This winter I replaced my stock 75 bumper with a fiberglass one. I remove almost everything behind the old bumper and will not replace it. The fiberglass bumper is rigid enough to support itself.
The problem is I have a big empty place in front of the rad that I don't know what to do with.
Some build a nice aluminum air dam to direct the air into the rad. It would hang slightly below the front bumper scooping the air up and directing it through the radiator and for me would be simple and fun to fabricate.
But do I want to do this. I like to cruise between 80 and 90 with occassional burst much faster and I am afraid of building up air pressure under the hood contributing to a front end that floats at speeds. With my present setup 140 is the absolute top end before the front end feels like it is ready to leave the road.
Wouldn't directing more air with a air dame scooping it from below the car add to the problem?
I could also go with a flat aluminum plate closing off the area under the pumper and hopefully preventing air from being scooped up into the motor.
Nascar has very low front spoilers to prevent air from getting under the car. This is not practical on the streeet but I would like a little more safe, I know speeds like this are never safe on the street but I hate that floating feeling.
So guys what are your opinions on front scoops under the bumper?
I presently don't have a problem with cooling.

 

I wonder if someone has access to a computer program that could model the aerodynamics of the C3 front end?

Seems i ran across the website of someone here who is interested in running their C3 on the salt flats. I would think they had to modify their front end to do that.

Found him. "gkull" says he has taken his to 174mph and is going to shoot for 200 on the salt flats. He must have done something because the front of C3s gets light over 110mph in stock form.




[Modified by turtlevette, 7:33 PM 4/5/2003]

 

Actually, I have a magazine with some pictures of a '69 salt flat corvette that ran 210mph....and it didn't have any extra wings or anything....looked kind of stock.. :eek: :eek:

I will try to find the article and scan a photo. :cheers:

 

I've thought about adding ducts to remove underhood pressure. I had in mind something like the side ducts on a Trans-Am. Still haven't been bold enough to cut the hood yet though. The upper fender vents sold by some of the suppliers might be a possibility too, especially if you used the vents on the fenders too.

 

I'm actually almost in the same boat with you Norval. I removed all the heavy front metal bits, what I'm going to do is just add cooling ducts for the front brakes. I'm still going to keep my pace car style front spoiler to push the front to the ground at high speeds. Keep us posted what you are going to do! :cheers:

 

I need ideas. I have this big empty space when lying under the front of the car. If I push the lights up it is all empty up there. A sleek aluminum belly pan is one option or a scoop grabbing the air and pushing it through the rad is another but this is what worries me. I don't want lift.
I also hate the idea of big heavy 550 pound springs totally ruining the ride.

 

Norval , contact Gkull he sent me some pics a while ago of a setup he runs . I have been thinking about developing some thing along those lines myself .

Geo

 

norval, you could weld a bar on the front and add weights like they do with the tractor pulls. That will keep the front end down.

:jester

 

I believe it was in the Autocrossing forum that some were talking about removing the weatherstrippiing around the rear of the hood to allow air to exit there. I think they were C5s though. If this is desireable on a C3, maybe vents could be added to the front of the wiper area and leave the hood/hood gasket untouched? If the high pressure under the hood can be evacuated, wouldn't scoops in the front act just like spoilers, pushing the air up, rather than under the car? I'm very early into learning about this, set me straight if I'm off! :cheers:

-Chris

 

ram82fire. Thanks. I talk to George just about every day so I will run it past him.

Jvette73. No way I work at reducing weight not adding it.

RUXperienced. Do you know my car. It has a high rise scoop on it open at the back and a big hole in the hood for the blower

 

Indy ft. spoiler cleans up underneath, sweeps the air around the ft. tire & scoops air into the rad.!
Ride is affected more by the rear spring since that's where you are sitting.
You could add at least the FE-7 sway bars. I really like the FE-7.

:cool:

 

I am going to go for a 1 1/4 inch sway bar but I didn't think it would help in a straight line.
I could beef up the rear spring because on take of the front end does tend to rise alot.

 

No, I wasn't familiar with that aspect of your car, but naturally pretty familiar with you helpful posts around here :thumbs: So, with the blower-hole and raised cowl, how is there still danger of pressure building under there? I'm confused as to how the scoop could provide anything other than more downforce (or was that your original question?). For my own use, if anybody has comments on the usefulness of the mods I mentioned, feel free to comment!

-Chris

 

I personally like the Le Mans type from aluminum spoiler. Remember the old chrome bumper C3 with the rebel flag on it? I've concidered doing that myself, but the though of it getting ripped of via everyday driving makes me think twice. There is another front spoiler option. Try ACI's website. They have a front spoiler that looks kinda cool. Here is the link... http://www.acivette.com/index2.html

 

Even with the raised hood and open hole for the blower at about 140 the front end becomes extremely light and you get the feeling if a good draft comes at you the front end will wipe out. Maybe it wouldn't but at that speed I don't want to find out. I have the power to pull alot more then that easily but not the suspension.
I should do like George and go heavy duty all around but I don't want the harsh ride and pound the front end on rough roads.
I am also very familiar with roll cages and could easily build one for the vet to stiffen it up but I don't find the vet has that large an interior and don't want to further crowd it.
This is the cage I built in the mustang. It is 1 5/8th stainless and really tied the mustang together with frame connects and 4 link.
A proper cage really stiffens the car up



[Modified by norvalwilhelm, 8:48 PM 4/5/2003]

 

:seeya Hi, norvalwilhelm I believe if you check with Steve's (Merlin522) web site he had an interesting set-up done under the front of his car. :yesnod:

 

This is a good post. I'll be watching to see all the ideas.
I like the brake cooling idea (good for rushhour stop-n-go.)
Sorry I don't have anything to contribute.