Cold Air Intake (CAI) vs Fender Well Intake (FWI)

I'm waiting to see how this one turns out.

2day I brought the autolight dp 104 plugs. Buying a boost gauge and the 180 thermastat 2morrow. I removed the stock air box and replaced it with a spectra cone filter 4 now. Then looking at ordering the 3.5 pulley kit on that sight u showed me. Thanks 4 the help guys. Next mods will be the down pipe and the cat. From there the mufflers. Also will be looking 2 get it tuned and a fwi!

If your cone filter is still in the engine bay your going to be sucking in all the hot air from the engine & tranny heat....you need to isolate it or do a FWI first, otherwise the plugs and thermostat will not be as effective.

Thanks 4 the warning. What r some ways I can isolate the filter 4 now till I can get a fwi?

1wickedninja wrote:

Thanks 4 the warning. What r some ways I can isolate the filter 4 now till I can get a fwi?

Best thing you can do is try to keep the car moving as much as possible. That keeps cool air circulating through the engine bay. You can also remove the rubber strip near the cowl, below the windshield wipers. This will let out some of the heat.

thanks 4 the info aa. Just order the 3.5 pulley kit from zz! Can't wait till its all put 2gether! Looking 2 do the downpipe soon after if I get time 2put it in the shop.

Cool. If I were you, I'd get that intake taken care of before you install the new MPS.

sorry still a noob what does mps stand 4?

Modular Pulley System (it's your 3.5" SC pulley kit).

FWI vs CAI?

FWI all the way, get the coldest air you can. Which means get the intake as far away from heat sources as possible.

wheres the air come from now?

It comes from, in a stock air box, where your filter would wind up in a FWI setup. Only trouble is, the stock air system has silencers that impede air flow that you can't get rid of very easily. I'm not talking about the stuff you gut out of the airbox, there are little compartments that look unnecessary on the hose up closer to the throttle body. They're there only to keep the intake noise quiet.

This is the stock intake system, the filter is a flat panel that sits in the bottom of the box in the bottom right corner.


This is the CAI (cold air intake) from the Whippled Riv. Keep in mind that this one is custom built and VERY heavily modified.


This set-up is a FWI (fender-well intake.) Notice that if you're looking into the engine bay you cannot see the filter, only the intake tubing.


Here is the same FWI, photo taken from outside the wheel well with the splash guard pulled aside so you can see where the filter is.


I'm a visual learner, so I hope this will better explain the difference between the two.

Nicely explained, Andrew. I will add that a true CAI has some kind of thermal barrier wall separating the filter from the engine bay (the stock air box is actually a CAI by design). I can't see any effort by Whippled Riv to separate the engine bay air, so would call it a short ram, or "warm air" intake instead. Some think it doesn't really matter much, but it does - in a big way. Kenne Belle will not even warranty its superchargers when used with short rams or other warm air designs. They can tell from examining failed parts if you've used one.

98riv has built a good example of what a true CAI design should be. You can see how the filter sources air from the fenderwell, while the insulated walls and tube isolate from the hot air in the bay:

I sealed off that box under the intake tube. I tried my best to measure the opening. Drew a few circles on paper(1/8 smaller,1/8 larger an the same size I measured) and used the one that fit best to trace on a beer can. I glued the circle piece of aluminum in the opening. Works well for me and still looks stock

Chris, I'm confused. What are you doing with the aluminum circles?

he covered the holes in the stock intake tube were the air bong or what every they call it is that's used quiet the intake noise.

I don't think the muffler impedes flow in any perceptible way. Did it change the sound any?

It's a Helmholtz resonator that tunes the sound. Shouldn't hurt flow much. The tube's internal ribbing hurts more in that area, imo.

I cant really tell if it affected the sound at all. I gutted the box the same time I closed off the H.holtz res. I thought about filling in those ribs with something but before I go through all that trouble, I'll probably jus go with some other kind of tubing.

Looking for a cold air intake kit for 1997 Riviera? Any suggestions as to where or who sells this. thanks

There really aren't many good options for the Riv - making a fenderwell kit just draws it's air from the bottom of the transmission anyway, so unless you remove the lower portion of the splash guards and build a little scoop down there, you are mostly pulling in engine compartment air anyway.

Search around, AA has a nice writeup on his scoop.

trying to find out what cold air intake to put in my 98 any suggestions?

Flex Tube Intake or PVC Intake (click on links)