any body ever tried ducting there radiator strait through the hood?
i have this idea that is much like the c6r corvette. im building the car as a street legal race car built to run the silver state classic at 180mph. i plan on moving the full aluminum 3 core radiator forward as far as possible into the front end and tilt it forward at 45 degrees, running twin 10inch fans. we are going to make aluminum ducting that meets up with the hood . take the stock rs hood and do the heat extractor set up like the japan hood, only a little more agressive...... soooo any thaughts?

 

i only have one thought, do it. second thought do you need a co-driver? lol

 

Shelby did it back in the 60s on the Mustangs and daytona coupes.
Many other cars have done it since.
I have some pix of a few road race 3rdgens that have done it.

 

Oddly enough, I'm in the process of doing that to my trans am right now.



However, I've only taken out the factory upper/lower rad supports and made new mounts for radiator. Haven't had a chance to duct and cut the hood.

 

ttop350, can you post pics? and iansane its nice to see im not the only one who caught this bug.. and you have an LM7 also, ill be putting one in soon... do you have pics on your mounting position and setup with the bumper cover off?

 

iansane, what did you do for your lower radiator mount? ive already designed the hood, i just need to start on the front end and radiator mounting before i can start cutting the hood

 

What are your ideas for the hood? I cut the old mount completely out. I was going to reuse the flat portion but it was too deep. I just grabbed some 2" wide flat stock, drilled some holes for the factory radiator rubber support bumpers and then walled it in front and rear. Then welded in some support to the frame rails. Basically mimicked u-channel with really short uppers.

Nah, haven't had the bumper cover off with this setup. Don't know if I ever will?

 

well im doing it to my camaro so im going to follow the stock cowling body lines. im cutting into the stock lines, and the going to slope it down to make an opening about the same size as my opening in the front of the car, were the stock grill would have bean before i opened it up. then adding aluminum duct made out of sheet metal to match the hood for smooth flow. and ill mount the two fans inside of the duct. i like your idea about using the stock rubber for the mounts. im going to try and push the radiator as far forward as possible . the more room between the radiator and engine the better.

 

as far as hood mount? im doing hood pins, i already had two in the car as is, so ill just add two more...

 

anyone have any other pics of other cars that have done this?

 

The idea is sound, but unfortunately the Trans Am suffers from having no front grille opening that a typical race car uses for cooling air. When you pull air from under the car with an air dam it creates a lot of drag and also lift, but ducting the air out through the hood will decrease lift regardless of where it comes in from. You also need to seal off the engine compartment from the air going under the car with belly pans to maximize the effect (or it may just go under the car anyway). The last thing you need to do is duct the hot radiator air away from the radiator through a channel that has no where else to go but straight out the hood. A good example is the Ford GT of a few years ago - you can replicate most of that on a TA relatively easy.

Very nice engine fab work, BTW.

 

he is running a TA im doing an rs. which has an open grill, he is planing on ducting the hot air from the radiator out of the hood as well as i am, my problem is that the TA has more room in between the headlights the the camaro does . so im going to have to do everything custom fabricated from the ground up. and a belly pan would be great but doesn't the cross member and oil pan sit too low? or i supose you cound plate around it? orrrrrr the nice expensive way of doing a sump system lol

 

These are the only pix I have of it. I hope he doesnt mind...

 

Board members car?

 

thats bad ***, he used the factory possition for the radiator, so its not as extansive at iansane or mine, but way bad *** , love it. it makes it sooo much easier to get a plan in your head when you can see a rough outline infront of you. i hope that member doesnt mind either. thanks

 

Exactly what I was talking about - except that there is no smooth interface to the over hood airflow, but a HUGE improvement in terms of cooling, downforce and also drag reduction.

 

his idea is great, but yes the surface that the air travels over doesnt seam very aerodynamic. the air going through the radiator hits a wall and then travels up, which im sure the air flowing over the hood helps scavenge the air going through the radiator. thats why i would like to tilt the radiator forward and duct it to the hood in a more ...flowy? mannor ?? lol but either way im sure its very effective....

 

I would think that it doesn't matter 2 much if the rad leans or not because it has the same size "wall" to hit?????

 

yea i gues your right in that sence, i was thinking of the ducting behind it, if you lean the radiator and duct it to the hood your angle to the hood is more flowy. i was saying that the ducting that the race car shown has. when the air passes through the radiator into the ducting, it hits a wall befor it flows up... but it probley doesnt make that big a difrence other then appearance i gues

 

It does make a difference. The air is just like water, it doesn't like to turn directions very well. It builds up on itself and I would guess you'd get a higher pressure there because of it but I don't know for certain? It's not going to be MUCH of a difference, though. I don't know the rules for AI but he may be restricted to factory mounting location for the radiator? It's cool nonetheless.

 

If you want more airflow and you have an RS you can pull off the plastic grill and make the front air ducts fully functional. Those with a good airdam will give plenty of air. If you pull all the plastic crap out and box out the front of the radiator and add airducts to the two front "ducts" in the nose cover youll get all the air you will ever need.

The only reason I could see running a radiator at some funky position is if you had to run intercoolers for forced induction or wanted to run a big block. Knowing more about what you plan on sticking in there will help.

 

i have already gutted the grill and all the plastics infront of the radiator . its wide open, and im putting in an 450hp lm7. the reason in tillting the radiator forword would be to have a better transition in air flow thats being ducted through the hood. i think ianane and i are on the same page, or so it seams

 

It really depends on how the air is hitting all the little fins in the radiator, it is meant to hit straight through or at a little angle. If you tilt it say 30 degree, you will have another drag source and possibly than optimal cooling flow. I'm not saying cooling won't be adequate, but not optimal.

If you look at "Race Car Aerodynamics" pg216, Fig 6-52; you will see how a cooling system with a front opening and a hood vent is up to 2.5x more efficient than the typical production airflow through the radiator without any sort of venting (like a stock 3rd gen). Of course good transitional flow from the radiator to the over good airflow is important, but only a purpose built race car would have enough space for the optimal ducting. the book shows an approximate .015 CoD decrease by going to the mentioned cooling method - excellent considering it will cool better at everything but super low speeds.

 

thanks paul. it will be a purpose built car... as of right now there is nothing in the front end, its got and engine , sub frame and the wheel tubs, thats all, no core suport no nothing.. so to some degree i can do whatever i want..as long as it fits in the stock body ;]

 

radiator and fans got deliverd yesterday! woo hoo

 

don't forget to build a shroud! insane could probably increase his cooling capacity 30 to 50% if he would move the fans back 1 1/2 inches and box the radiator core with a simple sheet metal shroud.

 

Shroud = for when you're not moving. I'll be fine ducting everything out of the hood. Do realize that's not a finished picture.

 

i will, first i just need to get it all pt together and get the car fired up again. it hasn't
run for over 4 months.

 

iansane, hows your project going? any new pics?