71mm/88mm Low Boost Low Power

[paint94979]

Been trying to get an 06 CR 5.9 to run correctly... Problem is boost pressure. Previous tuners tune made 817hp then 750hp then 650hp same tune. Very inconsistent. I made a baseline tune for it.
920hp then 775hp then 825 again very inconsistent. S371 makes 40-45psi the 88mm is only making 18-20psi. Pinched the wastrgate hose and boom 1020hp basically all on the S371. Ran 100% stock file and primary 88mm still made 18-20psi. Any ideas?

 

[mike diesel]

What charger is the 88mm?

 

[paint94979]

It's a Borg Warner based charger. S400 frame

 

[dirtydmax]

Wastegate spring weak or broken?

 

[paint94979]

The secondary was rebuilt and the wastegate port opened up... No change

 

[Harbin_22]

Exhaust side of the 88mm is too big or something. Need a smaller turbine or housing to get it to spool

 

[mike diesel]

If it's an s400, then the exhaust side would be too small. The 96mm turbine isn't suited well for that big of a compressor. An s400 88mm might not be super efficient but it shouldn't have any problems spooling. I don't understand how it won't make boost.

My old turbonetics 88mm had a 112mm turbine and a 1.23ar turbine housing and with little 30% injectors, I could still get 25psi out of that.

 

[DPC]

Have you checked for boost leaks? Sounds like you have a leak between the primary and secondary.

 

[paint94979]

No leaks.

 

[Chevy1925]

Do the logs all look consistent on each of these dyno runs?

 

[paint94979]

So it's an S4T 88mm turbo from Industrial Injection. 1.45 A/R

 

[paint94979]

Yep holds rail. Timing is there and getting full uS. Pinched the wastegate hose and numbers become very consistent.

 

[mike diesel]

An s4t is not an s400 based charger. I can't find what turbine it uses but with that massive 1.45AR housing, that's your problem why it won't make boost. I'd swap an s484/96/1.32 ar, probably make more power and spool all day long. Those s4t's are old school from like 2004 and only rated around 120 lbs/min.

 

[paint94979]

Correct... I'm just tuning the thing... It doesn't run correctly at all. That setup should make 80-85 psi and it's hitting 60-65 psi. A 95mm charger based off of the S4T my buddy ran with the same secondary made over 1200hp so I'll guarantee they won't change out that charger

 

[paint94979]

Ok so update. Brand new 91mm center section went into the S4T same problem 18-20 psi on the primary. 55-60 psi overall. Im convinced it's not tuning as it is getting plenty of fuel. No leaks. The one issue that I think it may be is the wastegate actuator. When we tried to adjust the rod on the wastgate neither clockwise nor counter clockwise softened or hardened rod. What are the signs of a faulty internal wastegate? If the wastegate hose is pinched the power on the dyno becomes consistently over 1000hp but when it isn't pinched the power is all over the place. 700-1000.

 

[Burn Down]

Sounds like it's blowing the waste gate open Nick... If it's still running that 1.45 housing I would lock the wastegate closed. Not sure on how you adjust the actuator on that animal? Can you post a pic of it?

 

[paint94979]

This is the truck http://www.dieselworldmag.com/978-2/

 

[paint94979]

Magazines are full of shit lol. I was able to get it to 970hp with way to big of pulse width. The wastegate is now all the way shut. The load cell is messed up on the dyno so we're stuck to foot braking it

 

[Burn Down]

Not a bad looking truck. Except for the grill... And 1100 sounds way better than 970 Nick, Duh! Good job on the tuning, sounds like it was real pain:thumb:

 

[Chevy1925]

I think everyone was under the assumption you could adjust the boost via the wastegate. that doesnt look to be the case. if you put a boost regulator in line of that boost line to the wastegate, it should help get rid of your issue. if the gate still opens too early, the spring inside the gate is too weak and drive pressure is opening it.