Do Speed Parts Really Perform - Car Craft Magazine

Do Speed Parts Really Work Edelbrock Intake And Carb Making Horsepower

There's no reason to buy speed parts unless they make your car quicker. Want a Dominator or a nitrous kit just because you'll look cool at cruise nights? Then you're a turkey. Spend your money on more chrome and leave this story for those demanding dragstrip-proven value for their hard-earned bucks.

In the following pages you'll read 10 tests where we took average cars, added common aftermarket parts, and blasted down the quarter-mile to see if we'd wasted our time and money. We tested a few of these items because, frankly, we figured they wouldn't do squat. Surprisingly, they all did-we went quicker every time. We'll also share with you the cost involved, but be forewarned that prices will vary depending on your car and where you score the goods. Of course, the results of the speed tips shared here are also kinda car-specific, but you get the idea. In case you don't, here's a clue: Go faster, spend less. Yeah.

Do Speed Parts Really Work Edelbrock Intake And Carb Setup

The Edelbrock intake and carb setup (left) is a direct bolt-on for '65-'79 Pontiac 326-455 V-8s (except Ram Air V). Besides a reported flow increase, the Edelbrock intake/carb setup was 26.75 pounds lighter than the factory iron intake/carb setup. Edelbrock also makes aluminum heads for Pontiacs.

The Edelbrock intake and carb setup (left) is a direct bolt-on for '65-'79 Pontiac 326-455

Intake And Carb Swap
Price: About $400
How Much Faster?: 0.381 second/1.70 mph
Installing a four-barrel where a two-jugger used to be is supposedly one of the best mods you can make. To prove it, we did back-to-back, stock-versus-Edelbrock testing on a '74 Pontiac Firebird with a well-worn Pontiac 350 that was original except for aftermarket plug wires, dual exhaust with stock manifolds, and a few chrome bolt-ons. We chucked the stock iron intake and 355-cfm two-barrel in favor of an Edelbrock Performer Pontiac aluminum intake (PN 2156) and an Edelbrock Performer 600-cfm four-barrel carb (PN 1406). The Edelbrock combo ditched almost 27 ugly pounds off the 'Bird, and it went quicker too. We used Mickey Thompson slicks during testing to eliminate any traction concerns. -John Kiewicz

With the stock intake removed, we carefully scraped clean the cylinder head's intake mounting surface before adding the Fel-Pro 1233 intake gaskets. Most Pontiac V-8s feature a bolt-on lifter valley tray that is handy for preventing gasket scrapings from dropping into the engine. Afterward, we installed the new Edelbrock intake and torqued the intake bolts in sequence to 25 lb-ft. The new intake has various vacuum ports that should be plugged (using the supplied plugs) if not needed.
With the stock intake removed, we carefully scraped clean the cylinder head's intake mount
For proper mating, an Edelbrock 1/4-inch carb adapter (PN 2732) needed to be positioned on the intake prior to installing the carb. We found that once the Edelbrock carb was installed, the factory throttle and kick-down linkage bolted on after minor tweaks to the stock brackets.
For proper mating, an Edelbrock 1/4-inch carb adapter (PN 2732) needed to be positioned on
The Edelbrock intake/carb combo provided a notable improvement in throttle response and performance. However, the points-type distributor would misfire above 4,500 when the Edelbrock induction was really starting to pull hard. Even so, we trimmed nearly 0.40 off of our e.t. with the Edelbrock goods. Make sure to read "Timing Tuning" for more Pontiac tips.
The Edelbrock intake/carb combo provided a notable improvement in throttle response and pe

Performance Testing
Description	E.T.	MPH	Improvement
Stock two-barrel carb	16.631	81.89	Baseline run
Edelbrock intake/carb	16.250	83.59	-0.381 sec/+1.70 mph

Price Breakdown
Typical mail-order prices as of December 1, 1998
Item	Part #	Price
Edelbrock intake	2156	$156.95
Edelbrock carb	1406	$225.95
Edelbrock carb adapter	2732	$4.95
Fel-Pro intake gaskets	1233	$15.95
	TOTAL	$403.80

Source
Edelbrock
Dept. CC
2700 California St.
Torrance, CA 90503
310/781-2222
www.edelbrock.com

Do Speed Parts Really Work Timing Tuning

H-O noted that with the new free-flowing induction the engine wanted its timing advance to come in earlier for more power. Thus, H-O installed a set of light-tension springs for the distributor advance weights to bring in the 28-degrees of centrifugal timing advance much sooner. (Note: Without premium fuel, this mod may cause detonation at low altitudes on a hot day.) Testing proved an e.t. improvement of more than 0.20 second.

H-O noted that with the new free-flowing induction the engine wanted its timing advance to

Timing Tuning
Price: Pretty much free!
How Much Faster?: 0.276 second/2.25 mph
When we did the intake and carb swap on the '74 Firebird, the ignition timing for both the stock two-barrel and the Edelbrock setup was 9 degrees initial with 37 degrees total advance; point dwell was 30 degrees. However, the Pontiac experts at H-O Enterprises advised us that, when running an aftermarket four-barrel setup, changing the ignition advance curve makes a noticeable performance improvement. We put the theory to the test. Note that the Firebird ran 16.631 stock, and 16.250 with an Edelbrock intake and carb. With a quicker timing curve it went 15.974-an overall improvement of 0.657 second over stock! It was nearly 4 mph faster too.