Judge my Fan Shroud design for Track use

Judge my prototype fan shroud for my 1992 Turd gen Camaro.

I've been using 98-02 Camaro fans. (same fans as C5 corvette)
They flow around 2,800cfm and have a plastic shroud built in.

Had cooling issues during track days, 240F coolant temps 280F oil temps.
I added 7x of these SPAL fan shroud flaps to the 98-02 LS1 fans and lowered engine temps to 220F & oil to 270F.

SO to further that trend, I'm designing a fan shroud that uses a single 16in SPAL circle track fan (2500cfm)
and 21x of those same SPAL fan flaps.
I was told most track guys delete fan shrouds since they limit air flow at high speeds.
but I Track AND autocross, so I still need a shroud for low speeds.

(a bonus is this combo should be 3lbs lighter than the OEM LS1 fans)

comments, critiques?
am I looking at this incorrectly?
or am I dumb. 
 

I know nothing about fans and shrouds.

But what are you doing to let air out from the engine bay area?  Hood vents?  Fender air extractors?  Both?  The hot air has to go somewhere.

The shroud is mostly there to help the fan work. At higher speeds, the fans stall, so the shroud isn't needed (and neither are the fans). The flaps are great because they give you both - the fan should actually suck the flaps shut when the shroud is doing the most good, and then the flaps open when the fan's importance is falling off. I'd say this looks good and is certainly worth trying

From my experience it is jut as important (maybe moreso) to get air to the radiator.

Don't let air go under, over or around the radiator once it comes in the front of the car.

Fill up and holes or gaps around the radiator (in front of it) and make sure air can't ht it and just dump out the bottom.

The flaps look great, and I've only recently learned about these things, but their intended purpose makes sense. Bypass the fan while you're moving, close up and let the fan work while you're stationary. It's a beautiful thing. Isn't there a saying about engineering where if something looks beautiful, it almost certainly works beautifully?

No? Is that totally untrue? Oh. I have coffee here--while you're here, too, would you like some? Chobani cream if you like it...

You may want to offset that grid of flaps if you can. It'll probably make it a bit more rigid

I'd love to do something similar on my c5. the 90's fan are way thicker than modern bushless ones. Losing the fan entirely on the driver's side of the bay would make a lot of work easier over there.

Is there any opportunity to make the shroud thicker? It looks very shallow, which will create areas where air isn't going to easily be able to make it through the radiator and out of the shroud without changing direction

You're so far past where I ideally would want oil temperatures to sit that I doubt this is going to make enough difference to completely fix the problem. Sounds like you have an overall airflow challenge through the cooling package, or possibly a bit too aggressive on ignition timing or something driving the oil temps up. Or if it doesn't have an engine oil cooler, maybe it needs one.

In reply to gearheadE30 :

The shroud is 1 in thick but I could totally make that thicker. 

As far as oil temps I do have an oil cooler. RedLine said their 30WT race oil is good to 300F, But I know I'm dangerously close to that.

But I think that my engine is running a smidge lean at wide open throttle.

Wide band says about 13.2:1 at WOT.

Going to have my tuner look at the fuel map when the car is back together.

I think maybe my vacuum reference fuel pressure regulator line got pinched over time 

I'm surprised you haven't ducted more. The interior section on the front end of a thirdgen is a mighty turbulent area to be.

If you don't have these areas filled in, that is a huge part of the problem.

In reply to wvumtnbkr :

Sorry that photo was a little misleading. 3rd gens are mostly bottom breathers.

So the duct work is a bit strange. It has 2 tunnels from the front grill. And an air damn and associated ductwork underneath. 

there are a few small gaps here and there. I used tape at the track to close all those gaps and it didn't make any difference in cooling. 

The flaps however made a pretty significant improvement. 

Maybe this image will clear things up a little. 

It's most of the air gets damed up in front of their radiator. then a low pressure zone forms behind it and pulls the air through. 

Ah, gotcha!  That looks much better!  However, the inlets do look a bit small (imho). - edit: I wrote this before I saw your second photo with the bottom.

Hmmm.  That's an interesting design with the bottom open like that AND the front open too.

That airdam under the radiator should certainly make the air go up to the radiator.

I'd love to see some string tufts taped all over those parts and and the rad to see what the air is doing!

Also, from what I can see in the pics, this looks like a very nice clean build!  Good job!

Do you have number #35 (for both sides)?

Or I guess, do you think air is getting thrown out and around the radiator?

I know it's not wholly relevant to your question but sealing in those side panels could help?

I don't know enough to say that shroud looks good or not. Is there a significance to not centering the fan? Waterpump pulley clearance?

Wow, good size air to oil cooler and still getting that hot. I'm surprised, especially since it looks like all the ducting is there.

My only other suggestion coming to mind right now would be to make sure that the air dam/scoop is supported well enough that it doesn't flex backwards at speed. that's a pretty significant, thin part with a major aero load and if it pushes backwards even slightly, it's going to spill air downwards instead of directing it upwards.

If it were my car, I'd probably make some panels to take to a track or test day that connect that air dam to the panel in front of it, to kind of box the air in and contain the static pressure in front of the cooling pack. It would also add stiffness to the air dam. I'm not sure it needs to be or would even be helpful to be the full depth of the air dam, but it seems like having something there would prevent side spill and would stiffen the dam up significantly.

Looks like a remarkably clean build.

In reply to gearheadE30 :

That's something I could test.

Try to trap the air and keep it from going around the dam.

My oil temp sensor is at the exit of the block as well. So the readings are the absolute hottest the oil will see.

I think other cars like 911s have the oil temp sensor after the cooler.