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OBS 7.3 intercooling

Hyde

Andgoseek
Joined
May 26, 2020
Member Number
1468
Messages
160
Loc
North Idaho
Truck details first, 250k mile 97 F350, Alliant reman AD injectors, custom PHP tunes from when I had a buddy in the industry, 17* HPOP, DIY E fuel, 4" inlet AFE filter in the factory spot but no box, 3" downpipe to stock exhaust straight piped.

With the new trailer and the wheeler I'm grossing 16-17k depending on how much camping shit I shove in. I'm looking at adding a small camper or pop up into this mix so it's only going to get heavier.

Truck pulls alright, doesn't feel like I'm running out of power too bad but I have to back out to stay at 1200-1250 on basically anything but flat ground, don't get me started on the 10 mile Vantage grade in Washington.

Sorry for the novel but I try to give as much info as possible. So can I get some details on everyone's intercooler setups? I was considering air/water since I had good results on a previous rig and packaging is easy, I didn't tow heavy with it though. I'm afraid it might heatsoak in this application​​​​​​​

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Lots of write ups on sd 7.3/6.0 setups. All in all is a pretty easy deal.

I was talking with a kid over the weekend, he found a complete kit for $1600.

I mooched my known shops and suppliers and a buddy for parts, i did it for about $300. The only thing i did different than most was added a 5th boot at the alternator to gain a lil bit of length i just couldnt seem to get.
 
Lots of write ups on sd 7.3/6.0 setups. All in all is a pretty easy deal.

I was talking with a kid over the weekend, he found a complete kit for $1600.

I mooched my known shops and suppliers and a buddy for parts, i did it for about $300. The only thing i did different than most was added a 5th boot at the alternator to gain a lil bit of length i just couldnt seem to get.

What's your injector/turbo setup and what kind of egt change did you see towing?
 
I don't think that set up is near as heavy as you think. I was right at 20k with a 4k lb cab over and a full body 4runner on a normal car trailer. These trucks actually aren't *that* heavy, not compared to newer stuff. I think mine is around 6800 depending on fuel (cclb 5 spd F350) I guess it doesn't really matter since we're talking i/c not truck weight :flipoff2:


Here is my install

https://www.pirate4x4.com/threads/6-0-intercooler-conversion-in-obs-powerstroke.1754809/

I kinda hacked the pipes together with boots, I recently did these pipes.

https://www.carsonstaufferdiesel.co...-1997-7-3l/products/csd-obs-intercooler-pipes.

It's night and day better, basically went from constantly watching the gauge to flat footing it on most grades.

I wanted to do a water to air on a 90 dodge with a 12v I had, but it wasn't a row rig, more of a fuck around truck.

I'm assuming that if you did this, you'd just tap into the engine coolant system? Or would you want to run a dedicated system? I feel like tieing into the engine coolant wouldn't be a great setup, especially on long grades.

Doing a dedicated cooling system could be a good setup, but I'm not sure I'd want the complexity on a tow rig. You end up mounting a cooler in front of the radiator anyway.

Maybe do the water to air tied to the coolant than do a water/meth (really just water) set up to cool everything down on long grades? Or just nitrous :flipoff2:
 
What's your injector/turbo setup and what kind of egt change did you see towing?

I always see people say things like "200* egt drop"

I never saw how you could get an exact number on that. I will say the 6.0 ic was a life changer for towing.

One thing though is that it will create a little more lag.
 
I don't think that set up is near as heavy as you think. I was right at 20k with a 4k lb cab over and a full body 4runner on a normal car trailer. These trucks actually aren't *that* heavy, not compared to newer stuff. I think mine is around 6800 depending on fuel (cclb 5 spd F350) I guess it doesn't really matter since we're talking i/c not truck weight :flipoff2:
The truck and trailer both completely empty were 10,600 on Cat scales, the Ranger is pretty chubby and I overpack.

I'm assuming that if you did this, you'd just tap into the engine coolant system? Or would you want to run a dedicated system? I feel like tieing into the engine coolant wouldn't be a great setup, especially on long grades.
I did the air/water on a "built" 6.9idi a few years ago with a dedicated cooling system. It did 261hp/525lbft while shredding the clutch at a dyno event. Anyway that truck would never get over 1000 degrees with a small camp trailer but weight was significantly less and I didn't long haul much.

I'm leaning towards the standard 6.0 setup, wanted to see if anyone has done something outside the box though
 
I'm leaning towards the standard 6.0 setup, wanted to see if anyone has done something outside the box though

I love out of the box stuff, but with my tow rig I think the more simple the better. Everything on mine is a factory application except the tubes, but they're steel, so I'm not foreseeing an issue with them.

What pump would you use? I even looked into a small car water pump that could be mounted and driven off the crank. The good thing about that would be that if it did go out, you could hopefully get one at a normal auto parts store. That and no wiring.

I honestly can't remember if I found anything that would have worked though.

Another option would be looking at 6.7 parts, I'm not sure how the system works on them.

Edit: looks like the 6.7 uses a belt driven pump:grinpimp:

https://pensacoladiesel.com/product/...mp-single-alt/

If I were to do it, that's what I'd use. $150 isn't even bad compared to some of the good electric pumps I looked at.
 
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This is my tow rig and trailer setup, the trailer with jeep and camper is 12k.

The truck has a set of 150 swamps injectors, banks intercooler, and kc turbo setup. I was able to tow this setup all the way across country and only back out on hills twice in the Rockies.

In my opinion gearing is going to make a bigger difference than the intercooler, my banks setup only netted me a 200 degree drop MAX on full open pulls. My truck has 4.10 gears, with 3.55 the engine is too low of rpm's to pull considerable weight

Im assuming your truck is an auto, if thats the case pop it out of overdrive going into a steep hill and ride it out at 2500 rpm.

the banks intercooler was 1500 if I remember correctly and worth every penny.

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In my opinion gearing is going to make a bigger difference than the intercooler, my banks setup only netted me a 200 degree drop MAX on full open pulls. My truck has 4.10 gears, with 3.55 the engine is too low of rpm's to pull considerable weight

Truck is already 4.10, and I have to kick it out of overdrive even on small hills to keep egts in check, 35s on the tow rig probably doesn't help either
 
I hate to say it, but you may have some other issue. you shouldn't be robbed for power that much with 35's.

What are you seeing for boost numbers?

coolant temps ?

back pressure sensor operating?

up pipes leaking ?

what size exhaust housing on the turbo ?
 
I hate to say it, but you may have some other issue. you shouldn't be robbed for power that much with 35's.

What are you seeing for boost numbers?
Boost is in the lower 30s empty on the hot tune, mid to upper 20s loaded on tow tune

coolant temps ?
No real coolant temp gauge, oil temp usually around 215-220 towing, highest I've seen it was 230 on the 10 mile Vantage grade so I backed out

back pressure sensor operating?
Good question, I'll pull it up on the CTS when I drive home tonight

up pipes leaking ?
A little bit yes, not horribly last time I checked

what size exhaust housing on the turbo ?
Stock non gated 1.15

Truck has pretty good power but has always been egt limited, I can peg the gauge easily on any freeway on ramp empty
 
something definitely is going on with your current set up.

find out what it is and either fix it or fix it with an upgrade.

How's your blowby? Your symptoms is really similar to my truck's original 12v cummins. Power is there but always hot EGT.
 
I've always leaned towards it being normal with larger than stock injectors, AA OBS injectors are 90cc, AD Superduty injectors are 130-140ish according to most people
 
Truck has pretty good power but has always been egt limited, I can peg the gauge easily on any freeway on ramp empty

wow 30lb of boost, thats impressive. on my tow tune 24 is the highest I can achieve.

ever consider that it may be the tune on the truck ? some tunes are hotter than others
 
If i remember correctly anything more than 15 psi your loosing efficiency without a intercooler. ill get pictures later, but im running a intercooler in my obs idi. i never hit more then 1000 sustained
 
I'm still running stock obs Injectors with 330k miles, so I'm not pegging any of the gauges. :flipoff2:​​​​​​

With my 12v I could easily peg the egt gauge.

I doubt anything is really wrong with his truck, it's just at the point where it needs an i/c. After that, maybe some cooler tunes, but either way, towing with out an i/c sucks.
 
If you know your up pipes are leaking, get that shit fixed, it's not that hard. I am running the Dorman bellowed up pipes and I think I paid ~$200 for them almost 6 years ago and they are still going strong.

My setup is a 250,000+ mile 2000 7.3L, 6 speed, 33" tires, 3.73 gears. I am running the Donaldson AIS intake, Banks 4" exhaust (including the muffler) with the "Power Elbow" (fancy EBPV delete), WW II compressor wheel, and PHP Hydra w/ standard tunes. I am still on the original injectors and HPOP. In my 80HP tow tune, I can pull 7% grades at 70+ MPH while grossing 13,000-14,000 Lbs in 6th gear. The highest EGTs I have ever seen were 1150-1175ºF while losing speed and lugging in 6th gear on a long grades. I typically see 15-20PSI while in 6th gear pulling 7% grades, and the highest boost I see is a smidge above 25PSI getting on it to merge coming up on ramps.

My point is, I think your tuning is largely to blame. An intercooler would help, but a turbo upgrade would definitely help more, because the TP38 and GTP38 turbos are junk. I feel like the WWII and Power elbow (EBPV delete) helped a lot, but the GTP38 is still super laggy compared to more modern turbo designs, and has no boost below 1,500RPM, and doesn't really start spooling until above 2,000 RPM even though the 7.3L can move a lot more air faster than a 5.9L or 6.6L.

Getting up around 30 PSI range is really far outside of the stock turbo's efficiency range, and it wont live long doing that. Your drive:boost pressure ratio must be pretty bad at that point.
 
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Cxracing cheap eBay intercooler fits obs trucks pretty good. After running hard the cold side is cool and you can bearly touch the hot sides

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I ran a 6.0 intercooler on my OBS IDI. With some simple brackets, the intercooler fits perfectly with minimal trimming. It was like these trucks were made for them. With a powerstroke, the tube hook up should be even easier. I dont know if the PSD runs the same as an IDIT but lugging my truck would heat up both in EGT/water temp. Drop a gear and run it nearly to the governor and it would immediately cool down, both the EGT and water temp, and then just sit there as long as you wanted, hammering along.
 
I put a 6.0 intercooler on 95 F350. I think I spent $300 total. I only saw maybe 150 degree drop.

But it made a huge difference when towing. Instant drops are not great, it is the long term cooling you need. Things like the engine fan are not kicked on when you are just running the 1/4 mile or just cruising. On long grades I drive by the egts. when the engine fan kicks on I am able to give it more fuel.

I have the IDM mod and I didn't notice any lag difference.

Tuning is huge. I am having hard time finding a good tune again now. I had a TW 4 position chip that I loved but the chip went bad and I have been searching for something I enjoy driving as much but nothing yet, probably have to go with custom tuning.

I have intercooler, idm mod, diy intake. Ceramic coated downpipe, with big truck muffler, 4" exhaust. stock turbo, I think my ebpv is gutted don't remember, new up pipes, and 180cc diy injectors.
E4od with modified valve body, 4:10 gears, gear vendor over drive. 4x4. On 285 tires I dyno'd 690 ft/lbs don't remember the horse power like 290. Stock turbo, stock hpop

burnt up torque converter like first towing trip out. Finally now I am going to have to go through the rest of the trans. It is done.

Anyway, 18,000 lbs I think is my biggest tow trips. This thing is an animal. I absolutely love towing with it. It just works. The gear vendor is not quite as deep as the factory od so I shut the OD off and run the GV. it keeps the rpms up and that keeps the EGTs down. Hard on fuel mileage I suppose.

Friend of mine has a chipped 6.0 excursion and I love how his trans shifts, was thinking about a stand alone controller to make mine work that way. He will thrash me in a drag race but I always pass him going up hill and it drives him nuts.

I have a 2014 superduty with 6.7 and I have to say it doesn't tow the same load any better. Maybe easier, or maybe it will handle bigger loads, but they seem to pull the same hills at the same speeds. That old 7.3 is still today a decent engine.
 
I put some feelers out and I think I've found a 6.0 IC, and e99 spider and pipes. Hopefully with that and some up pipes I'll be pulling hills closer to the speed
limit
 
I put some feelers out and I think I've found a 6.0 IC, and e99 spider and pipes. Hopefully with that and some up pipes I'll be pulling hills closer to the speed
limit

Why would you want the early '99 intake stuff? Is it really an improvement over the '94-'97 parts? I know the Superduty guys all want to upgrade from the early '99 hardware to the late '99-'03 stuff.
 
Why would you want the early '99 intake stuff? Is it really an improvement over the '94-'97 parts? I know the Superduty guys all want to upgrade from the early '99 hardware to the late '99-'03 stuff.

The E99 intake spider is the one you have to use to intercool an OBS, the late99+ stuff won't fit the OBS plenums or turbo
 
my 97 350 srw zf5 would peg the egt gauge at will towing. I had 4 pos tony wildmans tune and 150cc single shots and a 6637. stock turbo non intercooled. I want to say it would push close to 40 psi if i let it. Truck would be intercooled if i still owned it.
fix your up pipes thats not helping thingss at all, or just put a t4 setup on it with a turbo that will actually build some boost down low like a 363sxe, or larger. dont waste money modding the stock turbo
 
my 97 350 srw zf5 would peg the egt gauge at will towing. I had 4 pos tony wildmans tune and 150cc single shots and a 6637. stock turbo non intercooled. I want to say it would push close to 40 psi if i let it. Truck would be intercooled if i still owned it.
fix your up pipes thats not helping thingss at all, or just put a t4 setup on it with a turbo that will actually build some boost down low like a 363sxe, or larger. dont waste money modding the stock turbo

I know I need more turbo for sure, this is my third stock one. Just haven't talked myself into ponying up the big bucks
 
Well decided to go with the known path and picked up a 6.0 intercooler
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While I was out i also scored a free superduty fuel tank. My rear tank I recently found out has started coming apart, going to go to the single 38 gallon plastic tank so I won't have to worry about it again
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