A while back I put on an HX-40 and an ATS exhaust manifold. Oddly enough after doing this my EGTs on the highway and while driving around actually seem warmer than they were with my HX-35. I was running the 35 at 45 psi of boost while this one is waste gated at around 35 psi. Does this make any sense?

Thanks,
Keith

 

The 40 probably has a bigger housing on it and will run hotter going down the road. If its not big enough to catch up with the fuel it will never be able to cool the temps off. I think a 40 only moves 200 more cfm than a 35. I really like a 35-40 hybrid better than a straight 40.

 

The HX40 would have to be an improvement over the 35 is you're pushing that little guy to 45PSI! Your lucky it didn't explode.

Try setting the WG on your 40 to 38psi or so. The larger turbo will have higher average EGT, but lower peak-- or it should, anyway.

jh

 

Well on short bursts around town up to around 60mph I have gotten it up to 1500 for a second or two with my box only on 4. Never tried anything higher because of low lift pump pressure at the higher numbers. Running down the highway at about 80 I get about 800 deg. temps and going up mild grades on the interstate usually get around 900 or 950 deg. All empty truck.

So would an even larger turbo help me or would I then need to go with a twin turbo setup? I really expected the HX-40 to make a bigger difference.

Thanks,
Keith

 

You have to keep in mind that the PMAX competition edition (PMCE) is about the hottest 24V box money can buy-- literally.

The other thing to remember is that your DD3s are honed sticks and won't burn quite as clean as some newer EDMs might. At least that was the case when I switched from honed DD2s to Mach 4s. Cruise EGT and ease of smoke actually went down.

Twins would probably cool the combo, but I can't think of any single that would limit your peak EGT to 1300 under load, (though maybe when just empty). The TST box is just an animal, and #4 on your box is like #9 on a regular TST, which is already a hot box!

The EGT numbers you are posting sound right to me for the combo you are running.

A couple things to consider besides injectors:

-- The TST adds no timing, and some kind of timing product (like a Smarty tuner or EZ box) would really help with bottom end response and cooling EGTs a bit. Smarty's the best, but you have to go with what your budget allows.

-- If your HX40 is just an off-the-shelf unit designed for a C8.3L Cummins, then it isn't optimized on your smaller engine. The 5.9 compared to the 8.3 needs higher pressure ratio, even at the same airflow because the smaller engine can't swallow the air as fast. The Holset Super40 is a much better match to the 5.9 because the wheels are designed for the higher pressure ratios we need on our 5.9s.

A shop like Hi Tech Turbo might be able to mod your stock HX40 and make it into a Super40. It's not a huge difference, but an improvement nonetheless. You'd probably be better off with one of their Borg-Warner based turbos if you want to stick with a single.

Twins work VERY well, and ultimately they are the most versatile and highest performance. Your stock unmodified 40 will work well in a twins setup. Just buy a kit designed to use it and you're ready to rock.


Honestly, you can dink around with singles that are marginally better at cooling, but to gain any real cooling you lose a good chunk of spoolup (and hence, towing). Going to twins will save you more heartache (and $$) in the long run, imo.

HTY

 

Just a dumb question, Where was pyro located on with your stocker turbo? Now where are you measuring the egt's at? I drill two holes in my ATS manifold and installed a drive pressure and pyro probe.

 

Thanks for that great info. I used to have the TST modified ECM but lost that which I believe modified my timing. I don't have alot of cash right now but will in the near future so I think I may look into a twin turbo setup and also new injectors since mine also have around 70,000 miles on them.

I am not sure if my HX-40 is an off the shelf turbo. The place I had put it on works with high performance diesel trucks and they specialize in turbos and fuel pumps. How would I know if it was something special? Could I tell by looking at the intake blades? If I call them what would I ask them? Just weather or not it was a standard HX-40?

What EDM injectors would you recommend? Considering I have the PMax I would think that maybe the Mach 3 or 4 would be all that I would need.

Thanks so much,
Keith

 

How long ago was the turbo installed?

The super 40 hasn't been out that long (~2yrs)....

Odds are that the diesel shop may have modded it a bit like PDR did to the 40s for awhile.

I'd call Paul at Hi Tech Turbo for help on turbo identification.....

TST-modded ECM?? Wow! That's old-school 24V bombing! It wasn't long before Cummins made him stop, which is all the sadder. In fact, they were so good I think that's what inspired Marco to continue refining the ECMs and ultimately produce the Smarty Tuner we are blessed with today.

 

The stock 40 I was running on my 97 run about 8 to 900 down the road and went to about 1700 under full trottle. On valet at around 325 to 350 horse I'm just guessing it would go to about 1300. I went to a 35 with a 58 mm wheel and a 3e with a 22cm housing and now can't get it over 1100 degrees. It runs 650 down the road and is now a pleasure to drive. I never did like the 40, it was a lag pig and never cooled the temps down. That's why I would rather have a 35-40, at least it is responsive even if temps are almost the same on the top end.

 

My turbo was installed last summer.

I loved my modded ECM but after some strange dash lights and a wierd idle Dodge told me the ECM was bad and I replaced it. Oddly enough the guy at Cummins told me that they had thrown it on a tester and it showed up as being fine. He also said that having a bad ECM was very rare.

I got my ECM modded by Mark as he was passing through the Kansas City area and I just met him in a parking lot and he did it there. What a kind and knowledgeable man.

What is the maximum safe boost for an HX40? I ran with my HX35 at pressures up to 47psi and it lasted for 130,000 miles then just slowly started scraping on the housing. Granted most of the time it was running around mid 30's in pressure but at least once a day it would get up into the 40s.

Keith

 

You have any problems with the drive pressure line plugging with soot?

Jim

 

Keep the HX40 under 40psi or you'll end up with a turbine wheel in your downpipe.

jh