big newbie question

[Nopantz]

I feel like a dumb ass asking this but I was talking to Aliate X about his HCI set up and he said he was running stock injectors still with a stock maf; he said he had an AFRP. What is an AFRP or what does it stand for? Thanks guys.....you can flame me if you want.

 

[Nopantz]

okay there might be a chance he said AFPR ...which i know what that stands for and if that is what he said.....using it can substitute for having to use larger injectors?? My ultimate plan is the tfs top end kit so I figured i would just get 30 lbs injectors but if i can get away using an AFPR which i think might be cheaper that would be awesome

 

[Nopantz]

bump

 

[8950HO]

AFPR=adjustable fuel pressure regulator.

 

[Nopantz]

AFPR=adjustable fuel pressure regulator.

okay but if i get one can i use it to supply more fuel instead of switching injectors from the stocks to 30 lbs....i am still gonna get a new fuel pump

 

[jrichker]

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines.

Example:
19/.5 = 38, 38 x 8 = 304 HP
24/.5 = 48, 48 x 8 = 384 HP
30/.5 = 60, 60 x 8 = 480 HP

The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.

304 HP x .85 = 258 HP
385 HP x .85 = 326 HP
480 HP x .85 = 408 HP

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

See http://users.erols.com/srweiss/ to get the calculators used in these examples.

 

[Nopantz]

jrichker thanks for the help that makes alot of sense....okay final question so if I were to go with the TFS Kit and didnt change my injectors but used a AFPR at 63 PSI would I be okay or do I have to change the injectors.

 

[srothfuss]

Why so high of a FP setting? The stock setting is around 39PSI... A H/C/I (N/A) wouldn't need much more than that to run properly.

But if your question is: "Can I set it at ##lbs.?" than yes it's possible, but you'll need to look for a regulator with those kinds of numbers.

 

[FORCED2DV8]

jrichker thanks for the help that makes alot of sense....okay final question so if I were to go with the TFS Kit and didnt change my injectors but used a AFPR at 63 PSI would I be okay or do I have to change the injectors.

It might last a little while, but your maxing out your fuel system. You would Need to change your injectors, If your base pressure is 63 PSI and then it increases as the engine requires more fuel. I dont know the ratio off hand but at 5000 rpms can you imagine what your fuel pressure would be?? If you have a pump that can give that kind of pressure and if the rest of your fuel system can handle it?? New injectors is the way to go

 

[jrichker]

It might last a little while, but your maxing out your fuel system. You would Need to change your injectors, If your base pressure is 63 PSI and then it increases as the engine requires more fuel. I dont know the ratio off hand but at 5000 rpms can you imagine what your fuel pressure would be?? If you have a pump that can give that kind of pressure and if the rest of your fuel system can handle it?? New injectors is the way to go

The fuel pressure regulator reduces the pressure by returning excess fuel to the tank. Set the base pressure at 63 PSI, vacuum off and that's as high as it will go. You won't see that 63 PSI figure except at WOT, and typically only for 15 seconds or less.

Having said that, you are correct, new injectors and a matching MAF are the best answer. Rasing the fuel pressure is best left for small increments to temporarily tune the engine.

 

[Nopantz]

thanks everyone ...very helpful

 

[93GTosu]

i thought you were going with a thumper combo? i havent been online in a week or so, did you finally decide on the trick flow kit? maybe im confuzzled.

just wondering.

 

[Nopantz]

i have kinda decided that in the end you save money with the trickflows (or I may go with a Ford Racing HCI package).....there just so superior to the e7s. Also I am not gonna be doing an HCI swap until at least the winter..I'm a college student on an extremely tight budget.