17 Psi on 450's

[GSX93DSM]

I was wondering can 450 injectors handle 17psi and an evo 16g

 

[ikickuintheball]

I don't think they'd be able to keep up. You'd be maxing them out for sure. Do you have your fuel pump rewired?

 

[delta448]

Yes they can handle it, but not much more.

 

[timloomis]

Get a datalogger to see if it does.I wouldnt trust the 450's though.I was running ~90% duty cycle at 16psi on the 14b with a bigger pump.

 

[Stapl3]

I ran 18psi on 450's and a big 16g. No problems, but I have 94 here. Like said above, use a logger and let your car tell you, not us with our guesses. No one here can tell you honestly, there's too many variables.

 

[GSX93DSM]

Yeah I have a 190 rewired and im at 13psi right know.

 

[steve]

Yeah I have a 190 rewired and im at 13psi right know.

So tell us your current IDC, because without that everyone is guessing.

Steve

 

[tstkl]

if you get an aftermarket fuel pump and bump up the base fuel pressure, I don't see why not. I ran 21 psi on 450cc injectors on the 14b at 46 psi base fuel pressure and saw 98% idc's. good stuff....

 

[tom04841]

or you could add water injection and boost 18-19 safely.

 

[Rice Over Wheat]

I lost 20whp on the dyno back when I increased from 15 psi to 17psi on a big T28 and 450s, stock fpr.

 

[spyderturbo007]

Yes they can handle it, but not much more.

Please tell me how you know this.

I was wondering can 450 injectors handle 17psi and an evo 16g

You need to look at pressure and airflow when determining what injectors you need to run.

Below are calculations I posted in a thread a couple of months ago. They are @ 19psi, but I can do them again for you at 17psi if you want. The comments relate to the person in the other thread I was giving advise to, so remember the do not apply to your situation

The 190lph FP not rewired can handle 38.72 lbs/min of air at 20psi, running 93 octane fuel(SG of 0.76) and an AFR of 11.3:1. Rewired, the 190 can handle 43.77lbs/min of air at the same specifications. So, if you have a 190, then there is no reason (yet) to get a bigger pump, just rewire it.

The injectors are another story. 450cc injectors are capable of flowing 1.9lpm (all 4). So running 93 octane and an 11.3:1 AFR they can handle 34.35lbs/min of air. Furthermore, it is recommended that you keep your IDC below 85%, which drops us down to 27.75lbs/min.

When I was running the 16g at 17.5psi, I was flowing about 28 - 29lbs/min with the stock cat back. If you are on an aftermarket cat back, you are most likely running a higher flow that I was at the same pressure. I would suggest that you NOT run the 16g @17psi on 450's.

 

[delta448]

Please tell me how you know this.

I guess I didn't take into account all of the variables, e.g. total airflow and base fp. I admit I shouldn't have assumed any of those things.

I run 17psi on 450's right now. I do see a fair amount of knock and pretty high (95+) IDC's, on pump 93. But I simply turn the boost down during the summer and I honestly don't plan on keeping the 450's very much longer, so I don't mind abusing them a bit right now. I run the stock 1G fp and the stock 14b on my swap. Airflow wise, I do also have a K&N and a 3"catback.

I would not recommend running 17psi on 450's to someone who drives under full boost for long periods of time, or someone that has larger cams.

 

[fallenauthority]

I have DSMlink and leaned out the rich stock tune to run in the 10.7-11.0:1 range and im running 18psi with about 90-93% duty cycles on the stock 450s no knock at all with my EvoIII flowing 28-29lbs/min

 

[92GSXBaltimore]

i wouldnt go past 14 - 14.5 on a 16g with stock injectors and stock base fuel pressure. I was right at 100% duty cycle on my 450s with a b16g, walboro 255, afpr(stock base), stock sidemount, @ 16psi.

 

[timloomis]

Yea you could use the n/t fpr and be ok.It turns your 450's into 505's.It lowers idc's by roughly 10% or so.I dont see how you guys think 90+ idc is "ok".When I put in my 550's at the same boost level,I could feel a major difference.It didnt die out at higher rpm's like the 450's did at mid 90% idc.

 

[1stgensleeper]

im runnin 18 psi on a 14b with stock 450's all day long, i dont get what the big deal is, up top im at about 85-88 IDC but im perfectly comfortable with that for short periods of time

 

[exiletalon]

I run 18 psi, if you barely pull on it, it will be fine. I drive conservative though, I have 650cc/alky inj. on the way, then I can have fun at my hopefull 26psi-75/25%
You can run inj.. and push 20psi all day.. have fun

 

[1stgensleeper]

what are all you guys running for fuel pressure, 3 bar?

 

[brute]

I'm running ~2.5 bar as a base fuel pressure. But I'm only running 13 psi because the Galant's a daily and I can't afford for anything to break.

 

[fallenauthority]

Im running 43.5psi and using dsmlink for leaning out my stock tune to run 18psi

 

[1stgensleeper]

THATS all your guys problem, why dont you turn your fuel pressure up. ive always wondered why in the hell DSM's need such huge injectors for such little boost and overall power, im not trying to be a dick but you guys should take a little page out of the SR20Det book and run full 4 bar fuel pressure my brother has a turbo Sr20 with the stock 370's hes making 235Hp and 210 Tq at like 80% duty cycle, because base fuel pressure is at 4 bar or 58 psi my DSM is also running 4 bar fuel pressure and im making almost those numbers, my torque isnt as high as it should be because the 14b runs out of breath and i have a stock 02 housing, but i see no reason why with a walbro 255 and an AFC running 4 bar fuel pressure you should easily be able to safely run almost up to 20 pounds of boost (maybe 18) but theres no reason why 450's max out at 15 psi

 

[Rice Over Wheat]

Uh, 235hp and 210tq is supposed to be impressive? Wow, I made 242/270 on pump, stock smic, 450s, and withOUT afpr (43.5) on my T28 @15psi. Considering the S13/S14 should be running a T28 stock and mine had a stock 11psi actuator that could not hold boost reliably...

Too much fuel pressure or too low, neither is good. Think about it, why the hell wouldn't we just set the fpr at 100psi then?

 

[1stgensleeper]

i wasnt trying to impress anyone i was pointing out that the stock 370's did that much without batting an eye, thats also only running 12 psi of boost with only a 2.5 inch mandrel exhaust and a homemade piece of shit intake pipe but the point is that 370's can support 235 to the wheels (with breathing room to do more) so long as you run 4 bar fuel pressure so theres no reason why; in order to make a measly 240-260 at the wheels you would need anything bigger than 450's

im not trying to brag about any numbers or prove any point other than its simple mathmatics, if an injector flows 450 CC/min @ 3bar or 44.1psi then they would flow approximately 530 CC/min @ 4bar or 58.8 psi the only problem becomes tuning no/partial throttle however i didnt have a problem with it and all i have is an AFC II and my car runs smoothly throughout the RPM band, yeah im at -23% fuel at idle, but who cares what im adding or subtracting as long as my IDC and my A/F are safe, im happy

 

[Rice Over Wheat]

Here's some recent info about fpr pressure levels...check out Steve's posts.

http://www.dsmtuners.com/forums/showthread.php?t=244069

 

[danyz250f]

Yes you can run it, is it good? NO! I had a rewired 190 evo 3 fmic and 15psi and it was running 105% IDC. I now have 750s and It now runs no more than 75% IDC at 20lbs and water injection. Pulls like a mother too.