Lol turbo kit will cost as much as your car and offer the same performance as a high flowed hypergear turbo if not worse.
I suggest you do some research.
That's pretty poor form from a tuner.
Could also be mixture related, once you get a wideband on, it should provide you with more insight on what's going on.
Close to stoich or stoich on a cold motor, will stall, too rich on a cold motor will stall.
^ you're better off using an external gate with a weak spring to emulate what Tao is doing with that flapper. A few guys have done that (not here) but Google!
Why not get something more modern with a billet wheel? Especially if you're getting new.
For the price of a brand new HKS kit (if they still even exist) you could get a BW EFR and it will shit all over that turbo.
log voltage vs. rpm vs. load
a bad alternator could drop voltage as rpm increases but still show 14.4v at idle... I had that issue, new Circuit Sports alternator and no more misfires.
Then Evo 9
Out of the box, stock as fuuark they will run 1m10 flat around Wakefield Park. Some basic mods such as a set of MCA Coilovers, Semi slicks, a basic re-tune and you'll be in the 8s
^ haha.. that's IP man, most tuners won't give that out
but generally advance intake, retard exhaust.. the magically number really needs decent dyno time to overlay the graphs.
At 40 degrees that idiotic, you want it at min. 80 for oi viscosity to be correct.. a R33 thermostat is perfect for this.
Each to their own, no point arguing if you barely understand what I am trying to say.
You'll get more economy if you lean more on the timing around cruise and take the AFR past stoich.
I managed to get mine doing about 9L/100km going up to Forster.
What you need to remember though if you go past stoich you'll decrease power and torque, richer mixers produce more torque.
Ideally you want to tune where pedal effort is minimum for a certain rpm and you're doing the same speed.
Evo 9, get some flex happening so you can have commuter fuel as Paul calls it for daily use and E85 for time away from the wife LOL
Also being the Evo 9 it has a larger tank than the previous models not to mention has MIVEC which will spool much larger turbos with ease if you ever decide to get more boogey