Need feed back on cold air for a 98. Presently I have a blackwing and want to get cold air for it. Question is , should I cut a hole in rad shroud, or drill hole on fog light bezel? Which will give best results?

 

Cutting a rectangle sized hole in the shroud under the blackwing should give the best results. That is how mine is set up. You could do holes in the fog light bezel but I think the BW would get more cold air with the first option.

 

Dave68 has done a mod using a plastic file folder. Looks like it would be exactly what you are looking for.

Here is a link:

Link

 

Cutting holes in fog bezel gets nothing, cold air sinks not instantly up and replacing hotter air.
Cutting hole behind blackwing helps but when you get off gas pedal then hot air from engine bay gets sucked in and can cause surging

Contact JR at Team ZR-1 he designed a full cold air unit he calls the Icebox that allows cold air to flow all around the blackwing and no heated air to be taken in
I have had one installed for 2 years and works very well with increase of colder airflow. The intake air temp equals whatever the outside temp is once over 10 MPH with Icebox installed

 

I do believe the Icebox device is better than just a hole behind the Blackwing or holes in the foglight shrouds. However, even when the car is not moving, the intake will be drawing in air, and the foglight shrouds are immediately below the Blackwing. The mixed air being drawn into the Blackwing, if the foglight shrouds are modified, has to be cooler than pure engine compartment air. And when moving, the foglight shroud holes will be even more effective, as again, the intake is drawing in air, and outside air is being forced through the foglight shroud holes, at greater and greater velocities as speed increases. Admiitedly, the air probably will not be quite as cool as the Icebox, but there is no doubt it'll be a lot cooler than air just drawn from under the hood. GM must have thought so too, as the Z06 has open shrouds for that same purpose.
Ed

 

This may be true if you bypass the "scoop" installation, but with the scoop in-place, cold air is funneled up and at the air filter quite efficiently. Yes, the intake air temps are a bit more stable with an enclosed box in place, but the downside is that engine heat, especially if headers are installed, tends to cook everything within the engine bay. The boxless opening allows some cold air to flow past the filter, keeping engine bay temps below egg-frying temps at low - to-mid speeds.

 

The reason the fog bezel is a thin plastic is because GM did their homework and that is not a low pressure area. The front is designed to push the air to the sides and not under it to induce front end lift, give a better C/D and get better gas mileage
Air is not going to enter the fog light area while car is moving forward and instantly make a 90% upward angle and overcome the hotter air at the top and replace the hotter air. What little change there would be is not as good as shroud cut behind the blackwing with a Icebox on top for I tested the blacking with vents in fog light area and then with the Icebox which allows a much better quality of colder airflow.

The fog light area is to the sides and not under the blackwing and the radiator shroud seals off the aircleaner right to the front frame support so the easiest path for airflow still would be at the very top and that is still much hotter air then what little would come from fog light area.

 

My engine is supercharged and has headers and with the Icebox the air sensor in the MAF reads the same as what outside temps are once car is going over 10 MPH so no the Icebox would only be hotter when sitting at idle but soon as car is moving the flow of outside air quickly cools the air in the Icebox. Its not made of metal so it does not retain heat like metal or cheap plastic would

 

It's not just the intake air with which I'm concerned; the plastic and rubber components inside the engine bay suffer shortened lifespans as engine bay temps increase. At least your Z06 has open front fascia panels. I still feel that blowing some cold air toward the upper part of the engine bay is an added bonus.

 

I did it to mine and I moved the MAF temp sensor to the Blackwing from the original position forward of the throttle body. Alos remember the C5 is a bottom feeder. Perhaps this is why the ZO6 has the open shrouds at he foglights. My $.02

 

if the c5 is just a bottom feeder, then why does vararam work so well on c5s?
i think air does go through the fog light panels once the car starts moving, thats if the fog light panels are opened up.

 

How can you see what the MAF is reading?

 

I didn't say that CAI like Vararam doesn't work well, Butyou often hear of sucking up water causing hydrolocking..trash bags, leaves, etc. You are correct once moving the airflow starts to come in. Moving in slow or stop and go traffic on say a sand sweeped highway seems to me with a bottom feeder like the C5 you'd be sucking up more debris then from in the fog lights. IMHO

 

perhaps he has HP tuner and a laptop in the car.....

 

I agree. As mentioned before, the Vararam does work very well. My tuner (Doug Rippie of DRM Motorsports) tunes Vararam equipped cars differently, than other aftermarket intake equipped cars, as they go lean at higher speeds. That's proof enough to me that opened-up foglight shrouds allow significant air in. Also, my hood insulation gets dusty pretty quickly (I keep my engine bay spotless) since I had the shrouds opened up. I don't really believe that GM eliminated the shrouds on the Z06 just to keep the engine bay cooler. Admittedly, the foglight area may be a lower pressure area, than immediately over the front air dam, but it certainly is not a negative pressure area. I guess the reasons I had it done were:
a) To cool the intake air charge by mixing
b) Cool the engine bay (I also have longtubes)
c) Accomplish a & b (above) without the downsides of a bottom-feeder, even though all the benefits of a bottom-feeder are not fully realized.
Our cars do not get all their intake air just from air flowing over the engine. The fan shroud intake area is not exactly a hermetically sealed chamber. I believe the fan shroud mod is absolutely worthwhile. Not quite all the benefit of a sealed cold-air intake, but very few of the negatives, also. It just depends on what tradeoffs a person feels comfortable with. Each to their own.
Ed

 

WTC5 - you have PM

 

Well said

 

So how does the VaraRam do it in that area?

 

So if I am going to install a VaraRam, it pays to have the cold air screens installed around the fog lights? Mid America sells them for $69. Also with the VaraRam the fog lights are not affected correct? It seems the VaraRam draws all of its air from directly behind the fog lamps & fog lamp shrouds......Anyone?