Bottle kneck somewhere, don't know where

Hello.

I have a Honda Civic Ek(97) with a built engine.

Problem: Engine isn't efficent past 20psi, and almost doesnt make any power past 28 psi. How do I see it? My engine doesnt want the fuel, so injector duty cycle is almost the same past 28 psi, afr reading around 11.5.

My setup:

Engine:

GE sleeved with forged internals b18c block

Head is heavily modifed(I'm not in talking terms with the builder), and should flow 327cfm.

Pulsar G35-900 turbo

full-race Ramhorn manifold

4" downpipe with 3" exhaust

2.5" intercooler piping

Water/meth direct port injection

id1700cc injectors

98 pumpgas(EU)

I have added a image of the vtec fuel table in 2d, and the duty cycle of the injectors.

the power difference between 26 psi and 36 psi i almost none. I have a Plex knock monitor and it doesnt pick up anything. Even with the water/meth off.

The person I bought the engine from told me to use Skunk2 ultra street manifold which did come with the package, but I used my Edelbrock Victor X manifold. Can the manifold be my problem?

Any suggestions?

I know my setup has worked in the past, because on my last setup(gtx3076r gen2, another engine and head) the dutycycle of the injector was 65% at 32psi, and that engine almost broke loose the tyres in 5th gear. At that point the plex knock monitor picked up knock.

I would suspect it's at least partially due to a poor cooling of the charge - remember, it isn't "boost" that gives the power but the charge density, and if the temperature rise is higher than the boost increase, there will be a net reduction in density. "Boost" is literally only a measurement of the restriction.

It may also be in part due to the camshaft and/or timing, if the charge can't get into the engine increasing boost may not be helpful - see above.

You don't mention valve springs, if they're weak, or installed with too much height, there may not be sufficient spring force to hold the valve closed against the pressure in the port(s), allowing leakage and loss of torque.

Can you log the plenum air temperatures? Also the pressure, and preferably temperatures, before and after the charge cooler?

Hi,

Thanks for the replay.

The IAT temperature, measured at runner number 3 in the intake manifold, measures around 28-35C.

Valvetrain is supertech. Valves, guides, springs.

Camshaft was "designed" by the engine builder(which I dont talk with), so specs on those are unknown.

I can make some outlet on the charge pipe and get som data.

Well, I found the problem: Vtec wasn't engaging.

Everything looked good. No faults, working solenoid, map switch, everything in the head was there.

The problem was a bad wire to solenoid. Good enough for no fault code, not good enough for engaging the solenoid. Car work as it should now.