RB Ram Air Duct with stock air box.
 

I know the this question was brought up in another thread, but it was never fully answered. Is it worth the money to install the Ram Air duct with the OEM intake? I have heard rummors of some gap, can it covered or connected? Has anyone done this? Any information or pictures would be nice.

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you're the best

There will be a gap, yes. Reason being is that the stock air box inlet does not extend all the way to the ovel opening the VFAD goes through.
If I were to get just the cold air duct, I'd fabricate a short extension to the stock air box that would bring the inlet against the hole in that front bar. Some piece of a rubber pipe would do I guess.

I had stock box with duct and didn't feel any difference. FYI I also had the green replacement filter. Since I didn't feel any difference I went ahead and purchased the whole revi intake to see if I would get better mileage like everyone else. I don't notice any changes as far as performance or even sound. I don't think I can hear any changes due to my borla exhaust. If I could do it again I wouldn't have purchased it. I'm waiting for someone with my same setup to get the interceptor to see if they get more hp out of it.

So are you saying that it isn't worth it?

Well, I can definitely hear some difference in the sound (I have the stock exhaust).
I also do get about 1 mpg better gas mileage with the REVi + cold air duct.
As for performance, perhaps a bit more responsiveness, yes, but not overly much. I don't push the car very hard though. Strangely, the idle is smoother, but I'm not sure how much is that attributable to the REVi or maybe something else.
I'm happy with it so far.

So then, 'no' I shouldn't get it?

I bought it. I'll let you know my opinion when I put it in. My car is stock except for tires as of the moment.

Please, let me know.

no, neither the REVi nor the air duct does anything. It was all in my mind after all....... Tee Heeee

what about th duct with the "old" k&n typhoon?

any intake that points to the stock intake hole in the front frame will benefit by the cold/fresh air inducted by the RB air duct

you won't get the 'ram air' effect as you would if you also got the REVi intake box, but you'll definitely get fresher/cooler air around the intake with the air duct, compared to just sucking random air under the front bumper :D

but of course, how much 'better' is this cooler/fresher air compared to random air under the front bumper in terms of better performance, now that's up for debate :D

Bill, you should have purchased the HKS racing suction.. =(

and a side benefit of the REVi intake box is in fact a better idle due to the better engineered air intake horn inside the air filter, compared to the half-chopped one in the stock air box, it still amazes me how a little change like that can smooth out the intake air flow of the engine this much :D

well most people here are claiming a 7 degree drop in intake temp. According to the SAE correction dyno factors (which aim to normalize everything to a common temperature) at standard pressure conditions the correction factor for 90 degrees F is ~1.013 while the correction factor for 83 degrees is ~1.006...

... therefore you could count on a .7% difference between temps, or if you have 200 rwhp about 1.4hp... yipee

How big is the gap?

Quite substantial: about 2 inches.

Honestly, I think Racing Beat should market an adapter that allows the stock air box inlet extend to the oval hole.
However, they probably rather want people to buy their whole REVi instead...

Is there any way to get a hose clamp on the stock air box and on the ram air duct? How large is the tube?

You can use a hose clamp on the stock air box, yes. But why yould you do that on the duct?

If you want to go this route, fabricate an adapter and clamp it to the stock box.

Wouldn't you need to clamp both? Otherwise it wounldn't be air tight.

hmmmm, any suggentions on the materials needed to fabricate the connection between the duct and the stock intake box? I haven't had the front bumper off myself so i dont know how it all looks firsthand...

Given the cost of these things, how about $$$ bills? Got to be cheaper.