Frankencooler is Here. Modular Auxiliary Cooling For The 5.7/6.1

[MattRobertson]

Dude you gotta read. :-)

[Davious 13]

I am but a mere novice at this, but I found in this thread the specifications of the pipe connector that screws into the stock trans cooler.
So, once I'd disconnected the stock feed line (top pipe, I seem to remember, check this thread to be sure), I just cut the line and inserted a pipe join, connecting it to my new cooler's feed pipe.
The return pipe from my new cooler just needed a new pipe connector of the correct thread size (for the stock cooler) fitted, then it screwed straight into the stock cooler's original feed port.

This is due to the original thread-writer's research that best cooling will be achieved if the fluid goes to the new cooler first, then stock cooler second.

The fluid returns through the stock cooler, and back down the stock piping to the transmission.
I only needed to cut 1 line / introduce 1 splice join with this method.

[MattRobertson]

This is due to the original thread-writer's research that best cooling will be achieved if the fluid goes to the new cooler first, then stock cooler second.

I can't emphasize enough how big of a deal this is. If you pre-cool the fluid with the additional cooler, the stock cooler takes it down further and I ended up with a car whose transmission fluid temps are only a bit hotter than when street driving, and which drop like a stone when you take the load off and coast into the paddock. With just one cooler the temps stayed out of crisis levels, but that dropoff didn't happen and temps stayed high into the next track run.

[arthur8]

Hi Guys,

I've just bought a 2006 300c srt8. I want to use it on track.

I live on Brazil and is very hot there, causing the motor temperatures go to 110~115 celsius when i press the gas pedal too hard for much time. On track this will get worst until i blow my motor/transmission.

I read almost this entire topic, but i have some few questions. First i would like to thanks @MattRobertson for all the help to keep our motors and transmissions cooler.

Matt recommended the Fluidyne ones and i want to go with them. Based on your experience:

1) For the motor oil cooler. What model do you guys suggest?
2) For the transmission cooler. What model do you guys suggest?

Thanks for all the help.

[arthur8]

I can't emphasize enough how big of a deal this is. If you pre-cool the fluid with the additional cooler, the stock cooler takes it down further and I ended up with a car whose transmission fluid temps are only a bit hotter than when street driving, and which drop like a stone when you take the load off and coast into the paddock. With just one cooler the temps stayed out of crisis levels, but that dropoff didn't happen and temps stayed high into the next track run.

Hey Matt. Can you maybe give me some suggestions? Thanks.

[moparmajba]

So, this thread looks pretty much dead and buried, but wanted to throw out my situation, more for grins/information purposes.

2009ish Dodge Challenger 5.7L Tremec. Used exclusively for SCCA road racing, no street driving. The car has been racing for about 5 years without any additional coolers and just the SRT radiator. This year it is getting an oil/air engine oil cooler and power steering cooler in addition to a larger Fluidyne radiator.

I only started taking temps last year (I've only been operating the car myself for 2ish years). Oil temp sensor goes to the plug in the block, after pump, before filter, so it is likely hotter than the sump. Still, I have routinely seen temps about 310F. As far as I know, it's been running that temp for years. From what I have heard in my own digging and asking around, basically the upper limit of a synthetic oil.

Now, I run a heavier weight "racing" oil that may not be appropriate for road cars and change it every season, and my current races are typically no more than 30 minutes, max. As far as I can tell, I have not had any issues: the car always runs fine and yearly oil analysis says the oil always has more life in it (and metal counts are low).

Obviously, I'm adding some cooling to hopefully help my oil out. Just wanted to offer up some perspective from a car that is only ever driven hard.

[MattRobertson]

Not entirely dead. I still come by from time to time.

Worth noting - We've got direct experience with power steering pumps blowing clean off cars (Cam on Big Willow leaving parts on track) and SRT engineers acknowledging the issue. Last I heard the Jeep pumps with steel innards were being retrofitted to Lx's, but that was some time ago. As Moparmajba notes, 310-degree oil has been measured and yup that sure is right at the max for a synthetic. Interesting that it still had no apparent consequences.

I bet I have said this before in the early portions of this thread: Priority for enhanced cooling is water first, power steering second (multiple known failures), transmission next and engine oil last. On water/radiator: On 100+ in the shade days on Thunderhill I have nursed my motor to maintain consistent temps well into the red, so to speak, using the old-school Mopar Maximum Duty radiator, which is a shade more capable than the SRT rads of the day. You really want the bigass radiator as your starting point. Especially since your added coolers will be dumping heat straight into the radiator since they seal to the face of it.

Lastly, remember a street driven car is going to have a WHOLE LOT more weight in it than a race car. I actually tried taking out the interior of my car and found it got too squirrelly and actually needed the weight to keep the back end planted on corner exit. thats what you get for taking a passenger car out onto the race track.

[Tikibeast]

I find that point interesting as I have always believed in taking the guts out of my cars for performance myself, but a while back I ripped the interior out of the Magnum for a deep cleaning after five years of service as a baby hauler. I left it out for a bit just because I enjoyed the extra volume and I needed to haul some lumber. Low and behold once I unloaded all of the lumber I took her out to goof off a bit in the canyons and from the get go the backend wanted to be everywhere...except behind me 😅 I'm pretty sure I lost a few months worth of rubber in a couple of hours.

[moparmajba]

Interesting... with the car fully stripped and a definite front weight bias, the car pushes like a dump truck. I will say, I've gotten a Hotchkiss front and rear sway bars (biggest we could find), re-valved (more damping) RC racing adjustable springs/shocks, lowered ride height, and 295 Hooser R7s all around. These all change the characteristics from a stock vehicle. And, my weight with driver is 3600-3700 lbs.

But, back to cooling: the car never experienced PS issues in the 6 or so years it's been running. I added an SRT cooler this year just for some margin.

I'm currently tracking down some issues with the new system: last race the water temps went to 250F (OEM sensor)/260+F (autometer sensor installed in "bleed" hole on water pump). Car actually ran fairly well but I'm sure it was pulling all the spark it could to save itself. No boiling. I have another race this weekend and have addressed some of the more glaring issues, we'll see how it pans out.

[300srt8v56]

So, this thread looks pretty much dead and buried, but wanted to throw out my situation, more for grins/information purposes.

2009ish Dodge Challenger 5.7L Tremec. Used exclusively for SCCA road racing, no street driving. The car has been racing for about 5 years without any additional coolers and just the SRT radiator. This year it is getting an oil/air engine oil cooler and power steering cooler in addition to a larger Fluidyne radiator.

I only started taking temps last year (I've only been operating the car myself for 2ish years). Oil temp sensor goes to the plug in the block, after pump, before filter, so it is likely hotter than the sump. Still, I have routinely seen temps about 310F. As far as I know, it's been running that temp for years. From what I have heard in my own digging and asking around, basically the upper limit of a synthetic oil.

Now, I run a heavier weight "racing" oil that may not be appropriate for road cars and change it every season, and my current races are typically no more than 30 minutes, max. As far as I can tell, I have not had any issues: the car always runs fine and yearly oil analysis says the oil always has more life in it (and metal counts are low).

Obviously, I'm adding some cooling to hopefully help my oil out. Just wanted to offer up some perspective from a car that is only ever driven hard.

I haven't had a chance to run my car hard around a road course, or any twisty roads since I've added this, but after installing a Milodon 160 T-stat and adjusting my fan speeds, my water temps rarely get over 175-180f, even after 8-9 hard pulls in a row(reving to 6500-6700). I'm also supercharged(6.1) which adds heat. Cruising around town and on the highway my temps hover around 158-165f when it's 65-75F out. Oil temps are around 200-220F after those pulls and 180-195 when cruising(Colder than ideal for the street I know).

I'll have to drive the car hard around some curvy roads in Mexico and report back on the temps.

I'm also running an Amsoil EAO26 filter, which is almost double the size of the standard size filter, and about in inch or so bigger than the Mobil M1-301A, which I believe is helping lower oil temps.

[moparmajba]

IMO, the road racing really taxes the cooling circuit since it's just constantly at higher RPMs and you can be racing inches from the guy in front of you. Drag racing you at least get the slow down area and the return road. Since ICE engine dissipate 1/3 of their power through heat, obviously upping HP drives load on the cooling circuit, possibly higher than what it was originally designed for.

For my part, I finally got temps a bit under control: 220/230F ECT (depending on the gauge) and the EOC seems to actually be doing something now, bringing oil temps down around 290F. Using CAN data, I have video that actually shows the fluctuation while I'm racing in traffic or even as I'm coming up on other cars. The changes I made were:
1) Re-installing spring in upper hose (pressure hose shouldn't need a spring, but I think it helps keeps form during install)
2) Installing spring in lower hose (not production, but I figured what the hell. The lower (suction) hose might collapse at high RPMs, especially with the long run our cars have. Mine is now essentially solid for most of its length)
3) Forced thermostat full open. We actually gutted the rad-side so there is virtually no restriction and forced the T-stat "down" so that the engine re-circ circuit is always shut. Race starts around 170F because that's how I set my fan, but quickly goes up from there. After a race, it's down to 160/170F within a few minutes.
4) THIS IS KEY: FINALLY bled the whole system. I don't know if it's the new radiator or what, but the thing kept getting massive amounts of air that it didn't want to burp. Finally started pulling the sensor for my temp gauge (where the plug is on the water pump). We'd pull it out completely and literally wait for a 3 count before water would come out. The Gen III Hemi's take some care to fully bleed.

[OttoPilot]

Throughout this thread there have been questions and speculations about the efficiency of various EOCs. Some manufacturers' data appears inflated versus others.

To get clarity, I gathered manufacturer data for some representative EOCs and, using heat transfer principles, converted the manufacturers' ratings into standardized ratings (all evaluated at the same conditions of flow, temperature, etc.)

When doing this, I found that most manufacturers rate their heat exchangers at dry sump flow rate. This gives a very large capacity rating but it's not representative of the capacity or pressure drop on a lower-flow rate wet-sump oil system, i.e. our street-based cars.

In the attached table, the manufacturers' data are in the red-shaded rows. The standardized ratings are in the blue-shaded rows.

Setrab is one of the few manufacturers that rate at wet-sump flow rates, so I used their conditions as the standard for comparison.

As Matt initially suspected, Fluidyne and Setrab rate very highly. A large Earl's cooler also rates well.

EOC_Comparo1.pdf