Jump to content
The mkiv Supra Owners Club

Fuel Cut Defender, FCD


Recommended Posts

Name:

Fuel Cut Defender

 

Also known as:

FCD

Boost cut controller

 

What is it?

It's a bit of electronics that changes the airflow signal to the ECU so that it never sees more than 1 bar of boost. This is to avoid Fuel Cut.

 

Pros:

No more fuel cut when hitting over 1.0bar of boost as the pressure signal to the ECU is clamped just under 1 bar of boost.

 

Cons:

Crap FCDs scale the airflow input so that when the stock sensor hits 1.25bar (it's maximum) the ECU gets a shade under 1.0bar. This also has the effect of scaling the ENTIRE airflow signal so the ECU always receives a lower airflow value than the engine is really getting. Messes up the whole fuelling map towards the lean end of the spectrum and is therefore highly not recommended.

Link to post
Share on other sites
  • 11 months later...
  • 1 month later...
  • 1 month later...
  • 1 month later...

Hi there, when my car hit about 14-15 psi, I did some times get the sudden loss power an then back on afterward, but no warning light come on, is that fuel cut?

If so, how much is one of the fuel cut defencer?

cheers

Link to post
Share on other sites
Hi there, when my car hit about 14-15 psi, I did some times get the sudden loss power an then back on afterward, but no warning light come on, is that fuel cut?

If so, how much is one of the fuel cut defencer?

cheers

Yes. My warning light never used to come on either, contary to what most people seem to get.

Try Thor Racing's website for FCDs

Link to post
Share on other sites

Hi Guys, I thought the fuel cut dont come in till 17psi, Im only set it at 15psi, looks like I have to reduce it, may be?

or if I have a FCD, what psi can I go up to, mine is stock TT with manual boost controler.

cheers

Link to post
Share on other sites
  • 1 year later...

... This also has the effect of scaling the ENTIRE airflow signal so the ECU always receives a lower airflow value than the engine is really getting. Messes up the whole fuelling map towards the lean end of the spectrum and is therefore highly not recommended.

Are you sure that the voltage is "scaled" in the entire range and not "clamped" after some value..

Link to post
Share on other sites
  • 3 weeks later...

I have read a few other threads but im still unsure on this.

I was driving along the motorway giving it some, I was in O/D mode and getting some speed up and my turbo boost gauge was reading around 1.4, im unsure but I think the pre owner said that they were set to 1.2 and running on Hybrid turbos, but now and again the boost does creep above that.

My car has been delimited and I believe is fitted with a fuel cut defender. Although, I am not sure what kind and to be honest I know very little on this subject. Apparently its has a restrictor ring set at 1.2 bar which is not the best way to restrict the boost, and that an electronic boost controller would be more reliable - but like i said, i dont know! Anyway, I was driving along then all of as sudden all power was gone as if I had hit the breaks, quite an abrupt feeling, then after a few seconds the power was back. Am I right in thinking that this is known as fuel cut and its to prevent your car from over boosting?

Is there anyway of preventing fuel cut at all, yet still preventing your turbos from over boosting, as I wouldn't want to damage the car, but would prefer it if the speed wasn't limited in anyway by fuel cut.

 

Cheers guys!

Link to post
Share on other sites
  • 7 months later...
  • 4 years later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.