How much boost can the RB20 take before running lean?

[NizzansDET]

I ran 20 Lbs the other day and hit fuel cut. so i turned it down to 18 Lbs.Does anyone know how much power the stock injectors are good for?

[Carl H]

um 20psi is certian death on 270cc injectors.so is 18.

[b00stJunkie]

yeah i was runnin 14-15 on a gt25r and pretty sure thats what happened to my motor, upgraded to 444cc an n62 maf = 20-21 psi =]

[NizzansDET]

so i have 4 550cc i need 2 more. so then where do i get my ECU remapped? or how do you tune it? SAFC?

[b00stJunkie]

eprom chip, someone can burn a chip for you here.

[Yellow4g63]

I ran 20 Lbs the other day and hit fuel cut. so i turned it down to 18 Lbs.Does anyone know how much power the stock injectors are good for?

20psi on the stock RB20 turbo? and stock injectors? Give this man a prize. You sir are crazy .

[NizzansDET]

lol my turbo is still working good. i was just testing for everyone. i wanted to see. but i need to get a wide band to see what my air/fuel ratio is. its probably running lean.

[Yellow4g63]

at 14psi my A/F was around 12.8 not safe for pump gas (when I had the stock turbo). Your 20psi is prob close to 14.0. Hope that fuel cut saved your ***

[NizzansDET]

lol 12.8 A/F is rich dude! 14.7 is that prefect air fuel ratio. anything below 14.7 is rich and anything above 14.7 is lean!

[Bwana]

lol 12.8 A/F is rich dude! 14.7 is that prefect air fuel ratio. anything below 14.7 is rich and anything above 14.7 is lean!

Actually, it's optimum for power, and slightly lean under high boost.

[NizzansDET]

lol true. but does the stock ECU do that?

[Yellow4g63]

lol 12.8 A/F is rich dude! 14.7 is that prefect air fuel ratio. anything below 14.7 is rich and anything above 14.7 is lean!

Yeah your right what do I know . You should be cool at 20psi on the stock injectors. That should put you at your magic spot of 14.7.

[NizzansDET]

lol yeah what do you know? cant even get a fuel ratio right?!?!

[nissanman04]

its probably running lean.

[DJButton]

20 PSI with stock injectors and turbo seems downright inane... gl with that though!

LOL

lol yeah what do you know? cant even get a fuel ratio right?!?!

[Yellow4g63]

lol yeah what do you know? cant even get a fuel ratio right?!?!

Yup make sure to hurry and get that SAFC so you can put your A/F back to 14.7 at WOT.

[digzsublime]

lol 12.8 A/F is rich dude! 14.7 is that prefect air fuel ratio. anything below 14.7 is rich and anything above 14.7 is lean!

You are kidding right?!?!?! Oh wait, you're not are you? Poor, poor engine.Tell ya what. All I ask is that you only tune YOUR engine to 14.7 AFR @18psi on stock injectors.Please don't tell any of your friends how you make all of that mad power. Wouldn't wanna let the secret out.

But for real, why ask a question in a forum and then act like these guys don't know what their talking about. They are trying to keep you from blowing up your engine you tool. Also, your "fuel cut" was probably just the engine running terribly lean and hesitating. My RB20 felt the same anytime the AFR's got over 12.0 on pump gas while running 12psi. That's just my experience.

[Carl H]

you didnt hit fuel cut you hit the boost limiter, which kicks in around 4.80v on the maf sensor.and no 14.7:1 is not safe, it is stociometric where all o2 and octane is burned off.you my friend are headded twards some burnt ringlands and a hole in a piston, why not just advance the cas as far as it will go, i bet it will run just as safe!

[NizzansDET]

wait. im confused... maf sensor. that reads the air flow. and the MAP sensor read pressure and vacuum. how much boot can the MAP read?I was just saying the perfect air fuel ratio is 14.7. you make more power running lean. but it will for surly burn up the valves, pistons, and rings. it is better to run rich because the extra fuel cools down the valves and spark plugs. o and what is the stock boost on the RB20?

[Bwana]

wait. im confused... maf sensor. that reads the air flow. and the MAP sensor read pressure and vacuum. how much boot can the MAP read?

The factory Nissan ECCS system does not have a MAP sensor, just the MAF.

I was just saying the perfect air fuel ratio is 14.7. you make more power running lean. but it will for surly burn up the valves, pistons, and rings. it is better to run rich because the extra fuel cools down the valves and spark plugs. o and what is the stock boost on the RB20?

While a 14.7 a/f ratio may be an "ideal" balance, it most certainly will not work long term for even part throttle acceleration. It is just too lean, and lean = heat. It's closer (though not quite) to an ideal "cruising" a/f ratio.

Basically, if you continue to overboost your engine (you're way out of the efficiency range of that turbo anyway) without supporting fuel mods, you will melt it down, soon.

Just trying to help

[Yellow4g63]

wait. im confused... maf sensor. that reads the air flow. and the MAP sensor read pressure and vacuum. how much boot can the MAP read?I was just saying the perfect air fuel ratio is 14.7. you make more power running lean. but it will for surly burn up the valves, pistons, and rings. it is better to run rich because the extra fuel cools down the valves and spark plugs. o and what is the stock boost on the RB20?

NizzanDET I must thank you very much. I thought I would never change my Sig quote untill now. Eh? I'm sorry man but his quote beats out the fairy dust.

[240z4u]

I am surprised noone has mentioned that your turbo may very well shed its blades as well over 13 or so PSI. Its not if, its when your going to tear up the stock turbo.

Just wanted to give you heads up, incase you were not aware.

Evan

[SeVa-S13]

*prays the kid's using the stock SMIC*

[Bwana]

Wow, Blake showed up!

[Joe]

lol 12.8 A/F is rich dude! 14.7 is that prefect air fuel ratio. anything below 14.7 is rich and anything above 14.7 is lean!

promise me something

never tune a car, ever.

[eh?]

lmao

I hopeyou have an autometer a/f gauge! tune your car till it turns green!

[Carl H]

yeah dude the christmas tree is ALWAYS right.

[vicious]

haha if these are the numbers he is running with a stock turbo

i dont even want to know what he would run with something aftermarket

next post we are going to see is

30 lbs of boost on stock engine, it blew up, is this bad??but i bet it would make mad power for about a sec with his a/f haha

[NizzansDET]

Your right. i dont know **** about tuning. i never have tuned my own car. i dont have the tools to do it. and i dont give a **** about the turbo in the car. and the 270cc injectors are good for 283 Hp at the crank at 100 Duty cycle. i know i dont have close to that much power well maybe at 19 PSI

[RB280SX]

Dude, for the sake of the intelligence of Washintonian's, please just shut up. If you don't know anything, stop talking and start reading.

You just stated that you're "running" 20lbs, hitting a cut, and now stating that the injectors have a 100% duty cycle at 19lbs? You just answered your own stupid question .

Also, if your turbo blows to bits and pieces while blowing lots of air through the intake manifold, where do you think the pieces are going to go? I'll let that mystery befuddle you .