Oil Cooler Surface Temps

[Tractor Junk]

Fellow track rats,

I need a favor from someone with an upcoming track day and a temp gun. I’ve got my front fascia disassembled for some track related repairs. On the backside of the fascia, the airstream is actually very dirty through the coolers and out to the fender liner vents.

My plan is to seal the air path so that that the flow is directed solely through the coolers. Obviously, I don’t want to melt the rubber seals I use....soooo.... can someone please take some surface temp readings for me from the coolers? Thanks in advance!

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[nastang87xx]

I'm SUPER tempted to say "just don't mess with it" but after reading once twice thrice, I'm a touch confused. Where is it dirty now and how is it restricting flow? I get the fender vent but how is it THAT dirty that it's clogged?

 

[Tractor Junk]

There’s no airflow restriction. Opposite, in a way. If you pull the fender liners, the air flow pattern to the coolers on the sides is obvious.

The air comes inboard through the front fascia of the car, where it’s “dumped” into an open area and eventually either finds it way out through the fender liner vents or up into the engine compartment. It’s a very inefficient path for cooling on track.

My goal is to drop my 280 average oil temps on the track, without having to upgrade the cooler itself (yet). It appears that there’s some “low hanging fruit” on the cooling side by sealing the airflow paths more efficiently.

 

[honeybadger]

I have your regular run of the mill weather stripping between my radiator ducting and my oil cooler/coolant radiator and haven't had problems.

Something non-flammable should be fine.

 

[JAJ]

Fellow track rats,

I need a favor from someone with an upcoming track day and a temp gun. I’ve got my front fascia disassembled for some track related repairs. On the backside of the fascia, the airstream is actually very dirty through the coolers and out to the fender liner vents.

My plan is to seal the air path so that that the flow is directed solely through the coolers. Obviously, I don’t want to melt the rubber seals I use....soooo.... can someone please take some surface temp readings for me from the coolers? Thanks in advance!

You might want to leave well enough alone on this. My right front fender liner melted behind the trans cooler - see below. It's possible that "cleaning up the airflow" so that cool air can't mix with the hot behind the cooler might be counterproductive.

Driving with that big hole was risky because of the risk of damage to the cooler, but I have to say the gearbox did run a lot cooler!

 

[Tractor Junk]

Was this a track failure or did it happen under normal street driving? Wow!

 

[JAJ]

Was this a track failure or did it happen under normal street driving? Wow!

The car has a bunch of track days on it, but I didn't notice until spring cleanup this year, it must have happened late last year at the end of the season. You can see the missing slats hanging down inside the opening - they were intact and rock solid in that position - they melted, fell down the hole and then hardened in that position. You can see that the two slots below the hole are also stressed - they have a wider gap at the center of the slot. The new fender liner slots have already developed this "wider gap" after two track days this year. The liner on the driver's side has the wider gap as well, although the slats haven't failed on that side yet.

 

[dguzzi]

I'd cut those out and fasten a piece of metal screen to protect the cooler. Looks like it would really improve the air flow.

 

[JAJ]

Ford was good enough (thanks!) to warrantee the liner, but as of the end of this track season, both sides have melted (one has melted again). I've got the stainless screen on hand and I'll work a fix over the winter.

 

[Tractor Junk]

I’m terrible at updating threads.

I ended up chamfering the louvers in the fender liners, and opened them up to ~double the OEM size. I also built ducting that seals the backside of the coolers to the fender liners, so the air flow is “managed” and not buffeting around the inside of the front fascia.

At the same time, I sealed every gap/ air leak/ loose fit on the backside of the front fascia. All air that comes through the front of the car is directed through a cooler or radiator now, with no alternate paths or leakage.

Did it lower temps on track? I don’t know. My attention to the oil temp gauge on track isn’t very precise. I need to data log it. What this DID do is completely eliminate the hood buffeting at high speed. No more hood lift. No signs of melting or deformation on the fender liners so far, either. My AP brakes are monsters at shedding heat, so this might be contributing to “saving” the fender liners.

 

[honeybadger]

Ford was good enough (thanks!) to warrantee the liner, but as of the end of this track season, both sides have melted (one has melted again). I've got the stainless screen on hand and I'll work a fix over the winter.

I'm truly baffled how you're managing to do this haha

I’m terrible at updating threads.

I ended up chamfering the louvers in the fender liners, and opened them up to ~double the OEM size. I also built ducting that seals the backside of the coolers to the fender liners, so the air flow is “managed” and not buffeting around the inside of the front fascia.

At the same time, I sealed every gap/ air leak/ loose fit on the backside of the front fascia. All air that comes through the front of the car is directed through a cooler or radiator now, with no alternate paths or leakage.

Did it lower temps on track? I don’t know. My attention to the oil temp gauge on track isn’t very precise. I need to data log it. What this DID do is completely eliminate the hood buffeting at high speed. No more hood lift. No signs of melting or deformation on the fender liners so far, either. My AP brakes are monsters at shedding heat, so this might be contributing to “saving” the fender liners.

Nice work. Got any pics of the chamfering by chance?

 

[JAJ]

I'm truly baffled how you're managing to do this haha

I haven't got a clue on why this is happening - I assume the heat is coming from the brakes because it's happening on both sides with more on the right side, and it takes a lot of heat to melt the liner. The problem with that theory is that the hot air must be blowing forward in the wheel well. To see if I could affect it, I re-installed my Cool Tech brake completion plates - we'll see if that redirects the air enough to stop it. Thing is, slats on both sides have broken this year but they haven't collapsed yet, so they might be salvageable somehow. I've got one more track day this year at Area 27, so we'll see how it goes.

 

[Lurker_350]

....The problem with that theory is that the hot air must be blowing forward in the wheel well.....

I think I read that the OEM brake vanes are directional. Is it possible that the passenger and driver side rotors are swapped? Or do you have an AP racing/other non-OEM setup?

But it would surprise me if the rotor could move enough air to overcome all the flow through the front fascia and that entering the wheel well.

 

[JAJ]

I think I read that the OEM brake vanes are directional. Is it possible that the passenger and driver side rotors are swapped? Or do you have an AP racing/other non-OEM setup?

But it would surprise me if the rotor could move enough air to overcome all the flow through the front fascia and that entering the wheel well.

I'm running stock calipers and Racing Brake CCB brake rotors. They're the Corvette ZR1 rotors and the vent holes are big. I'm not sure if they're directional or not - I don't think so. The thing is that air that blows through the vanes hits the inside of the barrel of the wheel, so it's hard to imagine it finding its way to the front of the wheel well, especially, as you point out, with relatively cooler air coming from the front through the oil radiator. It makes no sense - it's truly a mystery to me.

EDIT: it occurred to me later that I do know why the slats break - they get hit with pick-up rubber as it's coming off in strips. That's what breaks the slats, but it's not what melts them. And, I suspect that if they weren't hot enough to melt, they wouldn't break either. Still a mystery.

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