What am I doing wrong?? VRT advise needed!

[sleepymike 15]

Hi, right basically I seem to be having trouble getting more power from my VRT.

It's just been remapped today and it now has 332bhp at 18psi I was hoping to get more than that but it appears that as the boost is turned up the power seems to go down.

Im still running a dizzy and have been struggling with a misfire at higher boost at high revs but making the gap smaller on the plugs seems to sort it.(planning to convert to coilpack ASAP)

The spec is

Obd1 2.8

K&n air filter

3" stainless pipe into 4" turbo inlet

Gt3076r

Cast spa turbo manifold

2.5" intercooler pipe work

Modified rx7 alloy intercooler

Homemade front short air intake made from 3" stainless pipe

Bosch 440cc injectors

8.5.1 C2 spacer

HKS blow off valve

38mm Tial wastegate

Electronic boost solonoid

Map sensor

Omex management

3" exhaust right through with 1 silencer

Ngk platinum Pfr7 spark plugs gapped to 0.4

So with this spec should I expect more?

I'm thinking about changing the guy who maps it as they are more used to suburu's but I'm pretty sure he knows what he's doing as he does a lot of rally cars.