HE400WG vs HE351CW for towing compound turbos? Turbo experts have a look

[2004HPCR]

Howdy,

Its true, I spend way too much time thinking about diesel performance, turbos, compounds and all manner of turbo diesel related things.

Ive done lots of reading on compounds, as it pertains to sizing and power levels/goals. Ive got a pretty good idea what im looking for, but a little advice would be appreciated.

Im putting together bits and pieces for a quick spooling towing compound setup for my early 2004 5.9 with NV5600. I have BBi stage 0.5 on their way, I dont plan on running big power (400hp at the most), just a efficient and smooth with as broad of a power band as possible. Sort of what Power Driven Diesel did with their ultimate towing compound kit.

Currently I have a HE351cw that I machined to accommodate the 76x64mm 10 blade turbine, a 60x86mm billet wheel and your run of the mill rebuild kit w/ gapless turbine seal. Ive been real happy with this turbo for the last 2 years. But I want more. Who doesnt.

I got a screaming deal on a brand new borg warner K31, its the version that is from a MAN engine. This one: Turbolader 53319707508 generalüberholt MAN D2876LF13 - Vorrätig ✅

Its the primary that im set on using, and seems the sizing is perfect for what ill be doing:
-71x94mm forged milled 7+7 compressor
-86x75mm 11 blade turbine
-20cm wastegated T4 housing (About 1.0AR).

I was planning on using my he351 as the secondary, but then I made the mistake of looking at what else was available...

I found this HE400wg. Looks like a he351 center cartridge with an hx40 turbine, but with a divided 13cm wastegated housing. This is the unit: He400wg |

I thought it was real interesting. I can think of a few benefits, what do you guys think?

From what the seller said, it has the 76x64mm turbine as well. And im pretty sure it would have the 60x86mm compressor that we all know.

I really like the idea of a divided turbine housing, at 13cm that should spool real close to what my 9cm undivided he351 does and without the restriction of the 9cm. Looks like the outlet is not as big as the he351 which would be great for when I weld up my hot pipe (3" nominal schedule 10 304 stainless elbow, 3.5" OD 3.25" ID). And I like how the wastegate isnt mounted to the compressor cover. One less thing to have to fab when you want to change things around. Looks like a promising unit I think.

Only issue is that im not sure what the wastegate looks like, probably would have to drill a hole between the scrolls just like what guys do with the hx35?

Should I give it a whirl?

Other questions:

Is there any benefit of using a 3.5" interstage pipe between the primary and secondary?

How about 3.5" piping all the way to the intake horn? I could modify the intercooler end tanks for 3.5" too. Its no big deal.

What about the silencer ring on the secondary, remove it or does it help?

Another idea I had was to weld thin inlet guide vanes just before the compressor of the secondary, to straighten out the air flow into the blades.

Anyways, those are the things that have been bouncing around in my head.

 

[AH64ID]

First off, if it's not too late I would get the BBi Stage 1's over the 0.5's. Every set of 0.5's I've worked around hazes, and generally cannot be tuned out. The Stage 1's have the same nozzle, just minor differences in how they are fired. You're going to want custom tuning either way so the Stage 1's will not be too large for what you're planning.

As for the secondary, I'd stick with the HE351. You own it, it spools well, and with a WG enlargement will flow plenty of air for your plans.

 

[2004HPCR]

Well, its too late for the BBi's. All the research I was able to do turned up some of what your saying, but that the trucks that haze sometimes had the same issues before the injectors got changed. As Martin mentioned, pointing to compression or valvetrain issues. Either way, there is a good reason why I went with the 0.5 over the 1's. But im not going to post that on here.

Would you agree with the statement that a divided 13cm T3 housing would perform nearly the same as an undivided 9cm T3 housing? With the same turbine in each of course.

If yes, then I think the biggest pro with the 9cm would be the really good wastegate design that it has, more than anything else. The wastegate hole is prioritized, angled towards the flow and can be easily made as large as needed. Cons: starts causing restriction above 20psi in the drive pressure tests that ive done, even with the bigger turbine. Also, the he351 outlet flange doesnt seal very good, and must be reduced quite a bit for the 3" nominal hotpipe.

The 13cm housing on the other hand, doesnt have nearly as good of a wastegate design. Right angles and im assuming only one scroll is probably wastegated. But the turbine outlet size looks better to work with and *IF* the spool is near identical, then the same restrictions might not be there. Some work could be done to help out the wastegate situation im sure, just have to get out the die grinder.

I have the opportunity to sell my HE351 plus get a good core out of it. So I could always change it up in the future too.

Just some ideas.

 

[AH64ID]

The flow will likely be similar, but...

If you're only talking 400 rwhp I don't think you will run into any detrimental flow restrictions... even at 450 rwhp.

I was running 375 rwhp on dad's 06 with a modded HE351 and just the 70x60 wheel and ZERO EGT issues, even at altitude.

 

[2004HPCR]

Gotcha. Well I definitely don't have EGT issues either. I have to really work it to get to 1000F. Because I keep it on a low tune most of the time.

By restriction I mean more drive pressure than boost. At 20psi it's 1:1, then at 25psi it's 30psi drive pressure, 30psi is 35-40psi. Etc. With the factory turbine it was way worst. Basically anything over 10psi the drive pressure would rise exponentially. At 30psi I was seeing 50-55psi drive pressure with the stock turbine. This is on stock fuel, and SW 2...

As far as I am concerned any time you can get rid of drive pressure, the better. It's unlocking free horsepower and torque, and efficiency (mpg)!

 

[2004HPCR]

Another question, whats the likelyhood that HE400WG is a good chinese knockoff? Anyone have access to the holset data base to run the assembly number?