: CTS-V Differential Cooler



MReiland
12-17-09, 08:52 AM
There have been questions asked here before about the rear differential cooler and its availability. It is a substantial kit including a heat exchanger, fan, pump, mouting etc... The correct part # is indeed 20792934 as posted in some other threads, it is required for export vehicles which is why some of the people here are reporting that it came stock on their vehicle. It is a GM part# and can be fitted to your CTS-V by a dealer to maintain your warranty.

Any of you that are wishing to purchase this should be able to get it from your parts counter. If you can't get availability on it, you can email me back and we will figure out how to get it to you. If you will be tracking your car with sustained high speeds, a diff cooler should be on your list of things to add.

proexpert
12-17-09, 09:50 AM
Will this be added to all V's for 2011?

MReiland
12-17-09, 09:55 AM
Unfortunately I don't have any info for 2011 option content. It isn't needed for non-track driving here in the states.

Krug Ford
12-17-09, 10:08 AM
I have them available for 3500.00

If anyone wants one let me know.

demorgan59
12-17-09, 10:26 AM
GM retail is $2,995.

MReiland
12-17-09, 10:33 AM
I have them available for 3500.00

If anyone wants one let me know.

Is that installed price? If not what kind of cost is there to install it?

dvandentop
12-17-09, 10:40 AM
good lord cant believe they are so spendy.

$1500 would be a more idealistic price for this

demorgan59
12-17-09, 10:50 AM
There have been questions asked here before about the rear differential cooler and its availability. It is a substantial kit including a heat exchanger, fan, pump, mouting etc... The correct part # is indeed 20792934 as posted in some other threads, it is required for export vehicles which is why some of the people here are reporting that it came stock on their vehicle. It is a GM part# and can be fitted to your CTS-V by a dealer to maintain your warranty.

Any of you that are wishing to purchase this should be able to get it from your parts counter. If you can't get availability on it, you can email me back and we will figure out how to get it to you. If you will be tracking your car with sustained high speeds, a diff cooler should be on your list of things to add.

Any way we could get a group buy on this to get the price down to about $2,000?

wait4me
12-17-09, 10:52 AM
Yeah i can make kits for around $1200 that are very high end... Maybe that will be the goal this week and next... I have all the part numbers for the parts, just need the exact fittings, and powdercoat the metal box protection frame...

MReiland
12-17-09, 11:08 AM
Any way we could get a group buy on this to get the price down to about $2,000?

Unfortunately one of the supporting dealers would have to be the vendor. The kit is expensive but it is fairly extensive. I can help make them available to the dealer if they can't get them from SPO, I recieved a very helpful call this morning from the guy who designed it!

Looks like W4Me is interested in providing a new product, also GMPartsDirect is closer to what you are looking for at $2,180.36 plus some typically crazy shipping price of course.

Krug Ford
12-17-09, 11:23 AM
that was an installed price

DrewDog
12-17-09, 11:29 AM
How much does this diff. cooler weigh?

dvandentop
12-17-09, 12:08 PM
anyone have any good pics of the unit off the car??

demorgan59
12-17-09, 12:42 PM
Try this for a schematic view:
http://www.rmsautoparts.com/proddetail.php?prod=20792934

undertaker
12-17-09, 12:45 PM
I'd be going Jesse's route with the aftermarket and 1200 bucks deal, thats usually what you're looking for, for a track proven setup used on C5 or C6 vettes...including all the pumps, lines, thermostats, puller fans etc.

Hawkeye2
12-17-09, 12:59 PM
If I remember - without searching back threads - in Canada it was over $5,000 to have it installed!

Z06ified
12-17-09, 03:59 PM
Wow that's a lot of cash! How much does a whole new differential cost? Couldn't be much more! I think I'll take my chances without a cooler. If I run Mobil 1 full synthetic diff oil, and if I pit whenever a diff overtemp warning comes on, I don't think the diff will be damaged without a cooler on the track.

Still, I wonder why GM didn't integrate cooling fins in to the diff case, like BMW did with the new M3. Seems to work well, and is a simpler, less expensive, and lighter solution.

Dr. Design
12-17-09, 07:17 PM
Hello,
Yes, this factory export only part is quite pricey. This is why we have manufactured our own rear diff cooler with functional 1250CFM fan a while ago. If some of you remember we had a image slip out of what the unit looked like. We will post more images soon.

http://i143.photobucket.com/albums/r134/ctd3rnd/Converted_IMG_4254.jpg

This was the leaked image ^. We are installing another one for a customer after the holidays. We will take more pictures and such at that time. MSRP is $1250 for this COMPLETE SYSTEM. This is a complete plug and play system and will require no permanent modifications to the vehicle (typical D3 fashion). There is also an optional master override switch that can be installed. These coolers are being built to order now. If you are looking for a high quality professional rear differential cooler unit, give us a call.

Please let us know if there are any questions.

Thank you,

Dr. Design
D3 Cadillac

MReiland
12-18-09, 07:51 AM
Still, I wonder why GM didn't integrate cooling fins in to the diff case, like BMW did with the new M3. Seems to work well, and is a simpler, less expensive, and lighter solution.

I'm not a Mech-E but my guess is that it has to do with the Diff housing being cast iron instead of Aluminum. Aluminum with cooling fins can probably shed heat much faster than cast iron. The rear end on the V has to handle a bit more torque than the M3 so maybe that is why they chose the Cast Iron to be bulitproof. My guess anyways.

Z06ified
12-18-09, 03:32 PM
I'm not a Mech-E but my guess is that it has to do with the Diff housing being cast iron instead of Aluminum. Aluminum with cooling fins can probably shed heat much faster than cast iron. The rear end on the V has to handle a bit more torque than the M3 so maybe that is why they chose the Cast Iron to be bulitproof. My guess anyways.

Yeah, I think you're right. I just read Ed's post about it too, and I didn't realize the diff is cast iron on these cars. I understand the strength benefits of the cast iron, but I think the ZR1 has an aluminum diff (AND a cooler), and it cranks out more torque than the V does, so I'm not quite sure what the deal is. Maybe being part of a transaxle makes it stronger in the Corvette (transmission directly attached to the diff in the back). I know GM didn't want to deal with the differential issues of the V1 again.

Karch
12-18-09, 08:29 PM
Yeah, I think you're right. I just read Ed's post about it too, and I didn't realize the diff is cast iron on these cars. I understand the strength benefits of the cast iron, but I think the ZR1 has an aluminum diff (AND a cooler), and it cranks out more torque than the V does, so I'm not quite sure what the deal is. Maybe being part of a transaxle makes it stronger in the Corvette (transmission directly attached to the diff in the back). I know GM didn't want to deal with the differential issues of the V1 again.

With an extra 1000 pounds of weight, the load on the V is probably substantially higher than on the ZR1.

Also, I would imagine there is a good deal of heat generated in the twisties from the differential clutches, if that is the type of limited slip unit that is used. Anytime you have clutch material where friction is involved, heat is generated.

As for the iron vs. aluminum, I think it plays into it, but not sure how much. My guess is really the diff. clutch friction.

JamesPDX
12-08-10, 07:14 AM
This is a very well designed system, but has a minor flaw. I have built many similar systems for engine oil and transmission fluid used with different vehicles in the past. The fittings should not include any barbed fittings, but rather high quality AN-06/08 push-on fittings with complementary hoses. Steel braided hose ($) is not required for this type of application. This recommendation is an insurance type policy for reliability and longevity of the installation.

Can the individual components of the cooler kit be purchased? It seems that the most costly part of their setup would be the specific pump. Is it available as a single replacement part, and is there a known price tag on the pump? What are the specifications on the pump?

I would imagine the pump to be 90-150, the cooler to be 75, the instrument/switch to be 15, the fan and shroud to be 45, the frame to be 60, and all the AN fittings and hoses to be 40, for an approximate total of less than $500 budget. The labor and availability might raise this estimate some.

JamesPDX
12-08-10, 07:35 AM
With regards to the cast iron differential (beyond the heat issue), part of it's selection may be due to the higher center of gravity in the V as opposed to the vet. The added weight will lower the center of gravity and lessen the probability of roll-over during high speed cornering.

GM-4-LIFE
12-08-10, 08:35 PM
I am really surprised that the diff cooler isn't a factory option that you can order when the car is built. Very odd. To this day, it isn't available.

BeagleBrains
12-08-10, 09:31 PM
Z52 Performance Package including dry-sump oil system and Differential Cooler is standard on the Corvette Grand Sport. My 2007 Corvette Z51 Option includes a Differential Cooler. GM has the components in hand, only requiring specific wiring, a couple of fittings and brackets to install on a CTS V. WTF!
No need to reinvent the wheel (Diff Cooler). Existing parts should be very cost-effective for GM and the customer.
A $3,000.00 price range is rediculous!!!

baabootoo
12-09-10, 01:57 AM
This is a very well designed system, but has a minor flaw. I have built many similar systems for engine oil and transmission fluid used with different vehicles in the past. The fittings should not include any barbed fittings, but rather high quality AN-06/08 push-on fittings with complementary hoses. Steel braided hose ($) is not required for this type of application. This recommendation is an insurance type policy for reliability and longevity of the installation.

Can the individual components of the cooler kit be purchased? It seems that the most costly part of their setup would be the specific pump. Is it available as a single replacement part, and is there a known price tag on the pump? What are the specifications on the pump?

I would imagine the pump to be 90-150, the cooler to be 75, the instrument/switch to be 15, the fan and shroud to be 45, the frame to be 60, and all the AN fittings and hoses to be 40, for an approximate total of less than $500 budget. The labor and availability might raise this estimate some.

Yes to all in another thread. I would never spend $2K on this!

tccaux
12-13-10, 05:22 PM
The GM cooler is now on back order with no ETA on next release. Latest from gmpartsdirect and local parts dept.

MReiland
12-13-10, 05:41 PM
I will look into the availability this week with the parts Guru to get the lowdown.....

jzchen
03-17-11, 12:16 PM
Any updates? Someone mentioned a switch. Does this mean you turn it on when you need it or is everything automatic? I have a primarily street car, don't want driveability issues... Thanks anyone for clarifying.

Dr. Design
03-17-11, 02:26 PM
Hello,
We do offer a optional switch if users do require such a feature. The primary system is activated automatically and requires zero user interface. No drivability issues at all as we have had them installed on cars for a couple of years now (street & track).

Please let us know if there are any questions.

Thank you,

Dr. Design
D3 Cadillac


Any updates? Someone mentioned a switch. Does this mean you turn it on when you need it or is everything automatic? I have a primarily street car, don't want driveability issues... Thanks anyone for clarifying.

spearfish25
05-21-13, 02:32 PM
Where does one wire the pump and fan into under the car?

flyingv
05-21-13, 06:33 PM
Inside the trunk, where the battery is there is a fuse panel with extra open fuse locations. I used an "add a fuse" from autozone to run down through the trunk floor and under the car. I'm using a thermostatic switch to control the on off function.