24v twin issues

dodgeram2500

dodgeram2500

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Apr 9, 2008
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208
I built a twin set early last year and have been having some issues. My turbos consisted of an ATS Aurora 3000 and a 32cm Ht3b. I first built the kit with an external wastegate (as the aurora has none). When I first fired it up, There was a huge cloud of smoke that came out near the turbos. After a few miles of driving i noticed soot everywhere, max egt was about 1600, and I only had 30psi of boost pressure. It didnt spool till about 2500rpm. Then I got a 23cm housing for the Ht3b, it spooled about 2000rpm but no more air. I rebuilt the hot pipe and figured that would cure my boost problem and egt problem. Not the case. My last rebuild consisted of removing the external gate, and building smaller piping ( 3in piping vs 4in piping) The truck ran a 14.1sec quarter mile @ 97mph with my current setup at about 40psi and 1400 degrees. (HRVP44, 100hp JL injectors, Edge, Methanol, twins) My big issue is the exhaust leaks. I have torn down, inspected, and rebuilt this twin setup more times than I care to think about. The exhaust is coming from where the hot pipe meets the smaller turbo, and between the manifold and small turbo. I've been wanting to rebuild the engine soon to be a drag race only truck, but with the issues I've had, I'm about to put it back to stock and go back to a gasser. I've put in hundreds of labor hours and thousands of dollars to get this truck to run good. And now I think it runs worse. I'm not the best metal fabricator/welder, but I can do just fine. I am wondering what my issue is. besides the exhaust leak, i can't find anything else wrong with the truck. The smoke is un-controlable, same as the egts. With no load at 65mph, it runs about 1000-1100 degrees. Going up a hill pretty much pegs the pyro. Ive been told to run larger injectors, but wouldnt that make the truck run hotter??? Anywho, That still wont fix the exhaust leaks. If anyone has any input, I would appreciate it. I just don't know where to take it from here???
 
How did you do your charge pipes? Are you 100% sure you dont have any boost leaks? I bet if you have exhaust leaks like that, then you probably have boost leaks like that too
 
Larger injectors needs more heat/fuel to light the chargers I ran a 35 over ht3b with about 75 psi you need more fuel or something is not Right...

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The first place I would start is to remove the manifold and top turbo and machine/ or belt sand/ or whatever it takes to get those two surfaces to seal.

Once the exhaust leak between the manifold and top turbo is fixed, take a test drive and check spool-up. If you still can't spool till 2100+ RPM, there is something either wrong with the top turbo (burnt turbine wheel), toasted bearings and one of the wheels are rubbing, bent shaft causing a funky wobble that won't let it spool up normally, hung open wastegate that's bypassing exhaust flow.

The HT3B with a 23 cm housing will spool by itself in the 2200-2500 rpm range you're describing.
 
My cold pipes are made from 3inch mandrel bent exhaust pipe. I am pretty sure there is no boost leaks, but it's been a few months sense I checked that. All my rubber boots are new with spring clamps. Last check was good. I actually had a boost gauge in the small turbos compressor housing and in the intake manifold, and they read identical. Never more than 45psi on a very cold day. Now for the exhaust leaks. I've tried to belt sand everything. I would think that having a Hot Rod VP44 and 100hp over injectors would be enough fuel to get the turbos to fire. But maby it's not. I just had the Aurora turbo rebuilt because of shaft play. The fresh turbo didnt change a thing. I dont have any good pics at the moment, but give me a few minutes and I'll run out to the barn and snap a few pics. Another thing, I live at 6000+ ft, if that would change anything were talking about...
 
Elevation will slow spool time but it shouldn't be by that much. Just remember that every drive pressure leak is taking away the energy you need to spin the turbos.

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There may be some underlying problems also, but I think you not having enough fuel is the biggest problem. What size nozzle and stock lift? I bet you are about right for an aurora 3000 as a single. I ran 7x0.10's with a 62/68/14cm, drag comp with a SO pump. I think you need to jump to 7x0.12.
 
Get rid of your hot side leaks first. Check for gasket and warp issues. You can't have big exhaust leaks and run well.
 
RonA said:
Get rid of your hot side leaks first. Check for gasket and warp issues. You can't have big exhaust leaks and run well.
Click to expand...

Listen to Ron, he know how to make power with twin turbos and fuel only.

I personally have had lots of experience with exhaust leaks, they always hurt spool-up and overall boost/power delivery.


Until your exhaust leaks are fixed, you won't know if there are fueling problems, internal turbo problems, etc.

I personally think you have plenty of fuel for 60+ psi out of that twin turbo setup. Is it possible to add a bung and install a cheap $20 oil pressure gauge from Autozone on the inter-stage cold pipe and see how much boost the HT3B is making compared to overall boost at the manifold?

I'd also suggest you build a 3" pipe section with an air fitting so you can pressure test the whole boost system from top turbo outlet to the intake valves. Sometimes nasty leaks can appear out of nowhere on the charge air cooler, CAC boots, intake air horn heater gaskets, intake manifold plate gasket, etc.

To recap, first and foremost is correct the exhaust leaks, especially anything between the head and the top turbo. Leaks in the hot pipe from top turbo outlet to bottom turbo inlet will hurt overall boost and topend performance but won't have a large impact on spool-up or the lower 1/3rd of the power band.
 
Ok. So I guess the first thing i have to do is get the exhaust leaks fixed. Then I will check for a boost leak with my tool. It seems like I've done this many times.:bang I have a 3 boost gauges installed at the moment. Primary is about 20psi, Secondary has about 40-45psi, and 40-45psi at the intake horn. I usually run the truck without the comp box because it smokes like a coal train with it on. When I do use it, it's on level 5x2. The Edge box is the drag version if that makes a hoot. The injectors I am using are from JL Machine. I'm not sure of the lift/size/etc. He told me they were 100HP over stock.

Before I did the twins and JL injectors, I was just running the Aurora 3000 and a HRVP44. Without the edge box on, the truck ran nice and cool. With it on, it ran good, but a bit toasty. So I figured I'd add an Ht3b to the mixture. The truck wouldn't spool the turbos at all. After speaking with a few people about what size injector to go with, I got the 100hp over stockers. And you know the rest of the story...

I also swapped out my 5spd manual for a 47RH that I built. I did this at the same time as I did the twins.
 
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