fuel cut defencer for 2gen turbo

[riff22]

just wondering if anyone has done this mod?wwww.gc.dsm.org/faqs/2gdefencer.htm if so what exactly does it do i have a 2 gen turbo and im running very lean, wondering if this would fix it? it says make sure the air/ fuel gauge dosent go past 14.7? my guage dosent have numbers?
thanks

[JoeWagon]

The link doesn't work, but a fuel cut defencer puts a cap on your airflow signal so that the ECU never sees fuel cut. It's not a good idea because if you ARE flowing air, and not letting the ECU see it, you are going to run lean. Unless it's a new option, a FCD doesn't do anything with a/f ratio directly.

[riff22]

www.gc.dsm.org/faqs/2gdefencer.htm

[kjewer1]

Not a good idea for our cars.

[mavisky]

what you need is more fuel. your ecu is already throwing all the fuel it can at the motor and you're still running lean. what you should get is a nice set of 550cc or 660cc (depending on your goals) injectors and a good way to control them such as an apex's S-AFC II or better yet DSMLINK.

[riff22]

its stock tho???

[riff22]

its stock tho it shouldnt need more fuel, correct?

[96TSi]

Originally Posted by mavisky

what you need is more fuel. your ecu is already throwing all the fuel it can at the motor and you're still running lean. what you should get is a nice set of 550cc or 660cc (depending on your goals) injectors and a good way to control them such as an apex's S-AFC II or better yet DSMLINK.

i must agree, the best defence from fuel cut is more fuel flow.. think about it. dont try to "hack" past it with some engine killer's idea. Fuel cut is there for a reason.

[mavisky]

Originally Posted by riff22

its stock tho it shouldnt need more fuel, correct?

check my reply in your other thread.

[kjewer1]

The ONLY thing that affect fuel cut is airflow. Fuel has nothing to do with it. The ECU has NO idea how much fuel you are flowing... And the fuel cut point has nothing to do with the stock fuel systems limits. All kinds of myths being kicked around here!

I think the "FCD" in question (I didnt look at the link) is just the fancy name being applied to a resistor on the baro or IAT signal line. Pisspoor way to tune. I would avoid. You can benefit from leaning out slightly on the stock maps (if the car is in perfect running order), but its better to do it the right way. DSMlink, AFC + logger, etc.

[96TSi]

wow i didnt know that, i guess i was slung into the "myth" along with alot of people

[mavisky]

Originally Posted by 96TSi

wow i didnt know that, i guess i was slung into the "myth" along with alot of people

here's what's happening. if you're hitting fuel cut, and you'll know cuz its like rearending someone for a split second, then you're simply flowing more air than the car's ecu can understand so it pulls the ignition and you get a big buck. what you can do is switch to larger injectors (which you probably need at this point anyways) and then using an s-afc or dsmlink you will pull away from the airflow reading. for instance 550cc injectors are 22% larger than your stock 450cc injectors so you will be taking away roughly 22% of the vehicles airflow to make the injectors idle and run at a decent level in lower rpm ranges. basically you lie to the computer as far as how much airflow its really seeing. the mass air sensor still reads the high airflow numbers, but before that reading makes it to the computer the s-afc or dsmlink (or whatever other device you use) lies to the ecu and essentially hides a percentage of that airflow putting you back underneath the ecu's "fuel cut limit".

[96TSi]

thx for the info

[kjewer1]

A little more of my nitpicking, then I'll stop, I promise! The ECU has no limit to what it can "understand" for airflow. I'm running double what the fuel cut limit is, or more, and the ECU works perfectly. Another thing is 550s are 18% larger than 450s, as far as compensation goes. Old injector divided by new injector, minus one. Minor issues, carry on.

[mavisky]

yea my math sucked there, didn't seem right when i did it the first time.