2g anyboost > 19psi, engine flutters/cel trips

[stiggity99]

As soon as I adjust my MBC to anything greater than 19lbs of boost, ill get into it in 2nd gear, and right as the engine reaches >3800RPMS, you can hear the power STOP and a fluttering through the exhaust. If I try to stay into it, it bucks, and I get out of it. I can ride 19psi till 7000RPM and it runs perfect. As soon as the boost pressure is changed to 20/22/23/25, Whatever, in 2nd gear especially it loses all power, flutters, and that's where im stuck at. Fuel pressure is set to 43.5 via Fuel Lab regulator, -6an from filter to rail. Is there a difference between 1g and 2g fuel filters? Let's say (im pretty sure not), im running a 1g fuel filter.. could this cause the problem? Anny help would be greatly appreciated.

--Steve

 

[1990dsmkid]

What kind of bov are you running? Kinda sounds like your getting turbo flutter. Might need to adjust the bov.

 

[stiggity99]

my bov is a GReddy RZ, and is about 4 yrs old. I will tighten it down a turn or two... if that's my problem all along, I will knock my own teeth out... :-/

 

[1990dsmkid]

I wouldnt do that. Might be worn out and possibly a new spring? I dont know how long those springs last before they need replaced.

 

[jimsgsx]

Get rid of that greddy! I personally have nothing nice to say about them.

 

[GofaST4life]

What are you tuning with?

 

[mercaholik]

What's your spark plug gap? You can try closing out down .02 at a time. Really your gonna have to start eliminating things. How about data logging some sensors (o2, maf, tps, ect, ks,etc.) And what trouble codes are stored?

 

[LandSpeed-DSM]

Knock..?

 

[stiggity99]

im tuning via ECMLink v3, plugs are gapped to manu settings (NGK BPRE7), not a trace of knock.
I cranked my Bypass Valve down pretty far, and besides the unit not releasing pressure correct, I could swear
the car runs much more responsive. I did a boost leak test, and as soon as the pressure gets to 12/13psi the bov leaks out the outlet. So I turned it in a few turns, and it held till 15psi.. going to get a tial unit, and see whats up..

thanks for the replies..

 

[Cougar232]

Yea that spring gets weaker and requires more tightening til its out of boost range and youll get a boost leak above stock levels 12psi and higher on most, and adjusting per psi to hold. I hate knowing my 2g stock BOV is most likely leaking and not doing 8-10lbs of boost

 

[stiggity99]

cougar...
yer right, this is my 4th engine,but this time its fully built. I now wish I had went with a bigger turbo, exh mani, etc.. the bov was definitely the problem. I rode 20psi till 6kRPM and no flutter.. felt pretty good, considering that's the highest pressure I have been able to hold for 8months.. going to peak at 25psi, just not sure if I need tuned in the higher RPM range. Got my injectors dialed in, idle is fine, cruise trims are good. (thanks, Chris!! ) just don't want to turn it up to 25, and detonate, etc.. would like to be sure. So, in short... PROBLEM RESOLVED!! (too bad im missing my front teeth!! )

 

[1990dsmkid]

Lol I told you not to knock your teeth out

 

[boostedfrak]

Whats your afrs ? Then you can see if you are close to detonation