Yes, I've searched the forums. Went through half a dozen threads on the subject, but wanted to describe my situation to see if anything varies since I didn't find any threads that match me exact gripe.


Stock turbo
Stock Injectors
Aftermarket Intake and IC pipes.
Turbosmart BOV
TBE
EBC
Walboro 255
Ecu Flash

Having problems getting full boost. Yes, I've done a leak test. When its colder outside, i'd say about 50f and below, I can hit my target 23psi just fine with the occasional spike if I'm not on top of my EBC setting for that days particular tempurature.

Warmer days however, it's impoosible to get full boost. I cap out around 1.5bars before getting fuel cut. Turning my EBC up above about 70%, and I get cut more and sooner the higher I raise the %. At 75%, on a warm day, forget it..I get cut after a few seconds like clockwork.


My question is this - Would an obvious answer to this be that I'm hitting my load limiter, or do I need to install my 680cc injectors, get retuned, or a combination of all three?

If I left out any pertinant info, let me know and I'll reply with it if I know it.
Thanks.

 

get a walbro 255 recheck all lines to

 

Got the fuel pump. Haven't checked my lines though...i did have to remove my fuel rail to change my alternator, but I haven't noticed any significant drop in gas mileage or smelled in leaking gas...I'll double check though.

 

Wastegate / BOV / Turbo problem or most likely a boost leak. What's your boost limit set at?

Fuel pump/injectors have nothing to do with you hitting boost cut before achieving full boost.

 

Boost is set at 23psi.
You're right that the fuel pump/injectors wouldn't cause a boost cut. But it's a fuel cut. The car tries to throw me through the windshield when it happens.

Here's my theory - Warmer outside, car has to work harder to get the boost I want. Increased turbo strain = increased load. Too much load for my tune, hits the load limiter, it cuts my fuel to take away the load.

BOV is fine, I just took it apart and cleaned it today. I'll check the wastegate, but it should be fine too, i'm only pushing 23psi with an electric boost controller. The EBC settings are fine and it's doing what i want. I just want to figure out why I'm getting cut...I really think it's my load limiter, but I want some other opinions.

 

Yes, your hitting your boost limiter number. Turn down your EBC's duty %. If your hitting the limiter before your hitting target boost (that you were previously tuned for), then you probably have a boost leak.

Load = Boost, as measured by the MAF. Load in the ECU is roughly scaled as absolute kPa, which can be directly converted to PSI. Since the MAF is before the turbo it measures the amount of air entering at the intake before the turbo. Cold air is denser than warm air and creates more load, not less load.

The most common way you can have high load with out high boost is if you have a leak after the MAF or your boost gauge is not accurate and your really running 28psi but you think your running 23. You mention that your not able to achieve full boost.. classic signs of a leak. Another thing that can cause your Load to read abnormally high is an intake of poor design disturbing the airflow to the MAF and rendering the OEM scaling in-accurate. Assuming your car was tuned properly and you havent increased the boost beyond what you were tuned for you most likely have a leak after your MAF.