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1999 Corvette Exhaust System - Totally Exhausted

Can You Get Zo6 Output From An LS1 With Just Bolt-Ons? Let'S Find Out.

Dan Ryder Jan 1, 2008
Sucp_0801_01_z 1999_corvette_exhaust_system Rear_view 2/14

Living here in the good ol' USA, we have options-too many as far as I'm concerned. one can choose where they want to live, what they want to live in, and for a little extra-oK a lot extra-what kind of amenities they would like. I remember as a child drinking water from the tap-yes, we actually used a glass and drank the same water as our fellow neighbors. Now we have an abundance of plain bottled water, flavored water, and vitamin-enhanced water to choose from. Talk about a spoiled society.

Well, there's no turning back now and the automobile is no exception. When purchasing a new-model vehicle, one has many choices: Do you go with the 4-, 6-, or 8-cylinder engine? If you choose the 8-cylinder, do you buy the standard or the high-horsepower version? Many options can be had depending on your budget. Think with your head and not over it (as most of us are guilty of the latter).

Sucp_0801_06_z 1999_corvette_exhaust_system Stock_system 3/14

Once our baseline dyno runs were complete, Hank Jr. drove the C5 over to the SLP Installation Center to put it on the lift and allow the exhaust system to cool for removal. Here's a shot of the stock cat-back system, not bad for nine years and 50,000 miles worth of service.

For this particular LS-engine installment we are looking to take a base model 1999 Corvette, which is equipped with a 5.7-liter LS1 engine rated at 345 hp and 350 lbft of torque, and take it to (or exceed) the power level of the 2001 Corvette Z06, which was advertised at 405 hp and 400 lb-ft of torque. This could easily be achieved by employing a nitrous system or even some forced induction, but what's the challenge in that? Let's see if we can turn our tap water into a great tasting energy drink.

For part one of our journey we decided to facilitate better breathing by upgrading the entire exhaust system. While many products are available in the aftermarket, we decided to call upon the pros at SLP (Street Legal Performance) in Toms River, New Jersey. SLP is known as a topnotch leader in LS-powered technology. SLP designs, manufactures, and tests the majority of its products in-house, as quality control is of utmost importance. Whether your needs include something as minor as a gasket, or something as major as an all-out, firebreathing monster, SLP has you covered.

Upon arrival at SLP, Hank Daniecki Jr., director of engineering at SLP, greeted us. Our first order of business was to strap the Corvette on SLP's Super Flow chassis dyno to get some baseline numbers. After a couple of runs our stock 6-speed '99 rolled to the average tune of 312 hp and 323 lb-ft of torque-pretty impressive for a bone-stock LS1. After a little mathematics, that equates to an estimated 360 hp at the flywheel (that's 15 hp more than it was rated at).

We were impressed, both by the quality of SLP's parts and the ease of installation. Better still were the "after" dyno results. Not only were the peak numbers excellent (338 hp/348 torque) but the important digits under the curve were outstanding as well.

We are on our way.


SLP Performance Parts
Toms River, NJ 08755



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