[Steve91T]

So now that I've decied to convert my LT1 front end to an LS1 front end, I've been thinking a lot about making it a front breather.

Why don't more people do it? Seems like a little trimming of the Impact foam and bumper beam and you could duct air directly to the radiator instead of scooping it from the bottom. The openings in the bumper are about 70 sq inches combined. Seems like it would be plenty for the radiator.

Seems like it would be a more efficient design and create less lift at speed.

For those who have done it, how does it preform?

[Steve91T]

Other than race cars, nobody has made their car a front breather?

Alan, two more questions.

1: Is 70 sq inches a large enough opening for adequate cooling?
2: Any issues that you know of with cutting two 5x7 openings in the bumper beam?

[Blainefab]

Other than race cars, nobody has made their car a front breather?

Alan, two more questions.

1: Is 70 sq inches a large enough opening for adequate cooling?
2: Any issues that you know of with cutting two 5x7 openings in the bumper beam?

My SWAG is 70" is not enough - measure the area of the entry into the OEM bottom breather plenum - that is somewhere about 5" - 7" x the full width of the radiator - I would consider that a minimum since you will likely have a lower pressure in your duct than exists in the OEM duct.

Here's my first iteration front breather on my LT1 car - there is a sealed duct from the opening to the radiator, and I removed the airdam to drive the car to events - which were 400 to 1200 miles one way. I had no overheating issues cruising on the freeway, but with my gearing my cruise RPM was in the 1500-1800rpm range, with no AC. There is a lip on the top of the opening to help pack air into the duct - in the pic it is on edge so not obvious.

(IMG:http://blainefab.com/projects/aeromaro/photowize2004%20209.jpg)

At 185mph, there is a LOT of cooling available with the front breather and air dam, and the the opening creates drag, so in later events I taped off parts of the opening, and removed the upper lip, for the races - like this:

(IMG:http://blainefab.com/projects/aeromaro/photowize2004%20202.jpg)

which worked well, till I got too greedy and taped off too much - probably 30% less than that last pic, for my last ORR race on NV318 - got my fasted top speed but coolant temp went to 250+ and the clutch started slipping so we only averaged a tick over 170.

The bumper beam does tie the fronts of the frame rails together - cut the beam up and you'll lose some rigidity up there, and a minor front corner impact will be more likely to pop the radiator and require frame pulling to repair.

[Bud M]

At 185mph, there is a LOT of cooling available with the front breather and air dam, and the the opening creates drag, so in later events I taped off parts of the opening, and removed the upper lip, for the races - like this:

(IMG:http://blainefab.com/projects/aeromaro/photowize2004%20202.jpg)

which worked well, till I got too greedy and taped off too much - probably 30% less than that last pic, for my last ORR race on NV318 - got my fasted top speed but coolant temp went to 250+ and the clutch started slipping so we only averaged a tick over 170.

The bumper beam does tie the fronts of the frame rails together - cut the beam up and you'll lose some rigidity up there, and a minor front corner impact will be more likely to pop the radiator and require frame pulling to repair.

Looks like you're having some website issues, Alan.