Tirekiller

Hey guys im a little new to the honda scene. I recently bought a 91 civic dx hatchback, which has a d15 with pgmfi dual point throttle injection. Im looking into inreasing the output of the motor. I really dont want to do a turbo or supercharger before i do an engine swap. You guys have any suggestions where i should start on the motor other than swapping heads and intakes?

DumpdEJ6

Nitrous is about the only thing other than a turbo or supercharger that's going to have any significant effect on HP. I suppose you could convert to MPFI which you'll have to do before swapping anyway, that might get you a little extra.

4drEF

Since the DPFI ECU doesn't have any support for tuning, any mods you do will not give you an significant increase that you will notice.
I'm not sure why you say "where i should start on the motor other than swapping heads and intakes".
Swapping the intake from DPFI to MPFI is the foundational change to gain power.
It is the entry to being able to do modifications - without it, really don't even bother trying to get performance out of the economy minded motor you have.

Pro-SeriesFab

nitrous kit.

Easiest/cheapest increase in HP.

No need for computer tuning . . . just watch the a/f and adjust with the jets.

Tirekiller

I have thought about doing nitrous. Not a bad idea, but i do agree 4drEF, i do need a new intake bc throttle body injection is ****. Im rather going to do a z6 intake, skunk 2 pro series or a edelbrock performer x. Im also doing a manual swap from a wrecked crx. If I get a intake and high pressure injectors, whats my performance increase going to look like? bc i saw 410 injectors online.

ratchetEDsedan

Tbh I would just find a different EF before going through all that work. I mean I hate to be that guy, but I'm coming up on one that's already swapped and running, with a b18a, for 750 bucks, reasonably clean for the price. It'd just be more worth your dollar to buy a good foundation. I've seen z6 swapped EFs for around a thousand, to fifteen hundred. Unless your car is literally pristine, it'd probably be less work.
To answer your question though, output is pretty pitiful on these things. 98 hp if I recall correctly. MPFI and OBD1 swap will basically turn your car in to an EG DX, which is around 105 hp.
After that you're limited by the block itself, to about 180whp, because the rods are weak. I think some D16 rods will work with notching but at that point the engine is out and you may as well swap it.
410's with just an intake mani? What for? With a stock cam and ports the D15 is never going to flow enough air to make that necessary, or beneficial. You'll hit airflow walls before you hit fuel flow walls on the stock injectors. I'd bet you'd max it at about 125-130 hp, maxing the timing, and tuning for it, and I'm sure the stock injectors would do that fine.