Downpipe from stage 3 onwards. The jump to stage 1 gives the biggest bhp per $ increase. Suspension upgrade is a great idea, just don't forget the brakes, you'll find you carry more speed into/out of corners so some fast road pads won't go amiss.
Agreed, simply bolting on a bigger turbo wont give more power, it may mean reaching the maximum performance of the software quicker and for longer but thats all, you need a re map to make the most of the hardware upgrade.
Some of the guys here have the aero turbo with stock and stage 1 upgrades, its a bigger unit so may give more lag, the 3" down pipe massively reduces turbo lag............
I guess what I'm saying is chose a tuner that you can grow with, you will want more after stage 1 so bear that in mind, the Nordic guys seem very helpful too if thats your preference
You can put also Aero"s (HOT) software in your car. I have change Aero"s turbo, software , air intake pipe and fuel pressure control in my own 2.3t lpt -00. Max boost is about 1.1 bar and run just great
i found a TD04 off a aero for $350 with 60K miles! anyone tried rebuilding a TD04? also, are there any other major concerns with upgrading turbos without the software, bedises the lag, and lesser performance as compared to the aero? i dont have the money at the present moment to upgrade to the aero software, unless someone knows where i can find it for cheap.
You dont need to change the downpipe, for the turbo upgrade.
The only parts you require are
4 pipes(2 water & " oil) and 2 banjo bolts and washers.
10-11066422 x4 washers
10-9136524 x2 banjo bolts
You are looking at about £100.00 for all the parts new, or if you can find an Aero or Viggen in a breakers, you can use them.
I think thats all.