KompressorLOgic

iTrader: (6)

my freind has a 87 t2 with enuf mods that it should be pushing at least 10-12 psi,

but for somre reason it wont boost past 6psi, shaft play is minimal, and turbo looks fine, and shouldnt really have any problems, high compression in the motor.

is it posible that the twin scroll actuator isnt working , and thats making the lose of boost?? i dont fully understand how a twin scroll works anyway could someone enlightenme??

FC3S.USD

iTrader: (2)

The twin scroll mechanism aids with low boost on S4 turbos. Meaning it tries to spool it up faster. At least thats my understanding.

Now if he cant boost past 6 psi. I dont think its related to the twin scroll system.

And what are your freinds mods ?

hondahater

iTrader: (2)

no it doesn't have anything to do with twin scroll. Twin scrool would either be stuck shut in witch you would build boost rapidly (to much) and if it was stuck open you just would have a little more lag but still have full boost.

Bentot

Im the TII with the problem...My and Kompressor worked on it yesterday and found that the actuator had been removed and held shut so it only boosts at 6 LBS. we moved the gate to open and now it tops out at 15 PSI whcih Im not comfortable with....
I have a WOLF 3D which needs a lot more tuning and I have the stock TMIC with 750 sec and 3 " DP and exhaust and street port and 3MM seals
any opinions on where to set it to make it around 10 LBS

RotaryEvolution

iTrader: (30)

you need a boost controller.

Bentot

will it work properly with my twin scroll(cuz its not really their) or will it eliminate it?
I can boost cut my boost with my EMS, but its not really good for the motor.

Ill post pics tomorrow!~

RotaryEvolution

iTrader: (30)

you can bypass the twin scroll by just pulling the vacuum line off the actuator and plugging the line, this will keep the twin scroll inactive and in the open position.

if you have no way of controlling the wastegate actuator(ie. a boost controller) then you will need to install a boost controller to see anything much higher than stock boost levels due to the spring calibration in the actuator.

bigdv519

iTrader: (3)

I will assume your have some type of enlarged wastegate. But then again, assumption is the mother of all F*** Ups. Your wastegate controls boost. Your wastegate acuator is acuated by intake manifold vacuum/pressure. A possible culprit could be a weak wastegate spring. Get some type of boost controller.


Hondahater has it right. The twin scroll will still allow you to reach full boost whether closed or open. The lag changes with the twin scroll.

Bentot

OK, like I said the twin scroll is not working. The vacuum was removed, all that is left is the gate. I can move it to open or close (i.e. 6lbs or 15 + lbs.) but know it open every time I I go WOT...Just trying to figure out if I can lock it into place somehow and make it stay around 10 PSI. But by the sound of it it prolly only works open and close..
thanks guys

hondahater

iTrader: (2)

yeah the twin scroll is not there to control boost! Best thing you can do is either get that twin scroll working correctly or eliminate it all together. On my car the lag was not that noticeable without the twin scroll setup so I just removed it all together. I would recommend you port your wastegate to control boost. Just do a search for wastegate porting or go down to your local books a million and pickup the newest rxtuner magazine and they have a writeup on how to do it. Basically the stock wastegate is really really small, I couldn't even fit my pinky down in the hole but one you port it and put a new wastegate flapper on it keeps boost constant.

Bentot

apreeesh dude!
Thanks for the help

hondahater

iTrader: (2)

no prob man

RotaryEvolution

iTrader: (30)

i'm not quite sure on what is going on here. do you have anything controlling the boost or is the turbo hooked up as it was stock? if it has stock actuation then i think you are confusing the wastegate control arm for the twin scroll control arm, you can generate 6lbs with the wastegate fully opened if it has not been ported, leaving the port closed can cause your engine to pop if the turbo feels basly enough to push enough pressure and volume through the motor that the fuel system can't keep up with.

for reference, the twin scroll flapper is on the bottom of the manifold, the wastegate is on the rear of the turbo facing the rear of the car and is in a higher location than the twin scroll. if you already know this then sorry for posting the obvious but im trying to figure out what is going on.