Old School HX35/HT3B vs Modern Compound Setup

Thanks diesel_importer.

No towing yet, my weekends are WED/THU and it's been a long 6 day work week of midnights so far. Hopefully this weekend after I finish the gassers I'll do some towing. I'm planning to do a boost leak test, GSK stud protrusion/adjustment, and timing check in this weekend as well. I'm going to log all of this so I have a baseline to build on. I'm debating on changing the timing, I suppose we'll have to see if it's slipped and how far if it has.

I'm really itching to slam the camshaft/tappets/springs/timing case in, but doing so without insuring there are no existing issues would void any results I had. I will say I want the camshaft to be the only change in the truck for before/after testing. I think many folks change timing and such when they do a swap therefore altering the "cam only" results. I can't blame them, I mean it's right there when you're swapping stuff. I really wish we had a decent dyno close by to supplement the modifications, but we simply do not, at least not for diesels.

-Dustin-
 
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Get an intercooler before anything else. We did an intercooler test a couple years ago for the magazine with my 97, and loaded it at a simulated 7,000 pound load up a grade for about 2 minutes on a Mustang dyno. The aftermarket intercooler ( it was a BD I think) dropped the EGT by 250 degrees! And that was just with a small S300. I bet the stock intercooler is killin ya.
 
JQmile said:
Get an intercooler before anything else. We did an intercooler test a couple years ago for the magazine with my 97, and loaded it at a simulated 7,000 pound load up a grade for about 2 minutes on a Mustang dyno. The aftermarket intercooler ( it was a BD I think) dropped the EGT by 250 degrees! And that was just with a small S300. I bet the stock intercooler is killin ya.
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And I looked for and re-read that article a few weeks ago and now I can't find it to reference. Anyways, I thank you guys for doing informative 12v articles like that. I know the 12v is a dinosaur in regards to "modern diesel technology" but I feel it's the SBC of diesels and I'm a old school kinda guy. Furthermore, the aftermarket continues to grow for 12v's, keeping it relevant in today's work/competition world. However while reading it, I did wish it was a real world tow. If I remember correctly it lowered EGT's by 100 cruising as well.

Found it online: 1997 Dodge Ram - BD Intercooler - Diesel Power Magazine


I've been talking to someone I went to high school with who does some fabrication on a tractor down the road from where I grew up. Perhaps folks have heard of Cope's MF "Warpath". We are discussing what he can do for me without breaking the bank. Problem is we need to get our hands on a durable, efficient, and correct size core to fabricate around. I like the BD design which uses a unique extruded tube design compared to the stock tube/fin style, but I'm sure we'd have a hard time sourcing that.

While on the topic, ask yourself what makes an aftermarket intercooler out perform the stock one? The inlet/outlet tubes/restrictions, thickness, internal design, etc? I think the BD is going to give you better efficiency and less pressure drop just from the tube style. If I was going to buy an aftermarket one it's hard to look away from a BD that's priced around the same as others, but clearly has a superior design for air to air coolers.

CAC_stuffed_tubes.jpg
CAC_stuffed_tubes_closeup.jpg


VS

CAC_BD_Int_tubes.jpg
CAC_BD_Int_tubes_closeup.jpg


Trust me, I'm really trying to get the most from this truck. Lots of folks just throw as much fuel/air they can to make a number, but I'd like to increase it's efficiency and make useful power in the range that I need it. That Hamilton 12v head really has me excited for 12v performance, even though it's total overkill for my setup.

After an exciting 12 hour midnight shift last night, it's time to make some progress in the garage.

-Dustin-
 
We had a heat gun on the tanks and it seemed like if the intercooler couldn't match the cfm of the turbo (remember the stock ones are designed for an HX35 at about 19psi) then the air would "stack up" and start to get hot. At the end of the test there was a noticable intercooler-out temperature drop on the BD as compared to the stock one. A bigger core, bigger tanks, and less restrictive inlet/outlets all helped. We were actually all really surprised that the intercooler made that much of a difference under a 15,000 pound load, but it really did. And the test was repeatable. We actually got the truck pretty close to overheating before we ran into EGT issues.

Edit: A real world tow would have been nice, but we had plenty of load on it on the dyno...that turbo was screaming!
 
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Another interesting note...the truck could still peg the 1,600 deg gauge at wide open throttle cause the truck had way more fuel than turbo, so the intercooler wasn't the magic cure for WOT egts.....but it sure made a difference under a constant heavy load!
 
JQ, what were you guys using for a fan to simulate 55 MPH airflow over the cooler?
 
Great thread nice to see some real word info for twins in towing. I have been debating runing a single or a set of twins and run the elevation as you do more often then not.
 
One of those like 5 feet around shop fans. I doubt it was 55mph worth of wind, but it was all we had at the time. Probably why the truck got hot.
 
UPDATE:

When I was messing around with a fuel stop/limiter I've discovered a fueling issue which I thought I had licked. I messed around with the overflow valve and I can make the sputtering better/worse but can't eliminate it. I need to get a gauge on it and see what's up.

I'm looking into these from Tork Teknology:

To add a fuel pressure gauge: TORK TEK 12MM BANJO BOLT PRESSURE GAUGE SNUBBER PN BBS010 - Tork Teknology

For adjusting/managing fuel pressure: TORK TEK CUMMINS ADJUSTABLE OVERFLOW VALVE OFV020 - Tork Teknology

or

CUMMINS P7100 HIGH PERFORMANCE OVERFLOW VALVE OFV060HP - Tork Teknology

If it turns out to be a fuel pressure issue I'm somewhat torn between a Carter 4601HP pusher pump or scrapping everything and going to a FASS/Airdog setup. DTT has a belt driven fuel pump which also intrigues me. I like the Carter pusher idea because of reliability. I'll advise on what I find.

I also did some reading on the tuning twins tread, I hope to get some gauges to measure those pressures as well. I've got to get everything 100% before doing a true apples to apples comparison.

PS: Had a cold front come through this week, twins are spooling like they did in the northern air/altitude. Things are getting started around 1500-1550rpm

-Dustin-
 
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No I've been chasing this fuel issue, as well as other things on the other junk in the garage. Got a gauge on it, found my fuel pressure is erratic, dropping to single digits under WOT runs.

-Dustin-
 
adjustable ofv and the fass/airdog will fix it all. i have had several carter pusher pumps come apart or fail.
 
I'm kinda interested in trying one of these belt/mechanical pumps like what DTT has. Seems like a good choice, linear fuel curve, durable, and simple. Price ain't bad either

-Dustin-
 
Your 12v piston lift pump on the block should be pushing a lot of fuel for your setup..its cheap and dead nuts reliable. make sure you get the correct piston lift pump...they made one for the ve and its a lot lower pressure. also you can shim / stretch the pressure regulator spring in the pump. for a daily drive tow vehicle the psiton lift pump on teh cam would be preetty hard to beat for durability. I'd add a perm fuel pressure guage in you setup.
Good thread,
Thanks,
Deo
 
therabbittree said:
Your 12v piston lift pump on the block should be pushing a lot of fuel for your setup..its cheap and dead nuts reliable. make sure you get the correct piston lift pump...they made one for the ve and its a lot lower pressure. also you can shim / stretch the pressure regulator spring in the pump. for a daily drive tow vehicle the psiton lift pump on teh cam would be preetty hard to beat for durability. I'd add a perm fuel pressure guage in you setup.
Good thread,
Thanks,
Deo
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Maybe it should keep up and I like cheap and reliable, but, I've had a fuel pressure gauge on my truck for the last couple day and it's the same thing every time. 55psi idle, 30-35 cruising, down to 5ish @ WOT. I've already spent an afternoon modding the OFV with different springs, which is why it holds 55psi at idle. Unfortunately it's just not keeping up. The lift pump is a factory 12v, but it does have some miles on it [240k].

See my fuel pressure thread: P7100 Fuel Pressure - Competition Diesel.Com - Bringing The BEST Together

-Dustin-
 
The biggest gain I have seen when using the factory piston lift pump is upgrading the line from the tank to the pump. If you Upgrade to 1/2 inch or bigger line and a sump or pickup tube, the factory pump should be capable of supporting the power level you are at. the other thing to check Is the fuel heater, and the screen in the inlet of the lift pump. Ive seen many fuel heater screens and pump inlets clogged.
 
seriousdiesel said:
The biggest gain I have seen when using the factory piston lift pump is upgrading the line from the tank to the pump. If you Upgrade to 1/2 inch or bigger line and a sump or pickup tube, the factory pump should be capable of supporting the power level you are at. the other thing to check Is the fuel heater, and the screen in the inlet of the lift pump. Ive seen many fuel heater screens and pump inlets clogged.
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A friend and I were talking about this yesterday. I thought about seeing what would happen if we just removed bottle necks in the system. I see lots of VE/VP guys trumping up the 12v pump. This article gets into the nitty-gritty of the stock pump and line sizes: Technical Article Number Two - The Diesel Fuel System and Inlet Line

Pretty good read.

-Dustin-
 
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