Limitations of 550s, mkiv pump, and lex afm?

[Fletch124]

Went to the strip Saturday morning. Ran a best of a 13.6 at 105 with an ok launch. I know I could have been in the low 13s in Sac and supposedly capable of high 12s. But anyways im at 15psi with a 60-1, 550s, lex afm, mkiv pump, and SAFC 1, and a alot of other shiney stuff. Decided to try and turn the boost up alittle and see what happens. I have a Greddy Profec II. Launch spinning bad and hopping, grab 2nd and the car starts coming into boost and I watched my wideband go lean off the scale and the car jerk forward. Fuel cut? I then turned it back down to 15psi.

Are there any limitations for too much boost on my set up? I figured my car would handle atleast 20psi seeing as how i spiked 20psi once because I had to shim my wastegate because it started becoming weak. Didnt hit fuel cut then.

 

[87M-GTE]

I think that you should be fine with 20psi. and all you would have to do is tune it while on 20psi, to compensate the leanness you experienced the only thing I could think of is that you are running the mkiv pump which would not give as much as a walbro fuel pump. I would look into that.

 

[tissimo]

Do you have the FCO code, or did you CEL come on when it started jerking? if not then you didn't hit it. You might of ran out of fuel causing a lean missfire

 

[bountykilla0118]

The walbros and mkiv pumps are comparable aren’t both of them 255lh pumps? Either way both would supplying plenty of fuel for 550's and a 60-1 .... You shouldn't be running out of fuel. The stock 440's start running lean at the 18psi range with an afpr, lex afm and 255lh pump......

When my friend was on his 60-1, lex afm, 550's, SAFC II, afpr and walbro the dyno tuner said "you have to much fuel but hey you can’t have to much on a turbo just up the boost"

 

[BlackDevilSupra]

Please take you car to a dyno to get it tuned properly so that you can learn how it's performing, and what you're limitations are with current fuel / turbo setup. Otherwise.....