Hey guys looking for a bit of help,Ive got an S5 TII with a stock turbo/intercooler(ported wastegate),running a rtek 1.7 with 720 secondaries and an fd fuel pump,3" rb downpipe,with 2 1/4" duals,K&N,emissions removed...when I boost around 8-12 psi I,m getting crackling and slight hesitation(Im thinking lean)I haven't yet bought a wideband but its on the list.Rtek 1.7 with 720's should be good for 12psi all day?right?Any help is appricated.thanx Chad

 

I would get those injectors cleaned and flow tested and then get a wideband so you know if you're leaning out or not. And the rtek with 720's is just fine for 12psi.

 

stop boosting until you install the wideband and check your timing in the meanwhile.

also might not be a bad idea to just burn off the tank of fuel and refill with premium from a different station. while not common to get bad gas it is possible, very rarely.

 

Snap-crackle-popping is a definite sign of running lean. I experienced it once and got all freaked out about it because my wideband was pegged high at 16.00 AFR. It was probably higher than that, but it wouldn't read it that high. NOT safe for boost, so take RE's advice. If you have to, go to Lowe's and get some metal wire and use it to hold the wastegate open until you figure out what's causing it. It could be timing, clogged fuel system, improperly functioning injectors, a bad coil ignitor (like the gas thing; it's rare, but possible), a bad AFM, etc. I had an AFM stick on me once due to aluminum corrosion. Yours is S5, and I believe those are plastic, but not entirely impervious to sticking though. There's also a rheostat inside the AFM that could have a dead spot or spots. Good luck!

 

hey guys great info,I was thinking injectors,but my 720 were new 4000km ago but I never checked the 550's.any chance a dirty fuel filter could reak havoc?slight drop in fuel pressure?ive got one on order and hoping that may help.Ive had the car for 4 years and never changed it yet.hell it could be original for all I know.I never even thought afm or coil ignitor.thanx Ill post my findings.Chad