AFA turboing a Toyota that uses an AFM, or MAF. Both pre & post compressor mountings have benefits.
I prefer post compressor mounting (Especially with AFM's) because you'll gain a little response, enrichment, and the temp sensor going crazy is not really a concern. I find Toyota ECU's do not rely on the IAT sensors for very much in their OEM tuning. If you don't believe this, check injector duration at a constant rpm while changing the output of the thermistor with a rheostat (pot).
They're inconsequential changes as far as I have ever seen. Many times, no changes is seen.
Pre compressor mountings will make it easier to get to, and potentially easier to seal up. On ECU's that do heavily rely on a temp sensor in the intake, you can avoid problems of that nature. (Again, I doubt it would pose a problem, I've never seen it pose a problem on a Toyota.)
It's also more common... If that makes you feel good. (Doesn't mean anything tho.)
question: the intake manifold has several vacuum lines for various stuff. I have the egr worked out so it will go to the air intake pipe from the air cleaner-this will be under vacuum. do I need to run all the other vacuum lines to this same pipe?
All PCV & Crankcase breather systems will kill you (at some point) if they see boost.
The *correct* want to route them is to leave your normal intake manifold (high vacuum) intact with a 1-way check valve so that they have vacuum, but are shielded from boost.
They also need to be T'd (before the check-valve) to pre-compressor intake so that during boost there is a minor intake vacuum.
(There is very little vacuum pre-throttle plate. The breather system doesn't need much, but it needs something.)
AFA other vacuum lines. Depending on what they are, the best way is to use a 1 way check valve, or a vacuum tank connected to the intake (No boost can enter the tank). Depending on what supply of vacuum a component needs. Assuming no leaks, both will provide a supply of vacuum. (The maximum vacuum sceen will be stored.)
Some items may not care.
AFA the EGR system, keep in mind the EGR system will present a pre-compressor exhaust leak on most OEM systems. Due to their manifold mounted location. This would be bad for good turbine spooling, and would create varrying boost consistency if the system is located pre-turbo.
There is also more exhaust back-pressure pre-turbine than there is intake manifold pressure. I would be worried about being at part throttle, having boost, yet having the EGR system activated.
Because of the high back-pressure, you would be getting a boatload of EGR flow. That would also effectively enrichen the mixture an unknown amount.
If you have to keep EGR for emessions, I would most likely devise a way to seal it completely, and shut it off at will. If not, I would ditch EGR completely. It only creates problems.
