D24T.com  

Go Back   D24T.com > Technical Discussion Area > Performance and aftermarket

Reply
 
Thread Tools Display Modes
  #1  
Old 06-01-2017, 01:06 PM
718Pinz 718Pinz is offline
Junior Member
 
Join Date: Jan 2015
Posts: 19
Default Boost, EGT and smoke issues....

Hello everyone. I need some of your collective knowledge to help with my problems. Here is where I am sitting engine-wise:

Rebuilt motor bored to largest oversized pistons
12mm pump
Turbonetics Super 60 T3 with .82 ar
Turbonetics WG
Turbonetics manual boost controller
Air/water intercooler
Boost gauge
EGT
ARP Head Studs
3" DP

Now to the problems:

-Not building more than 10 lbs of boost...why?

-Black clouds of smoke (I think I about have this figured out)

-IP timing set to .96. Make minor adjustments with the inboard/outboard rotation. Outboard (to driver side) brings the EGT's down and runs better. Inboard raises EGT's and runs worse.

-Boost builds, then falls off at the high side of the rpm's. I initially thought it was due to excessive back pressure so I went up to a 3" down pipe. It helped with the smoke issue and seemed to help overall, but something is causing the boost to fall off and not reach over 10 lbs. My target boost is 20 lbs...just can't get there for some reason.

Any suggestions?

Thanks,
Phil

Last edited by 718Pinz; 06-01-2017 at 01:48 PM. Reason: Update about Boost falling off
Reply With Quote
  #2  
Old 06-02-2017, 08:27 AM
v8volvo v8volvo is offline
Administrator
 
Join Date: Jun 2009
Location: WA
Vehicle: '86 745, '83 764
Posts: 987
Default

Suddenly started doing this or been this way since it was first put together?

Sounds like an air inlet restriction issue. The smoke and high EGT suggests there should be more than enough drive pressure to spin the turbo but loss of boost with RPM says something isn't able to move enough air to keep up.

Where are you measuring boost PSI, after the intercooler or before it? If you are measuring it after the intercooler, have you checked pressure drop across the cooler?

What kind of air filter are you running? Checked vacuum on the turbo inlet?
__________________
1986 745 D24T/ZF
1983 764 D24T/M46
Reply With Quote
  #3  
Old 06-02-2017, 09:33 AM
718Pinz 718Pinz is offline
Junior Member
 
Join Date: Jan 2015
Posts: 19
Default

I am pulling the vacuum off the back of the intake. We smoked the entire intake yesterday and found a small leak on a weld in one of the intake pipes just before the intake manifold. The silicone is good quality and pretty small runs in between hard pipes. I am running 3" into the turbo and 2.5" from the outlet to the intake, which is a very short run.

These problems have been there since it went back together. There is nothing obvious jumping out at me about this. I even took the air filter out of the box, just in case that was a restriction.
Reply With Quote
  #4  
Old 06-02-2017, 10:30 AM
v8volvo v8volvo is offline
Administrator
 
Join Date: Jun 2009
Location: WA
Vehicle: '86 745, '83 764
Posts: 987
Default

Good to fix the leak but it shouldn't cause boost to fall with higher RPM. Something about the way this setup breathes isn't right.

Are you able to check the boost pressure ahead of the IC? Eg from the wastegate signal line? You are sure the wastegate is seeing the same pressure signals the intake is? If there is restriction in the IC then that's going to cause the exact issue you are experiencing. Boost controller and wastegate the right parts installed the right way, correct spring choice, etc?

The 3" inlet, is that direct from atmosphere or is the snorkel still in place?

How recent is the fuel filter? If there is fuel system restriction causing retarded timing at high RPM, that can cause issues. Pinzgauers have a primary fuel filter under the body in addition to the main secondary filter on the engine, are both of them fresh? Tank pickup clean, tank vent OK, etc? Checked fuel inlet vacuum under load?

How does it start and run otherwise, basics like cam timing and valve clearance are all right on?
__________________
1986 745 D24T/ZF
1983 764 D24T/M46
Reply With Quote
  #5  
Old 06-02-2017, 11:28 AM
718Pinz 718Pinz is offline
Junior Member
 
Join Date: Jan 2015
Posts: 19
Default Photos of intake

Here is the short air run. Straight to the turbo, super short run to the IC and then about 1 foot to the intake manifold.




Reply With Quote
  #6  
Old 06-02-2017, 07:26 PM
Cgingrich Cgingrich is offline
Junior Member
 
Join Date: Apr 2017
Location: Illinois
Vehicle: 740
Posts: 9
Default

Wastegate stuck open possibility? Or something up with the boost controller?
Reply With Quote
  #7  
Old 06-06-2017, 08:22 AM
v8volvo v8volvo is offline
Administrator
 
Join Date: Jun 2009
Location: WA
Vehicle: '86 745, '83 764
Posts: 987
Default

Nice looking setup. However we can't tell you much from the pictures unless you do some checks and get answers.

I suggest you start by plugging your boost gauge in somewhere ahead of the intercooler, best way may be to tap into the line running from the compressor housing to the wastegate. Take it for a drive and see if you are seeing the same boost response as you saw in the intake manifold.

If you see no change, then you'll need to check the wastegate and boost controller for correct configuration or other issues, and check again for possible restrictions in the air inlet to the turbo, the exhaust, or the fuel system.

If you do see different pressures from this test, then it means you have a restriction in the intake path between the turbo and the intake manifold, probably in the intercooler, the intake manifold inlet, or one of the hose connections.

We'll be able to help you more once you have concrete answers to these questions, until then, we can only speculate.
__________________
1986 745 D24T/ZF
1983 764 D24T/M46
Reply With Quote
  #8  
Old 06-06-2017, 04:10 PM
anders anders is offline
Supporting Member
 
Join Date: Jul 2010
Location: NW Washington USA
Posts: 738
Default

Is there still black smoke present when you have 10lbs of boost?
What is the EGT?

Are you going to try the .48 AR turbine housing or stick with that large turbine housing?
__________________
12mm pump heads, ARP stud kits and GTD nozzles available! http://d24t.com/showthread.php?t=1646
NA intake manifolds and 240 turbo pans for sale.
Need d24 or d24t parts? PM me!

1982 242 D24+T/M46- Super pumped! Build thread:
http://www.d24t.com/showthread.php?t=1545
1984 764 D24T/ZF build thread: http://www.d24t.com/showthread.php?t=1734
Diesel parts cars: 82 244,83 244, 84 244, 84 245, 85 745

Last edited by anders; 06-06-2017 at 04:12 PM.
Reply With Quote
  #9  
Old 06-06-2017, 04:56 PM
adamdrives adamdrives is offline
Supporting Member
 
Join Date: Feb 2016
Location: Hudson Valley NY
Vehicle: 1985 744 D24T M46
Posts: 133
Default

This is basic, but main fuel adjustment can have a huge influence boost behaviors. I won't pretend to fully understand why, just observed this from adjusting my pump over time. Have you played with the main fuel? From your specs it seems like you are familiar with the setup, but you didn't mention. Even a quarter turn can mean building 10 psi and bottoming out or building 20 quickly.

Backing out star screw (LDA, top of pump) really helped me with low rpm/boost smoke, at with noticeable change to overall power. No matter what power you're making, having that adjusted in fully will make clouds of thick black smoke with no real benefit in my experience.
__________________
1985 744 D24T M46 49mm t3 @20psi 280k
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 11:43 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.