i just got my new built bottom end...ls motor...weisco pistons (9 flat cr) and eagle rods...first of all, is piston slap common on weisco pistons? cus my motor and 2 other motors at the same shop have piston slap...its an annoying noise and it makes me worry, but it goes away when the motor is warm,sometimes its a faint noise when the motor is warm...2nd of all...what should i set my btm msd dial to on 5psi while i break my bottom end in...also i have aem wideband guage which thanks to god if i didnt have id probably would've blown motor by now...currently im using a vafc to do the fuel for my turbo...so far 8% throttle and under its lean as hell at 15.5 and higher...then 9%-44% throttle its rich...id say 11.7-12.5...but as i start to do WOT...it leans out past 16...i dont understand whats going on b/c ive set on my vafc...all rpm range to dump fuel...i have it on 9 at 1k and go up 1 per thousand rpm...now what im trying to figure out is...why is it leaning out when i do 45% throttle and higher...not sure if it matters but i havent gone over 4krpm b/c of break in...do i need a fuel rail? bigger injectors? or what size injectors should i be running? what kind of fuel pressure should i have? or is there a setting on the vafc that i can tune the fuel dump to a certain throttle percentage? and for future reference...i want to run 12psi for daily driver...what kind of computer should i get and is it safe on a stock head for that kinda boost? and my wastegate opens up at just under 4krpm's, is that normal? does that leak boost? ive heard that these turbonetics deltagate's leak boost....getting a tial would be my best bet...havent had any disagreements on that subject so thats one future plan...also i have a blitz blow off valve...im wanting to put the hks ssq...any pro's or cons on that? please help, i need to know as much as possible b/c i cant afford to blow this motor...my main goal is to have a safe setup but at the same time i want a fair amount of hp

 

Piston slap is common in motors using forged pistons. Its just something you live with. JE's have less of a clearance than others on the market and it helps, Ive never used Weisco's in a 4cyl but in my Camaro motor they slap nicely when cold.

What size injectors and how much fuel pressure are you running? You might just be running out of injectors when you start to go lean. What car is this motor in and what ecu are you running?

I cant really help you with tuning the safc since Ive never played with one. You should try and tune it a little richer at part throttle around 14:1 and as boost builds you want to go to a 12.5:1 ratio.

The wastegate w/o a boost controller will open as boost builds. If you have a controller it will open at full boost. Wastegates dont leak boost, they bypass exhaust gas from the turbine to slow it down from spinning past the preset boost level.

There really arent any pros or cons from swapping BOV's. Only reason would be for sound or if one was too small to release boost quick enough.