Steps to a successful DIY turbo build:
#1
03-20-2011, 07:50 AM
![Lyon[Nightroad]'s Avatar](https://www.fitfreak.net/forums/customavatars/avatar31469_2.gif){kind=avatar}
![Lyon[Nightroad] is offline](https://www.fitfreak.net/forums/skynetimages/statusicon/user_offline.gif)
Steps to a successful DIY turbo build:
I meant to send this to DSC but apparently its been sitting in my draft folder for a month now. It's useful info to all so I'll just leave it here as a motivational piece:
Sorry about that, my last reply was on my iphone so it may have been hard to read. Fuel management is possible, but it will require some research to tune it yourself. Even if I get a basemap setup for you, you still need to be able to tune it yourself to get it working reasonably well. So spend as much time as possible learning about how to use the FIC. Once you have the basics its all cake and pie. Let’s talk briefly about the order you will want to do things in:
1. Select your turbo
2. Select your manifold. Neukin might make one that fits. Contact them directly. Tell them what turbo you are using. The r18 manifold trick I came up with worked for me thanks to some sort of bizarre miracle. Its so very close to hitting the engine block and so very close to hitting the halfshaft but somehow it works. I would probably not risk it since every r18 manifold is different.
3. Once again, I have absolutely positively no idea how in the world neukin will be able how to make a correctly sized downpipe since this is going to vary with nearly every turbo and the clearance is so so bad under there. Ditto with the external wastegate going to the downpipe. If they can do it though, go that route, otherwise you are going to have to tow your car to a muffler shop to have a downpipe made.
4. Test fit your parts. Once you are absolutely sure that the turbo, manifold, wastegate, and downpipe fit and clear everything. Remove them. Go back to stock. Put them in a box, You aren’t going to be seeing them again for a while.
5. Alright, so now its time to get that FIC installed. If you are comfortable with a soldering iron you can do what I did and cut into the stock harness. It’s ALOT of work but saves you $225. Since you’re on a lease I would drop the cash and buy a pnp boomslang harness as a custom order. Just tell them you need an FIC6 harness for a GE8 and they will make you one, no soldering required.
6. Spend a couple days getting familiar with the FIC. Play with the numbers and log a bunch of WOT runs and label them. Do pulls from 1st gear 2nd gear standstill, rolling, make tons and tons of logs you will need them eventually and have no way to go back and remake them.
7. Get some injectors, rsx-s or larger. rsx-s is direct plug and play. I bought mine used for $100. I received them still attached to the fuel rail, for some reason this makes me more comfortable buying used.
8. Remove the intake manifold and install the bigger injectors. I did not buy new gaskets and I’m no worse off for it but in truth you probably should.
9. Tune for the new injectors. Drive around and street tune as necessary. Make sure you buy an obdii scan gauge to get those long term fuel trims as close to 0 as possible. Otherwise you are tuning in the dark.
10. Time to install a return oil bung on to the pan. Welcome to hell. Compared to all the other steps this is the only one I did not enjoy very much. You will need to remove the belt, the ac compressor, 3 covers, drain the oil, and disconnect the transmission shift linkage. Then you will have use a prybar to pop the pan off the block, which is also hell since they pry spots (which you absolutely must use) are too small and hard to get to. Then you have to drill and tap a hole in the pan above the oil level and weld or jbweld in a bung. Then you have to put messy difficult to use liquid gasket on the pan and struggle to get the stupid thing lined up and bolted back in.
11. Now you need to order every single part for the final assembly. Charge pipes, UEGO, Boost Gauge, oil lines, sandwich plate, coolant lines, vacuum lines, bov, etc. and load up your tune to the fic. Install everything. Double check everything. Check your oil feed line constantly. Mine has a habit of exploding. It’s ugly when it happens. I actually keep a repair kit in my car with 5 quarts of oil, braided lines, and various fittings, in case my oil line blows up again while I’m on the road.
Also for the sake of consolidation here's my drunken ramblings on tuning:
Sorry about that, my last reply was on my iphone so it may have been hard to read. Fuel management is possible, but it will require some research to tune it yourself. Even if I get a basemap setup for you, you still need to be able to tune it yourself to get it working reasonably well. So spend as much time as possible learning about how to use the FIC. Once you have the basics its all cake and pie. Let’s talk briefly about the order you will want to do things in:
1. Select your turbo
2. Select your manifold. Neukin might make one that fits. Contact them directly. Tell them what turbo you are using. The r18 manifold trick I came up with worked for me thanks to some sort of bizarre miracle. Its so very close to hitting the engine block and so very close to hitting the halfshaft but somehow it works. I would probably not risk it since every r18 manifold is different.
3. Once again, I have absolutely positively no idea how in the world neukin will be able how to make a correctly sized downpipe since this is going to vary with nearly every turbo and the clearance is so so bad under there. Ditto with the external wastegate going to the downpipe. If they can do it though, go that route, otherwise you are going to have to tow your car to a muffler shop to have a downpipe made.
4. Test fit your parts. Once you are absolutely sure that the turbo, manifold, wastegate, and downpipe fit and clear everything. Remove them. Go back to stock. Put them in a box, You aren’t going to be seeing them again for a while.
5. Alright, so now its time to get that FIC installed. If you are comfortable with a soldering iron you can do what I did and cut into the stock harness. It’s ALOT of work but saves you $225. Since you’re on a lease I would drop the cash and buy a pnp boomslang harness as a custom order. Just tell them you need an FIC6 harness for a GE8 and they will make you one, no soldering required.
6. Spend a couple days getting familiar with the FIC. Play with the numbers and log a bunch of WOT runs and label them. Do pulls from 1st gear 2nd gear standstill, rolling, make tons and tons of logs you will need them eventually and have no way to go back and remake them.
7. Get some injectors, rsx-s or larger. rsx-s is direct plug and play. I bought mine used for $100. I received them still attached to the fuel rail, for some reason this makes me more comfortable buying used.
8. Remove the intake manifold and install the bigger injectors. I did not buy new gaskets and I’m no worse off for it but in truth you probably should.
9. Tune for the new injectors. Drive around and street tune as necessary. Make sure you buy an obdii scan gauge to get those long term fuel trims as close to 0 as possible. Otherwise you are tuning in the dark.
10. Time to install a return oil bung on to the pan. Welcome to hell. Compared to all the other steps this is the only one I did not enjoy very much. You will need to remove the belt, the ac compressor, 3 covers, drain the oil, and disconnect the transmission shift linkage. Then you will have use a prybar to pop the pan off the block, which is also hell since they pry spots (which you absolutely must use) are too small and hard to get to. Then you have to drill and tap a hole in the pan above the oil level and weld or jbweld in a bung. Then you have to put messy difficult to use liquid gasket on the pan and struggle to get the stupid thing lined up and bolted back in.
11. Now you need to order every single part for the final assembly. Charge pipes, UEGO, Boost Gauge, oil lines, sandwich plate, coolant lines, vacuum lines, bov, etc. and load up your tune to the fic. Install everything. Double check everything. Check your oil feed line constantly. Mine has a habit of exploding. It’s ugly when it happens. I actually keep a repair kit in my car with 5 quarts of oil, braided lines, and various fittings, in case my oil line blows up again while I’m on the road.
Also for the sake of consolidation here's my drunken ramblings on tuning:
Ahh the art of street tuning. First, you must believe in yourself. Second, you must believe in your car. All else will fall into place.
With that being said, when I decided that I would tune my car myself I simply read everything I could get my hands on. The basic principles of piggyback tunning are remarkably simple. It consists of two basic parts. Don't ever let the stock ecu see boost and add fuel preportional to the quantity of boost.
To keep the ecu from seeing boost we need to modify the maf signal and the map signal. The map is the simplest. Out of boost we allow the stock ecu to see the actual map reading. 0-14.7 psi. In boost we always tell the ecu it has 14.7 psi no matter how much boost there is. This is accomplished by clamping the map signal so that it never exceeds the voltage equivalent of 14.7 psi. The maf is much more difficult to clamp, and is probably the most difficult part of the tune. To clamp the maf we log the maf signal on a WOT run bone STOCK. Then we analyze that log and see what the maximum maf voltage is at various rpm levels. We then take that data and put it into a spreadsheet. We instruct the FIC with that data to never allow a voltage exceeding the bone stock voltage to reach the stock ecu.
So now with the maf and map clamp written into our fic tables and our turbo installed, what will happen if we go wide open throttle. We will enter boost, but the stock computer will only inject 14.7 psia worth of fuel in! Perfection! This is exactly what we want. We want the stock computer to give us exactly 14.7 psia worth of fuel regardless of how much boost we make.
Are you following me cameraguy?
But how do we make it inject the correct amount of fuel then?
Good question!
This brings us to our second phase. Fuel mapping. This is actually very easy. You see if I am making 14.7 psi worth of boost (29.4 psia) that means to achieve the same air fuel ration as I normally would at 14.7 psia or no boost, I need to inject roughly twice as much fuel. Well we are in luck! We can easily tell the fic to do just that. With the onboard map sensor, the fic can tell exactly how much boost we are making. We create a fuel table that says, at 5 psi, inject 33% more fuel than the signal you are recieving from the stock ecu is telling you. So it adds 33% more pulse width and now we are running at stock afr again! Then we tell it the same for each boost level 66% for 10 psi 100% more pulse width for 15psi boost ... Etc. The fic will calculate between boost levels for you... Just with that alone it now knows that it should also do 50% more fuel at 7.5 psi of boost. It can do basic math.
It is actually a bit more compliated but if you follow me so far, you understand the essentials. You see with a table like above we would be running at stock afr, which is actually 13.x and boost requires 11.5 afr for safety so instead we actually add ~125% more fuel at 29.4 psia and proportionaly scale that.
Now with what we have so far we can actually start the car and drive it down the street. We can make a couple wot passes and record our afr at different rpm and boost levels and add more or less fuel at different points to fine tune.
Ahh! But what about part throttle. Well unfortunately this is where piggybacks usually fail. Our fuel maps are 2 dimensional boost x rpm. Until they make me a piggyback that can work in 3 dimensions boost x rpm x throttle it just isn't realistic to think you can 'hard tune' or in other words specifically write out the fuel levels for every part throttle fuel possibility. If they made me a damn tuning cube l could pull it off. Do you hear me developers! Make me a friggin 3 dimensional fuel map already! But I digress, anyway there is a solution for the time being. Luckily the fit loves to operate in closed loop. Literally, you are either in wot and open loop or you are at any partial throttle level and in closed loop. What can we do with this fact? Well in closed loop as you know, the stock ecu will add or subtract fuel on to the base map to keep the car near stoich. So even if you can't add enough fuel in part throttle the ecu will add more for you to keep you at stoich. But we don't want to be at stoich, you say! You are right. So what do we do? We change the signal from the o2 sensor so that when the engine is running at stoich, the computer thinks it is running lean. The percentage we change the signal by, determines how much more fuel the ecu will add. As fate would have it, the maximum the fic allows, 50%, is exactly how much we need to modify the signal to make the stock computer think that 11.5 afr is 13.7 afr. So in other words in part throttle, the stock computer will keep adding fuel, regardless of how bad your non-existant part throttle fuel map is, until you are running at 11.5 afr. Perfection! Then we just clean up the little bit of part throttle fuel map we do have so that the stock ecu doesn't have to work too hard to get the afr right!
Also pull timing, takes like 5 seconds, 1 degree per psi at first.
Wasn't that easy?
With that being said, when I decided that I would tune my car myself I simply read everything I could get my hands on. The basic principles of piggyback tunning are remarkably simple. It consists of two basic parts. Don't ever let the stock ecu see boost and add fuel preportional to the quantity of boost.
To keep the ecu from seeing boost we need to modify the maf signal and the map signal. The map is the simplest. Out of boost we allow the stock ecu to see the actual map reading. 0-14.7 psi. In boost we always tell the ecu it has 14.7 psi no matter how much boost there is. This is accomplished by clamping the map signal so that it never exceeds the voltage equivalent of 14.7 psi. The maf is much more difficult to clamp, and is probably the most difficult part of the tune. To clamp the maf we log the maf signal on a WOT run bone STOCK. Then we analyze that log and see what the maximum maf voltage is at various rpm levels. We then take that data and put it into a spreadsheet. We instruct the FIC with that data to never allow a voltage exceeding the bone stock voltage to reach the stock ecu.
So now with the maf and map clamp written into our fic tables and our turbo installed, what will happen if we go wide open throttle. We will enter boost, but the stock computer will only inject 14.7 psia worth of fuel in! Perfection! This is exactly what we want. We want the stock computer to give us exactly 14.7 psia worth of fuel regardless of how much boost we make.
Are you following me cameraguy?
But how do we make it inject the correct amount of fuel then?
Good question!
This brings us to our second phase. Fuel mapping. This is actually very easy. You see if I am making 14.7 psi worth of boost (29.4 psia) that means to achieve the same air fuel ration as I normally would at 14.7 psia or no boost, I need to inject roughly twice as much fuel. Well we are in luck! We can easily tell the fic to do just that. With the onboard map sensor, the fic can tell exactly how much boost we are making. We create a fuel table that says, at 5 psi, inject 33% more fuel than the signal you are recieving from the stock ecu is telling you. So it adds 33% more pulse width and now we are running at stock afr again! Then we tell it the same for each boost level 66% for 10 psi 100% more pulse width for 15psi boost ... Etc. The fic will calculate between boost levels for you... Just with that alone it now knows that it should also do 50% more fuel at 7.5 psi of boost. It can do basic math.
It is actually a bit more compliated but if you follow me so far, you understand the essentials. You see with a table like above we would be running at stock afr, which is actually 13.x and boost requires 11.5 afr for safety so instead we actually add ~125% more fuel at 29.4 psia and proportionaly scale that.
Now with what we have so far we can actually start the car and drive it down the street. We can make a couple wot passes and record our afr at different rpm and boost levels and add more or less fuel at different points to fine tune.
Ahh! But what about part throttle. Well unfortunately this is where piggybacks usually fail. Our fuel maps are 2 dimensional boost x rpm. Until they make me a piggyback that can work in 3 dimensions boost x rpm x throttle it just isn't realistic to think you can 'hard tune' or in other words specifically write out the fuel levels for every part throttle fuel possibility. If they made me a damn tuning cube l could pull it off. Do you hear me developers! Make me a friggin 3 dimensional fuel map already! But I digress, anyway there is a solution for the time being. Luckily the fit loves to operate in closed loop. Literally, you are either in wot and open loop or you are at any partial throttle level and in closed loop. What can we do with this fact? Well in closed loop as you know, the stock ecu will add or subtract fuel on to the base map to keep the car near stoich. So even if you can't add enough fuel in part throttle the ecu will add more for you to keep you at stoich. But we don't want to be at stoich, you say! You are right. So what do we do? We change the signal from the o2 sensor so that when the engine is running at stoich, the computer thinks it is running lean. The percentage we change the signal by, determines how much more fuel the ecu will add. As fate would have it, the maximum the fic allows, 50%, is exactly how much we need to modify the signal to make the stock computer think that 11.5 afr is 13.7 afr. So in other words in part throttle, the stock computer will keep adding fuel, regardless of how bad your non-existant part throttle fuel map is, until you are running at 11.5 afr. Perfection! Then we just clean up the little bit of part throttle fuel map we do have so that the stock ecu doesn't have to work too hard to get the afr right!
Also pull timing, takes like 5 seconds, 1 degree per psi at first.
Wasn't that easy?
Last edited by Lyon[Nightroad]; 03-20-2011 at 07:55 AM.
#2
03-21-2011, 09:45 AM
So when you say bring it back to stock can I keep my bolt ons such as PRM intake and axle back?
#3
03-21-2011, 09:51 AM
You can certainly keep those on. You just need to be NA when you log your intial runs for your MAF clamp.
#4
03-21-2011, 09:53 AM
Also a very easy way to get a good blow through maf setup is to follow my DIY intake instructions and use the MAF tube you cut out.
#5
03-21-2011, 09:56 AM
Now if I'm correct the GE8 has a MAF and a MAP now at which point do you clamp these sensors after the stock WOT runs?
#6
03-21-2011, 10:00 AM
When logging the stock runs I don't clamp the sensors yet correct? Only when I finally bolt the turbo on i clamp these sensors. Also ...... How do I clamp these sensors, is this the" diode trick"
#7
03-21-2011, 10:00 AM
You can actually clamp them as soon as you install the fic. Since all your clamp is doing is making sure the maf and map voltage never exceed the stock wot levels. In fact if you clamp them while you are still NA you can make more logs and see if your clamp is too low, too high, or just right throughout the rev range. Once you actually install everything it's too late to go back and capture that data.
You clamp them with the voltage tables in the aem fic. It looks alot like an excel spreadsheet. I'm on my phone so I can't post an example but it is a bit tricky.
You clamp them with the voltage tables in the aem fic. It looks alot like an excel spreadsheet. I'm on my phone so I can't post an example but it is a bit tricky.
Last edited by Lyon[Nightroad]; 03-21-2011 at 10:03 AM.
#8
03-21-2011, 10:08 AM
Here we go, this is a great example of what a completed maf clamp looks like. All those lucky gd people have no idea what a nightmare it can be.
#9
03-21-2011, 10:45 AM
Great info. My FI plans have been stalled because of a tuning solution. Unfortunately Boomslang can't do a custom harness.
"Right now we cannot. We are unable to purchase the connectors that the 2009+ Fits use."
"Right now we cannot. We are unable to purchase the connectors that the 2009+ Fits use."
#11
03-21-2011, 11:27 AM
That's what makes it complicated, the voltage = a specific amount of airflow. Now wot runs through the full rpm range so 3000 rpm has a lower voltage than 5000 rpm at wot because it is flowing less air.
#12
03-21-2011, 11:38 AM
So you you can't tell throttle position on MAF just airflow at a specified RPM is what your saying?...... Another thing, does the maf take into consideration what gear you are in. The reason I'm saying this is because isn't there more airflow required at 3000 rpm in 4th gear as compared to say 2nd?
#13
03-21-2011, 11:53 AM
There is a slight difference between gears but its not enough to be significant and there is no way to compensate for it. You are correct, the maf just measures airflow. Now the FIC functions by intercepting the MAF output signal, processing it by making any changes you have in you table, and then sending it to the ecu.
So with the table above lets assume we are doing a wide open throttle run.
So let's say we start at 3200 rpms. We are in boost and flowing 4.5 volts on the maf sensor. However if we were NA we would only be flowing 3.54 volts on the maf. So back to boost. The fic, with this table, first sees the incoming voltage as 4.5, then it checks your table. it goes to 4.5 X 3200 on the graph. On the graph where 4.5 would intercept 3200 it instructs the fic to output 3.54 volts to the ecu even though 4.5 volts is comming from the sensor. In other words, even though we are flowing boost the ECU thinks we are only flowing an NA quantity of air.
The FIC does this thousads of times per second. As we climb through the rev range it outputs all the different maximums. So think of the range on the left as the input voltage and the number in the table as the output voltage.
So with the table above lets assume we are doing a wide open throttle run.
So let's say we start at 3200 rpms. We are in boost and flowing 4.5 volts on the maf sensor. However if we were NA we would only be flowing 3.54 volts on the maf. So back to boost. The fic, with this table, first sees the incoming voltage as 4.5, then it checks your table. it goes to 4.5 X 3200 on the graph. On the graph where 4.5 would intercept 3200 it instructs the fic to output 3.54 volts to the ecu even though 4.5 volts is comming from the sensor. In other words, even though we are flowing boost the ECU thinks we are only flowing an NA quantity of air.
The FIC does this thousads of times per second. As we climb through the rev range it outputs all the different maximums. So think of the range on the left as the input voltage and the number in the table as the output voltage.
#14
03-21-2011, 11:58 AM
This is a great video that helped teach me how to write the MAF clamp.
YouTube - F/IC Software - MAF Clamp
YouTube - F/IC Software - MAF Clamp
#15
03-21-2011, 12:42 PM
7. Get some injectors, rsx-s or larger. rsx-s is direct plug and play. I bought mine used for $100. I received them still attached to the fuel rail, for some reason this makes me more comfortable buying used.
8. Remove the intake manifold and install the bigger injectors. I did not buy new gaskets and I’m no worse off for it but in truth you probably should.
9. Tune for the new injectors. Drive around and street tune as necessary. Make sure you buy an obdii scan gauge to get those long term fuel trims as close to 0 as possible. Otherwise you are tuning in the dark.
8. Remove the intake manifold and install the bigger injectors. I did not buy new gaskets and I’m no worse off for it but in truth you probably should.
9. Tune for the new injectors. Drive around and street tune as necessary. Make sure you buy an obdii scan gauge to get those long term fuel trims as close to 0 as possible. Otherwise you are tuning in the dark.
- I know that the RDX injectors are interchangeable (and slightly larger) with the RSX-S injectors on the K series engines...I wonder if these would be plug and play with the L15a7?
#16
03-21-2011, 12:50 PM
- Just out of curiousity...did you notice any significant gains once you tuned the injectors (before adding the turbo)? Were you still using the SRI when you tuned the injectors NA? Were you still using the WR header at this time as well?
- I know that the RDX injectors are interchangeable (and slightly larger) with the RSX-S injectors on the K series engines...I wonder if these would be plug and play with the L15a7?
- I know that the RDX injectors are interchangeable (and slightly larger) with the RSX-S injectors on the K series engines...I wonder if these would be plug and play with the L15a7?
#17
03-21-2011, 01:20 PM
There is a slight difference between gears but its not enough to be significant and there is no way to compensate for it. You are correct, the maf just measures airflow. Now the FIC functions by intercepting the MAF output signal, processing it by making any changes you have in you table, and then sending it to the ecu.
So with the table above lets assume we are doing a wide open throttle run.
So let's say we start at 3200 rpms. We are in boost and flowing 4.5 volts on the maf sensor. However if we were NA we would only be flowing 3.54 volts on the maf. So back to boost. The fic, with this table, first sees the incoming voltage as 4.5, then it checks your table. it goes to 4.5 X 3200 on the graph. On the graph where 4.5 would intercept 3200 it instructs the fic to output 3.54 volts to the ecu even though 4.5 volts is comming from the sensor. In other words, even though we are flowing boost the ECU thinks we are only flowing an NA quantity of air.
The FIC does this thousads of times per second. As we climb through the rev range it outputs all the different maximums. So think of the range on the left as the input voltage and the number in the table as the output voltage.
So with the table above lets assume we are doing a wide open throttle run.
So let's say we start at 3200 rpms. We are in boost and flowing 4.5 volts on the maf sensor. However if we were NA we would only be flowing 3.54 volts on the maf. So back to boost. The fic, with this table, first sees the incoming voltage as 4.5, then it checks your table. it goes to 4.5 X 3200 on the graph. On the graph where 4.5 would intercept 3200 it instructs the fic to output 3.54 volts to the ecu even though 4.5 volts is comming from the sensor. In other words, even though we are flowing boost the ECU thinks we are only flowing an NA quantity of air.
The FIC does this thousads of times per second. As we climb through the rev range it outputs all the different maximums. So think of the range on the left as the input voltage and the number in the table as the output voltage.
#18
03-21-2011, 01:42 PM
It hides the boost by outputting by intercepting the maf sensor signal, reducing it down to the NA equivalent voltage at that rpm level and sending it to the ecu. All it's doing is changing the voltage based on the rpm before it gets to the ecu. You have to program what voltage it needs to output at what rpm. The video shows how to make that table.
#19
03-21-2011, 01:50 PM
We change the signal from the o2 sensor so that when the engine is running at stoich, the computer thinks it is running lean. The percentage we change the signal by, determines how much more fuel the ecu will add
Edit: Golden info btw. Thx for sharing.
#20
03-21-2011, 02:37 PM
Join Date: Sep 2010
Location: Chicago, Illinois
Posts: 4,424
Nice, I was wondering when you were gonna put one of these together! You nailed it, this is exactly how its done. I hope a lot of people learn from this and we start to see other DIY boost guys running around.
Texas Coyote is working on installing his Meth kit now too, so it looks like we may have entered a new era in Fit tuning...
One of the couple advantages you have in tuning your GE as cruel a mistress as they can be, is the MAF sensor.
Maf Hz/Voltage output is literally engine load. It is a direct measure of how much air enters the engine and really cuts down the time it takes to plot your VE map. Most MAFs now come with an IAT and a Baro sensor so it will even correct your VE based on those two and their associated correction factors!
Which is pretty handy vs. my GD and its pure Speed Density setup. But there is also the possibility that you will over run your MAF and the signal becomes choppy which means timing and fuel delivery can become erratic. This can lead to dangerous lean fluctuations under load. Which is why you have to hide the positive manifold pressure and extra flow from the ECU so it doesn't freak out.
How close are you to your Max Hz/Voltage now?
Another little differences between GE/GD is that if I blow the coupler off a charge pipe on pure SD vs. you and your MAF/SD hybrid... I will at least be able to drive home like an NA.
You will be swearing and shouting till you find your boost leak or you have to suck it up and go into "limp home" mode.
MSILV You are right on the money, load will be different in different gears. This is the same reason the turbo spools sooner in 4th than in 2nd. This is the same reason why you need to monitor TPS voltage in your datalogs.
There is a tuning algorithm called "Alpha-N" which is based entirely off of TPS and that determines the load range on the VE map, and this is notoriously unrealistic for boosted applications. This is where MAF and SD system prove to be superior. Because they are actually metering and calculating the air entering the engine.
Alpha-N relies on the oxygen, knock and EGT sensors, but those are all reading the conditions during and after combustion so the first few pulls when tuning a new motor can be nerve wracking because you have to hope you are running rich enough but not too rich, because those sensors can't really tell you anything until it is almost too late if it doesn't just go boom..
BnD You really won't see any gains from just an injector swap unless there is a huge difference in the ability of the new injector to atomize the fuel and disperse it in a wider arc to mix with the air charge. Even then on a 1.5L there is little gain to be had from injectors alone.
z06dustin Narrowband simulation or lock the voltage and tweak the DA tables accordingly in the cells that are involved in a typical boost sweep.
Texas Coyote is working on installing his Meth kit now too, so it looks like we may have entered a new era in Fit tuning...
One of the couple advantages you have in tuning your GE as cruel a mistress as they can be, is the MAF sensor.
Maf Hz/Voltage output is literally engine load. It is a direct measure of how much air enters the engine and really cuts down the time it takes to plot your VE map. Most MAFs now come with an IAT and a Baro sensor so it will even correct your VE based on those two and their associated correction factors!
Which is pretty handy vs. my GD and its pure Speed Density setup. But there is also the possibility that you will over run your MAF and the signal becomes choppy which means timing and fuel delivery can become erratic. This can lead to dangerous lean fluctuations under load. Which is why you have to hide the positive manifold pressure and extra flow from the ECU so it doesn't freak out.
How close are you to your Max Hz/Voltage now?
Another little differences between GE/GD is that if I blow the coupler off a charge pipe on pure SD vs. you and your MAF/SD hybrid... I will at least be able to drive home like an NA.
You will be swearing and shouting till you find your boost leak or you have to suck it up and go into "limp home" mode.
MSILV You are right on the money, load will be different in different gears. This is the same reason the turbo spools sooner in 4th than in 2nd. This is the same reason why you need to monitor TPS voltage in your datalogs.
There is a tuning algorithm called "Alpha-N" which is based entirely off of TPS and that determines the load range on the VE map, and this is notoriously unrealistic for boosted applications. This is where MAF and SD system prove to be superior. Because they are actually metering and calculating the air entering the engine.
Alpha-N relies on the oxygen, knock and EGT sensors, but those are all reading the conditions during and after combustion so the first few pulls when tuning a new motor can be nerve wracking because you have to hope you are running rich enough but not too rich, because those sensors can't really tell you anything until it is almost too late if it doesn't just go boom..
BnD You really won't see any gains from just an injector swap unless there is a huge difference in the ability of the new injector to atomize the fuel and disperse it in a wider arc to mix with the air charge. Even then on a 1.5L there is little gain to be had from injectors alone.
z06dustin Narrowband simulation or lock the voltage and tweak the DA tables accordingly in the cells that are involved in a typical boost sweep.
Last edited by DiamondStarMonsters; 03-21-2011 at 02:46 PM.
