Engine/Transmission (1998.5 - 2002) Better towing turbo-Super B or Phat Shaft 62

[fox]

Much better? Much better for what?



Or is it that nobody buys them because of reasoning like JGoss's? Like the HTBG/12, which is a great little turbo and can handle 400+ with no problem, but most folks, including myself at the time, figure that spending the little extra to get a "better" turbo is the smart thing. Even against the advice of a friend that had one working well on a 420hp big-tired automatic that towed. I'd probably still have the 'BG on my truck if that was the one I had originally bought.



You have to get off the "spool faster" thing. Good towing characteristics have little to do with how fast the turbo accelerates. The balance of the aerodynamic load between the compressor and the turbine is what counts. The drag from the larger wheel effectively robs some of the power available from the system (more drag with same input energy = less actual work being done, meaning not as much air can be pumped). The smaller wheels can transfer more of the exhaust energy into intake energy, because they don't waste as much due to drag. This is, of course, providing that both turbos being compared are still within their map. Where the larger compressors gain the advantage is when the smaller ones run out of their map and superheat the air charge. If the turbo is maxed out and the egts are still going up (like around 32psi with the HX35/12), then a larger turbo will probably do you some good. If you're not hitting 32psi and egts are an issue, then a larger turbo probably won't help.



I've seen the map, and they both look to max out right around 58ppm. That only shows one part of the equation though. Turbines and exhaust housings aren't factored in, so you really have no idea how they'll actually work on the actual engine. There isn't anything on that map that tells us how it works on a mildly tuned truck that tows heavy. And maybe its rated higher than the stocker because the turbine side is less restrictive, or maybe because the stocker needs to be wastegated to maintain a lower psi to stay in its map, thus causing the pressure delta to go way negative?



Having a turbo that is already online and responsive vs. having to goose the throttle or downshift to light it up is the key to a good towing turbo, and that's accomplished with a turbo that's sized close to stock. At least that's what I've found out over the past 8 years or so of experimenting anyway. YMMV. Do let us know how yours works for you.



And out of curiosity, if you haven't towed with it yet, how can you recommended the Stage 2 as a good towing turbo?

So you think driving a truck and driving a turbo is a good thing? Why not size the turbo to be there for your needs?

 

[AH64ID]

Much better? Much better for what?

Or is it that nobody buys them because of reasoning like JGoss's? Like the HTBG/12, which is a great little turbo and can handle 400+ with no problem, but most folks, including myself at the time, figure that spending the little extra to get a "better" turbo is the smart thing. Even against the advice of a friend that had one working well on a 420hp big-tired automatic that towed. I'd probably still have the 'BG on my truck if that was the one I had originally bought.

You have to get off the "spool faster" thing. Good towing characteristics have little to do with how fast the turbo accelerates. The balance of the aerodynamic load between the compressor and the turbine is what counts. The drag from the larger wheel effectively robs some of the power available from the system (more drag with same input energy = less actual work being done, meaning not as much air can be pumped). The smaller wheels can transfer more of the exhaust energy into intake energy, because they don't waste as much due to drag. This is, of course, providing that both turbos being compared are still within their map. Where the larger compressors gain the advantage is when the smaller ones run out of their map and superheat the air charge. If the turbo is maxed out and the egts are still going up (like around 32psi with the HX35/12), then a larger turbo will probably do you some good. If you're not hitting 32psi and egts are an issue, then a larger turbo probably won't help.

I've seen the map, and they both look to max out right around 58ppm. That only shows one part of the equation though. Turbines and exhaust housings aren't factored in, so you really have no idea how they'll actually work on the actual engine. There isn't anything on that map that tells us how it works on a mildly tuned truck that tows heavy. And maybe its rated higher than the stocker because the turbine side is less restrictive, or maybe because the stocker needs to be wastegated to maintain a lower psi to stay in its map, thus causing the pressure delta to go way negative?

Having a turbo that is already online and responsive vs. having to goose the throttle or downshift to light it up is the key to a good towing turbo, and that's accomplished with a turbo that's sized close to stock. At least that's what I've found out over the past 8 years or so of experimenting anyway. YMMV. Do let us know how yours works for you.

And out of curiosity, if you haven't towed with it yet, how can you recommended the Stage 2 as a good towing turbo?

From what I was told by multiple vendors they aren't sold because they don't move enough air to be worthwhile, if you were running it on a stock truck then maybe, but for any mods its not enough.

In one post you state that the HTB2 was too slow to spool so be effective for your towing needs, and then state that spool isn't as important? Moving more air at lower rpms is a function of spool, hands down.

The Stage 1 and Stage 2 both use 82mm wheels, the difference is the trim/inducer size.

I can recommend it as as towing turbo based on months of research, and speaking to people that have it. I have no doubt he will not be disappointed.

Lastly if you look at the MAP by Garrett you have to recall that its a marketing MAP, the stock MAP is the same on all of the powermax flyers, yet how many different turbo's were used? The HX35 is a 60-61 lb/min turbo. The Stage 1 uses the 52 trim wheel from a 3782. The PR is higher on the powermax flyer because its recalculated for diesel. There is also a typo on the powermax flyer where it says the stage 1 uses a 50 trim wheel, it's actually they 52 trim 59. 1x82mm wheel. But you can see its only 55-57 lb/min. The Stage 2 has the wheel from a 3582R and is 61. 4x82mm and rated at 65-69 lb/min.

The Super B Single is a good turbo, and is about 60-62 lb/min but would be operating at its peak for towing like the OP does, IMHO.

 

[PC12Driver]

So you think driving a truck and driving a turbo is a good thing? Why not size the turbo to be there for your needs?

That's what I said in post #18:

Since the turbo on our diesels shapes the powerband like a cam on a gasser, the correct way to build the engine would be to pick a turbo that puts the power where you need it, and then fuel accordingly.

 

[PC12Driver]

From what I was told by multiple vendors they aren't sold because they don't move enough air to be worthwhile, if you were running it on a stock truck then maybe, but for any mods its not enough.



In one post you state that the HTB2 was too slow to spool so be effective for your towing needs, and then state that spool isn't as important? Moving more air at lower rpms is a function of spool, hands down.



The Stage 1 and Stage 2 both use 82mm wheels, the difference is the trim/inducer size.



I can recommend it as as towing turbo based on months of research, and speaking to people that have it. I have no doubt he will not be disappointed.



Lastly if you look at the MAP by Garrett you have to recall that its a marketing MAP, the stock MAP is the same on all of the powermax flyers, yet how many different turbo's were used? The HX35 is a 60-61 lb/min turbo. The Stage 1 uses the 52 trim wheel from a 3782. The PR is higher on the powermax flyer because its recalculated for diesel. There is also a typo on the powermax flyer where it says the stage 1 uses a 50 trim wheel, it's actually they 52 trim 59. 1x82mm wheel. But you can see its only 55-57 lb/min. The Stage 2 has the wheel from a 3582R and is 61. 4x82mm and rated at 65-69 lb/min.



The Super B Single is a good turbo, and is about 60-62 lb/min but would be operating at its peak for towing like the OP does, IMHO.

I was told by the manufacturer that if I wanted to use ALL my power for towing I should go with a 14cm housing on my HTB2. That shows how out of touch even a manufacturer can be when it comes to the practical application of these things. The larger housing would have moved my powerband up another 100-200 rpm, which would be just about useless for towing. What he missed, and you are clearly missing as well, is that you'll hardly ever, if ever, use more than 250hp to maybe 300hp when pulling a trailer, and most of the time you'll be in the 100-150hp range. The full throttle, max output numbers that you keep bringing up are irrelevant. Again, size the turbo for the power you use.



Did I really say the HTB2 was "too slow to spool for my towing needs"? I'm pretty sure I would have said something more like it wasn't as efficient down low as a smaller turbo would be. To me, "spool" is the time it takes for a turbo to spin up to operating speed. Not at all what I'm talking about. At say, 1600rpm, there is enough drive energy to run the HX35/12's compressor into its efficiency range, and move enough air for light-to-moderate power requests. The HTB2 (or similarly sized turbos) won't even respond at that engine rpm without a healthy shot of fuel from a high-power request. The fueling from low to mid power needs won't generate enough drive pressure to wake the bigger compressor up and you end up with increasing fuel without the balancing air. EGT needles head for the redline while the boost needle barely moves.



Nobody tows at full throttle all the time. It doesn't make sense to size your turbo based on peak power if you hardly use it. If a guy says he tows heavy almost all the time, then he should size the turbo accordingly. Having something that throws away bottom end just so you can cool top end that you'll never use doesn't make a bunch of sense, does it? A weekend RVer such as yourself doesn't mind compromising some bottom end for the occasional tow so he can hotrod during the week, but we're talking about a guy who admittedly pulls heavy almost all the time. He'll always be aware of the missing bottom end, but hardly ever need all the top end that the Stage 2 allows for.



Not to be mean, but I'm spending way to much time making counterpoints to second hand internet information and marketing buzzwords. Go pull something heavy, get some first-hand experience, and I'll meet you back here.

 

[AH64ID]

You keep stating that your not talking about spool, but what you are describing is spool. If the HTB2 wasn't moving enough air at 1600 rpms its because it wasn't spooled and below its efficiency range, this is why the ball-bearing turbo's do so well, they spool easier and get to that efficiency range many rpms before a comparably size journal bearing turbo would. It allows you to go up in wheel/housing size and not compromise the low end response. You get a free flowing exhaust that improves response, power, and EGT's. Spool is the time it takes to get to operating rpms, and that's what you are saying the HTB2 didn't have.

The lack of back pressure from the Garrett at low rpms is also one of the reasons it responds so well, at very low throttle my truck is much more responsive than it was with the stock turbo, despite lower boost. It clears the smoke much faster, and the standard acceleration Smarty haze is all but gone, it moves more air down low than stock, period!

 

[PC12Driver]

So you're under the impression that the turbo won't accelerate below its efficiency range is because of the bearing type, not the aerodynamic load on the compressor?



You unloaded observations are irrelevant. The shortcomings show up when the engine is loaded up. Go tow something.

 

[AH64ID]

So you're under the impression that the turbo won't accelerate below its efficiency range is because of the bearing type, not the aerodynamic load on the compressor?



You unloaded observations are irrelevant. The shortcomings show up when the engine is loaded up. Go tow something.

There are multiple factors in how well a turbo spools. As I said if you have 2 same sized turbos, one is a journal bearing and one is a ball-bearing the BB turbo will spool much faster, probably hundreds of rpms sooner due to lower restriction. Just like a S300 270* bearing turbo spools faster than a S330 360* bearing turbo, even in the wheels are identical. . Its a well documented fact.



You really think a turbo will spool slower with more fuel? Thats awesome!

 

[JGoss]

Sorry for starting this war. I'll be honest, turbos are weak point for me, I rely on peoples opinions and actual use to base my decisions. I appreciate all of the replys. Hopefully the stage 2 will better the truck, but it may not. I will for sure post the results after I use it, (good or bad).

 

[RustyJC]

Sounds to me like you boys need to get 2 turbos of your choosing, a 16,000 lb trailer and a mountain and do some comparative testing instead of having a keyboard war of opinions.



JM2CW... ...



Rusty

 

[PC12Driver]

There are multiple factors in how well a turbo spools. As I said if you have 2 same sized turbos, one is a journal bearing and one is a ball-bearing the BB turbo will spool much faster, probably hundreds of rpms sooner due to lower restriction. Just like a S300 270* bearing turbo spools faster than a S330 360* bearing turbo, even in the wheels are identical. . Its a well documented fact.

Was there any question that a ball bearing supported turbo doesn't have less rotational drag than a standard version? Wasn't this a compressor size vs. towing discussion?



Incidentally, if this is a well documented fact, then you shouldn't have to use words like "probably. " Links, please.

You really think a turbo will spool slower with more fuel? Thats awesome!

Where did I say that? Please quote it. If you pulled that out of anything that I've said, then it is pretty clear that you have no idea of the concept that I'm trying to explain. But then again, why would you if you don't have anything but internet experience to base your side of the discussion on?



The thing about cutesy comments with exclamation marks is that they really loose their effectiveness if they're not based on anything the other party has actually said.



You're clearly excited about your new turbo. I have a feeling that no matter what the outcome actually is whenever you do tow with it, it will still be the best turbo ever.

 

[PC12Driver]

Sounds to me like you boys need to get 2 turbos of your choosing, a 16,000 lb trailer and a mountain and do some comparative testing instead of having a keyboard war of opinions.



JM2CW... ...



Rusty

Several years ago I did just that. I had the stock turbo and a hybrid that I was able to compare back to back, in the mountains, grossing about 18k. Same center sections, same turbines, and same exhaust housings. It was very obvious that the smaller compressor wheel was the way to go for towing, with less smoke, better throttle response, and lower egts with the trailer in tow.



So in a thread that is about which size compressors work better for towing (Super B vs. PS62, or now Garrett Stage 1 or Stage 2), I can give honest information based on actual experiences. AH64ID can tell you what he read on the internet. Even though he has the turbo and the trailer and could easily gain some credibility.



My intent for continuing this thread was to help someone who might be searching topics in the future put their money in the right place (as far as turbo selection), and to try and get folks to think before they buy into the "bigger turbo=more air fallacy". But, Mark Twain had some good advice for situations like this, and I think I'll take it...

 

[AH64ID]

It's pretty comical reading your posts. As it has been said multiple times there are a LOT more factors than just compressor size, and ALL of the factors need to be considered when choosing a towing turbo, or a turbo for any use. If all you look at is the compressor size you may as well run a Silver 62 for towing, as it has the same comp wheel as a PS62 :-laf



It has never been a compressor wheel size discussion, it has been a towing turbo discussion. There is more to a turbo than the comp wheel, if there wasn't the HE351's would be much better turbo's considering they have great comp wheels.



The word probably is used because each application will be slightly different and I am not going to put a definite rpm number on a spool rate. It is documented that they spool much faster.



Please re-read what all you have said. You keep saying that spool empty has no relationship to towing spool. In fact "irrelevant" is the term you used, which is false. My point is that if you spool like stock when empty you will continue to spool like stock when fueling harder and working the motor more, the load may even spool the charger faster. Yeah yeah. . I know you don't consider spool important...

 

[AH64ID]

Several years ago I did just that. I had the stock turbo and a hybrid that I was able to compare back to back, in the mountains, grossing about 18k. Same center sections, same turbines, and same exhaust housings. It was very obvious that the smaller compressor wheel was the way to go for towing, with less smoke, better throttle response, and lower egts with the trailer in tow.

I fully agree with that, and is what I would have expected. I have never argued that point, I am simply trying to make a different point. The Stage 1 is lower flowing comp wheel than stock and isn't an upgrade or a worthwhile replacement, especially when the OP has 90hp sticks and a Smarty on SW9.

I also don't disagree that the Stage 1 will spool quicker, but still beleive overall performance (entire rpm range/fueling profile) will be better on a 350 hp truck, especially one with injectors. The MAP's are very close on the surge line and the extra air is perfect for towing with more than stock power, and with the Stage 1 having less flow on the top end than stock its not good when pulling grades.

But don't worry I'll report back very soon I am doing some towing tomorrow and more as the week goes on. I have kept notes on how it preformed stock and will be able to quickly tell if its an improvement or not, and at what rpm. I rarely go over 2400 rpms so it will be clear if it spools at the lower rpms to meet the fuel/air demand, I also am about 350 rwhp but with stock nozzles.

 

[PC12Driver]

Please re-read what all you have said. You keep saying that spool empty has no relationship to towing spool. In fact "irrelevant" is the term you used, which is false. My point is that if you spool like stock when empty you will continue to spool like stock when fueling harder and working the motor more, the load may even spool the charger faster. Yeah yeah. . I know you don't consider spool important...

I don't have to re-read it - that's exactly the point I'm trying to make. Except I'm trying not to use that ten-cent word "spool", because it really has no definite meaning. Go tow something with that new turbo so you can stop wasting our time.



And how about that quote I asked for?

 

[AH64ID]

And how about that quote I asked for?

This is the line I was referring to. Unloaded is relevant to loaded, if you have flow issues without a load you will have flow issues with a load.

You unloaded observations are irrelevant.

What word would you like to use to call the time it takes a turbo to get to its operating speed at a given load/rpm?

 

[PC12Driver]

This is the line I was referring to. Unloaded is relevant to loaded, if you have flow issues without a load you will have flow issues with a load.

Exactly. But the inverse isn't always true.

But what I was looking for was where I said a turbo would spool slower with more fuel.

What word would you like to use to call the time it takes a turbo to get to its operating speed at a given load/rpm?

You're totally missing the concept. In all your internet experience, you've never heard of the condition of being "under the turbo?" Go pull a heavy trailer and learn something new.



Does your handle indicate any experience with turbine engines, or are you just a fan of the Apache?

 

[AH64ID]

Much to PC12's surprise, but not anyone else, this is an amazing tow turbo. There really isn't any getting under it, at least not with smart driving (and no, unlike what your thinking right now I'm not talking about shifting at 3K rpms to keep the upshift rpms high)...

2nd-4th gears it runs about 100-200* cooler than my stock turbo did, gets to 800-900 normally and stays there, regardless of light acceleration or heavy acceleration. 5th and 6th it will get to 1000 ± 50 and stay there, light or heavy acceleration. If I short shift it and start of in the next gear at 1300-1400 the EGT's are a little higher but not over 1100-1150, and that's driver error and did it stock as well.

6th gear (255/80/17's and 3. 73's) at 60 mph it will get to 1225 WOT on a grade, which is what it did stock as well. . but the truck has more power than it did stock for the same fueling. There is a grade that I do at 60 in 5th becuase stock it wouldn't hold speed in 6th, I pulled it easily in 6th today at the same speed as always. . still 95-100% throttle but never slowed, rpms were 1700.

I can easily tow in 6th at 60-65 with a TT and a 25 mph headwind and not get too hot on the EGT's.

Where we went this past weekend we go often and there is 1 good sized hill that is 60 mph in 5th, stock would run 1175* at the bottom and 1250* at the top, the new turbo ran 1050* most the way and the last steep part where the truck is at 75-80% load I saw about 1150*.

Boost is slightly lower across the board but EGT's and IAT's are lower. IAT's are up to 25° lower on long grades with similar boost, so the turbo is much more efficient than the stock HE351 and will be a lot more efficient than an HX35 wheel at higher boost levels.

I don't really know how the HX35 does on drive pressure but I was never more than a psi or two off of 1:1 for towing, something I never had with my stock turbo, 25 psi of boost in 5th at 2400 rpms was 35-37 psi of drive stock!

Slow speed is an absolute joy. I did about 70 miles of 20-30 mph towing mostly in 3rd, but 2-4 were used. The truck responds better than stock and has all the air I need at low rpms and low speed. I never saw over 650* in all those miles, not many hills but some small ones.

Normal driving in lower gears keeps the turbo ahead of the air demand, and shifting so that your at 1500-1600 after the shift is perfect in upper gears, which is where you should be shifting anyways to stay above peak tq rpm.

I am also showing about . 6 mpg higher on the OH than I normally do for that trip, maybe its nothing, but lower backpressure and a better breathing motor has to account for something.

With 4. 10's the turbo will work even better than my 3. 73's and over-sized tires.

I know some of my observations may be 3rd gen specific, but 2nd gen's have a better cam and exhaust manifold than 3rd gens do stock so my mods to those may not make too much of a difference relative to a 2nd gen, especially one with 90 hp sticks and a Smarty on SW9. . I think you will find the turbo an absolute dream to tow with. . it sounds killer too!

PC12Driver: Hopefully that's enough for you to be satisfied, but somehow I doubt it.

I'm both a fan of and a maintenance test pilot for the Apache.

 

[seafish]

AH64ID, You must be very happy that all your research and work just paid off with these last round of mods you did to your truck !!

Average 200* lower EGTs AND lower 25* IATs is a NICE combination for our CTDs !!!
So is shifting and loping at 1800 rpms... that all sounds just about right...
Despite other peoples opinions, obviously he Garret turbo you chose is a really nice turbo for these trucks, certainly when towing !!
Have you gotten to drive it much unlaoded yet (sorry if I missed the post) ??

Anyways, I look forward to even more impressions and observations as you get to drive/tow even more . Thanks for doing it and sharing it !! Oo.

 

[AH64ID]

I drove it to work about 4 days over the last 2 weeks and LOVE it. Empty its like a whole new truck. The truck really responds well to the lack of back-pressure. Its still weird to see little to no boost and have the truck moving like it does at partial throttle.

One thing I forgot is how much smoother the motor is above 2000 rpms when in cruise and towing. The stock turbo would have so much back-pressure it would oscillate above/below the speed more, this one just spools as it needs to and slows down quick, it really smoothed everything out. Towing in 5th at 60 mph before wasn't near as smooth or quiet, now I find myself doing it more as the load is down, the coolant and oil stay cooler, better oil pressure, etc. .

I am working on a big review and will probably post it tomorrow. It's more 3rd gen specific and includes a lot more detail on it. . but as far as I am concerned this is how Dodge should have built it!

 

[HEMI®Dart]

AH64ID,



Here is the degree symbol if you want to use it °