pressure sensor acquires pressure build from manifold..

this signals operation of the wastegate correct...

with an fcd installed...how is this affected...

if the actual psi is no longer accurate past a certain mark that is...

as its bein tricked by the fcd...

 

i also wondered about that but i don't think the FCD actually tricks the ecu i think it just bypasses the fuel cut ?

 

Basically the fcd tells the computer that you're still at the highest stock boost level. This way you still get the proper amount of fuel and as much boost as you want. If you are running full exh. and intake then your wastegate will open when you reach the max psi the wastegate spring can handle. Hope this helps. Hope this is right because this is basically how I understand it. Please feel free to correct me if I'm wrong.

 

you are assuming the the ecu sets the duty cycle off of the map sensor. for all we know it uses the tps vs rpms, or the airflow meter. an fcd doesnt seem to upset the factory boost control at all



mike

 

teamfc3s.org has an explanation on how it all works in the DIY FCD part of the website.

 

The line that goes to the wastegate is just hooked up to a nipple on the outlet of the turbo. The spring in the wastegate is set to open at a given boost pressure. The pressure sensor has notheing to do with the wastegate.

 

the 89 has a bleeder solenoid plumbed in, so the ecu can riase the boost a tad



mike

 

i don't think the FCD gives the proper amount of fuel at all when the boost raises...



I would think that more fuel is needed as boost increases...something the FCD is not capable of doing

 

http://www.rx7club.com/forum/showthread.ph...fcd+fuel+timing



Good thread from another forum on the subject.

 

unfortunately i cannot goto that forum due to religous beliefs...is this only an issue when a DP/full exhaust is installed..i might get a t2 in the near future so i;m worried about this often talked about topic of fuel cut bypassing