I did some research on here and found that many people said that it wasnt worth changing the fuel injectors but all the posts were guys inquiring who had mostly stock engines.. Just wondering if its worth changing with all the port/polishing, new heads, cam, and fact that soon I will be going Nitrous if its worth upgrading the fuel injectors or if the stock ones will be ok... I mean I just figured since its all going to be apart anyway if its needs/should be done now would be the time..

 

For modified engines it is a good idea to run new injectors.

You want to try not to go above 80% duty cycle on your injectors.
Figure what your estimated horsepower is then just use a fuel injector formula to figure out what injector you will need.


Here are a few sites.

http://www.rceng.com/technical.aspx

http://www.witchhunter.com/injectorcalc1.php4

http://www.iroczone.com/calcs/injectorsize.htm


Good luck

-Eric-

 

What does HP at the flywheel mean? is that what my estimated hp will be with all the accessories.. kind of hard to tell.. I mean here is my list of mods with "Manufacturer HP Ratings"

SSM Stage 3 Power Pak - 90hp
Vap Auto Intake Spacer - 5hp
Mac LT's.. No Manufacturer figure give but most say - 10hp
ASP Underdrive Pulley - 10hp
Magnaflow Catback.. Again No listed number but most say - 10hp
BBK Cold Air Intake.. Again No listed figure but most say - 10hp
BBK Throttle Body 65mm - listed as 7-10hp

I think that's everything.. well beside the tuner which is "supposed" to free up some hp.. i mean if those are the numbers i should be adding then lets see.. the car stock was advertised as 190hp.. so add in the above mods with thier "listed hp" figures and that would put me at approx 335 than add in the 75 shot of nitrous and we are talking over 400hp. again is that "truly" the hp results i will see.. i doubt it.. maybe safer to just round down to 300.. maybe.. idk.. however i do plan to dyno the car before all the above mods and after to see what she puts out.. i am at least hoping i will feel a difference with the above mods done.. if i dont then i give up lol..

 

If your really going to make 400hp then you will need 41lb injectors according to the formula.

You will need to upgrade your fuel pump as well and its a good idea to upgrade the fuel lines and fuel pressure regulator and fuel rails.

Estimated horsepower and bhp are of the same figure, if a company says its going to make 100hp then thats 100hp at the flywheel before it goes through the trans, driveshaft and rear end. If the factory says your car makes 190hp then thats at the flywheel.

So a 100hp addon to a 190hp engine makes it a 290hp engine, but you also have to figure that the estimated figures are at peak performance, perfect conditions and multiple runs. Not everyone will make 100hp with the same mod, the same goes for Nitrous. 75hp shot doesnt mean its going to be an exact 75hp.

What you make at the wheels is a different figure, auto's have more of a drivetrain loss than manuals do.

Say your car makes 500hp at the flywheel and you have exactly 10% loss then that means you will make 450rwhp (rear wheel horse power.)

Hope that helps, it may not make the most sense due to the fact that its late, im tired and I kept getting up and walking away from this.


-Eric-