2009 Supernova 6372 build thread

pwerwagn

Advanced Member
Joined
Jan 4, 2021
Messages
96
Location
Bosque Farms, NM
Hi all! Been a lurker for YEARS, as I have a 2005 Gulfstream 6316 Conquest Super C with the 8.1 with a whole bunch of mods/upgrades (fixing to be for sale). I learned a ton reading on here about the issues with the Kodiak Chassis Super C, and I have read a bunch about the shortcomings of the 4200 chassis as well, and I am comfortable taking on the challenge!

My Parents bought this 2009 6372 Supernova a few years back when my Dad retired. It was his dream to own a Supernova for many reasons. He recently passed away unexpectedly so I purchased it from my Mom to keep it in the family and keep my Dad's dream alive. We use our current Super C to tow our boat, our truck that we desert race, etc. We spend a lot of time in the dirt and absolutely love our current Super C, and we are looking forward to many good times with the new one.

I was a diesel mechanic for a few years, so I am very aware of the 6.0/VT365 short comings. I have already done studs and new HG's, new oil/egr cooler, TS MP8 pressure box, etc. I have checked the FICM, and voltage is good. I am currently talking to a few FICM tuners about a FICM tune, because mine is grossly underpowered. I was hoping the FICM was weak, but unfortunately its in good shape. My 8.1 in the 6316 loaded to the same weight will run circles around this VT365 on hills and in town. I also have an issue with the fan clutch as many others have. Mine is purely mechanical unlike the truck 6.0, and even after replacement it will never shut off. I recently readjusted the engagement temp on the clutch, and it still runs 100% of the time. I will adjust it a few more times, and then might bite the bullet and throw in a Horton EC450 clutch instead of elec fans.

My Dad and the previous owner also addressed some of the other shortcomings. My Dad replaced the main slide controller with one that can control the motors independently in case they get out of synch. The rear suspension was replaced with a rubber shackle mount setup (I'm drawing a blank on the name). It has Road King shocks all around. The RV drives like a dream, other than the noise from the fan and the lack of power.

Anyhow, just wanted to say hi. I know a few of you have done cool things like exh brakes, egr delete, water/meth injection, etc. that I will probably inquire more about!

--Jeff
 
It seems like you have lots of mechanical knowledge about these coaches. You are a lucky man because they can get complicated at times. Best of luck and enjoy.
 
Here is a picture of the RV, towing a 29' Yiro deck over Trophy Truck trailer:



It seems like you have lots of mechanical knowledge about these coaches. You are a lucky man because they can get complicated at times. Best of luck and enjoy.

Thanks Ray! They certainly can get complicated. But a challenge is always fun!

--Jeff
 

Attachments

  • 4361B7E3-BD07-4BDA-BCC4-CDCA1BA481E2.jpeg
    4361B7E3-BD07-4BDA-BCC4-CDCA1BA481E2.jpeg
    411.8 KB · Views: 34
Here's another pic of it parked with my 2005 Conquest in Bloomfield, NM:
 

Attachments

  • IMG_3513 (003).jpg
    IMG_3513 (003).jpg
    306 KB · Views: 30
Little update to this thread.

In my quest for more power, I removed the muffler/cat and it’s now 4” from the downpipe back with a straight thru diamond eye muffler. Noise is no different, spool seems a little better. I’m taking it on another trip this weekend to compare to last weekend. I also added a scan gauge so I can monitor EOT mainly. I already have analog boost/egt gauges.

I also am in contact with a shop working on tuning for the VT365. He already has a FICM tune that will work (I suspect the hyper max was only modifying ficm values). He has an econo tune and 40hp and sone bigger but will likely have egt issues with over 40.

Also figured out my ICP sensor wasn’t functioning correctly so I replaced that. I will see if the MP8 works any better with a good sensor, or perhaps the mp8 killed the sensor.

Other than the major lack of power compared to my old 8.1 super C, were loving the supernova. Drives way better, and much nicer once parked.

I’ll update as I get more tuner info if anyone’s interested.

Jeff
 
Little update to this thread.

In my quest for more power, I removed the muffler/cat and it’s now 4” from the downpipe back with a straight thru diamond eye muffler. Noise is no different, spool seems a little better. I’m taking it on another trip this weekend to compare to last weekend. I also added a scan gauge so I can monitor EOT mainly. I already have analog boost/egt gauges.

I also am in contact with a shop working on tuning for the VT365. He already has a FICM tune that will work (I suspect the hyper max was only modifying ficm values). He has an econo tune and 40hp and sone bigger but will likely have egt issues with over 40.

Also figured out my ICP sensor wasn’t functioning correctly so I replaced that. I will see if the MP8 works any better with a good sensor, or perhaps the mp8 killed the sensor.

Other than the major lack of power compared to my old 8.1 super C, were loving the supernova. Drives way better, and much nicer once parked.

I’ll update as I get more tuner info if anyone’s interested.

Jeff

Thanks for the update. I am very interested, I love my gulfstream just wish she had more power.

What scan gauge did you add?

Josh
 
Hi Josh,

I put in a scan gauge D. It was ~150$ and gives you some extra gauges like oil temp, egr position, exhaust back pressure, etc. Unfortunately it does not have IPR, ICP, VGT or FICM voltage values.

I have the list of added PID’s to program in if anyone needs them.

Jeff
 
Here are all the “x gauges” that can be programmed into the scan gauge for the VT365. It looks like a lot of work but it’s not bad once you have these codes. The owners manual will tell you how to program, takes about 2 minutes per added gauge and you can add 25. There are already ~20 or so before you add these. I watch oil temp and coolant temp next to each other. It also has all sorts of fuel mileage stuff, cost per mile, 0-60/ 1/4 mile timers, etc.

The PIDS below will save you a lot of time. I had to do a scan and manually input about 65 16 digit codes to scan gauge and about a week later one of their reps sent me back which ones were gauges with the inputs below. You can skip the whole section about retrieving codes.

Driver's Demand Engine - PercentTorque(%)
TXD: 00
RXF: 11F002040000
RXD: 2008
MTH: 00010001FF83
NAM: User Defined

Actual Engine - Percent Torque(%)
TXD: 00
RXF: 11F002040000
RXD: 2808
MTH: 00010001FF83
NAM: User Defined

Engine Speed(rpm)
TXD: 00
RXF: 11F002040000
RXD: 3010
MTH: 000100080000
NAM: User Defined

Transmission Output Shaft Speed(rpm)
TXD: 00
RXF: 11F002020000
RXD: 2010
MTH: 000100080000
NAM: User Defined

Percent Clutch Slip(%)
TXD: 00
RXF: 11F002020000
RXD: 3008
MTH: 000200050000
NAM: User Defined

Transmission Input Shaft Speed(rpm)
TXD: 00
RXF: 11F002020000
RXD: 4010
MTH: 000100080000
NAM: User Defined

Transmission Torque Converter Ratio(Ratio)
TXD: 00
RXF: 11F0020C0000
RXD: 1810
MTH: 000103E80000
NAM: User Defined

Accelerator Pedal Position 1(%)
TXD: 00
RXF: 11F002030000
RXD: 2008
MTH: 000200050000
NAM: User Defined

Engine Percent Load At Current Speed(%)
TXD: 00
RXF: 11F002030000
RXD: 2808
MTH: 000100010000
NAM: User Defined

Front Axle Speed(MPH)
TXD: 00
RXF: 11FE02BF0000
RXD: 1810
MTH: 001F32000000
NAM: User Defined

Relative Speed; Front Axle, Left Wheel(MPH)
TXD: 00
RXF: 11FE02BF0000
RXD: 2808
MTH: 001F0320FFFB
NAM: User Defined

Relative Speed; Front Axle, Right Wheel(MPH)
TXD: 00
RXF: 11FE02BF0000
RXD: 3008
MTH: 001F0320FFFB
NAM: User Defined

Relative Speed; Rear Axle #1, Left Wheel(MPH)
TXD: 00
RXF: 11FE02BF0000
RXD: 3808
MTH: 001F0320FFFB
NAM: User Defined

Relative Speed; Rear Axle #1, Right Wheel(MPH)
TXD: 00
RXF: 11FE02BF0000
RXD: 4008
MTH: 001F0320FFFB
NAM: User Defined

Hydraulic Brake Pressure Circuit 1(PSI)
TXD: 00
RXF: 11FD02E60000
RXD: 1808
MTH: 001D00020000
NAM: User Defined

Hydraulic Brake Pressure Circuit 2(PSI)
TXD: 00
RXF: 11FD02E60000
RXD: 2008
MTH: 001D00020000
NAM: User Defined

Transmission Selected Gear(gear value)
TXD: 00
RXF: 11F002050000
RXD: 1808
MTH: 00010001FF83
NAM: User Defined

Transmission Actual Gear Ratio(Ratio)
TXD: 00
RXF: 11F002050000
RXD: 2010
MTH: 000103E80000
NAM: User Defined

Transmission Current Gear(gear value)
TXD: 00
RXF: 11F002050000
RXD: 3008
MTH: 00010001FF83
NAM: User Defined

Nominal Friction - Percent Torque(%)
TXD: 00
RXF: 11FE02DF0000
RXD: 1808
MTH: 00010001FF83
NAM: User Defined

Engine's Desired Operating Speed(rpm)
TXD: 00
RXF: 11FE02DF0000
RXD: 2010
MTH: 000100080000
NAM: User Defined

Engine Oil Pressure(PSI)
TXD: 00
RXF: 11FE02EF0000
RXD: 3008
MTH: 001D00320000
NAM: User Defined

Engine Coolant Level 1(%)
TXD: 00
RXF: 11FE02EF0000
RXD: 5008
MTH: 000200050000
NAM: User Defined

Engine Intake Manifold #1 Pressure(PSI)
TXD: 00
RXF: 11FE02F60000
RXD: 2008
MTH: 001D00640000
NAM: User Defined

Barometric Pressure(PSI)
TXD: 00
RXF: 11FE02F50000
RXD: 1808
MTH: 001D01900000
NAM: User Defined

Engine Intake Air Temperature(F)
TXD: 00
RXF: 11FE02F50000
RXD: 4008
MTH: 00090005FFD8
NAM: User Defined

Engine Oil Temperature 1(F)
TXD: 00
RXF: 11FE02EE0000
RXD: 2810
MTH: 000900A0FE35
NAM: User Defined

Transmission Oil Temperature 1(F)
TXD: 00
RXF: 11FE02F80000
RXD: 3810
MTH: 000900A0FE35
NAM: User Defined

Fuel Level 1(%)
TXD: 00
RXF: 11FE02FC0000
RXD: 2008
MTH: 000200050000
NAM: User Defined

Percent Exhaust Gas Recirculation Valve #1 Position (%)
TXD: 00
RXF: 011B00000000
RXD: 0808
MTH: 000200050000
NAM: EGR

Barometric Pressure (PSI)
TXD: 00
RXF: 016C80000000
RXD: 0808
MTH: 000A00100000
NAM: PSI

Injector Metering Rail #2 Pressure (PSI)
TXD: 00
RXF: 018180000000
RXD: 0810
MTH: 000100010000
NAM: IRP

Exhaust Back Pressure (PSI)
TXD: 00
RXF: 018300000000
RXD: 0810
MTH: 000104000000
NAM: EBP

Mass Air Flow (lb/min)
TXD: 00
RXF: 018400000000
RXD: 0810
MTH: 000700190000
NAM: MAF

Extended Range Fuel Delivery Pressure (Absolute) (PSI)
TXD: 00
RXF: 018780000000
RXD: 0810
MTH: 000100010000
NAM: XFP

Auxiliary Vacuum Pressure Reading (PSI)
TXD: 00
RXF: 018880000000
RXD: 0810
MTH: 000100010000
NAM: AVP

Auxiliary Gage Pressure Reading #1 (PSI)
TXD: 00
RXF: 018980000000
RXD: 0810
MTH: 000100010000
NAM: AGP

Engine Oil Temperature (Degrees Fahrenheit)
TXD: 00
RXF: 01AF00000000
RXD: 0810
MTH: 000100040000
NAM: EOT

Transmission Output Shaft Speed (RPM)
TXD: 00
RXF: 01BF00000000
RXD: 0810
MTH: 000100040000
NAM: TOS

Jeff
 
Jeff,

Hey thanks for all the great info. I have been looking at the scangauge D just had not ordered one yet. I will be ordering one soon.


Josh
 
The muffler seemed to drop EGT about 50* or so. The max I can get it to with the TS turned all the way up is ~1175*. I didn’t notice much for power. Maybe a touch quicker spool.

Gonna try out some FICM tuning next and see what we can make happen there.

Jeff
 
Jeff (or anyone else) I pulled the water/methanol injection off of my 6400 SN if you are interested in it. I always used cold wether blue washer fluid in it as it would not freeze and cold weather washer fluid is mostly water and methanol and a very small amount of soap. When running the system the EGT temps were reduced by 50 to 100 deg. I took the system off my SN because I am doing some other mods to the engine and I no longer need the injection system.
 
So as mentioned, I have been unhappy with the cooling fan on my VT365. It runs nonstop, and its been replaced twice. I have adjusted the bimetal spring on this latest one (both were clutches purchased from IH, not ebay or something), and it still is on all the time. It is super loud, and has to suck up tons of power at 3Krpm.

I went ahead and bit the bullet and bought a Horton EC450 electric fan clutch. I am going to run it off a manual switch and a temp sensor. I will probably have it kick on at something like 200/210, since mine always seems to run right around 195 right now.

I also bought a small pusher fan that I will mount in front of the ac condenser that will be on when the AC is on.

I also sent my FICM out to get it "upgraded", and then I will be sending it to get a tune loaded into it.

I will let you guys know the outcome!

--Jeff
 
Jeff,

One other idea you may want to look at with your SN is enabling 6th gear in the transmission. To get the most benefit from this modification you could lower your rear diff ratio for off the line starts and pulling hills. But with 6th gear enabled you can still keep your top end speed. I spoke with my local Allison service center (Pacific Power Group) about doing this with my 6400, and they said yes it could be done. They had to check with the Allison factory to confirm as some vehicle OEM's restrict doing so. Apparently International did not put any such restrictions on my chassis so Allison had no issues with enabling 6th. I also have contact information for an Allison technician that can supposedly open up 6th gear remotely if you connect your vehicle to a computer. Or you can send him your TCM.
 
I found this document (VT365 HP and Torque curves) on gsowners a number of years ago and thought I would post it again.
 

Attachments

  • VT365 300HP Torque.pdf
    56.4 KB · Views: 42
Thanks for the info Tim! I had suncoast lined up to reflash my TCM but at the last min they said they couldn’t. I talked to Matt Lazier at Allison and he said I can go thru a local Allison shop to get it done.

Just gotta decide where I draw the line and do a motor swap. ;-). Either way 6th enable will be of benefit.

Jeff
 
Last edited:
Little update:

Got the horton EC450 installed, huge difference in noise. I havent taken it out on a trip yet to see if theres any power to be gained, but I will this weekend.

I got the FICM back and it had 4 bad modules in it. They rebuilt the FICM and it starts better, sounds better, revs cleaner, etc. Hopefully this helps out some too (and its now lifetime warranty and hopefully prevents me from being stuck on the side of the road with a dead FICM). I have not sent it for the tune yet as I want to see how it runs with these mods before changing more stuff. I also blocked off the EGR while I had the doghouse out.

I also finished sound deadening the interior. I put 80mil butyl noico on the firewall and floor, and then 315mil noico red foam on the fire wall and 150mil noico foam on the floor. I covered the doghouse in 80mil and 315mil. I also did 80 mil/315 mil in the doors. When I had the doors apart, both doors had the weatherstripping/guide for the glass in the tracks fall out. It was making the windows noisy when I rolled them down. Simple fix.

For any of you looking for a tune, Bill at PHP is now selling the tuner:
/https://gopowerhungry.com/orion-reflash-system-for-navistar/

--Jeff
 
Took the SN out for a trip this weekend. The changes made a pretty decent difference. The ability to turn the fan on and off is nice, and up the bigger hills that were pulling me down from ~65 to 30-35, I gained 5-7mph.

The sound deadening made a humongous difference, much more enjoyable to drive now.

I also got in touch with someone Tim referred me to, and sent him the info about my trans and he is double checking that he can enable 6th gear.

We are taking off on a ~4K mile trip in 2-3 weeks, so I will report back more later!

I did not spring for the tuner yet with my trip coming so close. I will get some miles on it as-is for more good data points then put the PHP Orion tuner on it and see how it goes.

--Jeff
 
Hi all, been watching this thread for a bit, anyone finally pull the trigger on the 6th gear? Any feedback on doing it? I had the rear end gears changed from the stock 5.29 to a 4.88 a while back and it really mad a change to the way it cruises on the highway (somewhat slower off the line and merging, but better at 65-70 MPH). I usually run about 1800-2000 rpm on the highway and am steady at 70MPH, fully loaded and towing my jeep wrangler unlimited. I'm interested in the 6th gear, maybe I should go back to the 5.29 rear end and enable the 6th gear, let me know, thanks.
 
I have not pulled the trigger yet. I was planning to do it before this trip I am on, but ran out of time.

I am considering 5.57 and 6th gear. That combo will lower my 70mph rpm by ~250rpm or so, and give me more low end.

I’ve put about 1k miles on it this past week on our trip and the Horton fan makes a world of difference. I have not put it on a temp sensor yet so I have to pay attention to temps, but I’ve been turning the fan off on most hills and it seems to make at least 5mph difference, and even more on the hills that I downshift out of 5th. Spinning 3000 in 4th you can absolutely feel the power difference with the fan on vs off. I put a small pusher fan in front of the condenser hoping that was enough air for 90% of the time, but hills in NM and 100* heat need the big fan more like ~30% of the time. Around town though, the small elec fan works good, just not enough fan for the freeway and hills and heat.

The FICM repair seemed to make a big difference too in how it runs. It smoothed it out a lot. I also threw some archoil 9100 in the T6 when I changed oil and it got rid of the small shudder at ~2500 under load, so that likely was stiction in a spoolvalve.

My ICP or pigtail seems to have gone bad again and I left my spare at home. So I can’t run the MP8 right now. It actually seemed to help a lot more after I had the FICM rebuilt, so perhaps the MP8 was stressing the FICM and I wasn’t getting the power I should have.

When I get back I’m planning to do the PHP Orion Tyne first, and if I still need a little more I’ll do the gears and 6th enable.

Otherwise it’s running great now!!

Jeff
 
Jeff,

Who did you send the FICM to for repair? Are you running an upgraded FICM power supply (e.g. Bulletproof Diesel) or the stock version?

Thanks for the information you are sharing - helps us new owners!
 

New posts

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top