GT2871 USERS. SR motor

[S13 curtis]

Originally Posted by codyace

Log your duty cycle. 550's are not enough for 400 hp, this side of completely maxed out at 3 bar. If running 4 bar then you'll have enough. You can think all you want, I know what duty cycle 50lbers/550's/Sti/60lb/615cc run at at 18-22 psi @ 3 bar of fuel pressure as I've personally logged multiple setups with these different injectors on different tunes.

Also you can't say 'oh it works great look, 25 psi on 110' because I know for a fact your setup is maxed out with a 1:1 regulator then, and at point your injectors are simple just dumping fuel. Thankfully 110 is pretty hard to detonate, and at that level you're not really making a ton of power. Try doing that with some big power and you'll have an explosion. (not to mention now you're on the level of 5/16 OE lines being to small)

Running injectors at 100% duty cycle 'to prove a point' is nonsense to me. But if it works cool. I'll reference you to multiple guys who had injectors literally 'burn up' and cause failure

those 550's wont make it at 25psi maybe 18 if that on a 2871r, 740's would be fine. with 550s he will be in need of a aftermarket fpr to keep the duty cycle down.

[2fast4y0u]

see this is exactly what i feared so i went 850s so i could run a bigger turbo later

[codyace]

Originally Posted by S13 curtis

those 550's wont make it at 25psi maybe 18 if that on a 2871r, 740's would be fine. with 550s he will be in need of a aftermarket fpr to keep the duty cycle down.

I know all this, but they guy who posted claims they are ok. Not sure how he thinks 'they are just fine'

[bshotts]

For those who are making roughly 350 hp/ft-lb at the wheels, do you know your duty cycles for 740s, or better yet, if you are running 550s? I suppose before I make the upgrade from my 2860 T28 I am looking to see if I have the supporting fuel mods. Currently running Walbro 255, Z32 filter, Nismo 555s, stock FPR, Enthalpy ROM tune at 16 psi max.

[codyace]

350 whp on 550's should be rougly in low 90's to support it. OBviously it's not an exact science but it's certainly to be noted that running sidefeeds to that high cycle will get them hot and could lead to failure.

At my power (400) with the 615cc's (60lbers) I'm at 89-90% WOT. Luckily for me these are designed to be able to run at 4 bar as well, thus making them equal to 740cc's. I guess that's one advantage of these new style injectors (plus they are half the cost of the traditional Rochester/MSD style 72lbers)...however that's all equalized when you figure in modification cost of the manifold.


FWIW: For those running 50lbers or 72lbers (EDIT: MSD or Rochester style, the fat body ones) at super high duty cycles (90%+) you are literally playing with time bombs. Some last, some blow up...no signs nor failures until you go super lean when they wear out. THis is the only downfall of those injectors. I know 4 people personally who pushed them (3 50lbers and 1 72lber) and broke them.

[bshotts]

Thanks Cody....sounds like I'll have to upgrade to minimum 740s when the time comes simply for an engineering factor of safety standpoint. I'm more in favor of longevity and reliability versus pushing components to their limits. I'll just have to keep my current setup optimized for this season and save, save, save for the step up.

Another question, since you have experience with Swain's white lightening, have you thought about having your exhaust elbow and downpipe coated as well to help exhaust flow and heat management especially inside the cabin? I'm considering.

[slider2828]

You know cody, sometimes people are so weird on this forum. If you bought 550 or 600cc's why not just buy 740cc's.... Makes no sense since they cost the same... So weird... My only guess is they are running SAFCs with no rom tune supports, but still... wtf... I just don't get why there is still talk about injectors....

[bshotts]

They may have bought them long ago before ROM tunes became widely available or before they learned about the capabilities of the 2871.

I remember in my case I bought the 555s because you could "scale" them down using an SAFC (before I was knowledgable about it's shortcomings) and I saved somewhere around $100 for a special purchase price at the time. Hindsight being 20/20, no one really has an excuse to get anything smaller than 740s even if you are running a mild turbo setup compared to stock, especially being similar in price and relatively simple to tune for even being ROM-based.

[Soup Nazi]

Originally Posted by bshotts

They may have bought them long ago before ROM tunes became widely available or before they learned about the capabilities of the 2871.

I remember in my case I bought the 555s because you could "scale" them down using an SAFC (before I was knowledgable about it's shortcomings) and I saved somewhere around $100 for a special purchase price at the time. Hindsight being 20/20, no one really has an excuse to get anything smaller than 740s even if you are running a mild turbo setup compared to stock, especially being similar in price and relatively simple to tune for even being ROM-based.

So with my turbo setup, which is mild at 300-315 HP with a ROM Tune. The 555's wouldn't be worth it?

[jspaeth]

^ What's the point? If you are buying NEW injectors, there is no reason not get 740s, like everyone says.

The 740s should be good to at least 450 whp, but will work quite well for the 300 hp you are talking about.


The biggest way to waste money on cars is to buy parts without having foresight. Why buy injectors twice if you can buy them once?

[Soup Nazi]

Originally Posted by jspaeth

^ What's the point? If you are buying NEW injectors, there is no reason not get 740s, like everyone says.

That's what I wanted to know, since I'am buying new.

[codyace]

Originally Posted by jspaeth

^ What's the point? If you are buying NEW injectors, there is no reason not get 740s, like everyone says.

The 740s should be good to at least 450 whp, but will work quite well for the 300 hp you are talking about.


The biggest way to waste money on cars is to buy parts without having foresight. Why buy injectors twice if you can buy them once?

This is perfect advice. This is why I went with the injectors I did, and always tell anyone to just get the larger injectors. With the betters tunes available, the day s of undrivable injectors are gone.

[zurud]

So you're saying the ecu can handle big injectors like 1000cc.

[codyace]

Originally Posted by zurud

So you're saying the ecu can handle big injectors like 1000cc.

JWT offers 96lb/1000cc programs in conjunction with 90mm Lightning MAF on a rom tune. Obviously the amount of people on that program are probably low (i mean, 96 lb injector is the 500-600 range) but it does exist.

[Oneoverwrx]

I guess i will just have to learn the hard way. Did it for a season and a half on a different car and ran faster than probably everyone in this thread(2871 users).

On the other car we were on 17 psi and we started having fuel pump issues, thought it was injector so he bought 850s then realized it was wiring to the pump. On this car with good wiring to the pump, same exact set of sti injectors i am a full point richer at wot throughout the range at 1psi more boost. Put this car on 110, on this same tune at 18psi, will probably be in the 10s(afr). As far as duty cycles go....no way to log them, if i do start having an issue i have a meth kit which will allow me to pull fuel out once again.

I will say this...I have not been around nissans a whole lot, i have been around hondas and subarus for quite a while, the sti injectors on a stock sti will support 325+whp....thats to all four, another thing is the efficiency of the suby motor.....junk compared to just about any Inline 4 motor. AWD loss is roughly 30% so a 300whp sti make approx 428 on the flywheel. Assuming a 15% loss for rwd Mt cars you would end up at 364whp....this is before you look at efficiency of the sr over the ej.

I may be thinking about this all wrong but i am using what i currently have. At 18psi and my correction on the safc in the 7-8 range towards redline, i am in the mid 11s(afr) I believe that the car is roughly at 330-350whp, judging by the way it has ran with a few local cars. I also believe at this power/boost level the car should trap in the 115-117 range, i could leave it there and it would still be impressive for a stock sr on a 2871.

One last thing, I understand the way things work with tuning a car. I have seen this setup work well in the past with no failures. What i am doing is simply testing the waters of these injectors, this turbo, an addition of a meth kit, and ect. I dont even know how this turbo will act above 18psi. Im sure it wont mind a couple more psi but not sure if the efficiency will be there at 25. Should be but who knows. This is also NOT my only car, if it blows up...im not really that worried about it. In no way am i trying to encourage people to use this setup. I absolutely hate the safc as you are so limited by everything that you can adjust/tune. I will encourage this setup for someone who doesnt have the money for a real ems, at 15-18 psi, it is solid. Keep an eye on your wideband and understand how an safc works and you will be fine.

[S13 curtis]

Originally Posted by Oneoverwrx

I guess i will just have to learn the hard way. Did it for a season and a half on a different car and ran faster than probably everyone in this thread(2871 users).

On the other car we were on 17 psi and we started having fuel pump issues, thought it was injector so he bought 850s then realized it was wiring to the pump. On this car with good wiring to the pump, same exact set of sti injectors i am a full point richer at wot throughout the range at 1psi more boost. Put this car on 110, on this same tune at 18psi, will probably be in the 10s(afr). As far as duty cycles go....no way to log them, if i do start having an issue i have a meth kit which will allow me to pull fuel out once again.

I will say this...I have not been around nissans a whole lot, i have been around hondas and subarus for quite a while, the sti injectors on a stock sti will support 325+whp....thats to all four, another thing is the efficiency of the suby motor.....junk compared to just about any Inline 4 motor. AWD loss is roughly 30% so a 300whp sti make approx 428 on the flywheel. Assuming a 15% loss for rwd Mt cars you would end up at 364whp....this is before you look at efficiency of the sr over the ej.

I may be thinking about this all wrong but i am using what i currently have. At 18psi and my correction on the safc in the 7-8 range towards redline, i am in the mid 11s(afr) I believe that the car is roughly at 330-350whp, judging by the way it has ran with a few local cars. I also believe at this power/boost level the car should trap in the 115-117 range, i could leave it there and it would still be impressive for a stock sr on a 2871.

One last thing, I understand the way things work with tuning a car. I have seen this setup work well in the past with no failures. What i am doing is simply testing the waters of these injectors, this turbo, an addition of a meth kit, and ect. I dont even know how this turbo will act above 18psi. Im sure it wont mind a couple more psi but not sure if the efficiency will be there at 25. Should be but who knows. This is also NOT my only car, if it blows up...im not really that worried about it. In no way am i trying to encourage people to use this setup. I absolutely hate the safc as you are so limited by everything that you can adjust/tune. I will encourage this setup for someone who doesnt have the money for a real ems, at 15-18 psi, it is solid. Keep an eye on your wideband and understand how an safc works and you will be fine.

Atleast get an adjustable FPR or something i would hate to see you lean it out and waste the motor.

[Oneoverwrx]

I have a nismo fpr available, i have heard bad things about it but if i start having issues i will use it and increase fuel pressure. However as stated before many times, i dont think it is nessesary. On good fuel and the addition of a 5th injector(meth kit) there will be no need for added fuel pressure.

[idahotuner]

i ran 740cc on my last set up. going to run 550s on a stock turbo with a z32 maf, just as an upgrade, until i go bigger with the turbo. but i picked up six deastchwerk 550 injectors for 250 shipped, if i was to go to like 740s i would almost get them for free with the core exchange of six injectors at 50 bucks a pop. so it can be worth it to run 550s

[codyace]

Originally Posted by Oneoverwrx

I have a nismo fpr available, i have heard bad things about it but if i start having issues i will use it and increase fuel pressure. However as stated before many times, i dont think it is nessesary. On good fuel and the addition of a 5th injector(meth kit) there will be no need for added fuel pressure.

Do you have links to said bad Nismo FPR reviews, as I've NEVER read or heard of one failing...and I could list darn near 100 cars that I know that run them (both FWD and RWD, SR and KA) without qualm. It's a bolt in 1:1 solution, that works well. The more info the better obviously.

Also, you will most certainly need fuel pressure to raise with boost. Adding Methanol injection isn't going to solve your fuel delivery needs when you're fighting against 15-20 psi of boost. There is a reason why all cars have these, this side of those guys with boost a pumps (which suck, burn up, and don't work).

I'm not sure where you're getting your fuel supply information from but it's certainly not very good/dangerous. Differentiating from the norm is one thing but the idea of eliminating a 1:1 FPR is pretty poor at best.

[S13 curtis]

how high can you turn up the fuel pressure with the nismo FPR?

[Oneoverwrx]

woah....

Im not trying to have a pissing match here, i read somewhere over a year ago that someone had a hard time keeping the nismo regulator to hold pressure. Not sure which forum or which thread. I agree that upping the base pressure would help the issue but as stated before...im having no issues at stock pressure. If i do...i will post up. Im not trying to prove anyone wrong here. I understand the importance of proper parts such as fuel delivery and good ems. I am very suprised to be getting bashed over the injectors and not the safc. Either way....neither is ideal and i know this but i believe this can be done safely and i dont think i will have an issue. Why not wish me luck and see what happens.....who here....in this thread, right now has tried this and failed???Because i have tried it...use it on every nice day and it works! When the track opens i will be able to tell you all first hand exactly what happens. Probably start with 110 octane and about 23psi and see where we go from there. If i need the meth at that point i will use it and if i dont, i wont.

[codyace]

Originally Posted by S13 curtis

how high can you turn up the fuel pressure with the nismo FPR?

It's got an adjustable screw right on top. This raises/lowers Fuel Pressure.

(this is from my turbo Altima, as it's a decent picture in relation to showing it)



That screw on top adjusts the base fuel pressure for your car.

Originally Posted by Oneoverwrx

woah....Im not trying to have a pissing match here, i read somewhere over a year ago that someone had a hard time keeping the nismo regulator to hold pressure. Not sure which forum or which thread.

Neither am I, so I excuse my tone persay -- I often type things bluntly. My point does stay the same though abotu the Nismo units. Certainly objects fail...I mean even new cars blow up...but that should not be taken for the norm.

Originally Posted by Oneoverwrx

I agree that upping the base pressure would help the issue but as stated before...im having no issues at stock pressure. If i do...i will post up.

I run stock pressure as well. That's not so much the importance of the FPR in our situation. Certainly it can help make a global correction, but the main job is to provide reliable 1:1 fuel to boost delivery (one psi of fuel per one psi of boost) compared to the stock on. Will the stock one work? Certainly, to a degree. Most stock cars won't have an issue. Some 300/400 hp guys dont' either. The fact remains that it's still a 1:1 regulator, just without adjust ability.

I think that is where we were confused with each other, honest internet mistake

Originally Posted by Oneoverwrx

Why not wish me luck and see what happens.....who here....in this thread, right now has tried this and failed???Because i have tried it...use it on every nice day and it works! When the track opens i will be able to tell you all first hand exactly what happens. Probably start with 110 octane and about 23psi and see where we go from there. If i need the meth at that point i will use it and if i dont, i wont.

My point was (again just a mis understanding on both our parts) that while you may have a stock regulator, it still raises fuel pressure 1:1 like Nismo does. The issue is, stock ones are known not to control higher pressure situations well.

And again, I never want to wish for anyones car to have an issue - in the same respect I also am not going to wish luck on a wishy washy idea - I'd rather you be safe than sorry. If it works, great. Awesome. Congrats - but that doesn't make it right foreveryone. Trust me, when I saw I sprayed a 150 dry shot through the MAF of a rental Grand Marquis, it worked....would I sugest all owners to do this? Certainly not.

[Oneoverwrx]

I now understand what you are concerned with, a failure of the stock fpr itself. I had heard nothing of its issues until now and will be sure to keep an eye on it. I have a fuel pres gauge so i should be able to watch it a little.

I agree with you on the part about not right for everyone but i also think that not everyone doing this swap, turbo, and ect are looking for 400+whp. For the people looking for 325-350 i feel this is a great budget set up. The injectors will be in a very safe range and the fpr should be fairly safe as well as i would say a 2871 on 14psi would produce close to 325 or close to.

[slider2828]

Yeah for me, I just run 740s and call it a day. I don't have an adjustable FPR, just a stock one... I have never heard of a stock one failing and I just don't want to add another degree of difficulty to tuning.... I might in the future add a nismo, but at this point running around 380hp on a dynojet... Ima cool...

BTW I just came back from the track running 18PSI all day which is my tune... Car feels too damn fast as the 240sx chassis without rollcage or welding just plain sucks.... Heat dissipation should be on everyone's list if going to the track.... but otherwise it was ok.....

[codyace]

Originally Posted by Oneoverwrx

I know understand what you are concerned with, a failure of the stock fpr itself. I had heard nothing of its issues until now and will be sure to keep an eye on it. I have a fuel pres gauge so i should be able to watch it a little.

It's not so much that they fail, is that they really don't keep up to the pace. I mean you'll never 'not' have fuel if that makes sense, but you may not have enough pressure under high boost.

Originally Posted by Oneoverwrx

I agree with you on the part about not right for everyone but i also think that not everyone doing this swap, turbo, and ect are looking for 400+whp. For the people looking for 325-350 i feel this is a great budget set up. The injectors will be in a very safe range and the fpr should be fairly safe as well as i would say a 2871 on 14psi would produce close to 325 or close to.

550's would be perfect for a 325-350 hp setup for sure, especially if they want to keep stock rails. BUt as said on here, if the owner is going to a top feed rail, there really isn't a good argument not to go 72lbs.

Originally Posted by slider2828

BTW I just came back from the track running 18PSI all day which is my tune... Car feels too damn fast as the 240sx chassis without rollcage or welding just plain sucks.... Heat dissipation should be on everyone's list if going to the track.... but otherwise it was ok.....

Thankfully you have E-85 I usually only run 12 psi on track days haha.

[slider2828]

Originally Posted by codyace

It's not so much that they fail, is that they really don't keep up to the pace. I mean you'll never 'not' have fuel if that makes sense, but you may not have enough pressure under high boost.



550's would be perfect for a 325-350 hp setup for sure, especially if they want to keep stock rails. BUt as said on here, if the owner is going to a top feed rail, there really isn't a good argument not to go 72lbs.



Thankfully you have E-85 I usually only run 12 psi on track days haha.

Hey Cody, I ain't on E85, I am running 97 octane.....

[idahotuner]

i wonder how .2 liters extra and 9 to 1 would affect spool up of a gt2871r .64 i wonder if it would gain 2-300 rpms spool up. might be worth running a .86 housing huh. thinking 810 cc injectors.

decided to go this route and just make a solid running engine then do some interior stuff and call it good on my car, until i get a house paid off. then its 2.8 liter sti time

[Oneoverwrx]

***you dont want a 2.8l sti. Stick with stock stroke, definately sleeve the motor for over 625whp, and use arp CASE bolts!!!!and some really good head studs, arpL19, or P&L has some 13mm studs out now, probably other options but i dont know them. Pm me if you want any advice, i have been down the suby road quite a few times. My best advice is forget the suby and do an evo, or build a badass SR, or anything other than a subaru. Ask any honest subaru person and they will tell you that you are handicapping yourself from the get go with that motor.

Back on topic....I would absolutely love to do some road racing in my car this year. Would definately have to switch diffs and turn the car down some but it would be a blast.

[Csomme]

So I bought my car with an SR with HKS cams, GT2871r, 550s, N62 MAF more shit, and a Power FC.

I bought the car, it had a shit tune on it and was pushing so much damn boost, so much that it lifted the head, and I didn't realize that the headgasket blew untill a few weeks later when shit hit the fan. Anywho, got it back together, and got a new base map from Steve Shadows, car was running perfect. I don't know how I never checked this, I could have sworn that I did, but I was driving down the road yesterday and I just checked my airflow settings and my Power FC was on the wrong damn MAF. wtf.

It wasn't running bad, it was running good, like perfect, however, even with the cams it never sounded like the car would "cam" at idle, it was always solid. So I changed it to the N62, and BAM. lol Fucking camming like crazy. what the hell is up with that? lol Confuses the shit out of me. lol

What that has to do with a gt2871r, not much, but I just wanted to tell you guys.

[idahotuner]

Originally Posted by Oneoverwrx

build a badass SR,

Back on topic....I would absolutely love to do some road racing in my car this year. Would definately have to switch diffs and turn the car down some but it would be a blast.

my sr i am putting together right now is a 2.2 mazworx block, last set up i posted earlier in this thread on a stock block i made 416 with a gt2871r .64

i saved everything from my last set up cept the turbo. but i think i want to run one of these again. if i got the exact same turbo i can compare the .2 extra and .5 higher compression to see the difference, just wanted to know what you guys thought about the cahnge in engine size and compression

my friends are all into "road racing" basically going out on long drives so i am
trying to get set up for that.


hey cody, which trim you running 56?