Having an issue holding boost, I have a 9 with AMS full ic set up full tb exhaust intake fuel pump and a forge recirc. On it with a turbo Trix tune. Car has 48k on it..I was driving it down the highway and all of the sudden my boost like lagged at full boost then started sputtering. At first I thought I blew a pipe off so I pulled over all the ic pipes were fine, got back in it boosted to like 15-20 fine...but as soon as I hit full boost (24) it will lag then sputter? Any thoughts. I'm thinking bad seal on the turbo bc after looking under the hood I noticed serious like black soot around my turbo and a little rite above it on the block..thanks for any thoughts!!!! The car runs fine and boost normally up to 20 pounds, so I'm hoping its nothing major

 

Fuel cut?

 

if it's black soot that kind sounds like exhaust? did you check you're exhaust bolts? i had that problem on my 240 and it was a loose turbo.

 

Not a fuel cut, bc that was happening before I got the tune on the car, and its exhaust for sure I'm ripping the header off today to check everything out

 

check ur afrs at idle as well..if there not really close to stoich(14.5-14.7) then it prolly is an exhaust issue, before i swapped my turbos out my afrs would b mid 15s to low 16s, once i put the new turbo in and made sure everything was "tight", afrs r perfect now

 

Boost leak test with soapy water. Just because the pipes look like they are not leaking doesn't mean much. Sputtering sounds like a boost leak to me

 

^^ that to, boost leaks can cause so many problems its not even funny, so suck it up and do a good one, also if ur max boost u hit is 24 or watever ur tuned for, test it to that or a couple psi higher

 

Never preformed a boost leak test, how would I go about doing it ? Also I took the car out today and noticed that as soon as the boost starts fluttering it dumps a nice cloud of exhaust out, if that helps any ha

 

ummmm first off wat color? cuz thats kinda important lol

 

Like just black grey-ish sorta just like regular exhaust, not white or anything

 

It hits full boost n hold it for like a second and then like cuts off n sputters and as the sputter happens it shoots a nice exhaust cloud out

 

gotcha, alrite ill try to explain how to boost leak test, evom chime in if i forget sumthing, first u need a 2.5 inch boost leak tester, i got mine from boostleaktesters.com, like 42$, very nice piece and has a gauge for pressure u dnt have to watch ur boost gauge, most of the guys just make there own, which u can do that as well, neways u need to pull the intake off the turbo and hook the tester up to the compressor side of the turbo, pressurize the system to watever amount of boost u r running, if u have to do multiple test i suggest after each test open ur oil cap to release air pressure in the crank case, once the system is pressurized listen for leaks newhere and everywhere, theres alot of vac lines behind the throttle body that pop off easily if not zip tied, plus when there is that much air in the system it should make a loud enough hissing noise that u will hear it....

https://www.evolutionm.net/forums/ev...er-5-02-a.html

theres a good article on how to make one urself, as long as ur running stock turbo which i assume u r, the inlet is 64mm or 2.5 inch...hope all this helps, good luck

 

Thanks a lot man. Appreciate it