Even Some Professional Tuners Get Transient Enrichment WRONG 

✅ Building a fast car? Get $400 OFF the all-inclusive VIP online course package deal: hpcdmy.co/vipy113 ⚡ Kickstart your EFI Tuning knowledge. Get 50% OFF your first online course: hpcdmy.co/offery113 🚨Want to learn how to EFI tune a standalone ECU like the Haltech we use for this example? Start with some free lessons right here: hpcdmy.co/EFI101y TIME STAMPS: 0:00 - Introduction 0:50 - Why we need transient enrichment 8:40 - Fuel/VE table must be correct first 11:50 - Transient ignition trim 12:50 - Setup walkthrough 17:55 - Async vs sync enrichment amount 20:45 - Transient throttle control parameters 28:25 - Tuning demonstration 35:30 - Questions

This is THE most underrated car channel on youtube. A lot of the things I've learned here as well as applying this knowledge to tinkering with my own car has allowed me to have a much deeper understanding of how EFI works that has even led me to fix cars on the OEM world that others had given up on for having strange issues. I also can't even name the amount of times where someone like me, who has no dynamometer has cleaned up fuel maps by "tuners" who only care about that wide open throttle run. Getting the car to run much better from cruise to medium throttle and gain a lot in fuel economy.

It's not just "some" tuners that forget about it or don't understand it, it's many! I myself have owned a GTR for the last 13-14 years and it's been through many different tunes and computers and to date it's only been myself and one other tuner who understand the concept of transient enrichment. I've found that many a tuner would either just enrichen the base map to a level where these lean spots get cancelled out but give your horrific economy, or they would just ignore the area of tuning altogether and then spin you a story about why the motor is lethargic every time you press the loud pedal. My best experience with the later was that it was my "twins" and that a "single" would fix it ;-) Having this area tuned by someone who knows what they're doing makes a difference like night and day, especially if you turn the feature on and off while driving and it makes you wonder just how many people out there could be getting so much more out of their pride and joy in every day driving...

Indeed, acceleration enrichment is one aspect where it is much more difficult to get as accurate as one could be for a fueling table. The thing to keep in mind is that engine response must be the main criteria, AFR/lambda is not helping much and could show some delay depending on the oxygen sensor location on the exhaust

In a Chevy type EFI or MAF plus MAP tables, you can easily affect transient fueling. If you can run MAF only and Open Loop, make the MAP/VE table slightly richer. This will provide richer fueling immediately when accelerator is pressed and is very tunable. For racing situations I don’t recommend Closed Loop. Open Loop will also allow you to easily control your deceleration AFR. You should not go for emission type tuning on deceleration, it should only stay close to 1 lambda and just a little lower to cool intake and exhaust while decelerating. This is an often overlooked and little known way to keep boost on tap and keep engine cooler. Awesome video!

Holy shit, I'm dealing with this now on my viper and the Tuner is THE Tuner for vipers.

Since I’m old school this must be the accelerator pump in a carbureted engine but since it’s fuel injected you can dial it in instead of the diaphragm pump just throwing fuel in.

I tried to get the megasquirt wall wetting algorithm to work for a while. But there is so many variables that I never did get it quite right, reverted back to tps based for now. I was only road tuning so I suspect on a dyno I might have more success.

Was told that for sequencal injection best to use sync and with batch fire to use async I'm just learning more details about it as struggling to sort table

thanks for everything you guys do…

Here i am a whole year later to ask another question. Great video as customary HPA team🏆 my question stems from a comment i heard made at an EFI convention talking about tuning accell Enrichment. The person speaking said they like to tune the initial tip-in AFR to the same AFR target as WOT. For example, if WOT was set to 12.2:1 set the initial tip-in to 12.2:1. what are your thoughts on that? Thanks

Solid video

Andre, excellent demo man. Carburetor tuning is another thing that will really help people understand the tuning. It's far more time consuming and nuanced but a necessity just the same. Tuning of the 4 parameters takes experience but is priceless in EFI tuning. It's based on the accelerator pump and jetting. Carb throttle plate position dictates fuel flow entirely based on resulting airflow. Carbs are brilliant when you think about what they do. They can be tuned to match EFI efficiency at a given ambient pressure.

I am confused on what the values in the enrichment rate table do vs values in the enrichment amount table. Are they not both doing the same thing? Or what is the enrichment rate actually doing and how do you look at the rate vs amount table when tuning them?

Great Video, thanks a lot! Is the Nissan SR20 an engine where you would activate async enrichment?

Is transient throttle used for throttle blipping in idle? Or when in decel and back on pedal? Whenever I accelerate after a decel, it feels jerky and hesitant.

watch out for smoothing factor on the AFR log / plot. might "eat up" the lean spike. sensor response time and sampling frequency also plays a major role.

Awesome vid - does this apply still for direct injection engines?

Getting this correct on my Sunny GTi-R with ITBs was a real pain

TPS get old and lazy and put out dirty signals, sometimes they output dirty signals when new and that's when some RF shielding of the TPS wires are needed. That could also be a reason for the erratic fueling. A few questions... 1. Are manifolds that have the fuel injector firing upstream in the runner better or worse when tuning transient? 2. Would it be proper to tune the overrun areas of the VE table to not inject fuel at all instead of tuning decel transient? Thanks - Pantyeatr1

How is it with direct injection, just curious

As always, excellent info

Thanks again for your time

The holley xp ultra 850dp has awesome transient enrichment.

Understanding it is 1 thing... Having facility to tune/iron it out consistently is another thing... This is where hub dyno with speed/rpm/load holding capability plays important role in tuning the backside of the driveability mapping

Throttle tip in enrichment / transient throttle was something I understood in theory but not exactly sure how to tune for. mostly just by seeing the initial afr during initial throttle application, if it leans out too much, then add the value until it reaches a point where its minimized, but i find leaving it a little lean gives better power.. though it may mean that ignition advance during throttle tip in can be optimized further.

This video is one of the most important I've ever seen, thank you!

Outstanding content ... Thank You for sharing .. cheers :)

👍🤙

I have dialed in Accel enrich for RPMs above 2k. But lower RPMs no matter what I do the engine still hesitates under almost any amount of throttle jab. The engine is big cam 6.9L LS3. I wonder if its because of the big TB and big displacement ?

if the enrich amount is 50 and the sync amount is 100 at a specific cell you will get 100% of 50 is this true

This was the most timely session. Will be trying some adjustments

I know this isn't really the best place to ask but I'm serving a Facebook jail sentence at the moment lol. But do you guys cover what the "P term" and "D term" terminology is supposed to mean in Holley EFI software? It's under the ignition timing section of the idle tab in my Terminator X software. The owners manual and Holley themselves weren't much help. Surprise....