Adding bigger injerters will it give me more horsepower

 

yes it will...but you need something to tune the fuel...like dtec....

 

How will I tune the d-tec

 

you can street tune it

 

how do you street tune with the d-tec.... and can you adjust boost per gear??

 

First off, is your car stock? Adding larger injectors by itself wont do anything. The SRT-4 already runs rich from the factory. If anything, you would be better off taking fuel out. That'll benefit your performance. If your stock, there are plenty of other mods you should do first.
With a Dtech, you can adjust the boost per gear.

 

Didn't you say you have a 50 trim, 750cc injectors, etc. anyway? The only way you can tune the Dtech or do anything with the fuel is if you have a Air fuel Wideband gauge. I don't see how or even why you have a Dtech without a wideband gauge. Other than that, if you really do have 750cc injectors, there is no reason you should get larger injectors unless you need to. The only reason you would need to get larger injectors is if you get a larger turbo.

 

I have bigger fmic, agp piping and agp wastegate, nitrous intercooler sprayer, intake and downpipe

 

you cannot tune a dtech per gear. only a standalone can do that.

 

if you add injectors and a dtec you can raise the boost safely to 18 to 19psi to redline....