Does anyone know how to tune Port injection? My tuner said it my AIC-6 needs about 30% cycle reduction.
Port Injection tuning
- Thread starter NoGuru
- Start date
I am running an E45 map with new HPFP, Walbro 535 and Walbro 450 on Hobbs set to 15psi with Bosch 550cc PI.
Dimitri at BQtuning is my tuner. He stated he does not tune PI as it is "too risky".
Dimitri at BQtuning is my tuner. He stated he does not tune PI as it is "too risky".
Interesting. I know he is good with DCT cars, but that wouldn't make me feel to comfortable. Some tuners are not PI fans, but will still tune a setup with it. Do you have the split second R4 software already downloaded? Hopefully someone familiar with the software to help on the tuning side of things. Also any idea what map you are currently running on your AIC?
If your tuner won't/can't tune PI, then you need a new tuner.
I heard he's a good tuner esp with DCT but I can kinda see his point in how it can be risky. It's not like tuning the oem injectors in which they're all calibrated. He definitely has the skill for PI but doesn't want to deal with the liability for stuff like non-flow matched injectors and such.
But then again, I would never send out a tune if I had to make the customer do a major part of it....
@NoGuru maybe its time for you to level up and create your own bin? If you can figure out the ancient UI that is the SS R4 controller, you can definitely pick up on TunerPro
Lets have the community build a tune for you lol
But then again, I would never send out a tune if I had to make the customer do a major part of it....
@NoGuru maybe its time for you to level up and create your own bin? If you can figure out the ancient UI that is the SS R4 controller, you can definitely pick up on TunerPro
Lets have the community build a tune for you lol
I am on the fence about having the tuner, tune the PI. On one had it is his job to tune, on the other hand, he risks his reputation if something does go wrong.
I am flow matched and I am pretty handy when it comes to working on the car or anything that is software related.
I have been strongly considering Tuning myself, problem is where to start? Maybe I will take a class at HP academy.
I am flow matched and I am pretty handy when it comes to working on the car or anything that is software related.
I have been strongly considering Tuning myself, problem is where to start? Maybe I will take a class at HP academy.
Well you’re in luck then. The N54 imo is one of the easiest platforms to get a grip on. On the MS43 dme you have to tune fueling via ipw or injection pulse width and that can be a real pain in the ass without a dyno to maintain certain loads and rpms.
All you gotta do is follow some direct injection fundamentals and be smart about afr’s certain blends and types of fuel require to make good safe power. 25+ psi on E70 and above fueling you’re looking at around 11.8 afr @ 7-8 degrees of timing. If you want I can send you my modified guidelines for N54 tuning
The only tricky part that needs experience to master is the WGDC and VANOS maps. Everyone has their own style on how they adjust them so basically adjust it to your liking and take it slowly. It’s pretty hard to cause a major overboost without purposely setting each map insanely high. The guidelines will guide you on vanos and such
Also i’m assuming you’ve got tons of logs already so you can already get a head start on stuff like fueling, timing and vanos. You paid for your tune and there’s nothing that says you can’t view your own logs and make a personal tune out of them.
Yes please! This is the best post I have read in forever. Please send the guide and I will start studying ASAP.
I have taught myself how to do a lot of things so I have full confidence I will be able to do this after some practice and study.
Is your tuning guideline available to anyone
? I have an n55 which I self tune and one area I would like to adjust/ learn is vanos changes. The requested values for intake and exhaust are smooth but the actual values are very jagged, which makes me think I need to adjust both. Just don’t know where to start. Searching around for information on tips or rules of thumb for tuning PI via AIC and came across this thread. Of course, as it turns out, i was the last to post over a year ago! lol
I have been tweaking my AIC map and am wondering if anyone has any tips/ rules of thumb to follow. Here are just some of the random questions that maybe someone has an answer to..
1. How early do you have the PI start spraying? I know this is hugely turbo/setup dependent, but do you have a very small amount start at 9psi so fuel consistently goes through the PI rail and to slowly bring in the PI fuel flow?
2. Do you account for injector dead time? I just learned about this. I believe it is the amount of time from closed to opened that a certain sized injector takes to open under a certain voltage and fuel pressure. My injectors have around 1ms dead time at 14ish volts. My AIC PI map had starting values of around .1 at 8ish psi to start progressively spraying fuel (I thought I was so awesome by having a really smooth ramp up). However, I just learned that the values entered in the R4 software are milliseconds, and since my injectors have 1ms of dead time, I wasn't spraying any fuel until my AIC map had values of 1 or greater! whoops. This explained why I have a slight deviation in my afr (slightly richer than what I have in my afr table) at 15ish psi, because that is where my values start being greater than 1 in the R4map, which is when fuel actually started making its way through the PI injectors. I am thinking this is inevitable, since the additional fuel comes in at the dme needs time to adjust, but I also have never seen any other logs of cars with PI. Anyone have any to share?
3. Would love to hear anyone else's strategy to developing their AIC map.
I have been tweaking my AIC map and am wondering if anyone has any tips/ rules of thumb to follow. Here are just some of the random questions that maybe someone has an answer to..
1. How early do you have the PI start spraying? I know this is hugely turbo/setup dependent, but do you have a very small amount start at 9psi so fuel consistently goes through the PI rail and to slowly bring in the PI fuel flow?
2. Do you account for injector dead time? I just learned about this. I believe it is the amount of time from closed to opened that a certain sized injector takes to open under a certain voltage and fuel pressure. My injectors have around 1ms dead time at 14ish volts. My AIC PI map had starting values of around .1 at 8ish psi to start progressively spraying fuel (I thought I was so awesome by having a really smooth ramp up). However, I just learned that the values entered in the R4 software are milliseconds, and since my injectors have 1ms of dead time, I wasn't spraying any fuel until my AIC map had values of 1 or greater! whoops. This explained why I have a slight deviation in my afr (slightly richer than what I have in my afr table) at 15ish psi, because that is where my values start being greater than 1 in the R4map, which is when fuel actually started making its way through the PI injectors. I am thinking this is inevitable, since the additional fuel comes in at the dme needs time to adjust, but I also have never seen any other logs of cars with PI. Anyone have any to share?
3. Would love to hear anyone else's strategy to developing their AIC map.
The PI fuel rail will be full of fuel as it is hooked up directly to the lpfp fuel line. You split it off and have one line go to your HPFP and another to your PI fuel rail. Once the injector is given the 'command' to open then it injects.
IIRC most start to spray above 15psi. This means you don't get into PI when you are really not on the pedal, if that makes sense. You do the same with Meth. You don't want to be injecting all the time when you are not 'racing' just driving around town having PI/meth inject at 8psi as an example. Waste of fuel/meth. So you only want to inject at a PSI higher than what you would build normally driving around town at say 1/2 throttle or so, the logic being if you are past half throttle you want the car to move. Obviously throttle mapping will make this slightly different from car to car.
If you are triggering your 2nd LPFP from a Hobbs switch a general good practice that you don't want your PI to start to spray at the exact same PSI your LPFP is trigger to turn on as to not cause a low pressure fuel dip. Just use an adjustable Hobbs and set LPFP at 15psi and PI at 17 psi as an example. Or LPFP trigger at 13psi and PI at 15psi. Whatever you want.
Thanks for the reply.
One persons strategy on the 9psi was to ensure the mix of fuel you are currently running will always be in the rail. For example, if I was driving around on pump but then filled up with e50 and had my pi spraying at 15psi and my pump tine maxed at 13psi, when I upped the boost with e50 on the tank, I will initially be spraying pump since that’s what was sitting in the rail. Does it matter? I have no clue haha.
In your logs, when your pi kicks in, does your afr dip rich for a datapoint or two?
One persons strategy on the 9psi was to ensure the mix of fuel you are currently running will always be in the rail. For example, if I was driving around on pump but then filled up with e50 and had my pi spraying at 15psi and my pump tine maxed at 13psi, when I upped the boost with e50 on the tank, I will initially be spraying pump since that’s what was sitting in the rail. Does it matter? I have no clue haha.
In your logs, when your pi kicks in, does your afr dip rich for a datapoint or two?
I think you are reading into it a little too much. Most people do not change there Emix that often enough to notice any difference in the little bit of fuel left in the rail. I have 19T's so only slightly larger then stock, and I start spraying at 15 PSI but only because that is when I need the extra fuel.
Adjust the map according to when you need fuel. Remember the stock ECU will also try and compensate to keep the AFR's where they should be so you only need to make a few tweaks to the AIC to get the spray needed.
Adjust the map according to when you need fuel. Remember the stock ECU will also try and compensate to keep the AFR's where they should be so you only need to make a few tweaks to the AIC to get the spray needed.
Yep, that is how I run mine.Well if that is the concern run a return line with fuel pressure regulator
Yeah just slightly larger than the stock 10T
Last edited:
Thanks for the replies. It helps me I understand that I am reading too much into it. I haven’t seen many logs with pi and had no clue if my approach was good so I wanted to verify. Car runs great which is a good sign.
I am basically doing what noguru described above.
Currently, I am in denial that I will never need a fpr and return line, but I’m sure it’s in my future haha. With the 535, I am running e60 at 600ish whp with zero issues, so I am in the clear for now.
I am basically doing what noguru described above.
Currently, I am in denial that I will never need a fpr and return line, but I’m sure it’s in my future haha. With the 535, I am running e60 at 600ish whp with zero issues, so I am in the clear for now.
