How much boost can I run safely with 550cc Injectors?

[SixSpeedSleuth]

Just as the title states, how much boost can I safely run with 550cc Injectors? I have the GT28RS with Enthalpy tune. This is on a S13 Blacktop SR.

[Nismo_Freak]

52 PSI

[SixSpeedSleuth]

52 PSI

I did a search to try to find the answer before I posted this. I assumed that Different Turbos equal a different safe amount of PSI to run with that size Injectors. Does anybody have a correct answer??

[virus77]

I would say 17 psi is a safe limit for your injectors. put you around 92% duty cycle. Of course there is no real way of telling with logging but thats a fairly good estimate. You can probably squeeze in 19 psi but I dont know how safe that is.

[SixSpeedSleuth]

I would say 17 psi is a safe limit for your injectors. put you around 92% duty cycle. Of course there is no real way of telling with logging but thats a fairly good estimate. You can probably squeeze in 19 psi but I dont know how safe that is.

Thanks for your answer. I will probably run 15PSI just to be safe.

[Beemen550]

i thought 550's were good for nearly 400hp, wouldnt it take a disco at least 20psi just to make 350hp

[deCksy]

i wouldnt push 400hp with 550cc, 350-60hp would probably be the most

[Nismo_Freak]

I would say 17 psi is a safe limit for your injectors. put you around 92% duty cycle. Of course there is no real way of telling with logging but thats a fairly good estimate. You can probably squeeze in 19 psi but I dont know how safe that is.

LOL... maybe for a KA.

At 17PSI he'd be around 300 - 310whp. At 19 PSI he'd be around 330whp ish.

I wouldn't go above 20 PSI.

[lrb_2000]

looks like you used the 1psi = 10hp rule....

SR20det stock.. 7psi = 205hp... 17psi = 305hp... 19psi = 325hp ...

lol

[BaliLover]

With an Enthalpy Dyno tune I got 315 @18psi on the GT28RS and 19psi didn't feel any different to my *** dyno. This was with 740cc injectors so I can't give an answer to the posters ? though.

[SixSpeedSleuth]

Do

With an Enthalpy Dyno tune I got 315 @18psi on the GT28RS and 19psi didn't feel any different to my *** dyno. This was with 740cc injectors so I can't give an answer to the posters ? though.

Do you know what Duty Cycle your Injectors were at when you ran 18PSI?

[BaliLover]

nope, no idea, but no where near maxed.

[supreamS14]

http://www.deatschwerks.com/ca...s.php @90% you could go as high as 360-370 but I say 350whp on pump gas and 400whp on 100+ race gas. You're turbo could make 350whp @ 15 psi depending on you're setup's efficiency.

[shift_SRDETuser]

Deautchworks or whatever injectors are s*** pure and simple. I ran their 740cc cheap a** 400 dollar injectors and the number 1 cracked in two and leaked fuel into the number 1 cylinder. Luckily it did it all at once so it was recoverable and really did not do any damage. I upgraded to the Nismo 740s and they are NICE-- at 17 lbs on my gt2871r I don't run over 70 percent duty --- get good injectors whatever you do --- do not waste your money or time on reman doucheworks.....they could have ruined my whole engine if they had done that while driving the car.

[dbrass240]

550cc injctors are really only good to 350whp. thats it.

Deautchworks or whatever injectors are s*** pure and simple. I ran their 740cc cheap a** 400 dollar injectors and the number 1 cracked in two and leaked fuel into the number 1 cylinder. Luckily it did it all at once so it was recoverable and really did not do any damage. I upgraded to the Nismo 740s and they are NICE-- at 17 lbs on my gt2871r I don't run over 70 percent duty --- get good injectors whatever you do --- do not waste your money or time on reman doucheworks.....they could have ruined my whole engine if they had done that while driving the car.

too much fuel can be hard to manage as well...

[shift_SRDETuser]

550cc injctors are really only good to 350whp. thats it.

too much fuel can be hard to manage as well...

not with a power FC and if the injector leaks and pours gas into your cylinders and intake it is not very good.

[dbrass240]

what % can a power fc control up to on injectors? i've never played with one, so dont have any experience at all. I just figured it would be easier to zero in on across the board

i'm sure u cant run like 1200cc injectors and just cut the flow in half and run the same precision as running like a 740cc size and tuning them....

just curious . . .

Deautchworks or whatever injectors are s*** pure and simple.

i've actually heard nothing but good stuff from DW - this is kinda a first . . .

[shift_SRDETuser]

what % can a power fc control up to on injectors? i've never played with one, so dont have any experience at all. I just figured it would be easier to zero in on across the board

i'm sure u cant run like 1200cc injectors and just cut the flow in half and run the same precision as running like a 740cc size and tuning them....

just curious . . .

i've actually heard nothing but good stuff from DW - this is kinda a first . . .

percentage pulse correction is based on the following formulas

for 550 cc injectors= 370/550= .6772for 740cc injectors= 370/ 740= .5000

as far as tuning -- I have a tuner with a power FC datalogit tuner. You can use the wand to tune but I would rather have someone who knows the power FC system in and out to tune it. The power FC is a great alternative to the AEM does not do some of the electronic things the AEM like multiple fan control but it is also half the price.....740cc injectors will handle 500whp or so and you do not have to upgrade from 550s later on. The deatchwerks things could have been just bad luck for me. Which would you rather have injectors made to flow at 740ccs or 370cc injectors drilled and cut on to flow 740ccs?

[dbrass240]

were your nismos complete drop in? its been like 5 years since i had a set - couldnt remember...

[shift_SRDETuser]

were your nismos complete drop in? its been like 5 years since i had a set - couldnt remember...

yes the nismos are straight drop ins. They come in side or top feed -- I made a little more power with the DWs but not enough to worry about and the Nismos make the car feel more stock and reliable. in the mid 300 whp range their is not 1 or 2 percent difference between them. Just I had bad experience with DWs I am sure other people may not have.....

[rc1honda]

I made 317hp on a mustang dyno about 340-350hp on a dynojet with 50lb injectors or about 525cc. To bad my FPR was broken so it wasn't boosting the fuel pressure 1:1. 550cc will get you to 350 but the duty cycle will be on the high side and closed to maxxed out at WOT. I would just get 740s or 880's and call it day.

Im just had the car tuned 3 weeks ago and im already unpgrading my fuel system and going back for another tune next week. Do things right the first time. I don't understand why 550cc injectors are so popular? Is it cuz you can use a SAFC and you can't with 740s? We all could go 740 for the same price and have the setup in place to go for more power when we want it.

It weird looking back that i notice a lot of SR's are built and modded by cheapskates, or broke kids on a budget.

[dbrass240]

well (i'm not a cheap kid on a budget)- but these cars are twenty year old nissans, most of which are rusted out or pretty banged up . . . when people tend to buy a car thats only worth maybe a couple grand to begin with, they probably dont have a lot of mula to throw around . . . hence - alot of corner cutting.

i agree, i also see a lot of guys doing unnecessary stages....horsepower is very addictive . . . i do know a lot of guys going from just t28's to gt2871+ and losing streetability and being a lil pissed. . . rare, but does happen..

[shift_SRDETuser]

well (i'm not a cheap kid on a budget)- but these cars are twenty year old nissans, most of which are rusted out or pretty banged up . . . when people tend to buy a car thats only worth maybe a couple grand to begin with, they probably dont have a lot of mula to throw around . . . hence - alot of corner cutting.

i agree, i also see a lot of guys doing unnecessary stages....horsepower is very addictive . . . i do know a lot of guys going from just t28's to gt2871+ and losing streetability and being a lil pissed. . . rare, but does happen..

speak for yourself this may be true for the s13s out there. S14s this does not hold water -- they are getting rare and hard to find....

[dbrass240]

i've owned both s14 and s13 - have an s13 now, but bought my first s14 back in 2000 - brand new i think they were $25k but i bought my 97 for $12k not even a full 3 years later...and their values keep falling . . .

cars are not an investment (unless dealing with exotics or original classics) maybe people need to be reminded of that every now and then . .

i invested over $20k in my s14 plus price of car when i had it - you're only talking about $32 invested - thats not a lot of dough in the grand scheme of things...hell, my fiance is about to buy a tahoe for $35k. I've seen guys build racecars locally for as much as $80k and still have built blocks in their garages . . . i've never seen any s14 OR s13 owner go that crazy. . . 240's are simply fun, easy to mod vehicles that i dont see holding their value - maybe someone can see what i'm trying to say

[dbrass240]

sorry to go so off topic btw