planning on using a Tial ext wastegate and running 15psi max boost.
is it just a case of using a 15psi spring in the wastegate?
i read on here that keeping the wastegate closed for as long as possible helps to spool the turbo quicker.or is the idea to use a lesser poundage of spring say 10 psi then use a manual bost controller to up the boost?

 

I would get a 10 psi spring and get a controller to fine tune your boost.

 

With the controller taking signal post intercooler

 

I run an 12psi spring with signal from the compressor outlet and it always hits 11psi every time, perfectly. It makes that number in 30*F temps or 105*.

 

Using a controller makes boost come in a little quicker and more abruptly.

If you want a steeper torque onset use one.
If not, just run the spring.

 

I've tried hooking up a boost controller in-line (like on the single port gates) and it made crazy, erratic MAP pressures and overboosted. The boost controller will choke-down the air filling the canister and things "aren't right". I then hooked it up how TiAL suggests and it worked perfectly at 16psi. However it was way too fast and now I run the spring and it builds boost just as fast as with no line hooked-up.

 

*****

 

^not yours.

 

Mine



Notice the 15 dollar mbc on the right getting the job done like a boss

 

bauce

 

Is that a valve cover breather stuck on the compressor inlet of your turbo?

 

Literally nothing bigger fits without redoing a ton of ****.
as it is there is about 1mm of clearance around it.
Works like a charm though.

The mbc made a HUGE difference in midrange btw

 

ok from what ive read so far in this thread.a mbc makes a big difference in midrange, makes boost come in quicker and more abruptly. so sounding good so far!!

so if i need 15 psi to get 300bhp i should use a lesser poundage of spring anything below 15psi so say a 10 or a 12 psi spring in the Tial then fit the mbc and dial in the boost to 15psi?
otherwise theres no point fitting an mbc if its going to stay closed as i wont get the benefit if iam already using a 15psi spring in the Tial wastegate?

 

You have to hook it up like this:

It will not lower target MAP RPM though because its a TiAL product that works perfectly if you install it as suggested.

 

I run a 16psi spring combo for my base boost and adding the Hallman MBC did make a big difference in mid range spool. I now get 16psi at 4500 rpms where before I made that at 5300 rpms

This was yesterday, in 5th gear

 

yes.

 

yeah there was no way for me to have mine hooked up like hustler shown and get 1-2 psi of control... it would just overboost because there is so little duty cycle change to hit more boost.

 

thanks for your post.ok you fitted a 16psi spring and boost came on at 5300rpm.
so when you fitted the hallman boost controller was it in closed position or do you have to open it until it just goes above 16psi.
what i was wondering is having a 16psi spring and your aiming to run 16psi anyway then by having a manual boost controller which isnt increasing boost doesnt sound like its going to make any difference?can you explain.Basically i cant see how a mbc can make any difference when it isnt increasing boost from the set boost controlled by the wastegate.

 

Read up on how wga's and mbc's work.

a wga will start slowly opening when car starts building boost. Meaning even though you will reach desired boost levels, the flapper is already open a tiny bit well before that point. meaning you will build boost smoother/lazier/slower.

An mbc is like an on/off switch. before preset pressure it forces the wga flapper completely shut, helping direct ALL instead of MOST gasses thruogh the turbine wheel. It only opens WHEN it reaches preset level, and not even a little bit before that.

that helps for boost to (sometimes) come in quicker and (always) come in harder/more suddenly.

 

Im running 17.5 psi now. That 1.5psi is worth it to me as having the MBC hooked up keeps the EWG closed just s bit longer to increase my spool. if you go with a n EBC that controls gain and all that jazz, youll see MUCH better results at the cost of a bit more complexity to tune.