Single Turbo Setup Can't Reach Wastegate Pressure

Arrtus

Private
Apr 24, 2021
32
4
0
Hey guys,

I originally had posted this in the N54Tech forum but got little to no help. I'm really stuck on and can't understand what is causing this problem.

This is a brand new DR700 setup and ever since making the swap, I am unable to reach more than ~9 psi (14 psi spring). The car is obviously way underboosting and I have no idea why. All the vacuum lines have been checked and are brand new. I have pressure tested from the turbo output all the way to the charge pipe and have found no issues. I also tested the compressor housing side of the turbo (and intake) and it did not leak whatsoever. I went through all the V-band connections and everything is on correctly and tightened to the max.

Symptoms: The car sounds different. I don't know if it's because of the single turbo but when going on WOT it doesn't sound like it's spooling. It's also very loud, like it just changes sound as soon as it starts building pressure.

With other maps, the wastegate (I think?) starts pulsing and sounding like it's hitting a rev limiter or 2-step while it's on WOT. It's most likely because of the mac that it's switching the air into the wastegate but it's not able to hold pressure or something. With maps aiming at higher PSI, it reaches ~12 PSI. What would cause the wastegate to do this? Can it be defective? It's a turbosmart gen V 45mm. I also checked the wastegate by putting some pressure on it and I can hear it open and closing. The MAC solenoid is also working just fine (which doesn't matter since it's not in use in map 0 and the problem is still there).

Log of a map 0 pull attached. Any advice or suggestions would be really appreciated!
 

Attachments

  • P30_M0_R1_210424_160558.csv
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SLOWESTN54

Captain
Feb 9, 2021
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B.C. Canada
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2007 E92 335i
WHAA that's crazy. Now I don't know what to think. I have the whole kit and a V2 manifold arriving at my house tomorrow, new. I don't know whether to try the V2 or send it back for the cast now or what
Sell the kit, and go with a speedtech :)
Edit, sorry it went that way, hopefully you find a solution that works.
 
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Reactions: Torgus

Steve135i

Specialist
Nov 16, 2020
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New Jersey
Ride
08 135i e88
Well I'm finally about to put my car back on the road. It's been done for weeks. Just waiting for nice weather. I have v2 manifold. So we will see what happens In the coming weeks
 

Arrtus

Private
Apr 24, 2021
32
4
0
DR is not doing well it seems. Cracking tubular ST manifolds that are welded in China. Now the china cast ST manifolds are cracking...

Speedtech is going to own the N54 ST market.
Are you serious? I thought they made their own manifolds? That's unbelievable

Can you provide details on where you found that info?
 
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Arrtus

Private
Apr 24, 2021
32
4
0
Well I'm finally about to put my car back on the road. It's been done for weeks. Just waiting for nice weather. I have v2 manifold. So we will see what happens In the coming weeks
Let us know how it goes! By the way, if you do a log, can you check to see when you're hitting peak boost?
 

Torgus

Brigadier General
Nov 6, 2016
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Boston
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ACF 6466 E92 + METH
Are you serious? I thought they made their own manifolds? That's unbelievable

Can you provide details on where you found that info?

Payam @ bms posted it on an n54 forum.

Apparently you can outsource anything these days.

I am sure they can and do make some of their own. Low quantity, prototypes, one offs, etc. But I really shouldn't speak of their capabilities because I know little.

But if the volume is there a pallet of manifolds might be the more economical way to go. Granted quality might be compromised. They have experience with cast products like their cast intake manifold, lots of other cast manifolds for various engines, etc. Speaking of which they promised over a year ago to offer a n54 sheet metal ff im. No news on that yet. But they seem pretty busy from instagram.
 
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