Wastegate Line

[cob32187]

I got my gauges installed so i decided to play with it. I made 2 runs on a stretch of road, one with the line plugged in and one unplugged, but the time was the same for both runs. When the line is plugged in i can get about 15 psi, with it unplugged i get about 22. My guess is that with factory programming, it doesn't dump enough fuel to make use of the extra boost. Also i notice when building boost for the launch, i had about 2 less psi with it unplugged. Also, what are the pros and cons with hooked vs. unhooked?

[sea71]

I agree 100%. When I was in Texas at the Sealy meet last year, I ran 1 run with the line plugged, and 1 unplugged. 15.91 on BOTH runs. So, more boost doesnt necessarily mean more power. I have also heard some of the techs talk about the extra air is wasted after a certain point.

[cob32187]

Yeah, ive heard that after about 28 psi the extra boost is a waste because the air ends up heating up so much.

[cob32187]

[SCUFFY828]

hooked or unhooked whichever works for you , you said it did get more boost which it should have , if you get you a cheap bost fooler and see if the extra boost along with the map sensor not trying to get the pcm to defuel , may get an advantage there

[cob32187]

it didn't throw any codes for over boost though.

[Hank]

Originally Posted by cob32187

I got my gauges installed so i decided to play with it. I made 2 runs on a stretch of road, one with the line plugged in and one unplugged, but the time was the same for both runs. When the line is plugged in i can get about 15 psi, with it unplugged i get about 22. My guess is that with factory programming, it doesn't dump enough fuel to make use of the extra boost. Also i notice when building boost for the launch, i had about 2 less psi with it unplugged. Also, what are the pros and cons with hooked vs. unhooked?

Hey Jake! Long time no talk!

I ran my truck with and without the wastegate tube connected. Hooked up I got 17 PSI. Plugged I got 23 PSI. No gauges yet. I was checking mine with a scanner hooked up to my laptop. I put it on the dyno last weekend and did the same test. Higher boost resulted in the truck defueling at a lower horsepower. Lesson learned: Get a fooler of some sort or you're wasting the extra boost gained. (No pun intended.)

Wheels/tires are stacked in the driveway. Sig below shows the new shoes!

Hank

---

Last edited by Hank : 06-29-2008 at 06:46 PM.

[SCUFFY828]

Originally Posted by cob32187

it didn't throw any codes for over boost though.

its few and far between that i see an overboost code , that doesnt matter , it still very well could be trying to defuel, get a boost fooler

[Southpaw]

Mine doesn't set a code til 24 psi. But it sets it every time. My green map sensor wire is grounded, so it won't defuel, but it sets the SES light everytime. That doesn't bother me. If you get chipped, you will build more boost than that and you'll want a map fooler if it defuels.

[gtspowerstroke]

More boost does not mean more power, and your tests once agian prove that. Especially if the truck isn't smoking at all. At 22-23 psi of boost I highly doubt the fuel is beind cut back. If you have a scanner hooked up you can see what the mass fuel desired is and that will tell you if it's cutting fuel back.

Trying to make to much boost by unhooking the wastegate can and will decrease power once you get out of the turbo's efficienty range. It starts heating the air more than it's flowing more air and can actually flow less mass of air at a higher psi being it's to much hotter.

Southpaw if your PCM is seeing enough boost to set a code then it's most likely defueling as well. You may need to put a different value diode in your grounded wire to prevent the code from being set.