EFI Tuning - How to Process Description

[mikesarge]

I like to think my several very stupid emails to Jamie helped spur him to publish this

mostly kidding, I know I'm not the only one who bumbled through their first EFI conversion using the vast resources of this forum, and reaching out to Jamie and others directly.

I and everyone else who will undertake an EFI conversion on this platform deeply appreciate all of your work to put this in one place, and your willingness to share your hard-fought knowledge for free.

This is the manifesto of how you can explain it to others, but you cannot understand it for others. Thanks Jamie!

[jpnovak]

Thanks everyone for the compliments. I will continue to refine some of the topics.

And I am still trying to fix the missing pics. they show loaded but don't actually show in the posts.

[Cloggie]

This is fantastic and could not be more timely for me...just starting the engine build with a Rasant provided Motec M130 - and who are now no longer in business - and tuning it scared me to death.

This gives me a lot of confidence and great detail, particularly with the Porsche specific points of view.

Subscribed.

D.

[wallra]

this is great for street tuning also https://evansperformanceacademy.vhx.tv/aem-infinity-training-course/videos/aem-infinity-part-39-megalog-viewer-hd-software works with aem infinity 506. helped me get my tune right. If the link don't work check it out on youtube. I see you can't see this because you need to pay. this guy helps a lot with tuning every ecm. evens performance.

[winders]

I would recommend tuning using Lambda instead of AFR. Lambda is what the sensors actually measure and AFR is calculated from that value using a fixed stoichiometric ratio. With is 14.7:1 usually used for gasoline. The actual stoichiometric ratio for the fuel may or may not be 14.7:1. By using Lambda, you don't have to worry about that.

[fanaudical]

Wow - Thank you! Subscribed! Maybe make this a sticky...

[onboost]

Good stuff Jamie, it should be very helpful as I head down this "dark desert highway, cool wind in my hair.."

Thanks for posting!

[EPorsche]

Subscribed

[mb911]

Working through this now and Jamie has been extremely helpful

[jpnovak]

I admit that Lambda can be useful for some. but my brain does not think in Lambda. I always feel like I am trying to calculate the ratio of actual AFR to stoichiometric AFR on the fly. that is too much real time math for me.

You are correct that 14.7 is considered stoichiometric for true n-heptane reference. Actual gasoline is usually E10 and has approximately 14.3 equivalent. It all changes based on true composition and octane rating. And yes, the tune must be compensated to allow for that.

Everyone is welcome to change their software to represent whatever units it can be programmed to handle.

[charlie.tango]

Is there a site or a repo of base/custom maps for MS that one can download from?

[brighton911]

Jamie, thank you for your very generous and comprehensive contribution(s) to the EFI cause. It's a fun learning journey that challenges one many a time. Never stop learning.

[safe]

If EFI and tuning it seam daunting, load it up on a trailer and take it to a tuner. He'll fix the tuning in half a day up to a day and get you 95% of the way, the important stuff. You only have to concentrate on fitting sensors and wiring. I've seen carb tuning taking way longer than that and still not working good....

Then you can skip 90% of page number 1, no offence to Jamie.

I've done that to all of my 3 converted cars, if there is small issues left I can adjust that myself later, like fine adjusting cold starts etc.

Learning to think in lambda instead of AFR is useful. Lambda 1 is always lambda 1, no matter what fuel.

[shamrok]

Originally Posted by jpnovak

everything EFI

This is a massive effort Jamie, thank you! Glad to see this consolidated into one post. It's encouraging to read through and know that I think I did it correctly? lol

Originally Posted by charlie.tango

Is there a site or a repo of base/custom maps for MS that one can download from?

When I was cobbling mine all together, I thought using a base tune would help but I feel it hurt me more than anything. In order for another tune to work with your car you need the same variables to line up. Same ignition, same injectors with same deadtime, same sensors with the same calibrations, same fuel pressure, same wideband calibration, etc.

A base tune may help you rough it in, but I felt I was chasing my tail quite a bit and ended up just doing my own from scratch after learning what all the settings do. TunerStudio has a massive support network with great documentation, which is the primary reason I went with Microsquirt. But as Jamie says, the concepts are the same regardless of the ECU. I feel I could confidentally tune another type no problem.

[jpnovak]

Magnus is exactly right. Ultimately, you need to know your skills and your limits.

I realize that there are many members here that are fully capable of installing and tuning EFI. There are a lot of documented success stories out there. I just felt like there were some missing details that would make the difference in either making the decision to get started or to remove a barrier once they have started.

I also agree that if you start with a base tune you are missing some of the learning process of how EFI files are setup. @shamrok is exactly right. There are lots of options for igntion, induction, engine build, Mainfold, wiring, etc that you should read up on how to set parameters. This does make a difference in the final outcome. Even more so if you get stuck but don't know which figurative button to push to get unstuck.

[safe]

Even though I'm confident in my skills to wire, setting up and getting an EFI running. I have limits, Its not easy or safe figuring out on the street if you can run 26 or 28 degrees of timing @WOT.
That you do on a dyno, so its just not worth the effort to do anymore tuning than you know that it works and revs up and can drive onto a trailer or to the tuner if its close. I like the trailer idea... with a winch....
There is plenty of stuff on the internet you shouldn't trust, fuel and ignition maps from other engines is one of them.
A simple thing as two injectors with the same flow rate but different brand/type doesn't necessarily flow the same amount of fuel. Or the exact same injectors might not flow the same on different engines because the voltage output from the generator isn't the same.
Having someone tune the engine on a dyno is the best money ever spent with EFI.

My 924 in the signature is getting back on a dyno in the spring after a clutch change so I can up the boost. Not something I would try on my own because its quite close to knock as it is.

[Joesmallwood]

First of all, THANKS, Jamie, for this outline. You, and this, have been very helpful in helping me work through the basics of tuning my EFI install. There is still a lot of things to learn as I continue to tweak the edges and find new nuances.

However, in my continuous quest for EFI info, I decided to ask ChatGPT what her/his thoughts are and this is the result:





FWIW, I also asked ChatGPT to help me write an arduino program to convert CAN bus data and display engine parameters on a small LCD. It was actually helpful, but it's still a work in process.

[icarp]

joe, you know what i think , yikes

ian

[safe]

There is reasonably priced CAN-displays readily available, for example: "CAN-Checked". Better ECUs have bluetooth interfaces so that you can connect any phone or tablet.

[Joesmallwood]

Originally Posted by safe

There is reasonably priced CAN-displays readily available, for example: "CAN-Checked". Better ECUs have bluetooth interfaces so that you can connect any phone or tablet.

My goal is to have a super small form factor display on the dash where the seatbelt/brake light is. It's about 1.5" x 3/4". Plus, I'm just trying to learn a little about arduino and CAN so it's just a fun project. We'll see how it goes. I may end up aborting and finding an off the shelf solution to fit where the clock is.