Towing with a 7.3 E350

[4x4pair]

Hi all,
I was hoping a few of you could chime in on turbo upgrades you've done to get your 7.3 E350's towing as well as possible. Since they don't have intercoolers I know it's always a battle on keeping EGT's down. I upgraded a lot of parts and the van scoots along great unloaded. However, once a trailer is hooked up, the power isn't there and the EGT's climb. I have Stage 1 injectors, a ported housing on the stock turbo, a 4" exhaust and towing tunes. I don't see boost over about 10 psi when towing though (mid 20's when unloaded). So it's making me think my turbo is on it's way out. I really want to stay away from water/meth so wanted to see what others have done to upgrade the van turbos.

Thanks in advance!

 

[IdaSHO]

What RPMs are you towing at, and what EGTs are you seeing?

 

[4x4pair]

Well, I try keeping it around 2500 rpm and under 1250 degrees. But it just won't keep pace like that. I hit some grades from Vegas to Utah or Vegas to Cali (so not horrible grades) and wind up in second gear at 3000+ rpm just to do 50 mph. As a reference, my 2001 E350 with a 7.3 (totally stock except towing tunes) with the same load does 75-80 mph at 2700 rpm and 1200 degrees or less on the same grades. HPOP's are new from Ford on both vans.

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[FDM2012]

Same gears/tires on both rigs?

 

[4x4pair]

No, but the overall ratio is pretty close when I did the math. One is stock 3.55 gears with 245 / 75 R16 tires. The other is 4.10 gears with 35" tires.

 

[djbonsu]

Thats odd that you would see less boost loaded than unloaded. Maybe your towing tunes are off? Are the boost comparisons made on the same tune? If the compressor wheel isnt chewed up and spins freely, you should be good, turbo-wise. Make sure the ebpv isnt closing up on you. I suspect a boost leak somewhere...check your intake plenums, spyder intake boots, boost line to map sensor or up-pipes?

 

[Drizzt]

What RPMs are you towing at, and what EGTs are you seeing?

Not to hijack this thread, but everybody says to watch your EGT's but what temps you should be expecting? I've not found any published numbers for what constitutes good or bad.

Also, seems like most EGT's I've seen are tapped into one exhaust header, so you're only seeing the temp on 4 cylinders so if you're having an issue on the other side you wouldn't see it.

 

[4x4pair]

Thanks for the suggestions. I'll check the up-pipes this weekend. Last weekend I tightened all the boots, replaced the MAP sensor and the vacuum hose to it and saw no change. My ebpv is gutted and the sensor and tube is replaced.
Both vans have an 80hp tow tune from DP that I was comparing. I ordered a 40hp tune thinking that would help but it's actually slower with that tune.

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[djbonsu]

Thanks for the suggestions. I'll check the up-pipes this weekend. Last weekend I tightened all the boots, replaced the MAP sensor and the vacuum hose to it and saw no change. My ebpv is gutted and the sensor and tube is replaced.
Both vans have an 80hp tow tune from DP that I was comparing. I ordered a 40hp tune thinking that would help but it's actually slower with that tune.

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Are you reading boost using a boost gauge or scangauge? If you are using the boost gauge, where is your boost line tapped into?

 

[djbonsu]

Not to hijack this thread, but everybody says to watch your EGT's but what temps you should be expecting? I've not found any published numbers for what constitutes good or bad.

Also, seems like most EGT's I've seen are tapped into one exhaust header, so you're only seeing the temp on 4 cylinders so if you're having an issue on the other side you wouldn't see it.

I have 4.10 gears and 35" tires and crusing on the highway, egts are between 700-800 deg f at 65-75 mph. Before the 4x4 conversion, egts were about 550-600 deg f. max allowable is usually 1250-1300 deg f for me

 

[4x4pair]

I read the boost on both through my Infinity programmer. I have two separate EGT gauges wired in my 4x4 van...one to each head.
I'm assuming the EGT numbers you posted are unloaded? Or is that towing?

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[djbonsu]

I read the boost on both through my Infinity programmer. I have two separate EGT gauges wired in my 4x4 van...one to each head.
I'm assuming the EGT numbers you posted are unloaded? Or is that towing?

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yes, those numbers were unloaded

 

[IdaSHO]

Not to hijack this thread, but everybody says to watch your EGT's but what temps you should be expecting? I've not found any published numbers for what constitutes good or bad.

Also, seems like most EGT's I've seen are tapped into one exhaust header, so you're only seeing the temp on 4 cylinders so if you're having an issue on the other side you wouldn't see it.

Cruising temps should be less than 800 degrees or so, almost regardless of vehicle.

Even with a big camper on my old (96') powerstroke (no innercooler), I see 650-750 degrees cruising at 65-70MPH on the flats.

I consider 1200 degrees to be my absolute max for sustained max EGT. As in, for minutes at a time, say pulling a serious grade.


And you are correct, most tap into one exhaust manifold (pre turbo) for temp readings, and yes, the readings can differ from bank to bank, so done this way you are never seeing the whole picture.

But for the most part, doing it this way is just fine. You want the reading pre-turbo as the reading post turbo can be considerably lower temp, and Im not about to install a second gauge just to watch the other bank, especially with an engine as robust and reliable as the 7.3. So I take my readings (from the drivers manifold) and call it a day.


I asked about RPM as the 7.3 loves to rev, and quite often you can LOWER your EGTs on a pull simply by downshifting, and increasing your RPMs.
Dont be afraid to rev the 7.3 all the way to red-line. It wont hurt it. I often pull grades in 3rd gear instead of 4th gear, at the same speed, even if 4th would pull it, simply to keep the EGTs in the green.

 

[fielder441]

I just got back from a 1200 mile round trip towing a little over 10k with my 97 E350 powerstroke. 37s and 4.56 gears with a 60hp tow tune from Dp and new swamps stock injectors. It pulls good but you have to be patient and I had to pedal it the whole trip to keep it under 1200. never drove over 70 and probably avg speed was 55. I have ordered an electric fuel system, d66 turbo and a new tuner to get some more hp/tq and lower my temps and make it a little easier on the old girl.

 

[Deshet]

what are you towing that you want to go 75-80 MPH?

I usually get trailer sway at those speeds unless it is a dually or a dually trailer.