Hyundai Forum: Hyundai Performance Forum banner
41 - 57 of 57 Posts

·
Registered
Joined
·
3,497 Posts
The stock ECU has absolutely NO IDEA that the engine has a turbocharger hanging of it...how would it? The way around the pressure level difference on a MAP sensed engine is to "clamp" the output voltage at its N/A max level. That is a voltage that needs to be tested and logged BEFORE the turbo is added. Then...once the FI system goes on..that feature is then performed.
Now...I put an asterix (*) beside the Input signals because I have to point out that it does alter one input....the first EGO sensor. If you alter the fuel curve that the ECU has output...and the EGO sensor is not relaying back to the ECU what the ECU "thinks" it should be getting back...it will try and compensate. And..as you rightly point out...it can't do that very well...and thus throws a CEL.
The HD has a MAF sensor. The ECU has the ability to see how much airflow is coming into the engine because of that. It will try to add/subtract fuel if the calculations are incorrect, but only will do this depending on the programming. The HD ECU is not programmed to have a wide range of fuel curves. It is rather narrow. To compensate for the increased pressure of air, fuel must be added to have the computations done by the ecu to be the equal as stock. You need to calculate how much airflow is entering the engine to determine how much fuel is needed, and what the ECU range is to keep the ECU happy. On a turbo or s/c setup, both do not have much boost at idle; if any. At high rpm, it will be under boost, and if you made your calculations right, you should be able to run a turbo or s/c on that fuel curve range the ECU has. Air temperature is also critical as well. What you want to consider is the fuel curve the ECU is able to adjust to, both low end and high end. How far can the ECU ecu trim the fuel. Ideally, you would want the injector duty cycle at the low end at idle and the higher end at WOT.

My engine for the turbo is not stock. It is completely custom with custom ground pistons that make the compression ratio where I want it. On the engine dyno (bench test), I have tested the stock pump and injectors vs a larger pump and injectors. With the stock pump and larger injectors the a/f ratio was 13.6. With the larger pump and injectors, the a/f is 12.6.
 

·
Registered
Joined
·
5 Posts
The HD has a MAF sensor. The ECU has the ability to see how much airflow is coming into the engine because of that. It will try to add/subtract fuel if the calculations are incorrect, but only will do this depending on the programming. The HD ECU is not programmed to have a wide range of fuel curves. It is rather narrow. To compensate for the increased pressure of air, fuel must be added to have the computations done by the ecu to be the equal as stock. You need to calculate how much airflow is entering the engine to determine how much fuel is needed, and what the ECU range is to keep the ECU happy. On a turbo or s/c setup, both do not have much boost at idle; if any. At high rpm, it will be under boost, and if you made your calculations right, you should be able to run a turbo or s/c on that fuel curve range the ECU has. Air temperature is also critical as well. What you want to consider is the fuel curve the ECU is able to adjust to, both low end and high end. How far can the ECU ecu trim the fuel. Ideally, you would want the injector duty cycle at the low end at idle and the higher end at WOT.

My engine for the turbo is not stock. It is completely custom with custom ground pistons that make the compression ratio where I want it. On the engine dyno (bench test), I have tested the stock pump and injectors vs a larger pump and injectors. With the stock pump and larger injectors the a/f ratio was 13.6. With the larger pump and injectors, the a/f is 12.6.

OMG.

You are STILL not getting it are you. Look....do your thing ok...blow your engine up...be my guest. Just because you have "built" the engine to take FI does not man a jot when the piston top melts from not enough fuel.
Oh..as I have mentioned to you in another forum...my HD runs a MAP sensor...you just cannot assume that the USA is the be all and end all and the rest of the world doesn't matter.....broaden your mind a little here.

Look...anyone who is reading this...do not follow his examples...I implore you. Do it right...get the right form of adjustment.
I know of NO engine tuners that would endorse doing what he is doing.
IMO its cheaper in the long run to have the fuelling sorted. Sure....build and engine...go for it.

What a waste of time....
 

·
Registered
Joined
·
3,276 Posts
Relax Rob, I understand what your saying. CC, hes trying to explan that the piggybacks just manipulate the ecu. The maf sensor still works between a 0-5volt range. The safc and emanage intercept the maf signal and spit it back out altered to your settings. Changing it too much will throw codes, lean fuel trim, rich fuel trip, map voltage low blah blah blah but once your tune is close enough it wont throw codes anymore. With a standalone engine management You will leave the stock ecu in place and intact you just steal all the wires from it you will need to run the standalone. Usually you can eliminate your maf with one and use a map with it. The piggyback will still work just the same for you, cant worry about a cel light after what you have already done to the engine :D
 

·
Registered
Joined
·
5 Posts
Good...a voice of reason.
I am relaxed...but it just annoys me when one person thinks they can fly in the face of convention. Manufacturers and tuners all over the world know what to do.....make the FI fuel curve differently from a N/A fuel curve.

Its just common sense. I just shudder to think that someone will come along and read this...skip over some key points and just whack a turbo on the side of their engine....and just put bigger fuel injectors on it. And when it fails...not if, but when....they will then realise it should have done it right from the start.

I am all for building engines to suit turbo charging...but look I am 36yrs old...I have been around for a long time and been involved with many builds. But..I have seen stock turbo engines with melted piston top, smashed ringlands and other damage all resulting from poor tuning. Even forged pistons will fail if the right amount of fuel is not being burnt at the right time above them.

lol...


There have even been people post in this thread that they HAVE successfully done FI add ons to their HD's....they are in their cars and driving around..not chasing fuel mixtures on an engine dyno that, quite frankly will not occur without manipulating injector pulses somehow.
 

·
Registered
Joined
·
3,497 Posts
You are STILL not getting it are you. Look....do your thing ok...blow your engine up...be my guest. Just because you have "built" the engine to take FI does not man a jot when the piston top melts from not enough fuel.
Oh..as I have mentioned to you in another forum...my HD runs a MAP sensor...you just cannot assume that the USA is the be all and end all and the rest of the world doesn't matter.....broaden your mind a little here.
How many engines have you custom built and boosted? I have done more than 1 and do know what I'm doing. I also know more about the ECU mapping than most because I have inside knowledge from Hyundai about what the ECU mapping is the way it is.

I have been running the engine for several days with my setup with zero problems. I also have the test equipment to see what the ECU is doing to see what changes I need to make. What you don't have is a Hyundai GDS scan tool. I have one. I can monitor anything that the ECU is doing in real time. Duty cycles, MAF voltage readings, o2 sensor readings, timing, CVVT timing duty cycles, the works. I use that data to make the necessary changes to the mechanicals to alter the way the engine is running.

Relax Rob, I understand what your saying. CC, hes trying to explan that the piggybacks just manipulate the ecu. The maf sensor still works between a 0-5volt range. The safc and emanage intercept the maf signal and spit it back out altered to your settings.
With piggyback systems, the ECU can override the piggyback system under a lot of conditions. That is a drawback to them and what people don't realize when they use them without knowledge of the stock mapping is it is possible that the ECU can trim the fuel too much and leave your engine starving for fuel when it needs it the most. Piggybacks tend to do best if the stock mapping is at default. When the ECU starts adapting the values, you have a problem because your tuning went out the door once the ECU started changing stuff.

Manipulating the ECU is always going to be tough and not as easy as it looks. Once you change 1 value, you have to consider what the other systems are going to do with that 1 changed value. Everything will be off as a result, unless you change everything to get it right. Ideally, a stand alone is preferred because you can custom tune the mapping. However, when you have emission requirements to consider, and having a system where you have other critical components run by the ECU, you have to work with the existing system. I have all of these to consider.

A maf sensor is more accurate than a map sensor. The fuel curves are more precise with the maf based system. The map system is easier to run with boost because the tuning with the stock PCM is much wider as a result of the type of sensor used.

I am all for building engines to suit turbo charging...but look I am 36yrs old...I have been around for a long time and been involved with many builds. But..I have seen stock turbo engines with melted piston top, smashed ringlands and other damage all resulting from poor tuning. Even forged pistons will fail if the right amount of fuel is not being burnt at the right time above them.
I'm a lot older than you, and have more experience doing it. I am not going to slap a turbo on the car and drive it until I know the engine will run properly. I do have the equipment to test and monitor the sensors to see what they are doing to know what the limits are. I am also not running close to a stock engine. Compression ratio is different as well as other things have been changed.
 

·
Registered
Joined
·
71 Posts
I'm going to agree with Rob on this one. Injectors and a fuel pump will only give you a very limited control on your motor. IMO built or not you will probably run into troubles during hot days when your FPR can't alter to the change.

I have seen turbo cars that keep the OEM MAF and place it before the turbo on the intake and then place a MAP in the system for the after market.

I would still advise a piggy back or stand alone for output to the injectors/injectors at minimal. You can leave all your engine sensors spliced to both the OEM and the after market. This also allows you to never touch all of your other electronics you seem worried about like your lighting, speedo, and so forth.

But if you are determined to run it this way please post dyno numbers and a quarter mile slip because many people would be interested.

Best of luck to you.
 

·
Registered
Joined
·
3,497 Posts
I'm going to agree with Rob on this one. Injectors and a fuel pump will only give you a very limited control on your motor. IMO built or not you will probably run into troubles during hot days when your FPR can't alter to the change.
That depends on boost psi. I don't plan on massive boost. Don't need 20 psi of boost here. The stock ECU can handle up to 10 psi of boost with no problems. The stock FPR can handle up to 15 psi. Having that kind of boost on a streetable engine is not necessary.

Also, with an intercooler, you can run boost with less problems. I found the engine will detonate when the larger injectors and stock pump is used without an intercooler. The intercooler cools off the intake air enough to prevent preignition. However, the fuel ratio with the stock pump is a bit high with 13.6 A/F. My goal was 12 A/F at wot. I got 12.6 A/F when I put the Walbro pump on. That is better, but not my ultimate goal, but it is workable.

Having massive amounts of boost is unnecessary on a street vehicle. You will never pass emissions and drivability will be compromised, unless it is a track only car.

The stock HD does run a bit fatter than the 06 and earlier cars. They ran fairly lean. My plugs on my HD are medium dark brown. The XD were gray. That tells me the mixture is on the richer side.

My 68 Chev truck is boosted and with the 572 big block, it has over 1,000 hp at the wheels with 10 psi of boost. It depends on what you do with it.
 

·
Registered
Joined
·
3,276 Posts
I would like to see dyno charts and a air fuel log. Im very unsure of what "mechanical" aspects you could be changing to tune the car? Fuel pressure? Adjustable cams? I have no way of controlling timing and with my lower compression on a stock beta ecu (upgraded from the accent one) and never had a problem, though now i run a water/methanol mix. The emanage also can adjust fuel injectors after the ecu but it doesnt work with the beta one ecu =-(
 

·
Registered
Joined
·
1,489 Posts
Get the damn FIC. It manipulates the injector pulses on whatever ecu you want and retards timing too! It works on my LC without any problems at all!!! No cel , no bogs. no problems at all. You can clamp ANY sensor you want at ANY voltage you want so the ecu is happy all the time. The car runs like no other!
 

·
Registered
Joined
·
3,497 Posts
I would like to see dyno charts and a air fuel log. Im very unsure of what "mechanical" aspects you could be changing to tune the car? Fuel pressure? Adjustable cams? I have no way of controlling timing and with my lower compression on a stock beta ecu (upgraded from the accent one) and never had a problem, though now i run a water/methanol mix. The emanage also can adjust fuel injectors after the ecu but it doesnt work with the beta one ecu =-(
You run high boost. I don't. 5 psi max. I run no changes in ECU because that is not what I need to do at this point. I am not into a high boost condition. Not necessary on a street application.

I can add fuel by using injectors with a higher output than stock with a fuel pump capable of pushing sufficient fuel into the motor for the amount of boost I am using.

What you guys do not have is an adjustable cam setup. The newer betas have this capability via the VVT system. The cam timing can be changed depending on throttle position, load and rpm by the ECU. This makes an advantage because the ECU will see the length of time the engine takes to increase rpm (load) and can adjust cam timing to make the increase faster or slower depending on throttle action, ignition timing and fuel duty cycle. This makes it possible to have no additional tuning on low boost conditions.

Get the damn FIC. It manipulates the injector pulses on whatever ecu you want and retards timing too! It works on my LC without any problems at all!!! No cel , no bogs. no problems at all. You can clamp ANY sensor you want at ANY voltage you want so the ecu is happy all the time. The car runs like no other!
Why? Why are you trying to force me to put a piggyback on my car when I do not want it on the car? I am not interested in 20+ pounds of boost and never will be. 20 pounds of boost is unnecessary. I don't want a lot of fuel being dumped in the engine just because you say it is mandatory. Why dump a gallon of fuel in the engine at high rpm? It is not going to burn that much fuel. You want the fuel ratio at wide open throttle at 6,000 rpm to be about 12 to 12.4. At cruise, the optimal fuel ratio on any engine, boosted or not should be around 14-14.7. If you are getting ratios lower than that, you are wasting a lot of fuel. The engine is not going to be able to burn it. It will be dumped out the exhaust, which creates a problem for the cat converter. It has to burn efficiently.

I did not come on here to say I need a lot of help. I don't. I just stated I have a boosted engine that I built for my car that I'm R&Ding because the question was asked about people using the stock ECU on some form of boost.
 

·
Registered
Joined
·
1,489 Posts
Boosting and having stoichiometric fuel ratio will givve you a nice hole in the piston wheter forged or stock...
my 2 cents
 

·
Registered
Joined
·
3,276 Posts
Hes reffering to cruising with the 14-14.7, not boosting. Low boost you should be fine if your monitoring your air fuels with a wideband. Woulding go cranking it up much though :D
 

·
Registered
Joined
·
3,497 Posts
Boosting and having stoichiometric fuel ratio will givve you a nice hole in the piston wheter forged or stock...
my 2 cents
When you are having no throttle action and going a steady 2350 rpm at 60 mph, why would you need 15 pounds of boost? Boost will drop at a steady rpm.
Hes reffering to cruising with the 14-14.7, not boosting. Low boost you should be fine if your monitoring your air fuels with a wideband. Woulding go cranking it up much though :D
The ECU is capable of dropping the fuel ratio from 14-14.7 to 12.6 quite fast when you put your foot into the pedal. This happens with or without boost. The ECU uses 2 wideband o2 sensors to monitor what the engine is doing. It wants to see the fuel ratio drop at full throttle. It adds fuel to do that.

At cruise, the duty cycle is about 20% where it should be (with boost and without boost). Naturally you have more air going in the engine with a turbo even at low boost, you have to compensate by having enough fuel pressure and fuel output to match the amount of air going into the motor to keep the calculations of fuel to air the same as stock, except that these numbers will be higher. The ECU does not care what these numbers are except that the end result is the same. All the ECU is making decisions on is the calculations of the difference of the o2 sensors. If they are the same as stock (the calculation result), the ECU does not care if the air meter readings are high. Since it sees enough fuel, it will ignore the high air meter reading. Now, if you boost too much and peg the air meter, then there will be a MAF code. If you alter/clamp the air meter readings going to the ECU, the lower numbers the ecu sees will result in less fuel delivery because you fooled with the metering numbers the ecu needs to have to determine how much fuel to add. Unchanged, the ecu sees a lot of air, but it is fooled by the larger injectors and pump delivering more fuel to the engine. It thinks that since the air fuel mixture is correct, there is no point in telling the driver there is a problem with the maf sensor that tells the ecu the airflow is much higher than stock. If you alter the air meter values, the ecu can determine that the engine needs a smaller amount of fuel at wot and then sees the o2 sensor readings get out of calibration, then it starts to tell the sensors and solenoids there is a problem, which you end up with a no start condition, or a 1/2 power situation where you get 1/2 throttle even though you are fully on the throttle and sets a code.

I have a 3rd wideband sensor to monitor things separately, but I can also monitor what the ECU is doing via the scan tool. I can see what the injectors are doing, what the timing is, the 1st and 2nd o2 sensors, air meter, cvvt duty cycle, and any other component the ecu is monitoring.

You do not want a fuel ratio at cruise below 14. You do want that to drop if you are on the throttle. You also do not want the fuel ratio to go below 12.

On the street, you are not full throttling the car all the time. At most, you should be cruising. Low RPM, and low boost levels.
 

·
Registered
Joined
·
71 Posts
Most of your information is correct and I'm not going to question any of that because you are very knowledgeable in your answers.

I am just wondering why you would spend the money to build the motor, internals and all, then only run 5 psi? At 5 psi why not just stay with a stock motor and save your wallet because I don't think you have any fear of damage to your motor at that level.

Most of the responses made, including my own, were thinking you planned to run high boost because of forged internals. Now I want to know why you built a motor to run very little boost and why you don't buy and ECU to better tune that modified motor.
 

·
Registered
Joined
·
3,497 Posts
I
am just wondering why you would spend the money to build the motor, internals and all, then only run 5 psi? At 5 psi why not just stay with a stock motor and save your wallet because I don't think you have any fear of damage to your motor at that level
Any stock motor is not built for forced induction. 1. The compression ratio is too high. The 10.1:1 on the HD is enough to cause pre ignition even with low boost. 2. Additionally, the crank on the beta is made of a softer material than is normally found on tock boosted motors. It can twist easy. The Evo stock crank is made of a harder material, which is more resistant to bending/twisting. I lowered the CR to 9.5:1, which is higher than most beta 1/2 forged pistons. Those are 8.5:1. I felt that under low boost, the lower CR will sacrifice power rather than create it. Under low rpm and a steady rpm, you normally are not under a lot of boost. A lower CR does lower your power output unless you have boosted it at a high level. Having a medium CR, you can run lower boost while making as much power as a low CR/high boost condition.

Most of the responses made, including my own, were thinking you planned to run high boost because of forged internals. Now I want to know why you built a motor to run very little boost and why you don't buy and ECU to better tune that modified motor.
The ECU on the HD cannot be changed because as I said, it runs the whole electrical system. It has to remain in place, and it is very pissy about things. If you remove the ECU, you are required to completely rewire the whole car to make everything functional. The wiring in the car is realitively simple and less wires are used because the same wires carry multiple signals at the same time. It is similar to a USB and internet connection on your computer. The USB connection allows multiple signals to run both ways to a devise and the internet connection allows more data to be sent and received to the ecu. It is no longer a simple power to switch to devise to ground circuit. On the new cars, the circuits are a computer to computer and switch to computer to computer and back to computer to devise through the same circuit/wiring. 2 wires are used instead of 10.

I am not done testing the limits of the ecu yet. I want to find out how much boost it will be able to handle without it freaking out. I am shooting for 10 psi next. Once I get that issue researched, and data taken, then I'll be able to install it.
 

·
Registered
Joined
·
8 Posts
Hi everyone,

We are running a Hyundai i20 NA-turbocharged 1.2L (low boost - 6PSI) on stock ECU with no add on piggyback ECU or RRFPR. All boost related functions are handled by the stock ECU with added custom calibration code.

Stock ECU wirh
1. Customized code
2. 2 bar absolute map sensor
3. Revised map sensor scaling - 2 bar sensor
4. Revised calculated load modeling
5. Revised target AFR map
6. Revised ignition curve for boost
7. Revised IAT compensation
8. Revised cam angle for intake and exhaust
9. Revised torque modeling / limit
all this and then some more...

Stock motor - stock block, rods, pistons.
OEM clutch - modified pressure plate
 
41 - 57 of 57 Posts
Top