Jackalope

Maybe not LewiSS. WHen you dynoed your car with the scoop did you get another high speed fan to point at the scoop? If not then if couldn't have gotten enough air for it to function as a true scoop all it would have done is have one more place to draw air from rather then just the restrictive factory lower box hole. So what I did was not seal it to the hood and removed the underhood blanket and its a BIG difference.

LewiSS

Yes, the real benefit is in NOT forcing it to breathe only through the stock fender inlet. In your case your's is breathing around the gasket (between the air box and the hood). In my case it's breathing through the hood, since I sealed mine to the hood. When I dyno'ed, we threw a plastic bag over the top and closed the hood forcing it to breathe just through the stock fender inlet. I figured that would simulate installing it with a good seal to the stock hood blanket. Then we ran it without the bag, letting it breathe properly. The same gains we got with the second run would apply to your system.

And, BTW, we DID have a fan blowing down the scoop (probably not 60 MPH worth, but enough to ensure there was some flow). The fan cooling the radiator was big enough to help air flow in the scoop.

Anyway, the key with the GMPP is to either seal it and let it breathe outside air (using a scoop or the RKSport hood) OR making sure it ISN'T sealed to the hood with nowhere to breathe except through the stock inlet.

Did you see a mileage gain? I've gone from about 24 to about 28 on my commute, but I also switched to premium so I'm not sure which did what.

ReggaeRampage

Thanks boss. Yeah, the model I have (LT) came with the fog lights, so the grill around it came that way from the factory. At the time of those pictures, I had blue aftermarket LUMINICS bulbs put in. Those blew out one by one. So as of right now, I've gone back to stock bulbs.

I forgot I even had those pictures in my gallery. They need to be updated...cuz I'm currently going thru an overhaul.

For a 2.2, WITHOUT a hood scoop, it's only around 2hp!
An SS (2.4L) WITH hood scoop, is about 10-14hp as LewiSS said...

Jackalope

Having my car dynoed this weekend and I'll tell you exactly what its worth with no hood scoop. All his scoop did was allow it to get more air, remove the underhood blanket and the rubber seal and it gets tons of air then too. I'll post my results asap. And I didn't realize the 2.2 and 2.4 would have different HP gains from the same mod. If it adds 10 hp to a 2.4 it should do the same to the 2.2 but I'll find out.

Mike85220

I read the description about the dyno gaining 12 horses with the scoop, but it was a measley 2 horses or less by itself.

No wonder GM Performance keeps the warrany going with this mod.

They didnt expect someone to add a hood scoop.

The only problem is the elements leaking in and causing problems.

If it rains hard, the filter will get soaked through the hood scoop and that would be bad for the engine. You could add a sliding piece that blocks the hood scoop for such a time as it raining I guess.

What about making the stock inlet bigger with some plumbing going down and making a ram air unit instead off the bottom?

LewiSS

I get no soaking of the filter, and I've driven in some toad-stranglers (for the Yankee's, read: Nor'Easters). It's amazing, but true. I'd be more worried with a low-mounted intake. I had originally planned to add a closeable baffle, but it turned out I didn't need it.

Making the stock inlet bigger, however, might have the same effect. I wouldn't get carried away with ducting it much lower - it will still be breathing outside air that's not in the engine bay.

As for GM not expecting a scoop to be added, the only reason I can see to build that box the way they did was for just that possibility. Otherwise it would have been cheaper to have closed off the top.

Jasper33

isnt it cheaper and just as good to go with an injen intake rather than your setup...i must admit it is a great idea tho...but i just dont trust myself cutting into my hood

LewiSS

It's probably just as good, but when I saw the GMPP and thought of the possibilities, I just HAD to do it!

Jackalope

::::sigh:::: Guys have you ever seen the GMPP intake in person? It replaces the TB adapter, the duct work with a polished tube, and the lid with an open top adapter for the filter to sit in. Now the open top has a rubber seal around it that is supposed to mate up to, seal against the underside of the hood. When you seal it to the hood it can only draw air in from the same small duct that the factory lower box connects to so no matter what the intake is its still getting no more air then the factory set up.

LewiSS when he added his scoop opened the filter up to be able to get in as much air as the engine wants. More air = more HP, LewiSS prooved that on his dyno runs with netting 10 more HP by opening up the air filter to more air then the stock lower could.

I by removing the rubber seal and removing the underhood blanket have done the same thing, allow the filter to access to as much air as it can possibly get.

I'll do just like Lewis did when I get my dyno time except I don't have a scoop just open in the engine bay. If I'm wrong, then I'm wrong but I don't think I am.

07cobaltowner

:jackalope:
cant wait to see the numbers, gonna be interesting!

Jasper33

Wouldnt you think your numbers may be a little bit lower due to the higher temp of air that your getting. Colder air is denser air and that mean more power (even though theres not a real big difference)

LewiSS

You should see the same gains as I did.

Since dyno runs are almost always done with the hood open, then, no, he won't see less. On the street in the summer (especially after slow traffic heat-soaking) then, yes, there might be a slight difference. I've not seen published figures for HP loss due to temp, although I know they're out there. But I understand 'lope is planning a mod to fix this.

ReggaeRampage

Good stuff...let us know how it works out.

Stl06LS

I pulled the seal off the upper intake box today and drove the same 40 mile trip, 37.5 mpg this time. I need to find a way to get more fresh air to the filter.

LewiSS

Click on the link in my sig about making the GMPP intake functional and see how I did that!

Stl06LS

LewiSS, that's a great idea. But, I really don't want to cut a hole in the hood.

Red07SSNA

I little more expensive -- I put a SS/NA front bumper/Fascia on my LS but instead of installing fog lights the right fog light hole is now a direct 3" tube to the bottom of my GMPP filter.

Stl06LS

That's more of what I'm looking to do.