1. The biggest question of all I have is can I get away with out a PFC, at least at the start?
APexi Power FC Is most probley a MUST when you are doing such an upgrade.
It basicaly maps out your enitre engine signals / sensors as for tuning wise its is very helpful, especialy towards your single high mount turbo.
2. When not using a PFC (or equivalent) is it OK to just keep the 2 AFM's by using a "Y" pipe?
Yes, pic below.
3. Seeing that you only have the one dump pipe with single turbo, would you simply bolt both the O2 sensors into the one pipe after one or another (or next to one another, whatever is best) ???
Yes, it is just visible in the pic below.
4. Is there anything important to look out for with other sensors that are hooked up to the induction system?
I would say just your Air Flow Metres and your 2 O2 Sensors. They are your main ones and probley the only ones in that area.
5. When running boost levels/air volume levels around the 1 Bar mark, would I still be OK to run my factory cams? I know that these are ideal for running 2560/2860's etc and in some cases have better results than aftermarket cams - but how would I fair with a single turbo conversion.
LOL! One thing leads to another, I would do the cams and also depending how much boost you want to run.
Seeing as that you want a single high mount its gonna be running probley abit more than 1 Bar.
6. Obviously you have all your oil/water line issues as well etc
Yep, car will run abit hotter, so you will need gauges to show the readings and improve / upgrade its cooling systems.
Install an Oil Cooler and upgrade the radiator.
7. I'm yet to decide on the turbo itself. So far I've only researched turbo sizes for a twin upgrade (as this was my original plan) but haven't done too much reading into single conversions. I take it that they would be quite similar to the single upgrades on GTST's, in the GT30 to GT35 region???
HKS T51-SPL, GReddy/TRUST T88H-38GK pretty much do the same job.
I think these turbos have similar specs, so you will get similar results, but also depending on your tuning.
They are some of the main points I've been pondering about along with what turbo size would run best with a configeration like that. Obviously, you'd have more tuning capabilities with a PFC if you were to run a turbo that has much different compressor efficiency than the two twins combined etc.
Could anyone please shed some light on these issues for me...possibly someone else who's done the same thing? Ie, started off with twin set-up and then converted it over to single configuration. Any experiences would be muchly appreciated.
Can I ask why you want to go single high mount?
Whats your purpose? Top end speed / drag racing..?
It will all depend on what you want to use the car for, which will determin your setup.
I prefer Twin Turbo low / highmounts as they are more responsive as with single high mounts, boost will not hit till later in the rev range.
Boost hits at 6000 RPM as I have test in the R33 GTR pic below with 455 awkW's