1987 Chevy Camaro Exhaust, Intake & Fuel System Upgrade - My Generation Camaro, Part II

Intake, Exhaust, and Fuel System Improvements

Jeff Smith Aug 1, 2001 0 Comment(s)

Step By Step

While the 305ci Mouse isn’t exactly stunning to look at, Tim bolted on the Edelbrock Performer EGR in an afternoon and we were up and running with a better intake.

Our ’87 Camaro required a specific Edelbrock Performer EGR (PN 3706) that has a slightly different intake manifold bolt pattern where the four center bolts are at a different angle than the outer bolts. Unfortunately, the EGR Performer manifold is more expensive than the non-EGR Performer.

We also found a dual-inlet air cleaner with a taller filter originally used on an ’80 Corvette, along with a used K&N filter (right) at a swap meet for $75. That’s the stock 305 single snorkel air cleaner on the left. If we had not found the dual-inlet air cleaner, Tim planned to add a second tube to the stock air cleaner.

The dual-inlet air cleaner needed only minor tweaks to make it fit. Burt Chevrolet found a right-side snorkel and the air tube that were originally used on H.O. L-69 305 Camaros. These GM parts are now discontinued, but you still might be able to find one.

It’s hard to tell that the Camaro is even launching in this photo, especially with sundial-slow 60-foot times. Adding the fuel pump and a better intake manifold finally resulted in some better performance. We picked up 0.70 second and 5.61 mph with all the changes over the baseline.

The Flowmaster exhaust system is now in place, but it still has to breathe through the single 2-1/4-inch catalytic converter. After we install the Edelbrock headers next month, we’ll add a larger 3-inch DynoMax performance catalytic converter to increase exhaust flow.

We added a leftover Holley fuel pump that Tim had from a previous buildup. To stay true to the price sheet, we included it at a Summit price of $49. This bumped the fuel pressure up to 5 psi down the entire quarter-mile.

Now that we had fuel pressure, we could make some jetting changes. The beauty of the Quadrajet is that secondary jetting changes can be accomplished very easily. Remove one small screw and pull the secondary hanger and you have instant access to the metering rods. If you search around the junkyard, you can accumulate quite a collection of Q-jet secondary metering rods for next to nothing.

These are the used 3.73 gears we pulled out of an ’80s 2.8L V-6 Blazer. Tim also added a rebuilt Posi. He’ll bolt all this into the stock 7.5-inch rearend, and in next month’s issue we’ll see what that does for performance.

We also have a set of Edelbrock headers that are going on the Camaro. Edelbrock offers two different sets—one with the smaller 2-1/4-inch catalytic converters, and one with a large 3-inch Y-pipe leading to the converter. The hot setup is the one with the larger Y-pipe for later third-gen Camaros.

We’re also using this PerformAire automated weather station from Helmet City to monitor atmospheric conditions at the track. This tool won’t improve e.t. or speed, but it will identify what effect the weather has on our performance results. This eliminates at least some of the variables in testing.

The adventures of CHP's fire-breathing 17-second 305ci '87 Camaro continue. We last left our hero Tim Moore contemplating how to push the budget Camaro into the 16s. For those of you attending this party for the first time, we introduced the My Generation Camaro in the previous intallment (see links below). Tim discovered this 305ci, TH700-R4 automatic-equipped Camaro at an auction for the incredible price of $271. After bolting on a new catalytic converter, wires, and assorted minor pieces, he had a great Camaro for a touch over $1,200.

We cruised the Camaro up to the track to baseline its performance. To no one's surprise, it ran a paltry 17.45 at 78.64 mph corrected to sea level from the 3,000-foot altitude at Los Angeles Country Raceway. Exhaust modifications are always a good place to start, so we installed a Flowmaster 2--inch after-cat exhaust system. We also bumped the timing slightly from a stock 0 degrees to 6 degrees before top dead center (BTDC).

In theory, this should have pumped some steroids into the Camaro's performance program, but when we went back to the track it only ran two-tenths and almost 2 mph quicker. At first this was disheartening, but then we talked to Flowmaster's Kevin McClelland, who has a wealth of experience with these cars. He explained that our stock fuel delivery system was weak, so when we added the better exhaust, the engine probably went lean. This would also explain why a richer metering rod change had no effect on performance.

This '87 was the last year for carburetors on third-generation Camaros. It employs a small electric in-tank pump that pushes fuel up to an engine-driven mechanical pump. Even this combination of electro-mechanical pumping action is insufficient, so that's where we went next. We bolted on a stronger Holley mechanical pump to ensure the feedback Q-jet carb had plenty of fuel.

Now that we had opened up the exhaust and improved the fuel delivery system, the next step was to swap the intake manifold. Edelbrock has the widest assortment of emissions-legal manifolds, including a Performer EGR intake for these late-model small-blocks that require a different intake manifold pattern for the middle four bolts. Tim swapped the intake on in a couple of hours.

To recap, so far we've added a K&N filter, a Performer intake manifold, more ignition timing, a performance fuel pump, a stock replacement 2--inch catalytic converter, and a Flowmaster after-cat exhaust. Those were all positive things. Unfortunately, we were still burdened with the incredibly tall 2.73 rear gear that was certainly going to prevent the car from going quick in the quarter.

We also decided to keep track of the weather on each trip to the dragstrip since, as the summer months progress, hotter test days will detract from the Camaro's performance. Helmet City was kind enough to send along a completely automated PerformAire weather station that will accurately track the atmospheric conditions during testing.

With all these new parts bolted on the Camaro, we went back to LACR's quarter-mile crucible to see if we could finally lay claim to a performance improvement. Keep in mind that all these components have a synergistic effect. In other words, for the exhaust system to deliver a performance increase, we also needed help from the inlet side and the fuel delivery system. Without each of these components, the bolt-ons would not have improved performance. This is probably the biggest lesson with this car. It's the combination of the parts that make this Camaro perform.

While still saddled with the 2.73 rear gear, our trip to LACR still proved worthwhile. The Camaro delivered a slight improvement, posting a 0.70-second and 5.61-mph improvement that broke us into the 16-second zone with a best time of 16.75/84.25 mph charge. While we can hardly call this a quick time, at least we're making headway.

The other way to look at this is that these times offer a tremendous amount of opportunity for improvement. Clearly, the 2.73 gear is a hindrance to rapid acceleration, so Tim went gear-ratio hunting. He discovered a set of factory 3.73 gears lounging in a 2.8L V-6 Blazer fitted with the 7.5-inch ring gear. Someone had even removed the rear cover and pulled out the spider gears, making our retrieval that much easier. Literally, in less than 20 minutes we walked out of the junkyard with a set of 3.73 gears for less than $25!

But we'll save the excitement of testing those gears for the next installment as our My Generation Camaro launches a full-on blitz to blaze into the 15-second zone.

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