Does anyone have any experience with Turbosmart’s FCD1 or FCD2?

My car can readily handle a bit higher boost than 22 psi, but I’m finding that i regularly hit the cut when iverboosting with “normal spirited” driving. I’m running a F21M which can flow at about half again as much as a stock JCW turbo, and I’m extremely happy with the Turbosmart DV.

FCD1 looks quite good...

(And yes, I know Manic tunes bypass it in the ECU...)

 

Certainly feels like the wastegate is opening...

 

whenever I get too close to 23 psi on manic stage 2 I hit boost cut. I'm pretty sure its the bov opening to purge that excess pressure though.

 

The turbosmart just puts a resistor on the stock diverter valve socket, hose to manifold controls wether it opens or not. There is some setup involved with the turbo smart iirc but i dont see how it would open unless its seeing differential pressure
If the wg is opening then vac on it isnt strong enough to hold it closed

 

Correct: turbosmart is pneumatic and puts a resistor in place on the DV to keep it happy. The WG is opened when the MAP reads too high a psi (if I recall correctly).

I'm not hearing the TurboSmart open, by the way...

No CELs but codes B2A00 and B2AAA show up.

 

Got a short full data log across a boost cut today... gotta now look at what happened. Will report log results here. Note: no CELs, no codes at all, just a Big Bang and a lurch all in the space of a second.

 

Are you sure its not just spark blow out?

 

That’s a good possibility. I’ve got a set of 1422s sitting around ... hmmm.

 

The whole purpose of the FCD is to keep the ECU from seeing high boost. It's the ECU that activates the WG and DV, and controls the fuel flow. So if the ECU never sees over 22PSI, it won't do anything to interrupt your power. The FCD's I removed after installing Manic cost under $50 for the pair, and that's all they did --- prevent the boost signals from reaching a voltage less than the 22PSI equivalent. Very basic electronics.

However, when boost is over 22PSI and the ECU doesn't see it, fuel flow and timing will be wrong, unless the map is compensated for it. My FCD's were installed along with a custom AP map which was set for 25PSI. Sometimes I pushed it to 28PSI but not often, and there were no ill-effects. Also note that when Manic was installed, there was about a 50HP gain with no other changes.

So, if you go with FCD's , be prepared to get another tune.