Will i need injectors on this setup? 400rwhp

[GUNR33]

Hi guys

i am getting my r33 gtr mildly upgraded. But i am in 2 minds about getting injectors for my car. Question is..will i need injectors at the power level i am chasing. 400 rwhp.

here are my mods:

internally stock r33 gtr with:

-garrett 2860 -7's
-pfc (non djetro)
-nismo intank direct replacment fuel pump
-slightly thicker fmic than stock
-2.5in front pipes, to 3 and 1/4 in cat back. hiflowed cat.
-stock dumps
-stock injectors

. car hasnt been tuned yet cause theres too many different answers for power outputs on stock injectors.

[GT-R Glenn]

Showing results 1 to 25 of 132

[Adam Kindness]

yes....

I was pretty much maxing my standard R32 GTR injectors at 1.3bar on 2860-5's and that was less that 400RWHP (410+fly)

[GUNR33]

i heard this from someone but dont quote me on it.

apparently the r32 gtr's make less power than the r33 gtr's with stock injectors due to a different base line fuel pressure?? or something to do with the stock fpr??

[GUNR33]

i dont want to have to change injectors for another reason. Down here in Aus they are very strict on power laws and modifications. Im going with a stealthy setup.

For an extra 20whp should i just get a nismo fuel pressure reg?


And i have another question?

Would i need to port my exhaust manifolds with the -7's?


some say yes and others say its a waste of money.

i will never run boost past 18 psi on a stock motor anyway.

[Adam Kindness]

to be honest i'd rather have enough headroom with the injectors without running at daft pressures.

I was running a tomei FPR (raised pressure), but running a bit rich unmapped on Mines ECU

[GUNR33]

looks like i am going to see what the stock injectors produce as safely as possible.

if it does 380 rwhp il leave it. After all it is an internally stock motor.

[icydude]

I maxed oem injectors at 420 whp. On a dynojet.

But that is absolute max. You need bigger to be safe.

[SmigzyGTR]

Originally Posted by GT-R Glenn

Showing results 1 to 25 of 132

LOL

[creedonsr20det]

im running 472bhp (393 athe wheels) with stock injectors on my r32 gtr.im running 1.1 bar with gt2860-5s i do have a tomei adjustable regulater.i wudnt push the boost any higher with stock injectors.Im running well over 90percent duty at this boost

[iVeR]

easy way to calc how large injectors you should have is

HP x K
-------- = Fuel flow (cc per minute)
C

Where hp = maximum horsepower, K 4,6 for naturally aspirated engines, or 5,6 for turbo/superchargrd engines, and C= numbers of cylinders

400x 5,6
-------- = 373,33333...fuel flow (cc per minute
6

373cc is what a 6 cylinder, 400 hp gtr needs every minute per cylinder

TF x 100
Injector static flow(cc per minute)= ----------
N x M


Where TF = theoretical flow, N = number of injectors per cylinder , and M=
injector duty cycle

Best duty cycle is somewhere between 60-80%

TF= 373
N= 1
M= we take 70% for now

373 x 100
----------- = 532 cc/min
1 x 70

So you can buy 500cc injector or 600cc you get lower duty cycle on the 600cc