trapp

I'm thinking of getting a Louvered hood to help reduce heat on the track...has anyone really seen a big difference? Do you get more downforce vs heat reduction... I have a supercharged GS and wanted to get feedback before dropping 2.5k on a hood that doesn't do much..

Tom

bosco022

Our oil temps dropped significantly after installing on our Rolex type Vette. (not legal for Rolex, but ok for club racing)

But our hood was a few hundred dollars, so it was a no brainer.

John Shiels

yes & yes but 2500 on coolers / rad is better spent. Hood may give you 5-10 degrees coolers and rad will give you much more.

Joy of 6

I have a buddy with a louvered hood that also adds more downforce. Well, I think that it eliminates the front end raising up due to the under car pressure to escape upward without lifting the car up. So in a way it creates some downforce...

JDIllon

It does both! but a upgraded radiator is money better spent for heat reduction, if you don't already have one. JD

travisnd

Buy a spare stock hood and put some of the CF louvers like Bosco has in it. Spend the rest on seat time.

0Anthony @ LGMotorsports

The louvers, if done correctly, will most certainly help with cooling and downforce.

Like the others have said though, if the radiator and other coolers are not up to par to begin with, it will not solve those issues.

Falcon

I've had louvers added to an old hood, and also a hood with louvers molded in, and neither helped much with coolant temps on hot days, and that's with a Ron Davis racing radiator.

The biggest aid for cooling that I found, is cleaning out the radiator before each event and making sure the shroud is as tight at possible.. Taking the radiator out and dropping it to shake out the debris is the most effective, but anything to get the sand, rubber, small rocks out from between the fins is a big help.

I'm talking about coolant temps, not oil temps.

davidfarmer

In theory, it will help airflow as the hood will "pull" air through the radiator, instead of just letting it get pushed through. Whether this helps your cooling depends on the cooling system itself, and how the air is currently stagnating in the engine bay. Similarly, pulling air out of the top of the hood instead of letting it spill out the sides/bottom will reduce lift.

If you get a chance, walk over to a car with louvers after being driving. The amount of heat coming from the hood will be immense. In my cars, it always makes you wonder how the plastic components in the engine bay ever survived with the heat packing in.

VetteDrmr

Extracting heat is always a good thing. Adding a pair of louvers to the hood of my LS1 Miata dropped my coolant and oil temps about 10-15 degrees.



However, it's really important to get the louvers placed in the right spot on the hood. For example, a lot of folks wanted to put the louvers on the Miata hood farther back on the hood. However, that's a high pressure point on the hood, and would probably be either a wash or have a negative effect on cooling.

Just got to do your homework.

HTH, and have a good one,
Mike

rfn026

I use the hood vents to get rid of brake heat. Notice the little aluminum strip in front of the wheel. Then notice the vent area above the wheel. I lowered my brake temps several hundred degrees with these changes.

Richard Newton
Vintage Motorsport Magazine

Last C5

I run this ACP hood on my track car and I get an additional 10 degrees + or - of cooling, but the additional down force is very noticable. You need the louvers set where these are to get the maximum downforce, although I would think you would get some additional down force just by reducing the underhood pressure with vents places elsewhere. I wouldn't buy a louvered hood to reduce temps. This hood cost just over 1K.

travisnd

Dennis did you ever drill any holes in your inner fenders to let air through those side vents?

Falcon

That's right. I've touched the louvers on the old hood I had and it burned my hand. It's amazing how much heat is contained under the hood.

0MTI RACING

I agree with Anthony, start with the radiator and coolers.

Then...as you have more seat time, and your speeds increase, it will be time to add the hood, front chin spoiler, side skirts, and rear spoiler.

(just like the White Z06 below, except for the wing)

trapp

Thanks for the input....I don't race as much as most of you...I do it about 3-4 times a year if I'm lucky. And when I say race its just timed stuff...no head to head bump and grind. I do it for pleasure...running 15-20 minute sessions on Hoosiers. With the supercharger I need to be careful to keep the temps under-control. I have a supercharger GS (manual with Dry sump). It has the same oil cooler as on the Z06. I have the LG supercooler upgrade to help with coolant temps. What is my next step. If a different oil cooler then what one??? or maybe an addtional oil cooler mounted somewhere else? Or for my situation the hood? This car is not a dedicated track car...

flink

This.

I race an e36. Before venting my hood I took some pressure measurements with a differential pressure gauge and a home-made pitot tube:





Results at 70mph:



The lowest pressure is at the front of the hood and the highest is at the base of the windshield. So I put the the vents as far forward as practical:



I put wool tufts at the rearmost edge of the hood and went for a lap. Yup, those tufts showed massive amounts of air flowing forward into the engine bay. This is all bad - it increases pressure in the engine bay (worsening the pressure difference across the radiator) and it increases drag. So I sealed that gap.

Attention also should be paid to the air intake. You want this to be in a high pressure area but you want the engine bay astern of the radiator to be low pressure. So the intake must be isolated from the engine bay. I made a hokey little box:



Also, any air which enters the front of the car and doesn't go into either the intake, the brakes ducts or through the radiator is bad. Again, this flow will decrease pressure drop across the radiator and will add drag. So get in there and seal all those gaps! Panels, foam tape, racers tape, etc.