Jump to content
SAU Community

Recommended Posts

10 psi = 10psi yes. But your cfm of air flowing through the afm will ring alarm Bells with your stock ecu.

A smaller turbo closer to stock you might get away with but the T04 will flow much more air at 10psi. Hence the car responding bad

Hey mate, I get the impression you are being serious... So I will give you as best a response as I can.

The above guys are actually correct. Your problem is your ECU. The ECU is not able to cope with the change to the new turbo.

To put it simply, pressure (boost) and volume (actual amount) are not relevant to each other. That means that 10psi from the stock turbo will be far less compressed air (power to be made) than 10psi from the T04Z.

Your car is literally a ticking time bomb, and I can assure you that if you persist you will blow the motor very soon.

You will need the following items ASAP:

700cc+ injectors

A good fuel pump (if you dont have already)

A map based ECU (running a Z32 AFM wont cut the mustard for a T04Z)

To all experienced forum members, can you please simply +1 my post if you agree. I believe the guy is being honest and is not long off wasting 3 years of hard work on his car and motor.

GL

thanks very much, thats all i needed to know. I was being serious. And as the first injected motor iv built, the electric side is all new, what is a good map ecu that will incorperate the auto properly?

In saying time bomb, will it be alright to wind down boost to lowest ( i think 8 psi) and still drive it? thanks again mate this is the info im after

ummm, that is very bad advice...

Seen plenty of cars die from Factory ECUs pinging, too much boost etc.

so a 25 with a t04z running 10psi and hitting "rich and retard" is going to be pinging? pick which side you want, you cant have it retarded and pinging, both instantly killing the motor.

fact: above standard airflow the standard ecu runs richer and richer, usually well into the 10s and sometimes into 9:1 AFR territory as it simply runs the injectors at 100%, impossible to lean out with the standard ecu unless something else is wrong.

fact: above standard airflow the standard ecu runs less and less timing

fact: maxxing the afm (5.1v) results in complete fuel cut

please tell me how this is going to cause grenade like pinging and instant death? i agree entirely that he needs bigger injectors and a better ecu, but until then turning the boost down will be sufficient

so a 25 with a t04z running 10psi and hitting "rich and retard" is going to be pinging? pick which side you want, you cant have it retarded and pinging, both instantly killing the motor.

fact: above standard airflow the standard ecu runs richer and richer, usually well into the 10s and sometimes into 9:1 AFR territory as it simply runs the injectors at 100%, impossible to lean out with the standard ecu unless something else is wrong.

fact: above standard airflow the standard ecu runs less and less timing

fact: maxxing the afm (5.1v) results in complete fuel cut

please tell me how this is going to cause grenade like pinging and instant death? i agree entirely that he needs bigger injectors and a better ecu, but until then turning the boost down will be sufficient

Cheers mate, ill pull the boost right down, so it is safe still? id hate to damage anything. i take from what you said as i cant really hurt it if it does do R&R? it is running quite rich i might add, i always thought if your not detonating, and running ruch, damage is near impossible

not sure what you mean by that but the whole more air at same boost thing is because of temperature. the bigger turbo makes the same boost much more efficiently and doesnt heat the air as much, so same pressure but different temperatures, hence different masses of air

Edited by JonnoHR31
  • Like 1

so a 25 with a t04z running 10psi and hitting "rich and retard" is going to be pinging? pick which side you want, you cant have it retarded and pinging, both instantly killing the motor.

fact: above standard airflow the standard ecu runs richer and richer, usually well into the 10s and sometimes into 9:1 AFR territory as it simply runs the injectors at 100%, impossible to lean out with the standard ecu unless something else is wrong.

fact: above standard airflow the standard ecu runs less and less timing

fact: maxxing the afm (5.1v) results in complete fuel cut

please tell me how this is going to cause grenade like pinging and instant death? i agree entirely that he needs bigger injectors and a better ecu, but until then turning the boost down will be sufficient

this is all correct but incorrect at the same time.

1. Once the injectors hit 100%, what happens? Does extra fuel magically appear the keep making it rich? Nope, it leans. In a very bad way.

2. Does the ECU just keep pulling timing until the timing is zero, or even a negative? How does the ECU know when to pull timing? Does it just magically guess, or it waits for initial detonation then pulls? Here is a fact, the ECU will only pull about 6 degrees max. Not enough for some idiot with a T04Z trying to run stupid amounts of boost.

3. I haven't experienced the "complete fuel cut"

It is still very much possible to put a big turbo on a standard ECU fitted car and blow it up. You're wrong if you think it is impossible. Seen it about 10 times personally, with a standard turbo.

  • Like 2

this is all correct but incorrect at the same time.

1. Once the injectors hit 100%, what happens? Does extra fuel magically appear the keep making it rich? Nope, it leans. In a very bad way.

2. Does the ECU just keep pulling timing until the timing is zero, or even a negative? How does the ECU know when to pull timing? Does it just magically guess, or it waits for initial detonation then pulls? Here is a fact, the ECU will only pull about 6 degrees max. Not enough for some idiot with a T04Z trying to run stupid amounts of boost.

3. I haven't experienced the "complete fuel cut"

1. afm maxxes well before you have enough airflow for 12:1 AFR's with the injectors at 100%

2. so 6 degrees from an already conservative map designed for the standard turbo and much more heat isnt enough? i'd agree if hes filling the tank with heptane. 10-11psi is stupid amounts of boost?

Seen it about 10 times personally, with a standard turbo.

and that there is exactly why its irrelevant in this case. standard turbos create a lot more heat at these boost levels and make detonation a hell of a lot easier, virtually impossible (unless something else is wrong, which would make that the cause and not the ecu like you say) to get knock with a t04z running ~10psi with the standard ecu's knock maps (which it will be using if there is even a trace of knock).

oh and for what it is worth, I have been tuning cars since 2004. I know ECUs, fuel, injectors, boost, flow, etc.

for what its worth what hes experiencing is the exact same "rich and retard" that everyone else experiences with standard turbos at 12+psi and is widely regarded as perfectly safe and just annoying.

  • Like 1

but you've been saying that you cannot kill a motor with the stock ECU, and that is absolutely rubbish.

Now you're saying other stuff, and getting into detail to try and cover your tracks?

The answer is this: You are wrong. You can kill an engine with a stock ECU and ANY turbo.

what is a good map ecu that will incorperate the auto properly?

Vipec or Power FC.

From my understanding & reading threads here, no stand alone ECU works perfect with the R33 Auto transmission, something to do with the fact that the Stock ecu will back off timing when the auto changes gears to smooth out the changes but no stand alone ECU does this thus you will get very harsh gear changes if you remove the stock ECU.

With the auto R34s if you remove the stock ECU the auto gear box will be stuck in 3rd (from what I have read).

i blew my motor on the stock ecu. my boost spiked to 16psi at WSID.

The Mafia hasn't said a word wrong IMO.

for example, you're comparing 10psi from a turbo that is sized like this (o) compared to a turbo sized like this (O) (my examples suck, i know). the air will travel at the same velocity, but the amount of air passing will be far greater on the bigger turbo because its BIGGER, bigger turbine, bigger housing bigger everything. it will create the same boost but more air is traveling. its pure logic mate.

my 3yr old nephew was checking out my turbo i had sitting on the floor. after asking me a few questions he said "you should get a bigger one to push more air" he said that while his mouth was on the compressor wheel trying to blow air into it at the same time. in comparison, he is a fucking mechanical genius compared to you.

  • Like 7

From my understanding & reading threads here, no stand alone ECU works perfect with the R33 Auto transmission, something to do with the fact that the Stock ecu will back off timing when the auto changes gears to smooth out the changes but no stand alone ECU does this thus you will get very harsh gear changes if you remove the stock ECU.

With the auto R34s if you remove the stock ECU the auto gear box will be stuck in 3rd (from what I have read).

im running a vipec with an auto r33. it runs perfectly. the r33's auto runs off a separate computer so there are no interferences between the aftermarket ecu and the auto ecu . i am unsure about the r34 though.

  • Like 1

my 3yr old nephew was checking out my turbo i had sitting on the floor. after asking me a few questions he said "you should get a bigger one to push more air" he said that while his mouth was on the compressor wheel trying to blow air into it at the same time. in comparison, he is a fucking mechanical genius compared to you.

Bahahahhahaahhaha!

  • Like 2

but you've been saying that you cannot kill a motor with the stock ECU, and that is absolutely rubbish.

Now you're saying other stuff, and getting into detail to try and cover your tracks?

The answer is this: You are wrong. You can kill an engine with a stock ECU and ANY turbo.

so you honestly believe that this guys motor is a ticking time bomb at 10psi?

your right you can kill an engine with a stock ecu and any turbo, you can kill any engine with any ecu and any turbo, it doesnt automatically mean the ecu is the sole cause of its death, which is my point.

example, go buy a mint condition (like new) r33, bolt a massive turbo on and run whatever boost you like. now dump all the oil and sit on limiter. if the engine dies is it because it had a standard ecu?

  • Like 1
  • Nope 2

not sure what you mean by that but the whole more air at same boost thing is because of temperature. the bigger turbo makes the same boost much more efficiently and doesnt heat the air as much, so same pressure but different temperatures, hence different masses of air

Hi Johnno

Additionally, the change in pressure also comes from the much larger turbine housing outlet which effectively uncorks the engine.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
    • Also playing with fire if they start to flow more air down low than what the stock twins can. It's not even up top you need to worry, it can be at 3000rpm and part throttle and it's getting way more flow than it should.
    • Any G40/1000 or G40/1250 results out there?  
    • You still want a proper tune on the stock ECU though. Stock tune + stock ECU with GT-SS/-9s is probably playing with fire if you're running more than stock airflow/power.
×
×
  • Create New...