1999 Chevy Camaro SS Intake & Exhaust Upgrade - Bookin' By The Book, Part 2

On the passenger side, Edelbrock's new, coated before-cat "extension" pipe goes up loosely with two bolts and the provided donut gasket. This pipe is needed because the outlet of the passenger-side header sits lower than the stock manifold, hence the OEM Y-pipe won't bolt on...

...without just a bit of modification, that is. The Y-pipe is cut just upstream of the stock passenger-side catalytic converter (interesting note: this bit of pipe is double-walled, presumably for quicker cat light-off). The instructions say to leave a half-inch of pipe ahead of the cat, but we find the need to leave a little more.

The Y-pipe is then removed from the car to allow the installer to complete a nice 360-degree weld. The new weld is painted to prevent corrosion, and the modified Y-pipe is bolted in place for good. Here's how the completed TES install looks from down below.

Time for Edelbrock's cat-back to go on, and it's a very straightforward affair. First, the intermediate and over-axle pipes are put in place loosely. Their clamps are only tightened enough to grab and not allow the slip-fit connections to move. While the connection where the intermediate pipe comes off of the stock Y-pipe is 2.75-inch, the pipes are 3-inch thereafter. The stock exhaust hanger on the passenger side is used to bolt onto a bracket on the Edelbrock pipe, allowing the assembly to hang from the factory location.

Edelbrock's patent-pending Sound Deflection Technology (SDT) muffler has no muffler "packing" whatsoever. It consists of an entry chamber (shown), resonator chamber (the start of this can be seen), and a so-called parabolic sound deflection chamber, all of which work in concert to reduce sound wave energy. It's claimed to produce "more horsepower than the most popular chambered mufflers on the market," while yielding a throaty exhaust note.

The SDT muffler slips onto the over-axle pipe, and Edelbrock's provided hanger/clamp combo is used on the driver side to bolt to the factory rubber hanger assembly. Unless I managed to misplace it, a matching bolt/nut to install through the stock rubber isolator was not provided, so we improvise.

The polished stainless tailpipes go on, final adjustments are made to all pipes, and all clamps are final-tightened. As it stands, the Edelbrock cat-back is a nice-looking piece; we're interested to see how its aluminized sections of pipe and muffler's Ti-Tech finish hold up to the elements.

With the exhaust all set, we address the intake. The stock unit comes off after (1) removing the pop rivets holding each side of the intake silencer against the upper radiator cover, (2) unsnapping the two lid clips at the very front of the airlid, (3) unplugging the MAF and IAT, and (4) loosening the clamp at the throttle body. This particular car does not use the filter assembly as part of the AIR system, so there's no hose to disconnect from the silencer. The stock paper filter comes out, then four 10mm bolts are removed to free the upper radiator cover/filter tray.

There are rubber cushions on the underside of the upper radiator cover, one on each side. Remove them by squeezing the nipple as shown. They'll need to be transferred to K&N's new upper cover ("heat shield").

The heat shield goes on with shiny new bolts and washers. Make sure the cushions go onto the radiator properly. You will have to pull forward on the assembly to line up the boltholes, as the radiator will be leaning back a bit from where it needs to sit.

The MAF and IAT are removed from the stock intake assembly. The IAT in particular will put up a bit of a fight, but don't break it--it's just plastic! Once removed, it's inserted into K&N's Filtercharger element using the grommet provided. Speaking of, this sucker felt awfully lightweight, then we realized it's REAL carbon fiber! At this point, we also screw the provided rubber isolator into the front of the filter, being sure to use the supplied rubber washer between it and the filter.

Acting in blatant disregard of K&N's instructions, we assemble the entire intake (consisting of two rubber hoses, the MAF, the filter element, and all associated clamps) before putting it onto the throttle body in one piece. Doing it our way, the metal tab at the front of the heat shield must be bent forward to allow the rubber isolator and its protruding stud to slide into place. While tightening the throttle body clamp, we hold the filter element parallel to the heat shield so that everything stays nice and aligned.

A nut is tightened onto the front of the rubber isolator, the MAF and IAT are plugged in (the latter is a bit of a stretch, but we're able to get it to work), the K&N decal and CARB emblem are affixed, and we're all set! On cars whose AIR system pulls from the intake, a small filter (provided) attaches under the driver side corner of the heat shield, but it's not necessary for this particular vehicle. There's no problem with the K&N intake clearing the SS hood, either. If you look closely, you can catch a glimpse of our new headers too!

On the dyno, the exhaust parts combined to add a bit under 10 hp and 8 lb-ft at the tires, even with a substantially richer AFR. This gain is within the range advertised for Edelbrock's TES systems, but we're guessing a cat-back with a straight-through muffler design might improve on this substantially. The K&N intake added roughly 8 hp and 4 lb-ft on top of this, bringing totals to 322.7/336.1 with all said and done. True, the intake didn't quite deliver the increase estimate quoted by K&N, but that admittedly was on a 1998 car (you can see we did verify the as-promised improvements throughout the RPM range; the same goes for the Edelbrock items). Also, it's critical to note that in keeping with CARB requirements, a bone-stock PCM tune continues to remain in place; though the final AFR curve looks pretty good, we're certain the skilled hands of TTP's Matt Sorian could tweak a few more ponies from the fuel and spark tables had we asked.