In Chevy High Performance they bought an 87 LG4 Camaro and stuck an dual snorkel air cleaner and exhaust.

87 Camaro CHP

"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."

I have an 82 LG4 with an open element on it right now, and will be adding 1 5/8 inch headers, 3 inch catco cat with a hooker catback.

I'm curious how an aftermarket fuel pump will affect gas milage and performance, also if I should get one even before I put the exhaust on.

 

I would suggest putting the exhaust on before the pump. Just because a magazine article says it's going to go lean, doesn't mean it's going to be the case for you. Unless your pump is worn out, but i don't see the need for an aftermarket mega-HV pump, though. I would think a "factory replacement" by like Carter or someone would suffice.

I wonder how many people are out there with the LG4 and an aftermarket exhaust and factory pump?

 

 

Are you experiencing any of the difficulties that are mentioned in the magazine article?

Like i said, what a magazine does and what goes on in the real world are often times two very different things.

 

I've never run the car on the track, so I don't have an improvement.

 

I have an 84 version of the LG4 (8.sucky:1 compression)
I was experiencing a lean-out condition when the secondaries opened up, after I had modded the stock 84 Z28 hood to an air-induction type (basically cut out the area behind the 'plates' and sealed the air cleaner base to the hood with some foam). A set of DG secondary rods cured that problem, and it still worked great after I installed the Hedman shorties, y-pipe, and Dynomax 2¾" catback. It still worked fine after I swapped out the stock cam for a still-small cam with .420" lift intake and exhaust.
The fuel pump has been replaced at one time with a parts-store cheapie unit that works fine.
With 220,000 miles on the engine, stock heads (never been off the block), a T5 and 3.42 open rear, this engine ran a 14.49 @ 98 in my 83 SC.
I don't think I have any problems with lack of fuel.
The CHP Camaro had 150,000 miles and probably still had the original pump, so even a stock replacement may have done wonders.
I continue with your other modifications, and don't worry about the pump until it proves to be a problem. You may need to pop in some new secondary rods soon; the DG's I have work fine in mine...others may recommend DR's.

 

my dad has the stock lg4 pump on his 355...so far it's ran an 11.84 @ like 111 something. i would say that it's probably a pretty good pump.

 

I ran the stock pump on a 400 in my 83 for many many years; about 360 HP or so. It was plenty.

Sounds to me like the magazine article was merely full of the typical magazine-article monkey-spank.

About the only thing worth changing, is the fuel pump drive rod. A lightweight one helps out ALOT at high RPMs, because the pump draws in fuel on the "push" stroke, and then sends it toward the carb on the "return" stroke. Its spring both pressurizes the fuel, and returns the rod. A lighter rod allows the pump to do more of its work on the fuel and less on the rod.

 

I took the advice of RB83L69, and I installed a new stock type Carter fuel pump on my 355 (got it at Napa for $11.99).

I had my brother-in-law over one day and got it running. He did somthing to the in-tank pump relay, and blew a fusable link somewere. Now the in tank pump doesn't work, but the new Carter stock pump is still keeping up with the 700cfm Double Pumper on my 355. I will be fixing my electrical problem soon but it hasn't seemed to hurt the new mechanical pump any.

 

When I first got the then-stock LG4 running in the '82 5 years ago, it wouldn't pull at WOT. The new-looking fuel pump apparently didn't like sitting around for the year before the swap. New replacement AC pump solved the problem, and it's still on the engine today.