Boost question.

zukgod1

zukgod1

Old fart
Joined
Jul 18, 2006
Messages
1,397
Hopefully you know about my truck, if not a quick run through.

07 5.9 truck with a 6.7 running the 5.9 electronics.
Industrial Injection 100hp R1tips
H&S Mini Max
CNG kit
Snow Water Meth kit
62/68/12 turbo
2 piece manifold
AFE intake
5"turbo back exhaust
ARP 625's.


I can barely hit 35psi if I'm under some serious load, otherwise ech on a good accel like a on ramp 30psi is seen.

With my listed mods I feel I should be able to load the piss out of that turbo and hit 45+ easy.
EGT's will hit 1400 by the end of said ramp with a pretty clean exhaust.

Am I high?

I've clamped off the waste gate completely and before that I adjusted the rod till it was out of adjustment.

Not that I want it to but I realized the turbo doesn't bark ever. Even under a heavy load like mentioned above and add a quick let off the skinny peddle just a quiet whoosh.

I've inspected the hoses SEVERAL times. Nothing.

I'm out of ideas aside from thinking something is up with the turbo.


sent from my mobile thingy while picking my nose.
 
madmikeismad said:
Pressurise the intake side?

Sent from my DROID RAZR using Tapatalk 2
Click to expand...

Not sure what that means?

Pressurise to check for leaks?

I did a smoke test tonight and after 30 min of nothing I gave up.


sent from my mobile thingy while picking my nose.
 
Last edited:
Begle1 said:
Inaccurate pressure gauge perhaps?
Click to expand...

Snow perf unit reads boost, H&S reads boost and I have a Autometer 0-60psi Guage.
All read within 1psi of each other.

sent from my mobile thingy while picking my nose.
 
Yes he meant check for leaks. You have to remember. Boost is not how much air your flowing. Boost is restriction. These 6.7's flow tons of air so you may not make as much boost as you think you should since your using up all that air flow from the turbo and out if the efficiency range of the charger. Get the larger turbo on there first and you will have better results most likely.
 
I've been leaning that way Gibson, I just didn't want to change it out only to discover there was another problem I over looked.
And that BW 66 I picked up had the wrong exhaust outlet on it so I'm leaning towards a II 66/71.

sent from my mobile thingy while picking my nose.
 
Im running sb66 with smarty factory sticks for now. i can only hit 38 psi. another guy i know with same setup was hitting 60? I have tried tightened the boost elbow and changed nothing. Its not like i need more boost. I was just curious what it would do.
 
What do you mean wrong exhaust out let? To run the box stock units you need to get the exhaust flange and clamp from forced inductions. It's about $35 for both. Just weld that to your DP and your golden. Don't get that II one.
 
Gibson said:
What do you mean wrong exhaust out let? To run the box stock units you need to get the exhaust flange and clamp from forced inductions. It's about $35 for both. Just weld that to your DP and your golden. Don't get that II one.
Click to expand...

Well here's the deal.
It has a HX40 outlet and I have a 3rd gen Jake Brake I want to keep. I have yet to find something I can put between the Jake brake and turbo that will allow me to use this one.

It specs out like this.

Compressor
Inducer, 66mm
Exducer, 96mm

Exhaust Turbine
Exducer, 73.3mm
Inducer, 79.6mm
.81 housing T4 non divided.

What scares me aside from the HX 40 hook up is the size of the exhaust wheel combined with the non divided housing.
Seems like it would be a lag pig/ not for towing turbo.
The compressor side is fine I think but the Exhaust Turbine.....
 
Remember it's not all about boost. It Sounds like the Turbo is doing it's job at that 35psi of boost. Egt are in check and not overfueled. How are drive pressures?

from phone
 
ClamDigger4 said:
Remember it's not all about boost. It Sounds like the Turbo is doing it's job at that 35psi of boost. Egt are in check and not overfueled. How are drive pressures?

from phone
Click to expand...


EGT's are not in check.

1400 in 2 blocks is not good. If I keep my foot in it 1600 shows up fast.
Just normal get up to speed on ramp is 1400 and clean exhaust.

If I floor it and stay in it black Smoke pours out the tail pipe as well and 35 is rarely seen. usually no more than 30.

Dont get me wrong this turbo does great I just REALLY feel I'm leaving power on the table with the 62 and I should get more PSI/flow out of it.
 
I guess the comparison was the 5.9 I took out, I could push 45psi with stock sticks and the H&S on Mild.

Now I'm running a 6.7 with 100hp sticks and a larger (not that much larger) turbo and I can barely hit 30.

Just seems off to me.
 
zukgod1 said:
EGT's are not in check.

1400 in 2 blocks is not good. If I keep my foot in it 1600 shows up fast.
Just normal get up to speed on ramp is 1400 and clean exhaust.

If I floor it and stay in it black Smoke pours out the tail pipe as well and 35 is rarely seen. usually no more than 30.

Dont get me wrong this turbo does great I just REALLY feel I'm leaving power on the table with the 62 and I should get more PSI/flow out of it.
Click to expand...

That's not the way I understood your op. The 6.7 can handle way more air and a larger Turbo mainly due to cubic inches. The bigger the bore the more air it takes to fill it. So boost will be lower on the 6.7

from phone
 
ClamDigger4 said:
That's not the way I understood your op. The 6.7 can handle way more air and a larger Turbo mainly due to cubic inches. The bigger the bore the more air it takes to fill it. So boost will be lower on the 6.7

from phone
Click to expand...

Now that makes sense to me and you arr correct I left out some important info on the OP.
 
They make a deal that goes from hx40 to the 351 outlet.

HE351 to HX40 Adapter Flange

Just flip it To the way that makes it work for you. Most use it for 351's to hx40 dp's but since you have an hx40 outlet and want to still use the factory elbow brake, you can still use this.

The non divided housing may be an issue but better than your current set up. . But don't get discuraged because the current charger is not acting the way it should. If you just listen and look at the results that others have listed and posted about you will be much happier.
 
running just h&s tunes with intake an 5in exhaust an stock charger i can hit 38psi everytime with my foot to the floor
 
DirtyMaxx03 said:
How many degrees of timing are you running?
Click to expand...

Whatever it auto loads. I didn't change it however, I did have it one step advanced until yesterday (not sure what that is) but I reloaded the tune and took it back to what ever it loads originally.

I bumped low boost fueling 2 steps as well

04cummins kevin said:
running just h&s tunes with intake an 5in exhaust an stock charger i can hit 38psi everytime with my foot to the floor
Click to expand...

This is what I'm talking about right here......... WTH?!
 
Your not getting the point.

Boost pressure is not the same as flow.

40psi from a stock charger on 5.9
VS
35psi on a 62 mm charger

I bet the 62 will make more HP everytime because it flows more air.

Also I could take and put a side draft intake on and port the intake/exhaust side. I'll gain HP but I'll loose boost pressure because I removed restriction.

I think you are just out of the efficiency range of your charger and over spinning the shaft drastically. And the engine uses up the charge air immediately. Hince the low boost your seeing.
 
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