooler as these guys are pushing their cars to some pretty far limits.

In terms of the kits holding up. We have been running the same diff cooler/fan/pump combination for over two race seasons. We even run our Coupe diffuser which closes off the direct airflow for the cooler and we still don't have any issues. You can see a small NACA duct directing air flow to the diff cooler in this picture -
http://d3groupinc.com/wp-content/uploads/2012/10/The-Legionnaire-by-D3-05.jpg

We are typically one of the quickest Cadillacs on the track and we are usually running full 20 minute stints all the way to the end at a quick overall pace. It is a testament to our diff cooler keeping our fluids cool while running at 10/10ths throughout the day.

Let us know if you have any questions.

Thank you,

Dr. Design
D3 Cadillac



Have any of you guys installed the rear diff cooler? Did you get the OEM GM version or the D3 kit?

For anyone who tracks/autoXs without a cooler, how is your rear diff holding up?

I tracked my Nissan 370Z quite a bit and the stock LSD quickly became an open diff without a cooler. I'm reluctant to do much with my V until I get a cooler installed unless I hear it holds up well without one.

brent38
06-13-13, 10:25 PM
Wow, that is an awesome looking Vuope! Any other photos?

:)

spearfish25
06-13-13, 10:30 PM
Dr D,

How do your kits come with regard to wiring? Do they have connectors to attach to the OEM harness under the car? Or are they just bare wires that need to tap in somewhere? If so, what do you tap the pump and fan into?

Thinking this is my next purchase, dare I say even before a new exhaust.

Dr. Design
06-13-13, 10:51 PM
Thanks! There's a bunch of photos floating around. But here is the same car in track trim.
http://cadillacrace.com/wp-content/uploads/2013/05/2013-Rd-4-Cadillac-Challenge-18.jpg
http://cadillacrace.com/wp-content/uploads/2013/06/2013-Cadillac-Challenge-presented-by-TOYO-TIRES-Round-6-WSIR-22.jpg
https://sphotos-a.xx.fbcdn.net/hphotos-ash3/601360_451968091506568_862484513_n.jpg

Thank you,

Dr. Design
D3 Cadillac




Wow, that is an awesome looking Vuope! Any other photos?

:)

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Hello,

Yes, our kits come pre-wired and ready for install along with an install guide. If you ever have any questions, you can call or email us and a technician will walk you through the install if need be.

Let us know if you have any other questions.

Thank you,

Dr. Design
D3 Cadillac





Dr D,

How do your kits come with regard to wiring? Do they have connectors to attach to the OEM harness under the car? Or are they just bare wires that need to tap in somewhere? If so, what do you tap the pump and fan into?

Thinking this is my next purchase, dare I say even before a new exhaust.

Random84
06-14-13, 09:46 AM
In spite of all of D3's customer service issues...

That is a hot car! And, you make some nice products for the CTSV. :)

thebigjimsho
06-14-13, 01:58 PM
Wow, that is an awesome looking Vuope! Any other photos?

:)

I don't know if Voupe is gonna catch on. hahahahahaha

spearfish25
06-14-13, 06:28 PM
I don't know if Voupe is gonna catch on. hahahahahaha

Vagon yes. Vedan...sure. Voupe sounds like what my 5 week old just did in her diaper.

soon to V
06-18-13, 08:28 PM
Here's another option to Diff Cooler. This is a Track Day Diff Cooler (CTS-V Sedan) that I have been using on my car. Just another product from my hobby garage, but I will sell it to anyone interested. Goals of the design were to keep the diff fluid cool for a day of 30 minute track sessions in reasonable ambient temperatures on stock and modified cars, but with a fan-less system that is hidden in the space behind the bumper. Cost was to be kept lower than current aftermarket race systems, but reliable enough for off road use (only). The system is intended to be turned on and off for each session, but can also be left on between runs to cool your differential fluid and minimize heat soak before your next run. Designed to keep component costs down, but also thought through to be as easy to install as possible - thus keeping install costs at zero and one people can do themselves.

If interested, you can read more about it on my site: V2VDesigns.net

117810117818

spearfish25
06-18-13, 08:37 PM
Here's another option to Diff Cooler. This is a Track Day Diff Cooler (CTS-V Sedan) that I have been using on my car. Just another product from my hobby garage, but I will sell it to anyone interested. Goals of the design were to keep the diff fluid cool for a day of 30 minute track sessions in reasonable ambient temperatures on stock and modified cars, but with a fan-less system that is hidden in the space behind the bumper. Cost was to be kept lower than current aftermarket race systems, but reliable enough for off road use (only). The system is intended to be turned on and off for each session, but can also be left on between runs to cool your differential fluid and minimize heat soak before your next run. Designed to keep component costs down, but also thought through to be as easy to install as possible - thus keeping install costs at zero and one people can do themselves.

If interested, you can read more about it on my site: V2VDesigns.net

117810117818

Looks like a nice product. I'm very curious how that cooler does anything if it's tucked in the rear bumper. How does it get any air flow?

soon to V
06-18-13, 08:43 PM
Looks like a nice product. I'm very curious how that cooler does anything if it's tucked in the rear bumper. How does it get any air flow?

Gets air from the scoop created to grab air under car and flows it across long bumper radiator and then exits out the rear bumper openings already there.

spearfish25
06-18-13, 08:57 PM
Gets air from the scoop created to grab air under car and flows it across long bumper radiator and then exits out the rear bumper openings already there.

Ok, so it's sedan only. My wagon has no rear bumper openings.

soon to V
06-18-13, 09:07 PM
Ok, so it's sedan only. My wagon has no rear bumper openings.

Yep. Sorry, sedan only.

spearfish25
06-18-13, 09:19 PM
Yep. Sorry, sedan only.

No love for the unicorn.