*Legal statement: I’m in no way affiliated with any venders referenced in this article. I mentioned them because they provide excellent service and my personal experiences with there products. Using the below referenced modifications on a street driven emission controlled vehicle at your own risk, could result in fines. *
My 25+ years associated with different racing venues confirmed the need for correct heat management; this series will focus on maximum exhaust energy transfer.
I’ve been lurking for a while now watching the wild rumors fly about this and that, and reading numerous posts regarding high exhaust temps and purposed remedies. I seems to me that many folks are addressing the by-products and not the root causes of what is IMHO a poorly designed exhaust system. After thinking thru this whole topic I figure its time to share a few secrets about turbo power and turbine efficiency. It ain’t often a successful racer is willing to share power tricks and based on my latest soon-to-be X-girlfriends opinion, probably not the last time I screw-up but I figure since someone was willing to help me, then I will try to help whom ever is interested.
Ok, here we go-
Allow me to digress a little. The internal combustion engine is inherently inefficient and waste about two-thirds of all energy produced. Loses are about one third to friction, one third heat (radiator), and one third to drive the piston down. Since a diesel is more efficient than gassers and we utilize the turbo to recycle part of the waste energy, any improvements to further manage heat lose directly effect performance.
I removed the entire exhaust system from manifolds to down pipe and began the project. Since I’m attempting to help the average 6.0 owner, I chose to use the most likely tools one might have. Although my plasma cutter would have made things much easier, a 4” cutting wheel was used for all mods..
If you cant afford to have the truck down for several weeks like most of us and would rather work the project on your easy schedule then contact www.powerstrokeshop.com
a supporting vendor btw and ask Bob Baumann to ship the following new OEM parts asap
5C3Z-6K854-CA EGR Tube
3C3Z-9430-AB Lf manifold
3C3Z-9431-AB Rt manifold
This kit can be had for about $390.00 shipped to your door!
**Many thanks to all who posted pics and methodology of your efforts to help improve the OEM exhaust system** My intent here is to build upon your efforts and help those willing, to achieve thermal dynamic bliss with your Turbo diesel.
Overall, the 6.0 exhaust design is depressing…the manifolds are EXTREMELY restrictive, the Y-pipe has enough pressure drop to choke a 4.0 liter (just look at the transition where the two pipes merge at the turbo flange. Here’s another area of extreme turbulence and heat reflection),
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The EGR scoop blocks a full 40% of flow from the passenger cylinder bank. The scoop and EGR cooler ARE the root cause of most “puking”. The other causes are directly related to ones right foot and extreme cylinder pressures from improper tuning.
First, the EGR mod to correct a design which IMHO (*the approving engineer should be demoted for- I would expect better calculations from a high school sophomore*) This modification will ELIMINATE the violent pressure waves caused by the coolant flashing to steam inside the EGR cooler. (yet another example of ignoring the laws of thermal dynamics by the blue oval crew) IMHO; if one takes the time to remove the EGR tube, then cut out the scoop and weld it up as shown below. I used a piece of 2" 409 SS tube and cut at the 4 & 8 "o-clock" postions to start, then TIG welded.
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*** No the scoop has nothing to do with boost control although the dealer would like us to believe that. In reality the EGR system acts as a waste gate but after reviewing the PCM code one has to wonder what they were thinking*** on my second 6.0, I choose the “easy” route and made a new passenger side section to avoid all the welding and grinding along with the now unnecessary expansion joint (yet another restriction point). It looks like it was delivered this way and I suspect most dealers won’t notice the difference anyway. No I won’t show the world this design just know it can be done. The Y-pipe is now one piece. Hint hint
Second- all exhaust ports were matched to ensure proper alignment and minimal restrictions. The exhaust manifolds aren’t too bad to work with but be careful should you decide to start grinding on them. The 6.0 heads need all the help one is willing to provide so go ahead and let a trained flow tech work his magic while you’re replacing the studs and gaskets. No picture because this craft is highly prized and can be expensive. If however you do this, an easy 25 to 35 hp is locked in the exhaust ports and manifolds. *that’s another hint* For reference purposes, compare a decent set of 302 or 350 manifolds to the new OEM units and you’ll see the carnage I‘m referring to. The 6.0 PSD is either 365 or 366 cubic inches depending on who you ask. To be very blunt about it, IMHO the 6.0 OEM manifolds are severely lacking and need a lot of TLC to help the process work to its maximum potential. They would make great trout line weights though!
Third- the turbine housing was “massaged” a bit to improve flow and reduce turbulence. (I’ll probably purchase another unit in the near future but for now the OEM unit is ok)
The VGT turbine housing forces the gases to make two 90’s, a sharp left, then right turns, so I smoothed and polished the internal surfaces just because I had the time Saturday afternoon. The VGT design works well but what a nasty pressure drop it has. Not much can be accomplished to really achieve the coveted 1:1 drive pressure across the torque curve but close is ok I guess. No picture here race secret! Just look carefully at the internal edges and passages while you’re cleaning the crud out and you’ll see the offending areas. There should be NO square corners anywhere within the exhaust path . Another hint folks.
Regarding the downpipe, apparently there seems to be some misgivings about what size it should be, and what effects a larger ID can have. Well, considering the 6.0 is displacing about 365 cubic inches, and the OEM turbo (on-a-good-day) moves around 750 to 800 cfm, a 3.5 in down-pipe is adequate for about 450hp and decent daily driven responsiveness. If however one improves and or increases the total BTU’s (thermal energy) entering the turbine wheel, then a 4in down-pipe will improve turbine efficiency and therefore increase mileage, horsepower, and overall street manners. *this area is very involved with differential pressures, gas velocities, and gas expansion as discovered by the folks trying to provide turbo upgrades. Please remember I’m only attempting to help the common 6.0 owner so reserves the flames. I know the parties are trying there best to resolve surging issues and I know it ain’t easy! I also know what there up against and the primary culprit is exhaust gas velocity.* There are a few ways to increase BTU’s such as increase fuel volume, combustion efficiency, reprogram the ECM or correctly manage existing BTU output. Since the fuel options require physical changes to the OEM systems and the “magic module” can only work with what little fuel is available, why not use the FREE BTU’s we already have?
Fourth- Called Stan at Engine Ceramics www.engineceramics.com
to have the entire system ceramic coated to provide a proven insulation factor, seal the metal surfaces, and provide a barrier from corrosion. pic-E The turbine housing will receive special attention with coatings inside and out. (*no need to “insulate from within”, but applying a friction reducing coating to the VG components greatly reduces drag and minimizes the soots ability to stick*) Now before anyone goes off about the merits of ceramics, the military has used these coating since WWII in applications ranging from mobile weapons, to aircraft, to aircraft carriers. Applications closer to home are NASCAR, INDY, and NHRA. The truth is that ceramic coatings when applied correctly work magnificently to reduce radiated heat transfer, lower engine compartment temps, etc, etc. The down-pipe is also coated (* to ensure the hot gases do not cool down and create drag as they exit the turbine*) and shielded to protect the transmission lines, bypass oil system, and the wiring harnesses that live very close by. Remember science class where hot gases flow faster and with less resistance than cold ones? The same applies to exhaust systems and especially to turbo’s. There are three national ceramic coaters most folks have heard of and many smaller shops that provide an excellent product. Just be aware there are many “questionable” companies using what amounts to header paint that does nothing to channel heat. Again, if you’re looking for maximum turbine efficiency and mileage, exhaust energy must be managed!
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I also coated the entire exhaust system of my CBR1000-RR. This toy is used for times when I just need to feel a real good rush!!! Dyno says 167hp in a bike weighing 396lbs. That feels like a power to weight ratio something similar to the Space Shuttle…..98mph is 1st gear! Yeeeehoooo!
For those interested in the ultimate combination to maximize your BTU’s, stay tuned for part two!