s16g @ 15psi + stock fuel fystem; will i have problems?

[AlphaAssault]

i sorta touched on this in my last post about tuning my car. since then, i have done some searching, but i never came to a concrete solution after reading the few threads about the subject.

my mods, as it pertains to this issue, are:

aftermarket boost gauge
small 16g turbo
greddy BOV
MBC
2.5in hard intercooler piping
aftermarket sidemount IC

My question is how safe is it to run 15psi on this setup with the STOCK fuel system?i have no aftermarket fuel pump, injectors, or logger. most of the threads i read about this were people turning up the boost on the stock 14b/t25 without any additional mods; and 15psi was (generally) considered safe. however, ive got a bigger turbo and bigger pipes that wont distort under increased pressure; all resulting in more air entering the engine despite the same pressure behind all that air.

even though i dont have a logger, i did a 3rd gear pull @ 15psi last night to see how things went, and i have to say it went very smoothly. the boost peaked at 15 and stayed at 15 until redline. i noticed no spike or dip in pressure throughout the pull. from what i can tell, this is a pretty good sign, but im no expert. So, 15psi. safe or no?

 

[Turbo Talon DL]

I would HIGHLY HIGHLY recommend that you buy a Logger before you go turning up the boost. You have NO idea what your IDCs are, you have NO idea what your intake air temps are, you have NO idea how many knock counts you have, you have NO idea what your coolant temps are, you have NO idea what your O2 volts are, you have NO idea if you have any stored DTCs or not, and you have NO idea what kind of timing advance you're getting under WOT. This stuff is usually pretty important when turning up the boost. Welcome to OBDloggers will save you lots of trouble and keep you out of some also.

I am running 13 psi on the stock fuel system with a few little extras over your setup. I was running 15 psi a while ago but backed it down in the interest of safety. I can run 15 psi just by opening up my exhaust cut out and making no other changes. You can check my profile if you'd like. I get a couple blips of knock under WOT (2 counts MAX) and depending where I shift and the air temp my IDCs will range from 76% shifting at about 5000 with humidity and 80* all the way to 92% cool outside (50*) shifting past 6500. Check your spark plugs for proper color since thats the only REAL indicator you have of whats going on inside those combustion chambers. If you accidently overboost, you wont know because the stock boost gauge only reads 14 psi. Its almost useless alone unless you know how to read it and what to look for. Feel free to PM me if you'd like.

 

[proto2]

You're fine to run 15lbs of boost without a logger on a small 16g. I had a s16g, full exhaust, fmic, etc but no fuel upgrades and ran 16psi without fuel cut. Now I'm on Garrett 60 trim running 14lbs and I'm still in the safe.

 

[Splitpi]

9 psi is safe.. I hit 78% IDC @ ~ 9 psi on a big 16G. Anything more and you may be flirting with safetly margins.

 

[CJTurbo]

You're fine to run 15lbs of boost without a logger on a small 16g. I had a s16g, full exhaust, fmic, etc but no fuel upgrades and ran 16psi without fuel cut. Now I'm on Garrett 60 trim running 14lbs and I'm still in the safe.

It is not a matter of fuel cut!! It has to do with running too lean and burning a hole in your pistons
Listen to Turbo Talon and at least buy a logger, very cheap and will save your ride.

 

[dikdiamond]

I've been running my s16g for 2 months@14psi,with stock sidemount and bov,everything else the same,with no problems. Changed out my knock sensor,as I was getting high knock,now next to no knock. So far so good,next I'm going to rewire the fuel pump. Def get a logger,just so you know for sure.

 

[fwdmaster]

Your good at 15lbs with the s16g, but like what everyone says get a logger

 

[AlphaAssault]

Ok, i hear what you say, but have a few questions:

1) I have inspected my plugs before to see what was going on in the engine, but have a question about the usefulness of that technique as it applies to this. wouldnt checking the plug to see if im running too lean only work after a WOT pull? i dont see how i could run WOT once, then a few days later check my plugs to see if everything is a-ok.

3) could someone explain knock to me? is it something you can feel while you are driving? and how does knock correspond to a/f ratios and combustion temps?

3) is a logger something i can tune with s well? also, which loggers do yall recommend? I would prefer something cheap... or cheap-er. is the cable w/ software for yer comp typically cheaper than the palm, or not?

oh, and ive got an aftermarket boost gauge, thats how i know that the boost didnt fluctuate at all under WOT.

 

[Stainbox12]

Ok, i hear what you say, but have a few questions:

1) I have inspected my plugs before to see what was going on in the engine, but have a question about the usefulness of that technique as it applies to this. wouldnt checking the plug to see if im running too lean only work after a WOT pull? i dont see how i could run WOT once, then a few days later check my plugs to see if everything is a-ok.

3) could someone explain knock to me? is it something you can feel while you are driving? and how does knock correspond to a/f ratios and combustion temps?

3) is a logger something i can tune with s well? also, which loggers do yall recommend? I would prefer something cheap... or cheap-er. is the cable w/ software for yer comp typically cheaper than the palm, or not?

oh, and ive got an aftermarket boost gauge, thats how i know that the boost didnt fluctuate at all under WOT.

Regarding the plugs, it depends when you suspect you are running lean, while cruising or at wot, i would suggest you do a wot pull with new plugs and check them, as well as some cruising with other plugs. Usually running lean while cruising, doesn´t do much harm.

Knock, is basically noises inside the engine. There´s a small sensor hooked up on the back of the block, that listens to detonations (noises), this sensor, sends a signal to ecu whenever there´s noise on the engine and it retards regular timing advance. Turbo engines suffer from detonation more than regular vehicles, due to boost, fuel octance, and some other things. When there´s too much knock on an engine, then you get timing retard and you will feel your car being slow, or held back. This is the ecu pulling timing to protect the engine. Now, there´s several kinds of knock, there´s lean knock, the most common one, there´s rich knock, and also phantom knock. Phantom knock, is when you have a bad sensor, or something in the engine, or chassis is making the stock knock sensor to pickup that noise, that is not precisly detonation (a bad strut, or bad lifters per example). Rich and lean knock, are regular kinds of knock, due to fuel mixture. Usually when you knock, because of being lean, then that gets your combustion temperatures higher. Knock, doesn´t correspond directly to a/f ratios, but it gives you an idea. It´s simple, if you don´t knock, then most likely your engine is safe from detonation.

Now that you understand a little bit of knock, here´s come into play a logger. Basically whenever you do fuel upgrades to support a bigger turbo, you will run rich, because the stock ECU can´t control larger injectors than stock. A logger, is a device usually a palm, with a self made cable that plugs into the diagnostic port. This port provides real time data, of how the engine is running. This little tool, while reading important sensor data, provides you with some information, to see if you knock, hows your 02 working, it checks also timing advance, fuel trims, etc. The ones i just mentioned, are the most common ones in order to tune a car. Whenever you do a pull, and you log that data into the logger, you are later on able to get that information into a regular PC, and check all the values. So, if you have a device, like an safc per example, that adds and takes out fuel, you are able to tune with, and the logger, will give you such data in order to know, where to take out and where to add fuel, for a proper tune. Per example, if you knock, then usually add a little bit of fuel to compensate that knock, if you dont knock, you can take out a little bit of fuel until you knock a bit, and then leave it there. This tuning method is very cheap, and used a lot, by people, that don´t want to spend on a dyno or on a wideband. It certainly doesn´t give you an excellent tune, but it gives you a very decent one. A palm can be found on ebay, very cheap, remanufactered or used, but make sure its the old models with serial port. The cable can be made, and there´s links on how to do it, is just a matter of searching.
There´s a little guide on the tech articles that will teach you the basics of tuning with a logger/safc combo, as well as a lot of other useful guides. Good luck. There´s still a lot to learn, make sure you search, its your best friend.

 

[anteversion]

I've run a complete summer with more upgrades than your setup without any problems at 15 psi. But i was supported by a logger to see what was going on. Looking for knock sum and fuel trims, and of course o2 sensor readings. And i was running with a 2 g maf too... and of course an safc to tune with. I have a 2.5inch turbo back exhaust line with no cat... anyway with some 450cc injectors, like the stock one in dsm turbo, you are good for 320 hp at 100% duty cycle.... but you dont want to hit more than 80-85 % .

 

[EagleTalonTim]

I personally run 14psi with an Evo 3 16g with all stock fuel (for a m/t...450 injectors) and max out the injectors around 6500 RPM. If I were you, I would set it at 12psi and leave it there if you want to stay safe.

 

[AlphaAssault]

so the problem at this point is not detonation, but melting pistons, correct?

 

[Stainbox12]

You, melt pistons because of running lean. Detonation, the names says it all.

 

[jongreene]

#1 get a logger.
Thats the only way youll actually learn how much your car can take and what its doing at WOT...a much better option then just asking other people their opinion of safe for your own vehicle imo, not all cars act exactly the same.

The logger is absolutely essential if you want to make good power.
get it, do some pulls and adjust boost till you see knock.

 

[nkosi]

u deffinately need some feed back tool to see whats going on in the engine ...u dont want to damage ## motor by doing seat of the pants tunning ...hers a better site fir the logger u need for a good price...DSMLoggers: Home ...hope this helped.

 

[omartsi]

just a question , wats the diffrent between the logger and dsm link

thanks in advanced

 

[ekanddsm]

Detonation is when you have unwanted combustion.

Basically(I hope I get this right) you get a flame,hot spot, or something inside your chamber that started to ignite before the spark plug ignited.

Hot carbon(on top of a piston) will glow cherry red hot when you begin to run lean.
Hot engine, "Thermal heat" like an overheating engine, will cause detonation.

The cars are all the same on here but they all run very different.

Try pricing a short block from slow boy racing and compare that price to a logger.

You can turn your boost up to 20 psi on a stock fuel system with a 16g, just go get some race gas.

The idea is look what your engine is doing with a logger, You can learn how to tune right off this site, or you can price a short block.

 

[Turbo Talon DL]

Detonation is when you have unwanted combustion.

Basically(I hope I get this right) you get a flame,hot spot, or something inside your chamber that started to ignite before the spark plug ignited.

Hot carbon(on top of a piston) will glow cherry red hot when you begin to run lean.
Hot engine, "Thermal heat" like an overheating engine, will cause detonation.

The cars are all the same on here but they all run very different.

Try pricing a short block from slow boy racing and compare that price to a logger.

You can turn your boost up to 20 psi on a stock fuel system with a 16g, just go get some race gas.

The idea is look what your engine is doing with a logger, You can learn how to tune right off this site, or you can price a short block.

Detonation (knock) causes the piston to move back and forth laterally inside the cyl bore. Thats why it knocks and pings. There are multiple flame fronts insted of one causing the mixture to explode insted of an even burn from the center outward. Preignition would be caused by a hotspot such as carbon. Just run whatever boost the wastegate allows and you wont mess anything up.

 

[Turbo Talon DL]

so the problem at this point is not detonation, but melting pistons, correct?

Correct.