Hi everyone, my brain is overheating, i just cannot figure out why this car won't boost no more than 8 psi, though it will boost at 6 psi with no problems, and if set it up to go a little higher it will just stall at 8 psi at around 5,500 rpms.

The car is a Honda EG with a B20 Vtec with a log manifold Tial wastegate 38mm, 750 RC injectors, 255 walbro fuel pump, turbonetics turbo, and tuning with s300

This is what we try to do, but nothing worked, replaced the wastegate spring for higher psi, falls to its face at no more than 8psi every time, connected the boost solenoid same result, changed map sensors, from stock to 2.5 to 3 bars, same results, we even tried another Hondata ECU, same problem, the only thing that worked was a 6 psi spring, anything above that the car will just fall to its face every time it started to see more than that.

I know it was not boost cut because we set up on purpose to cut at 4 psi and it did, and every time the check engine light will turn on, meaning that the ECU was blocking it, but when we set the boost cut at 14 psi, and replace the spring for higher psi, it will fall to its face at 8 psi, and no check engine light will come on, meaning that the ECU is not blocking the engine, something else is, but what??????

Any one with similar past experiences, i would appreciate your input, thanks in advance.

 

Define fall on its face. What does it sound, fell like? Will it rev past 5500 at all at 8 psi or hit some sort of limiter?

Have you tried addressing the ignition system, spark plug gap?

 

Why not check the basic first?
Any leak in the silicone hoses?
Or is there any leak somewhere else in the system?
Is the turbo spinning well without touching the wall?
BOV leaking? Wastegate leaking? Intercooler leaking? ------ SOLVE THIS FIRST....THEN IF OK, GO TO THE NEXT STEP.

You did not mention checking the basic.

 

It sounded like it hit the limiter, and then rpms will just fall even though it the throttle was wide open, the ignition system is stock with stock spark plug, will this have something to do with it?

We are going to try with another set of spark plugs see if it solves this issue, thanks

 

Everything was checked no leaks what so ever, we did a run without the turbo connected and the car rev to 8k without a problem, and when we connected the turbo back on it will stop making boost at 8 psi and the rpms will go down, like if it hit a wall.

all the datalogs it shows it was maintaing boost at 6 psi, but it just wouldn't boost over 8 psi, somebody mention about the ignition system, we are going to try that see if it works, thanks for you input

 

Did u check ur plugs? And fuel pump?...i had a similar issue with my cousins integra...fuel pump was shot

 

But was he able to boost at a certain level only or just every time he hit boost will it cut off?

 

Does not make sense to me. You said, you ran without the turbo and you rev all the way to 8,000rpm? No leak?

You ran with turbo, you have 750 RC injectors...it should rev all the way too.......... unless the turbo hitting the wall and having a friction.....and maybe you have 225 walbro "china made". Happened to me a few years back when I thought I bought a real walbro -- the fuel pump can't keep up
and found out later it's a stupid fake fraud made in china walbro.

 

Boost to 6-7 psi then fall on its face...took the kit off the car and it drove fine like nothing was wrong

 

Is the car warmed up? From what I remember, S300 software has a temp limit to on reves- check your ECT while your at it... make sure it's not loose or busted off- or change the software setpoint