Feedback for my custom AFC project

[txkprotege]

That'd be sweet, I have no use for this but I want it

[Lex]

As I mentioned, we had a few dyno runs today with our AFC - and it worked great. This was all for proof of concept so we ran a baseline where the car peaked at 113 whp, then we made everything rich and lost power (110 whp) then we made everything lean - made some power, and then on our last run, we attempted a mild tune and got 117 whp. In other words, our unit works!! I will post dyno videos, pictures and graphs in the next couple of days.

From here on, we are going to implement a couple of more small features, design a new pcboard, design a new case and a first version of the product will be coming out! I am not going to metion an exact date for this as final exams are coming up and I am doing my GTX swap later this month, and I am starting a new job in may. I would suspect a couple of months before the new product is ready to go and tested on a BPT motor (my GTX).

Stay tuned for the dyno graphs, pics, and vids and thank you for all your support and suggestions.

[D323]

Awesome! Congrats man... that is truly impressive.

[pigeon]

hey man, i was just wondering how fast this unit reacts...

for example, say someone double clutches down a gear, during the throttle blip... would it be quick enough to respond ?

[redfox]

if you want to test it out on a gtx motor with the gtx harness and ECU id be happy to be a test subject. after all your only a ferry ride away

[Lex]

Alright, so I am going to answer a few questions, then post the dyno data. In terms of response time of our unit, it responds within 1 ms, tested and scoped in the lab. This is a lot faster than any of us can push down the throttle, faster than the time between two ignition events of a motor spinning at 8000 rpm. So in terms of timing, our unit is plenty fast, and like I said, we've been driving it around with it and have tried it in many conditions on my friends prelude. No problems there.

Redfox, thanks a lot for the offer. I will keep you posted if we need any more test subjects.

I am also quite interested in testing our unit on some MAF sensor vehicles (as long as they have a 0-5V sensor range - a limitation we have for now)

Anyways, on with the dyno data.

The first graph here shows three runs, horsepower and A/F ratios. The 113 hp run is a baseline, the 101 hp run is when we ran her at 110% (too rich) across the board and lost power. Finally, the top run is when we did a mildly tuned run and got 117 whp at peak and close to 10 more whp at the top of the RPM range. His motor is basically stock with an intake (and does not take as much advantage of the AFC as a modified motor would) so we were happy to get those improvements. So, like I said, our unit works and imagine the gains on a modified motor. We could have squeezed more power out, but had to get off the dyno and tuned for performance only on the last run. Our unit as you can see was very effective in changing his A/F ratios.



This next one shows the same runs, but has torque on there as well



Videos still to come, unfortunately it's not a protege on the dyno.

[redfox]

yummy yummy

[D323]

w00t! Thats pimp dood.

[redfox]

any update on this bad mofo?

would be badass if later on you could take 1 of these units and add a boost controller and EBC to it...then there wouldnt be such a cluster**** of electronics in my car :\

[EGT95turbo]

Just to answer a few questions:

The unit will hook up to the power, TPS, O2, and tach signals of the car. It will splice between the air flow meter and the ECU. This hookup is very similar to the Apexi. So, wiring will not be a very difficult, but a couple of wires will have to be spliced. Install instructions will be provided.

Using the TPS signal to add fuel isn't the best way. I installed a 4-wire TPS (auto cars) into my car so I could have the variable signal going to my S-AFC. Fuel was added far before the turbo was spooled and resulted in backfiring upon quick throttle closing while under boost.

Why not use an MAP sensor to trigger fuel? Works really well in my S-AFC setup.

Jess

[atomicEGT]

Why not use an MAP sensor to trigger fuel? Works really well in my S-AFC setup.

that's a really interesting idea- you don't happen to have a write-up on this, do you?

[Lex]

The unit does use an AIRFLOW signal to trigger fuel, not throttle position. You can calibrate 2 curves however, one for low throttle and high throttle - but those curves are based on the airflow signal. It works very much like the SAFC. You can use your existing VAF as well as use a MAP sensor that is hooked up to the computer as your airflow sensor.

I am assuming you have removed your VAF and are running a MAP setup.

[EGT95turbo]

The unit does use an AIRFLOW signal to trigger fuel, not throttle position. You can calibrate 2 curves however, one for low throttle and high throttle - but those curves are based on the airflow signal. It works very much like the SAFC. You can use your existing VAF as well as use a MAP sensor that is hooked up to the computer as your airflow sensor.

I am assuming you have removed your VAF and are running a MAP setup.

Nope, still running the VAF but the S-AFC modifies that signal based on MAP sensor readings rather than TPS position. This way the fuel is added as boost pressure climbs rather than as soon as you put your foot down. Part throttle, high boost situations can result in a dead engine if the throttle is only partially depressed. Simply put, you can't tune the AFC well with TPS position since our N/A ECU has no clue about the extra pressure.

On a N/A engine with bolt ons, the variable TPS signal from an automatic equipped car might be just as easy as a MAP sensor and work just fine.

Jess

[Lex]

EGT95Turbo, perhaps you don't understand the principle behind the AFC. Like I said before, it is NOT actuated by the throttle - it interrupts the airflow meter (whatever the type) and multiplies it by a user-preset value for each 250 RPM range. So fuel delivery increase/decrease is triggered by engine load (ariflow meter value) at a certain RPM, not by the TPS.

[EGT95turbo]

EGT95Turbo, perhaps you don't understand the principle behind the AFC. Like I said before, it is NOT actuated by the throttle - it interrupts the airflow meter (whatever the type) and multiplies it by a user-preset value for each 250 RPM range. So fuel delivery increase/decrease is triggered by engine load (ariflow meter value) at a certain RPM, not by the TPS.

You are right, I didn't read through the entire list of messages to understand your project. I saw AFC and thought Apex'i S-AFC. I know the Apex'i unit inside and out and it does use a TPS signal to control fuel delivery. Unless you fool it like I did by installing a MAP sensor in place of the TPS signal input.

Still, the VAF door opens VERY quickly. As soon as you step on the throttle, even 30-40 percent to accelerate, the door swings nearly wide open. Are you running your AFC project or have you tested it? I doubt you'll get the results you seek if fuel if controlled by the VAF signal. A MAF system might be different.

Good luck figuring it out and tuning it. Sounds like a fun project.

Jess