I found out my twin scroll has been stuck shut forever..... never stopped me from making boost but i figured it wasnt all taht good for the engine.... i removed the actuator arm and now the car doesnt want to make boost.. i just put my avc-r(boost controller) in and it is maxxed out on the duty.. with the manual controller i wasnt getting any good boost either.. i have a 2.5 exhaust.. the most im hitting right now is umm 11lbs for a few seconds....with the flap closed i could blow up my engine on boost i could run it really high i kept it set at 14 but it would move around never more just would for some reason do less boost. so i took messed with the twin scroll and im worse off.. BNR stage 3

 

if its a stock S4 its not gunna run right unless u get ur twinscroll back....OR u port ur turbos wastegate and up the boost i hear if u modd the stock turbo config u can eliminate the twinscroll after upping the boost and performance...i dunno though could even be sumthing else!

 

bnr stage 3

 

He has a bnr stage 3, not a stock turbo.

Let me see if I understand correctly. It's slightly difficult to understand what your trying to explain.

You made boost WITH the twin scroll flapper in the shut position. OK. Then you removed JUST THE ARM for the twin scroll and now you make less boost?

 

yes i dissconnected the actuator arm for the twin scroll so it is always open. now i get less boost.. the car was faster with the scroll shut

 

Hmm, are you sure you didn't disconnect the waste gate instead by accident? Leaving the wastegate open all the time?

Just a thought.

 

im very sure

 

Ok, I got some more questions.

What is the normal max boost you run? At what rpms does it start to "fall off"?

Edit: Also, with the scroll shut, what rpms did you achieve full boost? Now with the scroll open, when does boost begin to build, and peak?

 

OOoooOOH now tahts just wierd....OOPs...sorry yea i thought it might be the wastegate purging all the boost

 

Of course it works this way.. I could have told you this. Disconnecting the twin scroll actuator will make a stock S4 turbo boost slower, THEN add that its a HYbrid? Yep, you lost alot of spool! Is the scroll control system still intact?

 

its wierd ill set the boost to 14 cuz it will spike to that at 4500 but settle back down to 11ish by the time im supposed to shift.. current boost im not sure cuz my datalogger is being an ***. my manual boost gauge shows at 11lbs but its only in one specific gear and not all the time... THEN other gears itll got to 12 and then back down. i want it to go to a set boost and stay there dag gone it. thats why i bought the avc-r. im going to dissable the gear senstive boost cuz i need a new speedo cable(the speed jumps around on the screen. soo my gear judge may be off. i need to get my exhaust remade to 3 inch before the Y.

 

yes its all intact.. my turbo builder said to take that crap out i have seen other people do it.... i would think since it a hybird too it would need that.. but the fact that the car was faster with the actuator ALWAYS shut is still odd... and the exhaust onthe turbo has been port matched

 

When I got my manifold/bnr 3 from bnr the twin scroll was removed complety.

James

 

Mine is gone because I ran an S5 turbo and manifold.

 

i just think it would be DUMB to install the flap to where its always shut again....

 

wrong thought
it would be even faster if he disconnected the wastegate

 

it spools faster faster because that was what the system is designed... all the gas is forced thru 1 runner,, makign ti spin faster

but then.... at high rpm,t i will choke itself if it doesnt open up

 

umm not really id didnt seem to choke BUT i cant see holding a flap infront of the exhaust good for backpressure on the engine.. i mean the choking

 

i put the actuator arm back on.. the actuator is actually broken and not moving... adn the ca ris faster with the twin scroll stuck...

 

Why is that? With the waste gate open at all rpms. The exhuast gas will by pass the turbine and get dumped right into the exhuast. Which will result in very little to no boost. Which is the symtom he discribed.

But he already made sure it wasn't the wastegate he dissconnected, so it wouldn't be the case in his situation.

And if your not building boost with the twin scroll removed/open.. then there is something wrong with your turbo. It would take longer to boost, perhaps 1k -2k rpm different compared to working system.

I would double check that the wastegate is operating correctly, closing all the way and opening only at desired boost, grab a air pump and pressure guage and pump it up to your set boost and see if it opens. Pump air into the boost controler/wastegate actualator.

 

if he unhook the wastegate line
it stays SHUT
pressure opens the gate
unhooked = no pressure

 

He said he unhooked the rod, not the vac/boost line. If he unhooked the line.. then there would be massive boost leak.

If he unhooked the rod, the wastegate will open with any exhuast flow.

 

quit it children, no one specified rod or vacuum line and the title was a bit misleading so i'm not gonna read through everything.

 

that twin scroll junk should not be an issue. i had a TII turbo on a stock port 12a and it made full boost by 3500rpms... no actuator in sight, the hole welded shut. i think your wastegate is pissed off.

 

ill start checking it again.. but i put my twin scroll actuator back together to find out the actuator is jammed shut.... so i i tuned the boost controller to run with it normal (the broken twin scroll always has been shut didnt know till now) the car si freaking fast keep in mind that the turbine inlet is matchported.. the car screams... i so badly wanted to embarass some fd but i didnt want another ticket...... 14lbs on bnr stage 3 .. i think my wastegate is holdin up just fine...