about Fuel cut Defencer

[ARPN]

im about to buy a HKS fcd but i need to know wich type does my car use, i got a 97 vr4 ec5a automatic transmition, i saw a few standars fcd on ebay TYPE I i want to know if this would work for my car ? many thanks

[Kieran]

Moved to Performance Modifications forum ;)


I thought, assuming the FCD uses the same naming conventions as the EIDS that you'd need the 'Type K' version. However, I'm not sure.

My first response would be however to question why you want a FCD? Have you got a way of monitoring your fuelling to ensure that you won't lean out and go pop?

[Wodjno]

My first response would be however to question why you want a FCD? Have you got a way of monitoring your fuelling to ensure that you won't lean out and go pop?

As Above :thinking:

[ARPN]

iam modifing my car, i got the complete 3 inchs exaust with 2.5 down pipes, EVC III boost controller, 2.5 inchs pipes and 3 inchs inlet outlet intercooler, hks turbo timer, 255 walbro pump, im runing at 14 pounds of boost, that would be 1 bar, but they suggest me to put a FCD so i can get more out of my boost. what can i do ?

[Wodjno]

iam modifing my car, i got the complete 3 inchs exaust with 2.5 down pipes, EVC III boost controller, 2.5 inchs pipes and 3 inchs inlet outlet intercooler, hks turbo timer, 255 walbro pump, im runing at 14 pounds of boost, that would be 1 bar, but they suggest me to put a FCD so i can get more out of my boost. what can i do ?

Still the same question ?? If you haven't got anyway of monitoring AFR's then it is not a good idea.. :inquisiti

[ARPN]

this FCD its for the ecu´s car not to shut down the engine on high boost pressure.

[Wodjno]

this FCD its for the ecu´s car not to shut down the engine on high boost pressure.

And you won't hold more than 14psi of Boost on Standard Turbo's :speechles

[ARPN]

what is a AFR? woodjno, iam crazy looking for a ECU that i can tuned my engine with, for this car, but i cant find it any where, i got a friend in japana who suggest me the trust emanage, but i think this is a piggy back

[bradc]

Wodj is right, if you don't have a way of monitoring your AFR then it isn't a good idea at all, because you just don't know what is going to happen!

AFR = air to fuel ratio

[ARPN]

im planing to run my car with 0.8 bar and 55 shot of nitrous, i think im goin to need the fcd and the speed limit defencer, what do you think wodjno?

[Wodjno]

what is a AFR? woodjno, iam crazy looking for a ECU that i can tuned my engine with, for this car, but i cant find it any where, i got a friend in japana who suggest me the trust emanage, but i think this is a piggy back

AFR is Air Fuel Ratio... And you don't want this going to Lean or Bang Go's your Engine :thinking:

I have an E-manage fitted to my car and yes your right it is a Piggy..

You can fit alsorts of ECU to your car ?? At the end of the day an engines an engine and can be mapped with any ECU whether Piggy or Standalone..

There is a group buy on A MAP ECU on this site at the moment.. I'll post the link in a minute..

[ARPN]

bradc i think i might blow the turbos hehhehee i did it once, i was runing at 17 pounds of boost they blow, i have to replace them but i put the stocks ones again.

[Wodjno]

bradc i think i might blow the turbos hehhehee i did it once, i was runing at 17 pounds of boost they blow, i have to replace them but i put the stocks ones again.

http://www.clubvr4.com/forum/showthread.php?t=21936&highlight=map

But you will still have to take it somewhere to get it tuned..

Where are you ????????????????? :inquisiti

[ARPN]

wodjno are you running on stocks turbos ? if so on how many bars ?

[ARPN]

iam from the dominican republic thats in the caribbean, but in the case that i buy something can be ship to miami, florida

[ARPN]

i can get it tuned that no problem, the think is, that a piggy wont let me manage many things on the engine.

[Wodjno]

wodjno are you running on stocks turbos ? if so on how many bars ?

Stock Turbo's

Boost on high Peeking at 1.2 and holding 1bar to 5000rpm and then settling back to 0.95 bar by redline ...

[Wodjno]

i can get it tuned that no problem, the think is, that a piggy wont let me manage many things on the engine.

The E-manage Ultimate will let you manage everthing !!

[ARPN]

where can i buy that ecu ?

[Wodjno]

where can i buy that ecu ?

You can buy the E-manage from E-bay or i can supply.. Or you can go for the MAP ECU in the link i posted... There other options to.. !!

[Wodjno]

See here: http://cgi.ebay.co.uk/GREDDY-E-MANAGE-EMANAGE-ULTIMATE-BASIC-UNIT-IN-STOCK_W0QQitemZ270036189357QQihZ017QQcategoryZ4312 0QQssPageNameZWDVWQQrdZ1QQcmdZViewItem?hash=item27 0036189357

[ARPN]

i read a little about that V2, and im goin to think about it, ill might be interested in that one.

[Wodjno]

Nice 1 :D Hope you can get a good tune on your engine... Have you had any power figures for your engine ???

[ARPN]

nope over here we dont have 4wd dynos :(, but i think my car its runing really good, the other day i race a 2004 m3 smg transmition, and i beat it for 2 leghts.

[Wodjno]

nope over here we dont have 4wd dynos :(, but i think my car its runing really good, the other day i race a 2004 m3 smg transmition, and i beat it for 2 leghts.

Thats a good result :scholar: But as to be expected to /rally

[ako]

Back to the topic as such -

I've always understood (and sold) the FCD, in fact almost any kind of fuel cut defender, to be a device which stops a signal exceeding a given VOLTAGE value, nothing more.

Works fine on anything MAP sensored - RX7's, most turbo toymotas etc

Mitsubishis use an air flow meter which puts out a FREQUENCY - all this is doing is clipping the tops of your voltage waves isn't it? Nissans, mazdas, toyotas etc put out a voltage signal from their AFM when they have one, we got the bung end of the stick here :)

Its not doing anything to the AFM signal except butchering it, as opposed to doing anything actually productive.

If I'm wrong there, correct away. Haven't ever personally used them, would rather an S-AFC if a quick fix is needed.

[Kieran]

Not quite sure that's right Ako. Pretty sure the MAF works on a 'hot wire' principe in our cars, so it's a voltage that's sent to the ECU rather than a frequency.

[Wodjno]

In basic Terms, the VR4 works on frequency Hz, Mazda works on the hotwire route(voltage)

And FCD is blocking the ECU on our cars by limiting the signal from the MAF, from seeing any higher frequency than it is pre programmed within the ECU.
The reason this is bad, is that we can then Add more air through Boost than our MAF can read, but the problem is our ECU and Fuel Pumps may not be able to match the right amount of fuel to the amount of air that is being inputted.
What this means is there is a great chance that our engines will then lean out(Not the correct Air to Fuel Ratio,AFR) meaning to much air and not enough fuel. ( A bit like not enough Vodka with your Tonic)This will then overheat the pistons and in extreme cases cause failure through the melting of piston rings or the pistons themselves!!
The only way of being certain this is not happening, is by the monitoring of the Air Fuel Ratios(AFR's) via a Wideband 02 sensor/controller, such as the LC-1( www.innovatemotorsports.com/products/lc1.php ) This way, you can be sure that the engine is not going to be damaged...

But as above !! Correct me if i'm wrong :speechles

[ako]

I get the whole "too much air not enough fuel = new engine" idea...

What I was getting at was I thought the FCD only is a voltage clipping device, i.e won't go over 6V / 5V / whatever you set it at. So that a car which is MAP or hot wire sensored and has a fuel cut at say 5V, you set your FCD to 4.95V, no more boost cut on cold nights or whenever. I had one in my turbo honda city of all things :p

Since mitsi's work on a frequency not a voltage, think of it this way - you have your sine waveform coming out of the AFM. Varying from say, -5V to +5V. If you put in a FCD which is only clipping voltages, all your doing is butchering the top of that waveform, making straight edges along the line of whatever voltage your FCD is set at. Imagine someone bouncing on a trampoline and the path they would take - now put a roof just above their heads :)

Unless of course it CAN stop a certain frequency - it kind of explains why most have limited success if any with the HKS FCD's on these cars. Any time I ever had customers wanting to tune around a fuel cut in a subby or mitsi, I'd sell some kind of AFC device - there's a few of them around the $400 mark. Also used to be one of the NZ distributors for the LC-1.

Not trying to be negative, just chucking this out there since I see a lot of people on here use them and not many of them having much use.

I'm quite open to anyone who can show me otherwise - I've always understood the above, as have most of the workshops I deal with. Just seems a bit dodge when there are much better ways to solve the issue, that work better - and are cheaper into the bargain.

[Wodjno]

I get the whole "too much air not enough fuel = new engine" idea...

What I was getting at was I thought the FCD only is a voltage clipping device, i.e won't go over 6V / 5V / whatever you set it at. So that a car which is MAP or hot wire sensored and has a fuel cut at say 5V, you set your FCD to 4.95V, no more boost cut on cold nights or whenever. I had one in my turbo honda city of all things :p



I agree with the above /yes

But the reason the factory fuel cut is there, is to stop the engine from leaning out.. You set you FCD to 4.95v so there is no longer any fuel cut ! This then allows you to cram in as much Air as your Turbo's can handle and stil no fuel cut :thinking: But how can you be sure your Fuel Pump is adding enough fuel :inquisiti Great it maybe that you can now max out at 18psi/rally But not so great that your overheating your pistons /pan You might not damage them straight away(but you also might) but the long term affect could be catastrophic /help

Fuel Cut is the best and quickest way of ensuring your Pistons won't melt.. Cos if there is no fuel, then theres no explosion in the cylinders, thus meaning no excessive heat that can damage them :pimp2:

[valmes]

It works fine... as long as you know your limits. I did consistent 13,7 passes with only FCD and HKS EVC3 fitted, all day long... on only 0,8-0,85 bars of boost, in a full weight Legnum.

However there is a limit to what your fuel pump, injectors and turbos can handle...

[ako]

I think we're on different wavelengths here - I'm questioning whether or not the FCD is actually achieving anything at all!

What I was saying is all you are doing is butchering the signal to the ECU, not limiting it. The frequency can still go as high as it wants, how thew ECU interprets the modified waveform is another story altogether.

[Wodjno]

I think we're on different wavelengths here - I'm questioning whether or not the FCD is actually achieving anything at all!

What I was saying is all you are doing is butchering the signal to the ECU, not limiting it. The frequency can still go as high as it wants, how thew ECU interprets the modified waveform is another story altogether.

The FCD does achieve something and can be a valued MOD.. But only if used correctly(preferably in conjunction with a wideband 02 sensor).

[valmes]

I think we're on different wavelengths here - I'm questioning whether or not the FCD is actually achieving anything at all!

What I was saying is all you are doing is butchering the signal to the ECU, not limiting it. The frequency can still go as high as it wants, how thew ECU interprets the modified waveform is another story altogether.

Our cars need FCD K (that is the only one that will work with Karman signal). It works by limiting Hz signal from MAF.

[Eurospec]

I agree with the sentiments of the guys here in the post.

An FCD, of whichever type, simply limits the maximum airflow value the ecu can see to stop it peaking out and hitting fuel cut.

Why fitting an FCD can be a bad idea:-
Fuel cut is the ECU's last ditch attempt to save the engine. The ECU is seeing so much air that it knows it cant deliver the fuel (in terms of injector pulse width) to burn it at a reasonable afr. Essentially the ECU knows you are running lean. It cuts the fuel so as to stop the airflow. At the instant you hit fuel cut it feels like you just hit a brick wall- the same feeling as hitting a speed limiter in a j spec car.

If you datalog a car accross a period of fuel cut, you will see a massive knock spike (like it will peak the logger out) at the instant the fuel is cut and you get that mega lean condition as the last bit of fuel is burnt.

I have known owners of cars who have continuously smashed their car into the fuel cut from running too much boost who have unwittingly blown their engines simply from the knock generated at fuel cut. Many of them thought they simply had a bad miss.

That said, if you can monitor afr and ensure you are not running lean, you can use an FCD to maximise performance and get that bit extra woof out of the turbos, whilst still stopping the pottential damaging cut occuring.

Even so, an FCD simply clamps the maximum value for airflow, so once it is operational the ecu will not see any more air, and will not legthen pulse width accordingly. So the 'deeper' you go past the FC value, the leaner you will run.

Cheers,

Ben.

[Wodjno]

I agree with the sentiments of the guys here in the post.

An FCD, of whichever type, simply limits the maximum airflow value the ecu can see to stop it peaking out and hitting fuel cut.

Why fitting an FCD can be a bad idea:-
Fuel cut is the ECU's last ditch attempt to save the engine. The ECU is seeing so much air that it knows it cant deliver the fuel (in terms of injector pulse width) to burn it at a reasonable afr. Essentially the ECU knows you are running lean. It cuts the fuel so as to stop the airflow. At the instant you hit fuel cut it feels like you just hit a brick wall- the same feeling as hitting a speed limiter in a j spec car.

If you datalog a car accross a period of fuel cut, you will see a massive knock spike (like it will peak the logger out) at the instant the fuel is cut and you get that mega lean condition as the last bit of fuel is burnt.

I have known owners of cars who have continuously smashed their car into the fuel cut from running too much boost who have unwittingly blown their engines simply from the knock generated at fuel cut. Many of them thought they simply had a bad miss.

That said, if you can monitor afr and ensure you are not running lean, you can use an FCD to maximise performance and get that bit extra woof out of the turbos, whilst still stopping the pottential damaging cut occuring.

Even so, an FCD simply clamps the maximum value for airflow, so once it is operational the ecu will not see any more air, and will not legthen pulse width accordingly. So the 'deeper' you go past the FC value, the leaner you will run.

Cheers,

Ben.

Thanx for the Input Ben :pimp2:

And i think you have confirmed exactly what i have said :scholar: