I just picked up a TD07 25G turbo and am now on the look out for injectors. It goes without saying that I need 1600cc secondarys, but what about my primarys. I'm shooting for approx. 400rwhp. According to the fuel calc. on rx7.com, 720cc primary and 1600cc secondary @ 80% duty cycle is good for over 500hp @ the flywheel. My question is this, on average how much hp is lost between the flywheel and the ground? Do I really need to run 720cc primarys or will I be safe with the stock 550cc?

Like I said, I'm shooting for 400rwph @ about 15psi.

Any thoughts?

 

550 prims and 1600 secs are fine for that setup, im shooting for at least 400whp on a gt 35/40 but im going with the 1000 prim/1600 sec combo from rx7store cause I <3 overkill.

 

550/1600 should be fine for your setup... thats what i run, some people say that you notice a stuble during the injector transition... ive felt it but its only in like 4th gear starting at low rpms.

 

Thanks guys, I just want to make sure that I don't lean out while I'm racing.

 

It doesn’t take very much effort if you want to take your unused 850s and modify your primary rail to accept them and give yourself a higher margin of safety in the fuel department. Plus if you ever need it will be there ready to go.
edit:
2nd gen woops! doesn’t apply, fds can be easily modified.