I have 1990 CRXsi with a D16A6 which I race at a local road course. The engine is stock with only a header and advanced cam timing. I want to upgrade the power (no I don't want a turbo). I have ordered a slightly hotter cam, an OBX intake, cam timing gear, and want to add a larger throttle body, new valve springs and retainers, do a mild port job and add a Hondata ECU. I guess I need to increase the injector size, but to what? I believe the stock is 235cc. If I jump to say a 270cc, how long will that hold me? Do I have to then get another set of yet larger injectors at each performance increase? Or can I jump to a larger size now in anticipation of future adds and power? Any help appreciated.

 

Raising the fuel pressure would help with the injectors you have now, and 270s will be plenty for a little allmotor D16. You shouldn't need more than that.

Oh, and welcome to Honda-Tech.

 

Thanks for the welcome, seems like a good forum. How do I raise the fuel pressure? And to what? Should I add a guage? Thanks.

 

There are many adjustable aftermarket fuel pressure regulators. B&M is cheap, takes some modifying the stock regulator to put on though. The more expensive ones replace the regulator, but you pay for the convenience. A gauge is a must, otherwise you're shooting in the dark.

The stock fuel pressure is 38psi. Raising it to 50 will make the stock 240cc injectors act like 257cc injectors, which is plenty.