'We're stoked! And at the same time, we're still driving a 14-second white '91 Firebird. Though you voted on CarCraft.com that a guy could drive it without looking like a Nancy, and a girl could drive it and probably look hot, we'll still feel geeky until we can produce a 12-second timeslip.
So were on it. Using basic cooling and tuning steps, and opening up the intake and exhaust, we drove the 'Bird to a corrected 14.19 at 95.94 mph. Considering that the '88 Firebird that we built in 2001 ran 14.40 on nitrous, we'd say we're ahead of the game.
But there's more. When we bought this thing about two months ago, we were hoping for easy speed for low dough. But the car barfed every critical TPI-specific part that controls idle and driveability then got hot in traffic and stalled (see it on CarCraft.com). So we're behind a little in money spent but way ahead in speed. Our plan is to prove that you can go 13s in one of these cars without cracking the seal on the engine or opening up a bottle. Then later we will spray our way into the 12s.
Fuel System: Critical StuffWhat we didn't mention in the first story is that we solved a lot of problems by replacing the injectors and fuel pump. These parts are actually a lot more affordable from MSD and Holley now that the car is nearly 15 years old. The MSD injectors are 22 lb/hr and are listed as factory replacements. The Holley in-tank fuel pump will flow up to 255 lph at up to 110 psi fuel pressure. Good if you are going to spray it like we are. Just look at it like adding a new carb and electric fuel pump on an old musclecar.
First Run: 15.00 @ 91.23We could call this a baseline, but really the car wouldn't always start or run when we got it, so the baseline would have us burning to the ground at the top end of the racetrack after a 20-second run. Instead, by the first run we'd already performed a basic tune-up, replaced most of the fuel system and computer, and modified the cooling system with a cooler thermostat and electric-fan switch. You can expect a healthy car to run 15s at high altitude or mid 14s at sea level. On street radials we ran an observed 15.00 at 91.23 mph, or 14.519 at 94.30 using the standard NHRA correction for Los Angeles County Raceway.
Intake: Easy PowerThere's an ugly restriction in the intake tract on '89-and-later Speed Density cars and it's worse for earlier MAF-tube sufferers. The first real performance piece we added was a cold-air induction system from SLP Performance Parts. It eliminates the stock air box and allows cold air to be picked up from the factory hole in the firewall. Installation is straightforward and the kit includes parts to relocate the charcoal canister to the driver side of the engine compartment by the battery.
Aftermarket intake runners are the soup du jour for TPI guys, and SLP makes a set that are actually easier to install than the stock pieces because of the thicker mounting flanges. These things are worked to make power by enlarging the intake tubes and removing the first inch or so of material between the runners where they mate with the plenum, essentially extending the plenum area. More plenum, more torque. The next trick is to cut the plenum divider and the gasket to match, but we decided to keep the first set of mods strictly bolt-on.