Steve-O

Im ready to bite 1/2 of the bullet and prop open my shroud,(on my 08 C6), since it can be reversed easily.

Im embarrassed to have to ask for some hand holding on how exactly you go about propping the shroud open, pics would help greatly.

I removed the airbox but I dont see where the shroud can be propped open. Ive heard that NO cutting is required.

Thanks in advance.

Steve

SK360

You need to look under the car, there are 2 plastic push pins that need popped out.

Steve-O

Matt,

Thanks so much for a clear picture of what area I need to look at. That is exactly what I needed to see.

I know there are various approaches as to what you use to "prop"" the shroud open. I have seen members used many different fasteners to accomplish this,(i.e.; threaded bolts and nuts or butterfly fasteners on threaded bolts, like you used), that part I can figure out.

Thanks again for the pic, its worth a thousand words.

Steve-O

PS, I am also wondering if anybody thinks using window screen material or even old pantyhose around the oem air box filter opening might help keep water out. I used screen material just to see if I could do it neatly.

SK360

No problem, glad it could help..

HOXXOH

The bottom front of the shroud is held in place by two plastic snap-in push pins toward the center. Pull those out and the shroud can be propped open to easily let outside air directly in to the filter.

Hardware consists of two 5" long 1/4-20 pieces of allthread, eight 1/4-20 nuts, and four 1/4 x 1 fender washers.

Put 4 nuts on each allthread near the center and then a washer on each side. Spread the shroud open and insert one end of the allthread in the shroud hole and the other end in the metal frame hole where the shroud was attached. Do that on the other side too. Then start running the nuts away from each other (2 one way & 2 the other) to spread the shroud open to about a 3" space. Then tighten the pairs of nuts against each other (aka jam nut) to hold the position. There will will be more than enough tension to hold the washers in place and not have any fear of the whole part falling out.

You can install this in 10 minutes and return it to stock in half that time.

I did this to a friend's LS2 at the track. He had made 2 back to back passes at 12.38 and was happy, as that was a PB. 15 minutes later after the shroud prop, he ran a 12.22 and then a 12.23. The trap speeds were 2 mph faster too. Ya shouda seen the smile then.

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Here's a water deflector that can be installed or removed in 10 seconds. I made mine from 1/8" plastic foam board, but you could also use something like plain corrugated cardboard and throw it away everytime after it got wet. A bungee cord holds it in place. After all, it's only used to stop surging water from directly entering the grille in front of the air intake. If you're driving in water deeper than the top of the grille opening, you need a snorkel, not a deflector.

Steve-O

HOXXOH,

Excellent step by step and thanks for the material list included.

When I combine your instructions with SK360's pic, I am sure I can get this done.

It makes way more sense than cutting up the shroud, and if your friend got a .15 et improvement and 2mph I have to believe that cutting the shroud couldn't improve those numbers by much.

Do you think my screen idea is "all wet" ?

corvetteflier

This worked great on my '06, but I believe the LS3s all use the Hitachi MAF. It is much more sensitive to turbulent air than the LS2 style, and when I did this on my '13 I got a slight surging at steady highway speeds of 60-65mph. That's why I went to the Halltech Super Bee with the shroud mod on the end to get outside air in. You may not even notice it, but if you do, it's the turbulent air coming in through the grill and open shroud to the filter. No question about added power due to the much cooler IAT the opening provides, but surging can be a problem however slight. Good luck! I just used threaded rod and a few washers and nuts. HOXXOH first warned me about the surging that was possible, btw. I guess I didn't notice it until he did and I started feeling for it. Once I did, it was clearly there. On a long trip at highway speed, it would be the most problematic. But, even if you do get it, you may not be concerned, it's that slight.

tomringo

What is this set up and the "prop" open project supposed to do exactly?

franman69

lower the air temperature that enters the filter and intake... This prevents the car from pulling timing (and HP) as the temperature in the engine compartment gets hotter...

Steve-O

tomringo,

Although franman69 gave you the technical answer to your question, I just wanted to add the following.

There are lots of us that don't want to make a permanent change to the car like cutting an opening in the shroud,(could be an issue when you need warranty service or in my case I worry about water intrusion,(I hydrolocked a LS1 with a vararam system and it cost $12,900 for a new crate LS1).

Propping open the shroud provides a temporary opening that allows for the filter to really get "cold" or "fresh" air vs the air under hood that is heated by the motor. The propping of the shroud open is reversible and HOXXOH's mod is an addition that can help prevent water from making it into the intake and is easily removed or added as needed.

Hope that in addition to the answer by franmans69 covers your question.

brywood

Let me jump on the "dumb" questions to ask. So my C6 will never see rain (3rd car)...couldn't I just open the shroud instead of cutting it to install my SC Vararam?

Steve-O

When you say "open the shroud" I wonder if you know of a 3rd option to get outside air ?

#1. Cut the shroud
#2. Prop open the shroud,(this thread)
#3. ?

Im not sure what you mean when you say "open instead of cutting" ?

Mr.Nubain

Your experience with the vararam spooks me when it comes to buying a CAI. I always wanted the Vararam too, I don't drive mine in the rain, but I just wonder "what if". What kind of CAI did you buy now? Looks like the blackwing?

Also, there is no such thing as "cold air" in Boca. Just cold people

Steve-O

Mr. Nubain,

First let me say the car was a 2004-C5, I don't think C6's are as susceptible.

When I posted about the hdydrolock experience, 2 years ago, I got LOTS of responses that questioned whether I had driven thru water so deep "it must have been 2 ft deep and I should have avoided the situation".

Briefly, I was in a parking lot,(they are pretty low lying areas here in florida) and the water was probably 6" due to a sudden downpour.

With cars in front and cars behind me, I found myself somewhat of a sitting duck. A large suv came toward me, pushing a wave of water ahead of it. My vararam was ducted from the fog light openings directly to the throttle body,(the fog light openings were 12" above the ground. Because the suv was pushing this wave, it went in the fog light openings and because the car was running, even though I was idling, it managed to get a few cc's of water into the tb. The car shut off, no noise, and never ran again.

It doesn't take nearly as much water or tremendously deep water as people think to get into a low hanging intake.

Both the shop and the insurance adjuster said they see 15-20 of these hydrolock situations a year.

Deftly

I had a VR on my '06 and that is the exact reason I got rid of it. I know many folks love them, but not for my car. Tropical Storm Fay was the tipping point for me.

Cherokee Nation

corvetteflier: I was looking at the Halltech intake,my question is how does that filter get ANY air without cutting or popping open the shroud? it is closed off from any engine heat for sure?