LMM: Duramax tuner Stealth s467.7/s484 low boost

Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
I have just recently changed my turbo set up from a Danville 72vgt over a s484(96mm/1.32ar) to the new Duramax stealth s467.7 over my s484. I broke the shaft on the 72vgt so I figured I would up grade to the s400 with a bigger shaft and try a fixed vane. With this new stealth 67.7 (83mm turbine .80ar housing internal gate)that Duramax tuner just releasted seemed like a great option for and not having to get a new twin kit or make a bunch of changes to fit a s400 style charger in the valley just had to change my hot crossover pipe and it has a internal gate and uses a stock style pedestal. So On the Old set up (72/84) I would see about 80psi of boost, 1400*-1500* egt's and on the new set-up (67.7/84) I am only getting 50-55psi of boost and if I pinish off the Wastegate line I will see 65psi of boost. The waste starts to move at 20psi and is fully opened at 45psi. I have a low pressure boost gauge coming from the 484 and I am seeing about 50 psi from the s484 is that normal? My egt's are high I can hit 1800* on the street on the 5 tune and I have checked for boost leaks a few times (plugged and pressured tested the big turbo) no leaks. sorry for the novel but does anyone have any ideas???
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
Mark retuned it for the 67.7/84. He originally tuned it in his dyno. Hmm I figured the s467 would have moved more air then the 72vgt. The 67.7 has a lot bigger turbine
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
I already sold the 72 there wasn't much left of it lol compressor wheel and turbine wheel and shaft were screwed, compressor cover was mashed up and and so was the exhaust housing
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
I will say one thing about this new set up is I like driving it better. It is a lot more streetable and was less lag just need to get to make some more boost. Should get it on the dyno and see what it does compared to the old set up
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
What size of turbine does the 4094 Vgt use? I would think the 83mm would be a lot bigger and I thought that would have helped ? I think there should be more power potential in this set up, just have to figure out what going on. I want to install a drive pressure gauge this week a should pressure test the exhaust side. This set up over a s591 has made good power
 
mike diesel

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
hondarider552 said:
Another problem is that 83 turbine. I hated mine.
Click to expand...

I'm not sure this is a turbine issue since he is seeing 50psi from the 84mm. That turbine is allowing plenty of flow. For whatever reason, the gate seems to be blowing open way to early from either drive pressure, or boost.
 
S

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
You need a external adjustable spring to control the new gate. The vacuum line setup won't get the job done. It's opening and that why all you boost us coming from the atmosphere.

Sent from my SM-G920V using Tapatalk
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
Harbin_22 said:
How did you break the shaft on the 72vgt? I have put mine through hell and back.
Click to expand...

Well.... It started out that I bent the shaft after a pull. Mark figures it was when I let out of it after the pull 80psi of boost on the one side of it and no pressure on the other side bent it. I didn't even know it was bent till I went to drive home, was about 2 hours away from home so I tried to limp it home and about half way the shaft completely broke
 
Frankin_truck

Frankin_truck

Member
Nov 22, 2013
147
0
16
Bumping this back up. How could I drive the high pressure (valley)charger harder? I should see more boost out of it no? Drive pressure is pretty much 1:1
 
You must log in or register to reply here.
Top Bottom