s13envy

Tried searching around a bit on this but haven't found much. I just recently picked up a '96 240 with a s14 sr. the motor is stock. with the greddy profec set on around 15psi of boost under full throttle as soon as it hits 15psi the car will basically shut off and fall on it's face. It's got an safc in it, wideband in it. When it cuts out I see the wideband hit 13:1 ish. My question is what would be causing this problem?

I've owned a s13 sr and knew quite a bit about it. Haven't really studied too much on the s14 though.

Are the injectors maxxing out with the t28 out could it be the mafs? Any input would be appreciated

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boost addict

sounds like the problem i was having, kinda sounds like it pops and sputters in bursts?

s13 drifta

Are you running stock 370cc injectors? Stock fuel pressure? Any supporting mods? Try lowering your boost level to about 10psi and see if the problem goes away. 13:1 AFR is asking for trouble on a turbo motor, should be between 11.5-12.0.

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s13envy

O I know 13:1 is trouble. Lol The car does just fine on 10-11psi. I believe the car has a walbro 255. I'm have to ask the previous owner though to be sure. stock injectors, stock ecu,.stock maf, stock fpr. I assume the maf supports the same power as the s13 sr maf? or are they the same maf even?

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s13 drifta

Yeah the s13 and s14 maf support the same power levels, around 280whp is the max. If the car is fine at 10-11psi and it starts cutting out at 15psi, I would check your plug gap. Also what heat range are the spark plugs? You should have a 7 heat range and gap at .28

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SLiDe_WaYz

Correct me if I'm wrong but isn't the stock T28 basically no good after 12psi it just spits hot air?

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s13 drifta

The t28 reaches its max efficiency at 15psi.

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s13envy

haven't checked the plugs or gap yet. This problem doesn't seem plug related. I've it doesn't spit or sputter. once is hits around 15psi, its like the car shuts off for a second. I obviously let out of the throttle immediately. could the car be maxing out the maf at 15psi? I'm not sure what the t28 is good for. I know the t25 is maxxed around 240hp or so.

one off topic question i have as well. I've got a set of jwt c2 cams for an s13 in my garage right now. will these work in an s14 sr? obviously getting rid of the vvt, but can they work?

s13 drifta

I know the answers to you questions, but you should really try the search button. It works.

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s13envy

In the time you posted that you could have told me the answer. I use my phone most the time on here so it's much more time consuming to sit through and search for threads where people ask the same questions and people like you give the same smart ass remarks.

Thanks for the info though. Ill go look

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BestOneLeft

That's fucked up.

s14tan

LMAO.



Sounds like you're hitting max injector duty cycle.
Turn down the boost until you get a tune and bigger injectors.

Keep it up and say bye bye head gasket, or worse.

Keep it safe, don't get greedy.
If you want more power, get supporting mods or you're just setting yourself up for failure.

Upgrade:
Headgasket
Injectors
Fuel pump
FPR
and TUNE!


You also said that you weren't sure if you have a 255? Keep it at 7 PSI until you find out for sure, if you don't get one ASAP before you even think about upping the boost.

If you do, keep it between 10-11PSI.

-Tan

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s13envy

Thank you! I came from an,s13 sr so I, want sure what the s14 and t28s were capable of. Im not about to push it that far on this car. All supported mods will come as time progresses.

How do the s14 sr Hold up power wise compared to the s13 sr? I was making right around 400whp daily driven. Id like to get back to that point with this car eventually

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jr_ss

Well, I can say that you should be no more than 10-11psi on an "untuned" motor. If you keep it where it's at youre going to break ringlands and trash that motor. Stock headgasket is fine IF you have ARP's. All SR's are the same when it comes to power levels. The S14 has VTC which helps low end torque and bpu mod for bpu mod will be faster/ make more power than an S13 motor. However, S13 motors flow more in the high rpms due to the hi-port intake tract design, which would be better for big power levels.

Keep it safe until you get the "supporting" mods. This includes atleast a fuel pump. I ran 10-11psi on my S14 SR with many drag passes, flogging and DD and had no issues. However, anything over 11psi you will need injectors and a tune.

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Carbomb

^ lol I run 21 psi on a OEM motor... no arps....(555 and z32 with a tune)

stories being told for years...
gap plugs to 28 n run it...

blingbling

Don't get mad when I laugh at the thread you post in a few months titled "HELP, CAN'T FIGURE OUT SR PROBLEM"

s13envy

Its set at 11psi right now. Im not going to run it any higher until I do injectors, mafs head studs. I just didn't realize the stock injectors were maxed out so easy on the s14 sr. I guess it makes sense considering the s14sr had the t28 and you can pretty much max the inj & maf on the s13 using the t25

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slim

what is the afc set at in the higher rpms? stock sr with stock maf, injectors, hg and walbro should still be good till 15psi. my bros has been there for 5 years now without 1 problem. might be maxxing out injectors with the afc by adding in fuel.

inopsey

ive been running 20-22 psi for over a year on stock head and block with a 3071 with no issues at all. checked the compression last fall and it was 145-150 across the broad. i have personally put over 60k km on the engine since i bought it. (lots of highway driving with lots of highway wot)

do you really think nissan engineered a block that can do 400whp reliably but the head to only hold stock psi??? if the block can handle over double stock hp im willing to bet the headgasket can too.(psi)

skinz180189

Sounds a bit like you're hitting fuel cut.

I'm running 17psi on the stock T28. Supporting mods: Tubular Mani,PSM Downpipe,Decat,HKS Hi-Power Silent,HKS wastegate actuator,FMIC,NGK BKR7 plugs,Apexi Power Intake,Walbro 255 fuel pump, Greddy profec B spec II and a map.

It'll run 1bar (14.7psi) all day long no worries on the stock map with the right supporting mods (manifold is a bit OTT at that tune TBH, but the car came with it)

s13envy

IIRC i flattened out all the high throttle settings on the afc last time i used it.

hmmmmm....

so a couple of you guys are saying the stock ecu, stock injectors and stock maf will support 15psi on the t28?

Carbomb

Ive been running this set up for YEARS!
Ive been toying with nissan longer then you been driving lil nga.

internet is the largest MISINFO place ive ever been...

all you young kids believe er thing you read... like some snot nose rich faggot knows some shit..

I can figure out any sr problem... can you?
I bet you can search like no ones bidness tho...

gap plugs 28 n go

s13envy

hey now guys, this isn't a bitch fest. i dont care whos been driving what for how long.

Just looking for opinions on what to check first.

This does not feel like improperly gapped plugs. i've had that before. I will however pull them out and check them anyway. also going to make sure that is does have a walbro. then i will report back. we aren't comparing dicks here guys

i will be wiring up my consult port as well since i've already got the plms cable and datascan software

jr_ss

The point here is to get a tune... No, stock injectors/MAF will not run at 15psi. Sure you can try it, but if it's not tuned, you'll blow it up. The turbo can and will push 15lbs, but it's hot air and not really helping you much. Don't push stock shit untuned, let alone tuned. Get what you need and get it tuned. I'm not saying you need ARP's, but it's cheap insurance.

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skinz180189

Without doubt. Not sure why everybody else is saying it won't, it's done in Europe a lot.

That is providing you have the supporting mods and run on at least 97RON fuel. I would check your plug gaps like people have suggested.

jr_ss

This right here is a big reason they can get away with it... The highest we have at a pump stateside is 93...

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skinz180189

Yeah I added that bit remembering you guys get different fuel. Our crap stuff is 95RON lol.

s13envy

Ill prob just end up doing a setup like on my s13 (2871, cams, inj, maf nistune, hg, studs) and mess with boost and tuning then.

Thanks for all the info though guys

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s13 drifta

I can only feed you so much info. Once I answer one question, you have two others. Keep your boost levels low until you know for sure what fuel pump you have. You can run 15psi on stock injectors if you bump up the fuel pressure, but you will be close to max duty cycle. Get some 480cc or 550cc and have it tuned to be safe.

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s13envy

Thank you!

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