I'm developing a turbo system for my car (99 Cougar 3L V6). I have everything done except for the vacuum routing. This is my first turbo system, so my knowledge of the vacuum system is limited.

My system has the following components:

Precision SC-61 Turbo
TiAL 38mm Wastegate
TiAL 50mm BOV
AEM TruBoost Boost Controller

So, my question is this. AEM recommends the following configuration for the boost controller:



However, I think taking the reading from the turbo outlet vs. the manifold cheats the pressure drop created by the intercooler. Therefore, I think it would be more accurate to do like the following diagram where 1 & 2 are tied into the manifold pressure, NOT the turbo outlet pressure. In this example, the turbo pressure port would be capped off.



Your thoughts and input are greatly appreciated!

BTW, below are some pictures of my setup:

 

off topic but thats the best cougar setup I have ever seen.

 

Thanks, it was all done by me in my spare time on weekends. I only have a MIG machine, so I had to use SS for the intercooler piping as well

If you want to follow the buildup of the car, I have a thread on the forums that I own/run. Word of warning ... the index in post 1 is outdated and the thread is extremely long.

http://www.newcougar.org/forum....html

 

tap the compressor housing for the boost source, you do not want the wastegate to see vacuum at all, and you don't want to over spin the turbo

BOV should have it's own source off the intake manifold with 1/4in ID vacuum line minimum

 

What about tapping my intake before the throttle body to get a more accurate boost reading post-intercooler?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FastCougar &raquo;</TD></TR><TR><TD CLASS="quote">What about tapping my intake before the throttle body to get a more accurate boost reading post-intercooler?</TD></TR></TABLE>
you could tap the outlet of the intercooler

 

So, as long as I tap the intake before the BOV, be it at the intercooler outlet or the intake pipe, I should be OK?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FastCougar &raquo;</TD></TR><TR><TD CLASS="quote">So, as long as I tap the intake before the BOV, be it at the intercooler outlet or the intake pipe, I should be OK?</TD></TR></TABLE>
before the throttle body yes, but i would strongly advise using the compressor housing as the source

 

Why run the source from the compressor housing when there is a pressure drop between the turbo and intake manifold? It seems using the intake manifold as the source would be more accurate as its the actual boost the motor will see. Or is this a matter of "signal strength" rather than where its referenced?

 

Can u over spool a turb? isk maybe u have leak that goes in an out because of heat(shrinking or getting bigger) an u have it at the intake. reads 10 psi but the turbo is push..13psi. maybe the heat of the motor fixs the leak..i dont think will happen..an now u boost 13psi which your not tuned for. follow? idk if that makes any sence.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Why run the source from the compressor housing when there is a pressure drop between the turbo and intake manifold? It seems using the intake manifold as the source would be more accurate as its the actual boost the motor will see. Or is this a matter of "signal strength" rather than where its referenced?</TD></TR></TABLE>
over spinning a turbo if there is a huge pressure drop (ebay intercoolers), sucking the diaphragm in and possibly damaging it (if it's on the manifold)

if you had a leak in your pipes/IC and the source was on the UICP you would probably overspin/kill the turbo

 

well, my buddy ran high 9's at NHRA this weekend, he, along with many other cars i know (including mines) use the compressor housing as our source. just food for thought.

 

Well, I ran the line from the compressor housing and everything runs great ... too great! at just over 10psi, I began to demand too much fuel from my stock fuel pump, so the car is currently down while I fit a Walbro 255 lph pump. Here is a nighttime run of the car, reaching 8psi:

8 psi night run: http://www.newcougar.org/media/8psi_night_run.wmv (2.13MB WMV file)

In the above video, I do a roughly 30-95 MPH run in around 8 seconds ... the car has PLENTY of power on tap and MUCH more to come!

 

Forgot to add ... all the A/F bouncing around was because I had the wrong spring in my BOV, which was opening during idle and sucking in air. I have since replaced both the BOV and wastegate springs and the car idles nice, with no fluctuation in the A/F. I put in a 13psi spring in the wastegate, so with the controller, I should be able to see 20+ psi. Once the fuel pump is in, it will be going to the dyno.

 

looks like a tight fit