it works in tandem with your stock ecu and takes over the running of the engine, not sure exactly. My car is a uk classic 97/98 so the ecu isnt mappable like yours. I had a ninja 100cell down pipe de cat centre and ninja back box on mine with a green panel filter. That made a huge difference to mine as it had 134000 miles on it.
I was looking into ecu's boost controllers etc and got a fright at the price.
One site i visited was dasteks and they phoned me to discuss my requirements
They said with the mods I was running id probably be running lean at the top end. They recommended a walboro fuel pump and an adjustable fuel pressure regulator. I got them fitted and took the car to them
I had it runing on BP ultimate (dont do that its crap - V power all the way)
The car made 220bhp on the rollers but on 195 lbs of torque. They also said it was running fine at the top end but too rich low down.
once they fitted an mapped the ecu on the rollers i got 258bhp and 260lbs of torque.
it was producing more torgue at 3200rpms than it did previously at peak power
They said if id used V power they could have ran more ignition advance and gained a little more.
Car transformed - better fuel economy too.
They fitted boost and oil pressure guages etc as well an I got a bill for just under a thousand quid.
Any future mods then just require time on the rolling road dyno to re-map.
Ive since fitted a vf34, 440cc injectors and when mapped made 289bhp they said that was a little bit modest for the turbo I had fitted and thought the intercooler was holding it back. ( id put br ulitmate in it again!! know better now)
Ill be back soon for another map as ive fitted an sti4 TMIC and Magnex headers and il def be using V power!
Im very happy with it an it runs smoother than I can remember.

 

mine has full hks system(no cats),headers and up-pipe,induction kit,walbro pump and newage wrx intercooler and running 260.1 now.very happy with it as only standard boost.really just looking to up boost slightly(3-4 psi)just for few more bhp.

 

biggest gain with it setup and mapped for the mods will be the power and torque throughout the whole rev range.. not just the peak power.. it is easy to focus on the peak power figure rather than a decent power band when talking figures etc..

Simon

 

Your VF34 is entirely capable of 340+ bhp on decat d/p/headers/V-Power. But you've not really upgraded by fitting a STi 4 IC - it's a tad bigger/efficient than your same ph.1.5 UK black one, but not by much. You'd've been better off doing the MY05 STi TMIC mod instead (that TMIC is good for 400-450bhp so that would have been something ticked off the list).

So either the STi 4 TM or the 440cc are likely to peg you to around the 320bhp mark. Mind, that said, that's prob a good thing re. your internals/'box!...

 

I know mate the old girls got 145000 miles plus on her and By fitting the VF34 an 440s i thought id crack 300bhp at least.
I got 289bhp on the old black tmic, stock headers an BP ultimate.
I got the sti 4 one for 99 quid. Certainly look miles better, magnex headers (i like shiny things) an ill make sure the next map is done on V Power!
If I get over 300bhp ill be delighted. Think any more with sti 8 tmics or FMICs might be a step too far specially on the stock clutch as well

 

Yeah fair enough mate. Makes sense.

You should - if everything's working fine - easily see 320+ bhp with the headers and V-Power, I would have thought...