Ford Mustang Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
411 Posts
Discussion Starter #1 (Edited)
Dyno'd the Hellion today. With the small blue spring (8.7psi), they were seeing only 5 to almost 6 psi on the dyno. 447rwhp by the way.

My question is the Hellion kit directions had me install the vacuum line from the wastegate to the outlet of the turbo. After what I saw today, it seems to me that this would not give the correct amount of boost at the manifold? Wouldn't I be losing a few psi between the turbo outlet, intercooler, all the piping and into the manifold? Thus while the turbo might be seeing 8.7 psi, what I am worried about is what boost is actually making it into the manifold, right?

Would there be any problems if I move the wastegate vacuum reference hose to right before the throttle body and would I end up getting more boost to the manifold this way?
 

·
Registered
Joined
·
3,647 Posts
I would put the line AFTER the TB.
 

·
Registered
Joined
·
300 Posts
Running your boost/vac source from the manifold/vac tree will get you the boost you want for the spring you have in the gate. I know on my setup, running the vac/boost source from the turbo housing got me way less boost than I wanted because the i/c that came with my kit sucks ass. Running it from the manifold got my what I wanted.
 

·
Registered
Joined
·
3,221 Posts
A couple things to think about.

Typically there is a couple psi loss in most systems between the intercooler and the sheer amount of cold side tubing. Referencing the manifold gives you a more accurate source if you want to match the wastegate spring setting. When in boost, it also put’s a vacuum on the wastegate diaphragm which keeps it shut longer giving you slightly less lag (and quicker spool between shifts).

While many do just that, keep in mind that most wastegate manufacturers do not recommend putting a vacuum on the wastegate diaphragm as it causes it to deflect in a way that could lead to pre-mature failure. That’s not to say they will fail (or conversely won’t), it’s just one of those things that most do at their own risk.
 

·
Registered
Joined
·
7,611 Posts
why is it that lot of people advise to get your source for the WG prior to the tb plate and not after it? pk
 

·
Registered
Joined
·
3,221 Posts
i have my turbo outlet hooked up to the WG and I see a solid, scary 10 psi?

Should I change it millhouse??
Not unless you want to increase the amount of boost your running. Remember, by referencing the turbo's your system does not take into account the pressure loss seen with the cold side tubing and intercooler.
 

·
Registered
Joined
·
3,221 Posts
tial's directions clearly show hooking the vac line right before the tb. not at the turbo.
That's because it's as close as you can get to manifold pressure without applying a vacuum to the system.
 
1 - 10 of 10 Posts
Top