I purchased a 2001 996 and car has the orange colored fabspeed cold air intake. The exhaust noise is much louder than normal and I understand this is true of the aftermarket air intake. Can anyone verify this. I am interested in buying a eom intake if anyone has one

 

It is not the exhaust note that is louder but the induction flow noise as well as the general engine noise filtering into the passenger cabin. Manufacturer's generally "tune" the induction pathes and filter box shape/wall thickness to both reduce the noise (hiss, flow, whatever you want to call it) of the incoming air -- which really can make a noticeable noise -- and to "tune" the chamber as a kind of echo/resonance cancellation chamber which can cancel unwanted engine sounds. This is really supposed to work: BMW is the acknowledged champion of that with their Z3 and Z4, which use a type of chamber to add to engine performance sound. Late model Camaros and firebirds also have some noise cancellation built into their air intakes - the two air-pcoket chambers on either side of the air induction path are their just to cancel engine vibration noises.

My experience with other types of cars is that aftermarket intakes often make little or no difference in performance at all, or only under extreme (drag strip) conditions, but result in more noise all the time because they are designed strictly for air intake, not used for the subsidiary noise cancellation effects. A lot of people like the additional engine sound, or equate noise with power, and thus buy them. I have a '04 996 that will stick with the stock intake. My neighbr has a Boxster with an aftermarket air box that made no difference in measured dyno output, but did make more noise.

I'd pick up a stock air intake from one of the salvage/parts companies advertising in the pca magazine.

 

I concur. Not worth the price and only good at high speed in the right environment.

 

We tested Evo motorsports intake on the 996 twin turbo on our mustang awd dyno, first we tested the stock intake, then put on the evo while it was on the dyno. We picked up 15HP and 15FT/LBs torque TO THE WHEELS with the evo intake. Thats to all 4 wheels. The right intake will make power.

 

Fine, if the HP increase makes you happy, keep it, but I remain unconvinced and I have never seen proof.

1) I spent three years and thousands of dollars in a very procedural search for aftermarket horsepower on my '02 Corvette. I also tested similarly on a Camaro and a Prosche 944. Among the items I tested on the 'vette were four different cold air intakes (Blackwing, MTI, Halltech and Blackwing, among them ones whose manufacturers claimed up to 20 HP increase. I never saw more than 3-4 HP gain. I did occasionally see increases of 15 HP on the dyno tests - BUT when I replaced the aftermarket unit with the stock again, I often saw most of that gain anyway. And on two occasions, putting the aStock unit back on gave more power than the most recent test with the aftermarket unit. Similarly, on the vette, only one of these (the Halltech, with its ran-air feature, unmeasureable on the dyno) made a noticeable consistent change in 1/4 times - about .1 second.

By the way, given the overall rule that I discovered that verifiable aftermaket HP costs about $85 per, these cold air intakes were not bad buys. Just overrated by a lot of owners in my opinion. (I used the Blackwing for two years, until such time as, with SC and intercollers, it no longer fit. It was a good unit).

2) Along the way, I also learned a lot about dyno testing, partly from just watching and studying, and partly from a wily old mechanic and former GM factory test engineer who showed me some "tricks" dsuring three years of paying for at least one test sessiona month, on the way from the vette's stock 357 RWHP to over 600 now. There are run-to -un variations on any chassis dyno of about 3% - a bit less on a Mustang brand unit with a really good operator, and bit more on any Dynoject if the technician is not real experienced. Sometimes, people simply overlook these many factors and so two back to back runs give different results. Other times, a real master can manipulate things like tire pressure, or the tension of the straps holding the car down to the dyno-rollers, or the cool-down time between runs, to push the test in any direction you want.

I'm not saying any of that happened, but I do not believe that a simple cold-air intake can add 15 HP to a 996. If you could get that much with such a simple addition, the factory would have done it: engineering the intake resonance out of any such intake would not be that expensive and well within what the factory could do.

 

You probably don't believe that smoking increases your risk of lung cancer either eh?

 

No, I believe smoking causes lung cancer because my mom, a smoker all her life, died young - of lung cancer. I have a degree in applied math as well as two in engineering and deal with statistics all the time, so I believe the general results reported, too.

But I also believe there is a tremendous amount of BS around, particularly from people who, for commercial or just bragging rights reasons, like to over-represent the power of their car's aftermarket HP. So unless I've seen it with my own eyes, or looked at the results of a transparently reported, "double-blind" test, or gone through a rigorous, quantitative and fact-based technical argument that 'proves' it, I just won't believe it. I've talked to a lot of people who claim big gains - 15-20 HP from air boxes, 50 from headers, 30 from cat-back exhausts. But I've never seen verifable claims - on the dyno or on the-track results, that bear those out: in general results, at best, are about half for each of those.