Suparslinc

This is my next logical step. I've heard from several reputable sources that an aftermarket fuel pump will make significant gains; even on a stock engine. I want to hear from some owners who have done this upgrade before I decide to buy.

My car:
1984 GSL
modified Nikki carb
Racing Beat cat replacement pipe
soon:
ACV block-off plate
remove airpump? (another question in itself)

Will an aftermarket pump really improve my bottom-line performance? I notice the car pulls well in the lower RPM's; then fades close to redline. I wonder if the pump will let me pull past 7k.

SilverRocket

In my experience, adding a fuel pump and FPR to a 12A car with full RB exhaust and no emissions does in fact result in a noticeable improvement. Now, that's not to say it's anything like installing headers, it's not 10hp more lol. In my experience, the difference is a firstly a feeling of slightly better throttle response, like the power is more "right there" when you nail the gas in 3rd gear. Second, like you alluded to above, power at high rpm seems to improve, and the engine seems to pull a little harder near redline.

Note that these observations are only what we noticed when installed these on a friend's car; ie. this isn't stuff that I've seen over and over, only tried it once.

My overall opinion would be, it likely will make a small difference with your mods, but nothing too hardcore. But, it's a necessary mod once you go to an aftermarket carb (I'm not sure how modified your Nikki is) and go to a full header exhaust, so you might as well get it taken care of. Plus, it's a fairly inexpensive mod.

BTW... it's important to realize that a major reason your power is falling off at high revs is that the Nikki is tuned from Mazda to run super *** rich at high rpm, which kills the power. You can't change the air bleeds on a stock carb, so you can't fix this problem - I was very impressed with how hard my Dell pulled on the high end compared with the Nikki. Again I'm not sure how modded your carb is. Remember too, the stock port motor limits the top end as well - if you're looking to really pull much past 7k you're going to need more than a fuel pump!

poweRX-7

I just did a fuel pump upgrade on a stock 12a. I have the stock nikki carb, but plan on an upgrade. The day after i did the fuel pump upgrade, i did a full exhaust. So the improvements that i saw were obviously mainly because of the header, and whatnot.
But, i did notice an improvement in the higher rpm's on the day i installed it. Although it is much louder, it pulled much smoother. Very nice upgrade for the cost.
Also, my pump wasn't putting out the pressure that it was supposed to. That is why i replaced it, and i am glad i did.
hope this helps.
jeff

Suparslinc

Very helpful, it sounds like the fuel pump is a a safe bet. My carb has enlarged primaries, bigger pump, and mechanical secondaries. Can you guess who rebuilt my carb yet . Not only is it more powerful, but more driveable if that's possible. . .
I guess after the fuel pump I should probably go with headers then ignition. An aftermarket carb is sorta out of the question for this car.