The Nismo Oil Cooler Mystery

[Drago86]

I was looking at some picture of the Nismo undertray online and it brought up some interesting questions.

1. Why is there a version with tiny cut outs for the oil cooler and on without any cutouts.
2. How does the coil cooler function at all with no cut-outs or such small cutouts on the Nismo.


At first I thought that the air flowed through the cooler and then along the under tray under the aluminum support and exhaused out the back like the normal cooler stack, but once I saw pictures of the other side of the undertray, and that it is sealed with foam tot he "dead end" area just like the normal Z is sealed to the vent area.

See photos below:

Bottom of undertray NO CUTOUT version:

Top side showing sealed oil cooler area with no flow through the cooler possible:

Close up of the two part numbers on the GR0A version, so they planned a version with holes and one with out to exist simultaneously, it's built into the mold. Why? Who gets the version with holes and who gets the version without?:

Here is a photo of the version with holes, the are literally the width of e pencil, there cant be much flow. and again why? who gests the version with holes?

To my best knowledge these were both off North American Nismo's.

I realize that the Nismo prioritizes downforce, and dumping the oil cooler output below the nose is detrimental to downforce, but at the cost of oil cooling? Is this really the best solution they could com up with? Fully or 97% blocking the oil cooler flow?

Who gets the version with the tiny extra cooling holes? Was this sold in hotter states? We could have owners report where the purchased, model year and if they have the holes or not to find out....


Am I missing something here? Does the Nismo have a hidden oil to water heat exchanger hiding somewhere to make this okish? I know it had the extra intercooler heat exchanger int he passenger side wheel well and the extra engine coolant radiator int he drivers side, but neither of those directly impact engine oil temps. How does the Nismo cool it's oil on track when the cooler is blocked??

 

[Drago86]

I figured I'd add some photos of the oil cooler on the Z and Z Nismo for those that don't know what it looks like. It has ducting attached that makes it output directly downward and seals to the undertray with foam strips. On the regular Z there are large holes for air to flow through.

 

[FSUZ33]

Mine has holes

 

[KrackaC8]

Identical cooler in both, angled the same way?

 

[FSUZ33]

Maybe I’m missing something here. To me, especially after looking at mine and the used one I bought from Z1, all of the pics above appear to have holes.

The enclosure holes are slightly smaller than the holes in the tray itself. The enclosure being the box that is riveted to the tray that seals the back side of the cooler. In the first pic (zoom below) you can see the outline of the enclosure holes through the hole in the tray itself. If there was no hole in the enclosure te middle wouldn’t look black, it would be the same color as the rest of the plastic.

is the 2nd pic supposed to be the one without holes? Because it looks like holes. If there were no holes those spots would blend in better or not be visible. Pretty sure I see wall…through the holes.

not crawling under my car for this, but plan to install the Z1 (metal) tray Sunday. But the used OEM tray from Z1 has that same marking/molding detailing the two pin’s/versions.

Maybe the original version had no holes or enclosure, and the plan was for the cooler to vent on top of the tray, and they realized it didn’t work and changed it. What’s weird is the default pn online is the one supposedly without holes (6GR0A). I can’t find anything that shows the 6GR1A (with holes).

Also, they’re about 1/2” wide. A little bigger than a pencil, but not by much.

 

[FSUZ33]

Z1 lists it as the no-hole, but has holes.
Mind sharing where you came across that Info/pics?
Was it sandwiched between threads about Flat Earth and the moon landing hoax?

 

[FSUZ33]

And not to beat a dead horse, but it would be quick and easy to enlarge them and/or make more holes.

 

[KrackaC8]

And not to beat a dead horse, but it would be quick and easy to enlarge them and/or make more holes.

I enlarged my 2023 Performance oil cooler vents:

 

[Drago86]

Maybe I’m missing something here. To me, especially after looking at mine and the used one I bought from Z1, all of the pics above appear to have holes.

The enclosure holes are slightly smaller than the holes in the tray itself. The enclosure being the box that is riveted to the tray that seals the back side of the cooler. In the first pic (zoom below) you can see the outline of the enclosure holes through the hole in the tray itself. If there was no hole in the enclosure te middle wouldn’t look black, it would be the same color as the rest of the plastic.

is the 2nd pic supposed to be the one without holes? Because it looks like holes. If there were no holes those spots would blend in better or not be visible. Pretty sure I see wall…through the holes.

not crawling under my car for this, but plan to install the Z1 (metal) tray Sunday. But the used OEM tray from Z1 has that same marking/molding detailing the two pin’s/versions.

Maybe the original version had no holes or enclosure, and the plan was for the cooler to vent on top of the tray, and they realized it didn’t work and changed it. What’s weird is the default pn online is the one supposedly without holes (6GR0A). I can’t find anything that shows the 6GR1A (with holes).

Also, they’re about 1/2” wide. A little bigger than a pencil, but not by much.

I think you might be correct, I was assuming it was two layers with one blocking but I think I was looking at it wrong, I think both examples have the holes. Thank you.


That still leaves the question of how the Nismo is cooling it's oil through two tiny slits.

 

[Drago86]

I enlarged my 2023 Performance oil cooler vents:

Interesting! Thank you, the regular Z also has the text about with and without holes.

Here is a pic of the regular Z, nice job enlarging it.

Here's a picture of the Non-Nismo openings and how much bigger they are than the Nismo

:

 

[FSUZ33]

I believe Z1 is the only one I’ve seen that has an aftermarket tray for the NISMO (the connections on the front bumper are different, not sure if anything else). Although theirs has larger openings than the OEM NISMO tray, its still much smaller than the opening on their non-NISMO. I’m completely with you on the “why?” though.
Is there something about the NISMO that requires less flow for that cooler?
Does the reduction in flow underneath the tray have a positive effect on aero that offsets the reduced flow for the cooler?
Both?
It could be that a different person designed the tray for the NISMO and it just came out…different.
Idk…

 

[ill-legal?]

I enlarged my 2023 Performance oil cooler vents:

Just curious if you happened to note any difference in oil temps after cutting out those sections of the undershround?

 

[KrackaC8]

Just curious if you happened to note any difference in oil temps after cutting out those sections of the undershround?

It's winter so it's tough to say regarding max temps, but I will say the temps have been more stable thus far with less fluctuation.

 

[trackratZ]

A lot of guessing game going on here about the Nismo vs non-Nismo vent sizes, interesting thoughts but we really need someone very familiar at Nissan to explain the design differences, must be a valid reason. Maybe @MCN1SMO can get a contact from the design team familiar with airflows and aerodynamics about oil cooling.