Normally I just boost to 5 psi as I have been a bit cautious with my build so far. Today I took it up to 7 or 8 psi and when at that level there is a constant high(ish) pitch fluttering sound. As soon as I drop down from 7psi it goes away. It is also a reproducible sound so its not random. Any thoughts?

- Evo 8 wastegate
- Evo 8 BOV
- 91 octane gas (iirc, premium)
- 255 Walbro
- 440cc WRX Injectors

 

Is that sound present when you're wot in acceleration or its when u release the gas pedal after boosting? If your boost is steady and at the right psi your wastegate should be ok. Your injectors and fuel pumo should also be ok if you're not running lean on your wideband. Your bov might be what is causing this sound since its not adjustable and is adjusted for the stock evos that boost over 12 psi so it might not be opening completely.

 

That makes sense with the bov activating when spooling high. The bov is normal when letting off the gas. An interesting thing is that it only happened when the weather warmed up. Its been a bit cooler the last couple days and it doesn't make the sound. I don't really want to test it anymore though as I noticed I am running lean under more than 5psi of boost. Drives me nuts as it has the Walbro 255 and bigger injectors :/

 

What rom do you use? Besause the fuel pump and injectors wont do anything good if they're not tuned properly

 

The one you sent me Its updated with the injectors.

Edit: I am digging through the rom now to verify the pump was updated. I am not seeing where I would have made that update though. Off to google... does it need to be an addition to the xml file?

 

Thats weird because im running 11 psi and i stay in the 10.5-12 afr at wot with full boost :/ did you buy used injectors? Are you sure they're wrx 440cc?

 

Your pump cannot be programmed its at its full power almost all the time

 

https://www.evolutionm.net/forums/ec...ion-table.html

Yes the injectors are used and they are the 440cc WRX. I can run it at 5psi without issue. Well, sometimes it will boost to 5psi about half throttle in a higher gear and still be about 14.7afr but not often. I have to do a 1200 mile drive in a two weeks and it will be my dad driving the car while I drive my truck. Its making me nervous.

 

Your afrs should be in between 10-12 with our setup to be safe. 14.7 afr should be ok when you're cruising but is way too low if you're wot and boosting.

 

Made a little run tonight (didn't go over 60, but didn't need to). Datalog and graph attached.

 

Do you have a wideband gauge and/or an exhaust temp gauge?

 

Yes to both. The wideband is included in the datalog. My egt will show a jump of 80 to 100 degrees when I boost to 5psi or more.

Edit:
Normal cruise = 190* - 210*
After boost = 290* - 300*

 

So you dont have an actual afr gauge besides the datalog right

 

Pic is a little blurry as I took a screenshot from a video but here you can see my gauges as well.

 

Holy crap thats really lean i wouldnt get in boost much if i were you. What year is your lancer is it 02-03 or 04-06? Is your afr gauge ground directly on chasis ground or spliced on another ground wire?