Old School HX35/HT3B vs Modern Compound Setup

Bersaglieri

Bersaglieri

Ron Swanson's Brother
I've been sporting my ole HX35-14/HT3B-26 setup for a few years. I tried churching it up by porting my manifold and the dual wastegated HX exhaust housing. But lately I've been thinking about changing it up. At first I wanted to run a smaller HT3B housing to help spool up even more, but alot of advances have been made lately and I think it's time to move up. I'm interested in something that spools as well or better, is more durable and keeps things cool while towing.

I've made a few phone calls and a few places have told me it isn't worth the money to upgrade. I'm hoping Compd can either kick me in the nuts or pat me on the back for wanting to step up.

I DD/Tow with this truck. All I tow is a 22ft low-deck gooseneck with a 3400lb Camaro to the track. However my current 4000ft altitude is not friendly to my 12v Cummin's oxygen needs, so a single won't cut it for towing. Mods: 5x.014, 181, GSK, and there is a Hamilton Cam waiting for install. The truck isn't a competition truck, it rarely sees much over 3200rpm. The only racing I do is occasionally toying with coworker's "off the lot" muscle cars.

So are the "shops" right?

Would it be foolish to upgrade to a S362/S475?

Should I be looking at smaller chargers in the S360/S471 area like the BD R700 kit to check temps sooner in the RPM range?

Would I be wasting my time building a HE351/HT3B-22 setup?

I can build my own piping, drains, and oil feed lines. Just got to buy the turbos and small parts.

-Dustin-
 
Have you ever dyno'd your truck? Honestly, for a tow rig, the 35/3b is a great setup. There are other ways to get to about the same place, but they cost a bit more. I ran a 35/40 hybrid over k31 that worked well, but didn't make any more power. A 35/40 hybrid over Gt4202 is an excellent setup also, but again, more expensive. If you are happy where you are power and egt wise, leave well enough alone and buy another toy to play with rather than take a loss on an existing setup and spending money on its replacement only to end up at the same place. You can only use so much power when towing.
 
what are your EGT's like when you are driving/towing/playing? Are they dangerous, or just a tad toasty? have you tinkered with the drive pressure, and made sure that your boost ratio isn't out of whack?

Yes, the HX 35 or 40/HT3B twins are dinosaurs. Yes, they have been around forever and a day, they are old and there is better turbo technology out there. But, they are boat anchor tough, can't really hurt them.

In my opinion, I would install the Hamilton cam, because that would help tremendously with airflow. Then, if you aren't happy, start looking at a new(er) set of turbos.
 
I've never dyno'd the truck, but I am ok with the power level, especially for towing. My problem lies in EGT's. The truck makes usable boost around 1750rpm if I remember correctly. With a tighter converter [Suncoast 44 series] and 3.54 gears moving a load down an on ramp can start out smokey and get hot towards the end. Cruising with a load [7000lbs] is generally 1200 on flat ground, hit a hill and I'm fighting to keep them below 1500. If I want I can peg the 1800 degree pyro, even empty. I was up north back in July and the truck performed far better with controllable EGT's, down here things just run hot.

I've done a few things to help this. Ported the top housing, ported the exhaust manifold, bought a camshaft, and I'm going to a smaller OD tire [285 from 315]. I thought about going to a 22cm housing vs my current 26cm to help even more. Tomorrow I'm picking up an aftermarket intercooler I found for a steal locally. I'm hoping the to-do list [33" tires, camshaft, and intercooler] will bring me into a more controllable EGT range, but I don't want to rule out moving to a better compound setup. I'm willing to spend money to increase the efficiency of the truck and make it more useful in the RPM range I use.

-Dustin-
 
Don't buy anything untill you back up and figure out the problem. That's way too hot for what you have. My gt4094/Gt55 setup at over 1k horsepower doesn't tow that hot.
Start with the basics and make sure your wastegate is functioning and staying closed till around 15 to 20psi. You can verify that with a regulated air source.
 
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Do some investigating to make sure your timing hasnt slipped or you don't have a boost leak, that does sound way too hot for what you have. And I would definitely not switch out turbos until you install that cam, a cam can make a huge difference IMO.
 
I too agree that it sounds too hot, something isn't right, either the pyro is wacky, or there are other issues causing the heat. 1750 rpm sounds a little slow to me as far as spool-up. Have you checked for boost leaks yet, as in pressurized the whole system starting at the connection between HT3B outlet and the coldpipe?

On your top turbo, HX35, are you running the stock 12cm exhaust housing that came on the turbo from the factory or has it been replaced? The reason I ask is just yesterday I was playing around with the stock WH1C from my 95' and the stock HX35 from my 98' 12 valve at the exhaust housings from the WH1C would fit on the HX35 and bolt up and appear stock, even has a 12 molded inside the divided inlet...... The problem with this is that the WH1C has a 70mm x 59.98mm exhaust wheel, the HX35 has a 68mm x 59.6mm exhaust wheel. Same blade count, looks to have the same blade pitch, blade height etc. What I'm getting at is if someone has swapped exhaust housings in the past there's a chance it has the wrong housing but it will look and bolt up like the correct housing and still work, just spool a little slow and run inefficiently.
 
RonA said:
Don't buy anything untill you back up and figure out the problem. That's way too hot for what you have. My gt4094/Gt55 setup at over 1k horsepower doesn't tow that hot.
Start with the basics and make sure your wastegate is functioning and staying closed till around 15 to 20psi. You can verify that with a regulated air source.
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Turns out the intercooler is for a first gen, I'm still getting for a friend to put in his truck. For $150 it's hard to pass up.

I'll check the wastegate today. My weekend starts today and I've been meaning to do it anyways, just need to get it done.

Muddin_dude06 said:
Do some investigating to make sure your timing hasnt slipped or you don't have a boost leak, that does sound way too hot for what you have. And I would definitely not switch out turbos until you install that cam, a cam can make a huge difference IMO.
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I'm not sure on the timing, I'll have to check. It slipped once before and the truck was breathing fire and barely running. Are you guys changing the lock washer every time? I'd like to just buy a pack of them from Fastenal, anyone got the size?

Last time I checked I was good on leaks, that was after I found a few holes in my old original intercooler. I'll check again though.

I'm hoping the camshaft makes a big difference, some say cams aren't worth it, some say they are worth every cent. I ended up catching the end of Hamilton sale and snagged a 181/210.

Big Blue24 said:
I too agree that it sounds too hot, something isn't right, either the pyro is wacky, or there are other issues causing the heat. 1750 rpm sounds a little slow to me as far as spool-up. Have you checked for boost leaks yet, as in pressurized the whole system starting at the connection between HT3B outlet and the coldpipe?

On your top turbo, HX35, are you running the stock 12cm exhaust housing that came on the turbo from the factory or has it been replaced? The reason I ask is just yesterday I was playing around with the stock WH1C from my 95' and the stock HX35 from my 98' 12 valve at the exhaust housings from the WH1C would fit on the HX35 and bolt up and appear stock, even has a 12 molded inside the divided inlet...... The problem with this is that the WH1C has a 70mm x 59.98mm exhaust wheel, the HX35 has a 68mm x 59.6mm exhaust wheel. Same blade count, looks to have the same blade pitch, blade height etc. What I'm getting at is if someone has swapped exhaust housings in the past there's a chance it has the wrong housing but it will look and bolt up like the correct housing and still work, just spool a little slow and run inefficiently.
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I'm calling ISSPRO today about the pyro. I've heard you can check them, we'll see if they have a procedure to verify the output. The truck has always seemed a little hot, maybe I have a bum unit.

HX35 has a 14cm housing which we ported. It also has a larger wastegate flap and is drilled through so it gates all 6 cylinders. I'll report back with wheel sizes as well, it's been two years since I measured them.

I appreciate the help guys, I've been trying to figure out why things are so toasty. Amazingly the truck runs good and hasn't melted any exhaust wheels.

-Dustin-
 
35 inch tires and 3.55 gears. And you are towing that much! Wow, no wonder it's hot.
Put those 285s on it and see how it does. It will change everything. Do one thing at a time so you can see what worked.
 
Bersaglieri said:
I'm not sure on the timing, I'll have to check. It slipped once before and the truck was breathing fire and barely running. Are you guys changing the lock washer every time? I'd like to just buy a pack of them from Fastenal, anyone got the size?
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Its 20mm. 3/4" might fit though. That being said, I've done timing many times and never replaced the lock washer. I've had my timing slip once, and thats because I got oil on the shaft when I installed the pump, and neglected to spray it down prior to installing the gear. I also torque mine a bit higher than the 144 ft-lbs. spec.
 
Diehard Ram said:
35 inch tires and 3.55 gears. And you are towing that much! Wow, no wonder it's hot.
Put those 285s on it and see how it does. It will change everything. Do one thing at a time so you can see what worked.
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i would still say to go to a 235/85/16 and you would still be geared to the moon. i have had good luck in the 1800 to 2000 rpm range for towing. you sound like it you are lugging it down in od.
 
I took the twins apart to check things over.

First shaft play, using a dial indicator. Thankfully they are both within the allowable range. Range for the HX35 is .013"-.020" radial, .001"-.005" end. HT3B is .015"-.023" radial, .002"-.007 end". Radial is measured as the total movement from one side to the other.

8225694027_medium.jpg


While I had them off I measured the wheels with a caliper. The battery in the caliper was on the way out, but I got..

HX35 [56/60/14]
Compressor Wheel 56mm/82mm
Exhaust Wheel 69.5mm/60mm
HT3B [76/86/26]
Compressor Wheel 76mm/107mm
Exhaust 97mm/86mm

Boost leaks: I thought my system was air tight, however I discovered a few problems when I dug in.

I found that one of the bolts were missing that holds the compressor cover on the HT3B. I'm guessing it rattled out. At first I didn't think much of it until I remembered the bolt holes are not blind and they pass into the compressor area. Obviously a leak right there.

Also found one T-bolt clamp to be broken. Although it was still "holding" it was only a matter of time before it just blew off. The way it was broken is probably wasn't holding the way it should have been anyways.

Fixed both of those and put everything back together.

Results? Well of course the truck makes boost faster, it's fun to drive around town again, and improved mid-range since things are getting lit faster. It could be my imagination but it seems cruise EGT's are a little lower as well. I'm wanting to tow without changing anything else to see how it acts.

P.S. I checked the waste gate operation, it is working, however it's not starting to open until 30psi. Looks like it's fully open at 38ish psi. I'm not turbo tuning expert but I want that around 20psi right? What's ideal? Moving at ??psi and open at ??psi?

So I'll keep checking and updating this thread, hopefully adding tech data as I go. I know these 35's are killing me with 3.54's. But I like them for the muddy hunting trips and the look, not to mention the way our dirt road floods every time it rains. However with the drawbacks it brings in towing, mileage, spool up, price, rubbing, cupping, and handling, it's hard to make a case for them.

gunracer1: The speed limit here is 75mph, so typically I do tow in that rpm range. I'm going to throw something on the trailer tonight or tomorrow and see how it tows now.

Looks like this is turning into a "Perfecting Old School Compounds"

-Dustin-
 
Your HX35 exhaust wheel measurements match my WH1C measurements. Does the compressor cover on your HX35 have a snap ring or a v-band clamp?
 
I also want to thank you for this thread, good info here. I want to see what your towing results are without the boost leaks.
 
Got Smoke? said:
I also want to thank you for this thread, good info here. I want to see what your towing results are without the boost leaks.
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Thanks, I'm working on laying out specific tests to evaluate my results from different fixes/modifications/changes. It's going to include throttle stops/limiters, varying tow tests [grades/flat/from a stop], and empty tests [grades/flat/from a stop], etc. It's going to include times, EGT's, boost levels, etc. Time to separate fact from fiction for DD/tow truck applications.

-Dustin-
 
Bersaglieri said:
Thanks, I'm working on laying out specific tests to evaluate my results from different fixes/modifications/changes. It's going to include throttle stops/limiters, varying tow tests [grades/flat/from a stop], and empty tests [grades/flat/from a stop], etc. It's going to include times, EGT's, boost levels, etc. Time to separate fact from fiction for DD/tow truck applications.

-Dustin-
Click to expand...

Anxiously awaiting those results. :rockwoot:
 
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