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MY K3500 HX40, FTB & Other Performance Mods

Also forgot to mention that I deleted my vacuum pump, and put a shorter belt on which is 995/8." The stock belt is 101".
 
DieselMike1 said:
No, with the hx40 with 16cm housing you have approximately 1 to 1 ratio or at most 1.3 on back pressure. With the stock gm turbo you have a 1 to 3 ratio on back pressure. So running 20 lbs of boost on the hx 40 is actually less pressure than the gm running 10 lbs.
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Respectfully, that's not how it works when considering cylinder pressure, head gaskets and "clamping pressure" of the head bolts.

The combustion chamber pressure isn't effected by the pressure ratio of turbine assembly.

It's a function of the start pressure in the cylinder when the valve closes and the compression ratio at TDC.

If you start at 10 psig boost and double that number to 20 psig, your cylinder pressures are similarly increased by the same multiple of 20:1.

A 6.5 in decent shape can/should hold 20 PSIG, but you're snugged right up to the limitations of a stock GM assembly......
 
Agreed, gw, but I think you meant "multiple of 2:1". 20 psi is almost 3 times more cylinder filling than a naturally aspirated engine (14 psi boost = 2x, 21 psi=3x). Assuming fueling is keeping up, combustion pressure and therefore torque will also triple. 6.5s already have head gasket problems with the stock boost of 7 psi, so studs are probably a good idea.
 
20 psi of boost from a gm8 is not the same as a hx40. You have to take drive pressure which equals back pressure into account. Drive pressure on a gm8 is much, much higher and this contributes to a lot of blown head gaskets on the 6.5. Also with increased drive pressure comes increased heat in the cylinder which also contributes to head gasket failure. The gm turbo is only a 9cm^2 housing, where as the hx40 is a 16cm^2. That is why you have lower egt's with the hx40 at 20lbs vs. the higher egt's with the gm turbo at 10lbs.
 
Did my first bit of towing with the new turbo setup, after picking up my new to me travel trailer (pics. below) this weekend. We were in the Ozark mountains of Missouri, truck pulls good, egt's got to 1200 on long grades, and boost was spiking to 18 to 20 when it kicked down a gear. Engine temps touched about 215 on a couple long grades, and trans. temp was 210 at the highest, normally stayed around 200, but I think my clutch fan may be getting weak, as I counld not hear when the fan came on or off. On mostly flat terrain with small grades, I just set the cruise at 70 and relaxed, as the truck had plenty of power, egt's around 800 and boost at 4 or 5. Fuel mileage towing the trailer was 11mpg. Overall was happy with the performance.
226402d1404697622t-my-k3500-hx40-ftb-other-performance-mods-camper-004.jpg
 
Need to also note, that not once while towing did I ever have the go pedal to the floor, as I am trying to take it easy on it, because Im still running stock head gaskets and the TTY bolts. Trying to make it last for awhile. I know there's others on here doing the same. I think 4thesporty is also running stock gaskets and bolts also, and haven't heard any catastrophies out of his yet. If I had a optimizer with studs, then I would really be able to tell how these improvements would be at max levels.
 
Ok guys, a little update, I mentioned earlier that the truck was running a little warmer than I liked, so I took the clutch fan off, and it feels like its ok, gonna do the spring mod on it for earlier engagement. I took out the thermostats, and they were Chinese ones, not good. I then got underneath to check back side of harmonic balancer and noticed it was wet around the weep hole of water pump. Decided to check crank pulley also, it had about 1/8 to 1/4 inch of deflection when I got my hands on it, and rubber had some dry rotting and small cracks. Also ive got a lot of fin straightning to do on my a/c condenser, other wise cooling stack was clean, as I washed it out when I bought the truck. But I went ahead and pulled the radiator to prepare for the new parts. The water pump and crank pulley are new oem take offs from peninsular diesel. $65.00 a piece.
WaterPump2.jpg
CrankShaftPulley.jpg

Also ordered fluidamper and oil cooler lines from Leroy diesel.:thumbsup::D
800141-1.jpg

Got new AC delco thermostats, and gates hoses ordered from Rockauto.
 
FD is being drop shipped. I odered the mechanical IP style FD for you it comes with the spacer to simulate the reluctor ring on DS4 trucks. You just wont use the spacer. You may find a use for the spacer later or convert to DB2?
I only send them this way as it cost the same, but gives you flexibility. FD is same idintical part either way.
Oil cooler hose kit "might" ship today.
 
Burning oil said:
FD is being drop shipped. I odered the mechanical IP style FD for you it comes with the spacer to simulate the reluctor ring on DS4 trucks. You just wont use the spacer. You may find a use for the spacer later or convert to DB2?
I only send them this way as it cost the same, but gives you flexibility. FD is same idintical part either way.
Oil cooler hose kit "might" ship today.
Click to expand...

Thanks, Leroy.
 
Here's the fluidamper, with it's friend the new peninsular take off crank pulley, waiting to be installed. It's like Christmas in July.:D
228393d1405544820t-my-k3500-hx40-ftb-other-performance-mods-truck-f.d.-etc-009.jpg
 
Almost forgot the new Hayden 2886 fan clutch arrived this afternoon also.
Yeah, I need to clean off my work bench.
228401d1405545210t-my-k3500-hx40-ftb-other-performance-mods-truck-f.d.-etc-004.jpg
 
I got the fluidamper, crank pulley, and fan clutch installed. I want to thank 4thesporty for giving me the tip about the HB removal kit from autozone, for installing the HB, it worked great. I have some pics. of the install. I used a 3/8" ratchet inserted into the puller to turn it. Just use the original washer off the HB bolt, and put some grease on it. So if anyone has problems finding the right HB installer, as I did, this works like a charm.
228513d1405640885t-my-k3500-hx40-ftb-other-performance-mods-inst.-pics-001.jpg
228529d1405640885t-my-k3500-hx40-ftb-other-performance-mods-inst.-pics-003.jpg
228521d1405640885t-my-k3500-hx40-ftb-other-performance-mods-inst.-pics-002.jpg
 
FellowTraveler said:
How has the HX40W tune worked out since you have run it awhile now?
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Sorry for the late reply, most of my updates are on another forum. I sent the ecm back to heath to do some re-tuning a few months ago. I had some timing, shifting, and fueling parameters changed to maximize torque on the lower to mid range rpms for towing. I am very happy with the re-tune.
 
DieselMike1 said:
Sorry for the late reply, most of my updates are on another forum. I sent the ecm back to heath to do some re-tuning a few months ago. I had some timing, shifting, and fueling parameters changed to maximize torque on the lower to mid range rpms for towing. I am very happy with the re-tune.
Click to expand...
Can you elaborate on specs on tune or?
 
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