The OEM K04-001 will flow 210gs around 260-265bhp out of the box (with a little added actuator preload)
9 times out of 10 its the engine hardware flow which will reduce the power and peak MAF flow not matter how good the mapping is,
I am seeing an more common now cars coming in wanting 260+bhp, but using cheap narrow TIP, Toyo FMICs with 2" pipes, 2" / 2.25" custom exhausts, stock down pipes with cats chopped out ect...... and moan a me when I cam only tuning them to 220-230bhp with turbos which can flow 30-50bhp more.
When I did the testing with my k04-001 and my hybrid versions I used the very best part to aid air flow in and out, my FMIC pressure drop was 4 psi, the Toyo FMICs are seeing around 9-10psi..
I was using the Milltek de-cat no res turbo back exhaust, ported exhaust manifold and Forge TIP. It was this combination of parts which made my car run a 13.9s with a k04-001.
IMO if the rest of your hardware is not to the highest flow then a K04-001 is a waste of money.
The reason Toby is the only person in the UK runnig a K04-022 over 300bhp is he was the first person to run the K04-022 with a combination of "new" high flow tuning products. The 80mm high flow TIP, which has been proven to gain 19bhp at stage 1 with a k04-023, the high flow relentles manifold setup which I have seen back to back result of around 35lbft and 26bhp on its own merits, then what most people miss the charge pipes, he ran these at 2.5" with smooth bends. All this was linked to the best flowing 1.8T engine out there, the AGU.
The car was running a good quality air filter, which was not up to the job and was eating away at around 10bhp on the peak power, with air filter it was around 299bhp, without filter 309bhp.
Spend all your money on getting the engine flowing before going big turbo, the better the flow the more power you will get for less boost and less heat build up.
I am seeing k03 RS6 hybird turbos only making 240-255bhp a lot of the time due to poor flowing aftermarket parts, the worse one being the ebay 2" Toyo FMIC kits, yes its a FMIC and cools the charge air but it flows worse than the stock OEM SMIC.
And to hold the power longer and stronger you will need a good WMI kit from k03 upto Gt35.... the best mod for your 1.8t not matter what stage of tune even stock. (Kits are less than £200 now)
