NATS Functionality Question (engine swap without BCM etc)

[dvm_nz]

I'm looking to find out how exactly the NATS system prevents starting on a VQ37 (from 370GT) as I'm doing an engine swap into a BMW chassis and will only be using the ECU + VVEL module. From the wiring diagrams it looks like the signal to the starter motor relay comes from the IPDM which is integrated via CAN to the BCM etc.

I'm hoping that NATS simply prevents cranking via this system and by rigging the starter to fire directly off the key it will get fuel / ignition ?

Hope somebody can provide clarification so I can avoid NATS removal $$

[Ben C34]

No way would it only prevent cranking. That is extremely wishful thinking!

[dvm_nz]

9 minutes ago, Ben C34 said:

No way would it only prevent cranking. That is extremely wishful thinking!

Yuuuur I do have to concede this is wishful thinking but thought its worth asking in order to save some money as its $500 NZD for the NATS removal as best I can tell.

[Duncan]

There may well be other integrations beside the security that will throw errors, eg BCM, IPDM and TCM. Won't it be less painful to go after market engine management?

[dvm_nz]

15 minutes ago, Duncan said:

There may well be other integrations beside the security that will throw errors, eg BCM, IPDM and TCM. Won't it be less painful to go after market engine management?

That was the original intention however its really quite expensive due to the VVEL and to a lesser extent dual throttles / DBW. The cheapest option is the Haltech Elite 2500 which does VVEL via the OEM controller over CAN integration but does not support dual DBW so need a secondary controller (Torque Rush x2). On top of this would ideally want to make a new harness then there is wide bands and tuning ... other options from there are the likes of Motec M150 and Syvecs S7-Plus but the VVEL control becomes more exotic (direct and not via OEM controller) and tuning quite specialised.

So it gets very expensive very quickly unfortunately ... hence wanting to go OEM for now if it will work without too much drama. Apparently the ECU is actually reasonably tunable so if it all hangs together I may look at a new harness once its running in order to eliminate all the crap thats not needed.