Rear axle cooler

[ek1]

2016 ACR manual says "NOTE: For track outings lasting longer than 25 minutes, an external
rear axle cooler is recommended.". Speaking with Mark Jorgensen @ Woodhouse, it's not actually possible to buy the cooler. Apparently, there is also no temperature sensor in the rear axle, so if you overheat it and cook the fluid, you would not even know it.

Does anyone have any sources/solutions? As per Mark, the old axle coolers made for earlier Vipers would still fit a 2016. Where can I buy a used one?

[Rapidrezults]

I also found this strange. All of the launch publications included information regarding this "finned differential cooler" ...

From the FCA 2016 Viper press release: http://media.fcanorthamerica.com/new...?id=16752&mid=

2016 Dodge Viper ACR
Standard equipment includes:
8.4-liter, overhead-valve, 20-valve, SFI, all-aluminum V-10 engine
Six-speed manual transmission
ACR double adjustable suspension with 10 rebound and compression settings and Bilstein coil-over racing shocks
Brembo Carbon Ceramic Matrix two-piece rotors with six-piston front brakes
Rear aero wing
Lower dive planes and carbon front splitter
Unique race alignment and race-tuned five mode, electronic stability control (ESC)
SRT hood
19 x 11-inch front, 19 x 13-inch rear; ACR Gloss Black wheels
Kumho 295/25ZR19 front, 355/30ZR19 rear BSW tires
Finned differential cooler
ACR lightweight Interior
Alcantara wrapped steering wheel with racing stripe, console, dash and door trim panels
Unique accent stitching throughout interior
3-speaker audio system
Lightweight battery

[steve911]

I have a "cloned" ACR-X diff cooler on my car. It consists of a pump, cooler, temp sensor, custom made wire harness with weatherpack connectors, relays, fans and hoses. The cooler only activates when the diff temp gets to 190 degrees., and shuts off at 165. That equates to 2 laps at road America when it turns itself on.

The original cooler kit was $1440.00 through Mopar. I made or bought everything exactly as supplied by Dodge and I still have $600.00 into it, and most items were bought wholesale. There is quite a bit of labor to install one. I have done 4 cars in my area. I attached just a few pics to give you an idea.

I do have one on my Gen V. As the old saying goes, "An ounce of prevention is worth a pound of cure".


IMG_0083.jpgIMG_0068.jpgIMG_0076.jpgIMG_0086.jpg

[LATAMUD]

I put together a similar kt as Steve above. I just bought all the components separately, Tilton makes a decent pump, 8-10" electric fan, found a used heat exchanger for $50, painless wiring relay kit, AN-8 hose and fittings. And did the same thing for my transmission cooler.

[01sapphirebob]

I also found this strange. All of the launch publications included information regarding this "finned differential cooler" ...

From the FCA 2016 Viper press release: http://media.fcanorthamerica.com/new...?id=16752&mid=

2016 Dodge Viper ACR
Standard equipment includes:
8.4-liter, overhead-valve, 20-valve, SFI, all-aluminum V-10 engine
Six-speed manual transmission
ACR double adjustable suspension with 10 rebound and compression settings and Bilstein coil-over racing shocks
Brembo Carbon Ceramic Matrix two-piece rotors with six-piston front brakes
Rear aero wing
Lower dive planes and carbon front splitter
Unique race alignment and race-tuned five mode, electronic stability control (ESC)
SRT hood
19 x 11-inch front, 19 x 13-inch rear; ACR Gloss Black wheels
Kumho 295/25ZR19 front, 355/30ZR19 rear BSW tires
Finned differential cooler
ACR lightweight Interior
Alcantara wrapped steering wheel with racing stripe, console, dash and door trim panels
Unique accent stitching throughout interior
3-speaker audio system
Lightweight battery

The GEN V ACR diff has fins on the diff for cooling.

[str5010]

Above is correct. To clear up confusion the differential housing is shaped to promote heat transfer (fins) by itself to help cool the fluid. An auxillary fluid cooler can be added as mentioned to actively cool the differential fluid through a dedicated heat exchanger and return the fluid to the differential.

[ek1]

Does anyone happen to have some pics showing the cooler installed on their car?

[steve911]

Does anyone happen to have some pics showing the cooler installed on their car?

Why yes I do. The cooler assy mounts to the bottom of the trunk floor and the pump mounts to the cross member behind the diff. The fans are on the forward side of the cooler and blow to the rear.
IMG_0010.jpg

[ek1]

Thank you! Now I have a much better understanding of the setup.

More questions if you dont mind:

Did the inlet and outlet fluid ports come from the factory or did you have to drill those holes and thread them yourself?

Since you may have seen pictures of the ACR's rear end, do you think that the cooler will clash with the covers and diffuser strakes on the ACR? Looks like it may.

[ek1]

By the way, here is an interesting article on differential coolers:
http://www.turnology.com/tech-storie...ssion-coolers/

[Dfunk]

Very good info. The cooler will be overkill for me. The track days I plan to attend won't allow me to be out more than 25 minutes anyway. Changing the diff fluid after every event is my plan.

[ek1]

So far all the track events I attended also topped out at 25 min sessions as well. Apparently there are some venues that have open track time, meaning the track is open for hours and if you sign up for an event, you can drive as long as you want. I am looking for those events.

I am also planning to try and drive in more than 1 group at regular track events I attend.

The biggest problem is that there is no temperature sensor in the axle, so you would never know if you are overheating the fluid. Once you do overheat it, it loses it's cooling and lubricating qualities and then you have a damaged diff. I think I have seen a thread here that replacement diffs currently have a 2-3 month lead time, which for me is half of my yearly driving season. I just dont want the pain if I can avoid it.

[steve911]

Thank you! Now I have a much better understanding of the setup.

More questions if you dont mind:

Did the inlet and outlet fluid ports come from the factory or did you have to drill those holes and thread them yourself?

Since you may have seen pictures of the ACR's rear end, do you think that the cooler will clash with the covers and diffuser strakes on the ACR? Looks like it may.

The diff comes with plenty of predrilled and tapped holes. No need to do anything yourself.

The cooler assembly actually mounts to the bottom of the trunk floor and exhausts thru the vent at the rear of the car. Not in the way of anything as you cannot see it by looking at the car. It sits above the rear diffuser panel.

[Jack B]

That is pretty slick. I would guess, even on the highway you are going to hit 190 deg F. i have some wireless thrmocouples that are slaved to a logging DDM, I will put one on the outside of the diff in the near future, just to see what the normal operating temps are.

Why yes I do. The cooler assy mounts to the bottom of the trunk floor and the pump mounts to the cross member behind the diff. The fans are on the forward side of the cooler and blow to the rear.
IMG_0010.jpg

[MomentaryRacing]

We built our own using some AN lines, T for the sensor, and a small pump. We ended up programming MoTeC dash to turn the pumps on every 2 minutes to cycle the fluid so temperature reading is correct, and then activate fans and keep the pump on if it exceeds about 200 degrees.

This is gen4 diff with 3.07:1 ratio. On a colder day, we saw temperatures stay below 160 degrees for extended sessions, until we blocked off the "passive" cooling airflow and went to "sampling" only pump activation until working temps are reached.

Now we can bring both trans and diff temps up to 190-210 degree range in about 10 minutes, and keep them there indefinitely.

If anyone is building this stuff, and you are looking for specific parts (pumps, sensors, etc), feel free to PM us and we will share details.

If you do not have access to programmable controller, thermostats are highly recommended, we had serious issues with gearbox when we were over-cooling.

We ended up taking out Tilton pumps as they are very heavy, and we felt are over-built for the application. We returned one, and use the other one for oil changes

Both trans and diff pumps we use now, combined, are lighter than a single Tilton unit! Tested in 6 hour and 1 hour endurance races, and multiple sprint events - so reliability is not an issue. They use a lot less power too, and are very quiet.

P.S. With no cooling, we saw temperatures approach 300 degrees on both gearbox and diff, in 20 minute test sessions at cool ambient temps (<60F). So both need cooling unless you like to rebuild often, or don't like to use 2nd gear

[steve911]

The temp sensors in both the trans and diff in my car cycle on at 195 degrees and cycle off at 165. No issues ever equipment wise since I installed 3 years ago.

[Stubbygda]

[QUOTE=steve911;204583]I have a "cloned" ACR-X diff cooler on my car. It consists of a pump, cooler, temp sensor, custom made wire harness with weatherpack connectors, relays, fans and hoses. The cooler only activates when the diff temp gets to 190 degrees., and shuts off at 165. That equates to 2 laps at road America when it turns itself on.

The original cooler kit was $1440.00 through Mopar. I made or bought everything exactly as supplied by Dodge and I still have $600.00 into it, and most items were bought wholesale. There is quite a bit of labor to install one. I have done 4 cars in my area. I attached just a few pics to give you an idea.

I do have one on my Gen V. As the old saying goes, "An ounce of prevention is worth a pound of cure".




Steve do u have a vendor/parts list for this setup? Or a kit u sell? I am interested in putting one on my ta 2.0. I have found some coolers i think will work but no need to reinvent the wheel since it looks like u figured it out already.

[ACR Steve]

somebody sell the kit ..............please lots of guys need it

[XSnake]

somebody sell the kit ..............please lots of guys need it

is Tom F not selling them?

[ek1]

Who is Tom F?

I am looking for a turn key install on my Gen V ACR

[1of1TA1.0]

Tom Francis with DMS South (Parts for Comp Coupes as well as ACRX)

[1of1TA1.0]

Pics of a set up I did, all told it was pretty close to $1,000 with all parts, sensors, lines etc.... As with others, this is a knock off ACR X piece



Here are a few of the ACR X transmission cooler if anyone is interested (purchase from DMS)

[Simms]

Tom Francis with DMS South (Parts for Comp Coupes as well as ACRX)

Tom is a great guy.

[ACR Steve]

I was told they no longer sell the kit?

[bluesrt]

where did you guys get the temp sensors at ?