Rather than completely disable the wastegate by removing the red hose, why not adjust it to open at a higher pressure by shortening the rod?

Then the wastegate would still function as intended but you could still get the increased boost.

I know when I tried just removing the hose it only added about 2 psi, I'm just thinking if I tension the rod down I can get alittle more, maybe low 20's?

I know on the IDI diesels this is how they adjust their boost levels with wastegated turbos, just curious.

Thanks,

Bowedup

 

Your right! It's just easier for people to pull the red hose for a 2-3psi gain then try and tighten that rod to compress the spring. I used vicegrips myself.
The "C" clip is easy to loose,but, if u get enough tension on that spring the arm will never come off without the c clip there...mine hasn't...i lost that dang c clip long ago.
Nut

 

Thanks, is there a max boost psi for these engines?

My cousin has a 1997 PSD with the TS 6 pos. chip and on Fuel 7 he can peg 30psi on his Autometer boost gauge. I'm not quite sure I want that much, don't wanna lift the heads off the block!

Bowedup

 

25 psi is what the stock turbo is rated too...but many have pushed them to 30 for short periods with no issues. I have run to 27psi. Several factors effect what level it will reach...i.e. motor tune, boot leaks...etc.
Nut

 

Stock head gaskets are good to 40 psi, that's pretty much the limiting factor on the engine itself. I've had the stock turbo to 32 psi, and frequently see 25+ psi, but like nut said, the turbo generaly won't last as long when running over 25 psi.

 

a good thing to consider also is the effectiveness of the turbo at higher boosts... i am ABSOLUTELY NO EXPERT on this subject, but i have noticed that my engine does not make any more power, (at least not any that i can tell by the seat of the pants method), after i get past 26-28 lbs of boost... if you look on a dyno chart, you will see that as rpm goes up, so does the hp and torque of the engine... but, at some point, as you continue to go up in rpm, your hp and torque fall off so you are actually making LESS power in those upper rpm ranges... when you look at these on an XY graph you get your hp curve and your torque curve... this is why we have GEARS..! so we can keep the engine running in an rpm range that makes sufficient power and minizes wear on the engine thereby extending it's life and reliability.... i don't know, but i strongly suspect that the same is true of our stock turbos... go beyond a certain rpm and boost level and you have LOST performance... if there is no gain from running any higher boost than that point were performance falls off, why do it..? if the "thrill" of seeing how high you can get that needle to go is more important than the health and long life of your engine, tranny and turbo, then enjoy spending money replacing lots of expensive things long before you should have had to do so...

 

I think I am going to adjust my spring tension to limit the boost to 24-25 psi. I already have the boost pressure regulator for the MAP, but I think the exhuast pressure sensor is seeing too much drive pressure and making the truck defuel. I cleaned out the tube going to it a few days ago and now I cannot get the boost over 26 no matter how hard I try.
Besides I don't want to overload the turbo. My goal is to make the truck last not be a dragster.

 

I completely agree, my cousins truck will peg a 30psi gauge! I am currently seeing about 16psi, 18 with wastegate unplugged. I was thinking of adjusting the wastegate to open in the low 20's, or do you think it will not make any difference?

Bowedup

 

I'm hoping for more fuel at the top end because it quit defueling. I'll keep you all posted.

 

I don't know how you feel about it, but that code eliminator for the exhaust backpressure sensor from Black Cloud will solve your de-fueling issues. And, since you've already wired your EBPV so that you have control over it, you won't have to worry about elevated EGT's when it's shut and doesn't sense it needs to open, because you can open it yourself if you have it closed, say to warm the truck up.

 

the highest i ever saw on the stock setup was around 22 lbs boost with the wastegate actuator unpluged... that was towing uphill with a pretty good load..

 

Good point. The stock turbo's efficiency peak is about 17 psi.....and once you get past the mid/upper 20's you're off the map. All you are doing past that point is superheating the air charge. After that you need a bigger turbo to burn up that fuel.

 

Maybe that's where water/meth would come in handy.

 

Indeed...that's were the fun part starts

 

Would an ATS housing help to keep the intake air temps down at the higher boost levels?