Trike

Does anyone know the differences between a S4 and S5 FCD? I'm looking for one right now and I see more S4 fcd's than s5. I have a S5 and murphy's law is in effect.

Just curious if i can just buy a S4 fcd and use it on my S5.

Thanks
Wing

rxse7en

From what I remember the S4 fuel cut is at a lower boost than the S5.

idsigloo

The s4 turbo suffers from boost creep more than the s5. I actually have a Knightsports S5 FCD that I purchased that I will sell you. I decided to go to Haltech so I no longer need it.

HAILERS

I believe the difference is in the wiring of the car and the FCD. If you would look at a FSM for the series four and series five, you'll find that the series four has a 12vdc source going to its boost sensor whereas the series five has no such 12vdc going to its FCD.

Bottom line, they're wired different.

I took this thread at face value and assumed you meant the FCD itself, not differences in boost etc. As in why can't you put a series four FCD on a series five.

Trike

gotcha. so technically you can still use a S4 fcd on a S5 as long as you have it wired correctly.

I was just wondering cause i see more S4 fcd's for sale than S5's. but i might just pick up idsigloo's fcd.

HAILERS

Nope. I meant you can't swap series four and five FCD with each other. Four for four and five for five.

Trike

Gotcha. Just bought idsigloo's S5 fcd.

Thanks idsigloo!