nitrodann

Hey guys,

Can anybody point me to the appropriate thread that I will find this as a 20 minutes search doesnt seem to have helped me.

Now that Ive made myself UNflamable (seriously, just kidding, please..)

Who has made some serious Radiator exhaust ducting? Im about to embark on a very large duct build that will direct about 90% of radiator air straight out the hood. Out a 4 inch by 3 foot cutout.

Who here has built this sort of thing, and why dont I see it everywhere?

Dann

curly

iTrader: (25)

Don't think anyone has, we just use mini scoops, or something similar, built into the hood or not. Look at my thread in the race section for ideas.

I thought about making something that doesn't attach to the hood, but directs the radiator heat up to the scoop. Like a big piece of aluminum going from the bottom of the radiator to the back of the scoop. Problem is I'm not sure I put it back far enough.

nitrodann

Thanks curly,

For everyone confused, this is my coreflute mock up.




Everyone has both an nice intake and a big exhaust, yet no one has looked at a proper radiator exhaust, just intake ducts to it. Basically I plan on using the low pressure area that causes front lift to pull air directly through the radiator. Hopefully generating some downforce at the same time, or at least cancelling a lot of lift.

Dann

nitrodann

Heres the first aluminium side plate done. It will be riveted to the back and curved piece which I will bolt to the top fan bolt holes and the lower ones.
Look closely you can see whats going on.





Dann

wittyworks

iTrader: (6)

Why are you doing this on a car with a stock radiator? It's a really cool idea and looks like you're doing a good job, but if you are putting this much time into some front aero, you probably have a future plan with a new radiator involved. It would be a hame to have to re-make this entire thing when a thicker radiator is installed.

nitrodann

Car is still atmo. I have a humongous diffuser coming, that Ive posted pics of (pics of the mould, it will be fibreglass sandwich constructed).

Also a very large splitter will come. Basically I want to see what Is achievable without replacing the radiator, its free to do and everything is a learning experience. I can onsell the whole setup when a new radiator goes in.

Besides just like the diffuser, I can sell all of the originals Im not happy with for what it costs me to make them so ive lost nothing but time, If you can call first hand aero experience a waste of time.

Dann

charredchar

Interesting idea, but if it was me I would angle the radiator much like you would see on a V-Mount turbo setup or on some MR vehicles. The Ford GT is a good example of what I mean and what you are trying to accomplish. Of course it helps that there isnt an engine in the way on that car. You would probably have to get rid of the hood latch in that case.

nitrodann

Welcome. Read a lot before you post questions here, trust me.

I cant really angle the radiator without cutting a lot, and running a smaller rad, and deleting the intercooler.

Cheers,
Dann

charredchar

Oh trust me, I am. Ive been reading since my join date. I am loving all of the information on this forum. lol

I figured youd have a cut the hood latch support and maybe a but of plastic depending how aggressive you go. I didnt know you had a intercooler though (stupid me, I didnt notice your signature and apparently the thread title ), Im actually trying to find some pictures of your setup to get an idea and having no luck.
But to be honest Im just throwing out an idea here and personally think it would flow air better doing so.

nitrodann

It would either require moving the bottom of the rad further back towards the crank pulley. which will make it a lot harder for the air to turn through 90 degrees as it will have less room to do so. or cutting the radiator support panel and moving it (too hard for my welding skills and the bonnet would have no latch, not mentioning despite doing this huge duct build I have to stay registered and not get massive safety defect fines) Can you suggest how I would get around this?

Dann

Pen2_the_penguin

iTrader: (4)

Im still learning about aero, but are you going to delete the fans?

If so, isn't the angle of attack to pull air out of the hood most important?

IMO, it seems an angle of that sharp degree is going to cause a bit of a flow issue...



But like I said, read my first sentence... lol

nitrodann

Most vented bonnets have an upward inflection of a similar angle in front of the vent hole. I dont know really, just looking as race cars, guestimating. It will be tested with wool taped to it, if the angles too much Ill make another.

Somebody tell me that not enough airflow into the engine bay will destroy everything...?

Dann

charredchar

This is pretty much what I was thinking, but I didnt even have the fans in mind which causes even more of an issue.

Pen2_the_penguin

iTrader: (4)

I think oil and turbo temperatures will suffer, but if the turbo is watercooled, the oil cooled in some way, and heat shielding around manifold, I dont see it being much of a problem.


Edit: Maybe a coolant reroute to remove that water neck might free up some room to provide a smoother angle

nitrodann

Looking at the pic with the for sale sign, about where the bottom left corner of the 'R' is I plan on putting a pvc tube, which will go through a hole cut in the curved part. It will extend forward until it is a couple mm from the radiator, solving the air flow across the ex mani issue.

In truth the templates Ive cut are 1-2 inches too short, so they will need to be built up to actually touch the bonnet, I can curve more or less using this top part.

In actuality the suction out of the bonnet vent will be caused by the low pressure area on the hood, which lifts the front of the car up at high speed, its lifting (sucking) up, not back, so a 45 degree angle should be fine.

Dann

Pen2_the_penguin

iTrader: (4)

I just know if the flow ends up mostly going straight up, and no angle toward the rear, it will cause more pressure instead of vacuum... thats all, but I am sure it will work out.

nitrodann

The flow has to equal out in total. Newtons 3rd law.

Low pressure over the hood, high pressure in the duct = downforce in the duct? Hopefully reduced lift.

yes no fans whatsoever.

Dann

ThePass

iTrader: (3)

Interesting. Biggest worry I would have is engine bay temps and how much higher they might get with absolutely no air circulating in the bay. Brake fluid, intake air, etc. are temp sensitive.

nitrodann

As I said it will have ducting the will be storm water pipe that runs straight back from right against the back of the radiator to holed through the curved duct part. Fixed? Or am I still not thinking hard enough?

Dann

ThePass

iTrader: (3)

Your ducting idea to get air from the radiator up to the hood vent is great, yes, I'm just saying that when you don't have that ducting, air that comes out of the back of the radiator circulates through the engine bay and then the air is evacuated out below/behind the engine. This helps to keep the air temp in the engine bay down, especially if there is a turbo. Ducting all the air leaving the radiator out the hood means that all the rest of the engine bay will essentially be static air, which is going to get superheated by the turbo and downpipe very quickly, which means some of the temperature sensitive things like the brake fluid and the air the intake is getting, might get much hotter.