The Killer Whale bakes the...
The Killer Whale bakes the Nittos on the dragstrip in preparation for another pass down the 1320. This time around, we shed almost four tenths with budget track-tested and dyno-proven bolt-ons.
So far, life in the fat lane has been good to us. As we mentioned last month, we immersed ourselves in the world of rotund Caprices by finding, purchasing, and drag racing a rather clean '96 Caprice we picked up for $3,000. With a smattering of mods (Edelbrock cat-back, Level 10 tranny with 2,400-stall converter, Metco control arms, 3.73 gears, and Nitto drag radials), we managed to whittle our e.t. from a ho-hum 15.251 at 91.11 mph to a respectable 14.802 at 91.77 mph-not bad for our first few weeks of ownership!
Our round of mods this month focuses on adding some time-tested bolt-ons that we'll track-test and dyno-test thanks to the capable hands at Crazy Horse Racing in South Amboy, New Jersey. What better way to show how power at the wheels really affects dragstrip performance in the real world than to run back and forth from the track and the dyno? Strapping our Killer Whale onto Crazy Horse's Dynojet 248c revealed a baseline of 245.6 rear wheel horsepower at 5,350 rpm and 320.6 lb-ft of torque at a mere 2,900 rpm. Considering the car is rated at 260 hp and 330 lb-ft of torque from the factory, the Killer Whale is sure running strong with just the Edelbrock cat-back exhaust.
At Crazy Horse Racing, Chris...
At Crazy Horse Racing, Chris Winter straps our LT1 Caprice onto the Dynojet 248c to get a baseline. With our previous best of 14.802 at 91.11 mph, we weren't surprised to find 245.6 rear wheel horsepower and 320.6 rear wheel torque. From here, we started testing every bolt-on we could get our hands on.
One of the most fabled no-cost upgrades to any GM car is to de-screen the factory mass air meter, that is, remove the meter's screen on the inlet side. Designed to straighten airflow into a more laminar fashion before it hits the meter's hot wire element for more accurate readings, the screen has proven to be a minor restriction on flow benches and dragstrips alike.
For us, this five-minute modification netted us an e.t. reduction of zilch (rounded off, that's a big zero). On the dyno, however, we did find some slight gains in the low- and middle-rpm ranges. For instance, at 4,000 rpm (the highest point of gain) we were up from 215.8 hp to 220.8. Torque also swelled by 6.4 lb-ft at 3,400 rpm, where it was up from 309.8 to 316.2 lb-ft. At the peak points, however, there were no gains, just equal numbers.
Being consistent with our first round of low-dollar upgrades, we then moved to the air filter and induction system. We replaced the convoluted and restrictive air intake system with a cold air kit we found on eBay. The kit simply replaces the forward air silencer and airbox with a straight steel tube and an open-element air filter.
For our first mod, we picked...
For our first mod, we picked up a rather "affordable" performance air filter system we found on eBay. It was listed as a "cold air intake kit," but the description was misleading, as it draws warm air from under the hood. But for $43, we decided to give it a shot.
Although the seller considers it a cold air system, in truth, it's not because it draws air from within the engine compartment, including its heat. But for the money ($43), we couldn't complain or resist being our cheap selves. The installation literally took all of 15 minutes to complete, as the factory parts came off with ease. A noticeable gain in underhood noise was rewarded with a drop in e.t. to 14.651 at 92.10 mph for a .151-second drop in e.t. and a 0.33-mph gain. The poor man's performance upgrade was certainly worth it, and to prove it, Crazy Horse's Dynojet measured a gain of 3.7 rear wheel horsepower and 9.5 lb-ft rear wheel torque, bumping our figures up all across the board with our peaks now at 249.3 rear wheel horsepower at 5,600 rpm and 330.1 lb-ft rear wheel torque at a stump-pulling 2,800 rpm.
Next up, we went with an underdrive crankshaft pulley. We knew it would net gains both on the track and the dyno, but the question was, by just how much? We were able to find a used unit for $78 from-you guessed it-eBay. The seller didn't know what brand it was, but he threw in the appropriate drivebelt and hardware. To no surprise, the modification helped horsepower at higher revs as our trap speed climbed to 92.55 and our e.t. went down to 14.520, despite the loss of favorable weather conditions. On the dyno, we found the unknown underdrive pulley to be worth 3.9 rear wheel horsepower, and the dyno graph clearly illustrated how most of the improvement came at 3,500 rpm and above. There was no gain at peak torque, so our rear wheel power tally was now at 253.2 horsepower and 330.1 torque.
 The factory air filter system...  The factory air filter system looked like a horsepower trap. With its multiple air silencers sitting inline, including the huge "home plate" assembly on top on the intake manifold, we were sure to find power here. Note how the indirect air path between the mass airflow meter and the throttle body restricts airflow. |  With the eBay cold air kit...  With the eBay cold air kit installed and the factory mass airflow meter's screen removed, we were able to find a noticeable 3.7 rear wheel horsepower and 9.5 rear wheel torque. On the track, it was worth a tenth and a half, and our e.t. was now 14.651 at 92.10 mph. |  While perusing the online...  While perusing the online auctions, we stumbled across this no-name LT1 underdrive pulley that came off of a Camaro Z28. Luckily, B-body Caprices and Impala SS sedans share the same front accessory drive systems with F-bodies, so these parts are interchangeable. The seller also included three mounting bolts and the appropriately sized drivebelt, saving us a trip to the local auto parts store. |
 All LT1 engines use a two-piece...  All LT1 engines use a two-piece damper design. The harmonic damper/pulley comes off the crank hub with just three bolts. This aftermarket pulley is rated at 25 percent underdrive, and side by side the difference in diameter is obvious. This will slow down the drive speed of all the engine accessories, reducing parasitic losses and increasing power to the wheels. |  Our unknown underdrive pulley...  Our unknown underdrive pulley squeezes in between the factory harmonic damper and the crank hub. The damper is reinstalled so that it can continue to control crankshaft harmonics. Please take the time to reinstall the damper into its original position by properly clocking it where it belongs. If it's off, the crank position sensor will pick up bad harmonics, and your OptiSpark ignition system may act up with a cylinder misfire that will make your car feel like a slouch. |  Going to an Edelbrock twin...  Going to an Edelbrock twin 52mm throttle body netted us some rather impressive gains. Around town, the car felt much perkier, and throttle response was crisper. Because the TPS comes installed and ready to go, installation was quite easy. As a safety measure, we also installed a 255-lph in-tank pump. It's a direct replacement and helps prevent a lean-out condition as our engine continues to make more power. |