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7.3 thread continued?

Got more time for a better response. The other FTE member is running the electronic actuator. He seems to have it dialed in and isn't having the problems he originally had. He has 205/80 injectors and a 4r100. Mine is the 3 Stage mechanical, the problem I have is similar but not the exact same. Because it's mechanical when I let off to shift the exhaust back pressure drops. (Actuator runs off ebp) When it drops it slams the veins closed causing a surge situation. Luckily it only does it in low boost/low rpm/low fuel situations. So it's not like it is super hard on the turbo. It is annoying when I'm driving or towing slow. Slow with a heavy load is the worst, shifting at say 1900rpm it will "chhhhtttt---tttt-ttt".

Of course I could open up the veins a little on the low end. It may help but I don't want to give up low end if possible. If I lose much low end I may as well go back to a 363/68/.83 imo. Lesser tuning helps but I like the power of an 80hp file when towing. So next I put together a Blow Off Valve that runs off the idle validation switch and a 10psi Hobbs switch. Made it from a 1-1/2" solenoid valve. Well, it works great but no matter what I can't cure the shift surge. VGT and BOV makes all the magic sounds one could wish for in a diesel. (BTW a bov can be pretty annoying). So far the best way is to drive around it. Don't slow shift, or low rpm shift. If you accelerate slightly spirited it doesn't surge at all. Still kicking around some ideas, a different compressor wheel or a dampener of some sort on the actuator.

Performance is great but some claims don't add up. 1500rpm will easily make 10psi+ boost and around 25psi @ 1900rpm. Overall boost is down from my 363/68/.83 (33psi vs 42psi). The claims of higher than a 1:1 boost/drive ratio are false. This thing makes a lot of back pressure. 33psi boost nets approx 54psi ebp. It will level out on longer pulls to approx 1:1.2. Typical to how VGT turbos run so quite normal IMO. At low RPMs EBP will be almost double of boost pressure. Just don't understand the claims, sales tactic maybe.

The VGT turbo runs the larger 73mm turbine wheel and the non-vgt 363 I run has the smaller 68mm turbine. Put tons of towing miles on the non-vgt it is IMO the best turbo for a mild 7.3. No EGT concerns ever but when towing heavy it will go hours without dipping below 25-30psi @ 2200rpm. It's a boost monster. The VGT tows different, boost levels out instead of climbing. It also takes less throttle input on low rolling grades to maintain speed. The VGT adjusts to keep turbo happy with less input.
 
Here is a modification that opens up a lot of debate. I enjoy trying new modifications and was unable to find anything about this part besides lengthy discussions. Typically 50% says yes it will help, 50% says no it won't. Personally I can't tell you either way because it's not my field of expertise. Decided to try them out myself because there was no real data out there. There were results and things did change. I'll put up the findings in a little bit.


 
For the tests I logged everything in Forscan. Both tests were ran with the same ambient temperature, stretch of road, driving style. Tuning was a custom file from a gentleman who used to work heavily with the PHP Hydra platform. The tune was very strong but would tank ICP pretty easily.

Both stock and FFD Oil log passes are on the same graph. The parameters are, ICP, IPR, FIPW, and RPM.

Testing yielded some results. Not the 3-400psi gain the manufacturer claims but a whopping 104psi!


FFD Log 3.jpg


The intensifier piston in an AD injector is 7:1. 1psi of ICP equals 7psi of injection pressure. 104psi of ICP equals 728psi of injection pressure increase at the nozzle (in theory).
 
The truck is less prone to a P1211 code than it was before. Maybe it makes a little more power somewhere in the rpm range. In theory it should run a little cleaner with better atomization. When I first installed them it made its cold start lope more pronounced with the tune I was running.
 
This does intrigue me, I have a healthy and new CNC Fab Stage 2 HPOP w/ 180/30 FFD injectors and havent seen HPOP pressure be a problem so I thought it was tailored towards people with older tired HPOP's but may be wrong.
 
Interesting how different these trucks can be.

I run 180/0 on Factory 1995 pump with 185k miles. There is only one tune I have that runs hard enough to run them out of oil and I almost never run that tune because It pegs my turbo gauge and scares me.

Are those rail pressures compared to with or without the oil hose cross over mod?

I have hoses that run between heads. 2 of them to help oil flow.
 
Performance is great but some claims don't add up. 1500rpm will easily make 10psi+ boost and around 25psi @ 1900rpm. Overall boost is down from my 363/68/.83 (33psi vs 42psi). The claims of higher than a 1:1 boost/drive ratio are false. This thing makes a lot of back pressure. 33psi boost nets approx 54psi ebp. It will level out on longer pulls to approx 1:1.2. Typical to how VGT turbos run so quite normal IMO. At low RPMs EBP will be almost double of boost pressure. Just don't understand the claims, sales tactic maybe.

The VGT turbo runs the larger 73mm turbine wheel and the non-vgt 363 I run has the smaller 68mm turbine. Put tons of towing miles on the non-vgt it is IMO the best turbo for a mild 7.3. No EGT concerns ever but when towing heavy it will go hours without dipping below 25-30psi @ 2200rpm. It's a boost monster. The VGT tows different, boost levels out instead of climbing. It also takes less throttle input on low rolling grades to maintain speed. The VGT adjusts to keep turbo happy with less input.
I enjoy seeing the constant evolution and change to these old dinosaurs, it does amaze me that people, like KC, are still innovating and investing in 7.3s and we still have people like yourself innovating with VGT's.

I have almost pulled the trigger on the DPS VGT multiple times but keep holding off for exactly what you said, "the claims dont add up." The DPS guy just comes off as a marketing douche that I do not trust. He has NDA's you have to sign to buy his product, his support seems to iffy when you have failures. It just keeps deterring me away.

I currently have my eyes on the new 364SXR, I am not the best at reading turbo maps but from what I can tell and from what I read it flows like a 363 on the bottom end and a 366 on the top end and while it isnt a VGT, the added technology from Borg Warner has basically helped it be more efficient all around.

The other one I am intrigued with is the S362VGT Prius lover is working on at FTE Forums. Is that an OEM VGT from a medium duty application?

Either way I am intrigued.
 
I enjoy seeing the constant evolution and change to these old dinosaurs, it does amaze me that people, like KC, are still innovating and investing in 7.3s and we still have people like yourself innovating with VGT's.

I have almost pulled the trigger on the DPS VGT multiple times but keep holding off for exactly what you said, "the claims dont add up." The DPS guy just comes off as a marketing douche that I do not trust. He has NDA's you have to sign to buy his product, his support seems to iffy when you have failures. It just keeps deterring me away.

I currently have my eyes on the new 364SXR, I am not the best at reading turbo maps but from what I can tell and from what I read it flows like a 363 on the bottom end and a 366 on the top end and while it isnt a VGT, the added technology from Borg Warner has basically helped it be more efficient all around.

The other one I am intrigued with is the S362VGT Prius lover is working on at FTE Forums. Is that an OEM VGT from a medium duty application?

Either way I am intrigued.
Yeah it's off a newer DT466E. Very similar to the DPS. Veins are the same shape and general design but a much smaller turbine wheel, 62mm iirc.
 
Interesting how different these trucks can be.

I run 180/0 on Factory 1995 pump with 185k miles. There is only one tune I have that runs hard enough to run them out of oil and I almost never run that tune because It pegs my turbo gauge and scares me.

Are those rail pressures compared to with or without the oil hose cross over mod?

I have hoses that run between heads. 2 of them to help oil flow.
The truck has the oem style oil lines, no cross over.
 
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