Engine/Transmission (1998.5 - 2002) Dodgezilla or htb2?

[AHire]

What are the pro's and con's of each turbo? 12cm or 14 cm?



Iwill be running them in conjunction with mach 4's. I will be towing from time to time 14000# at the most.



Any other turbo's i should consider?

 

[PC12Driver]

I had the DZ/14 and went to the HTB2/12. Absolutely, positively, the HTB2 is worth the extra money. Unless you're bent on keeping a turbo-mounted exhaust brake (mine is currently off the truck and in a box - I'm glad I didn't make that a restriction on turbo selection), then you need to stick with an HX35-based exhaust housing.



The low end response of the 'B2/12 is noticibly stronger than the DZ/14. That results in less smoke off the line and more power earlier in the rpm range. Much better for towing (why I changed turbos) and around town use. The 'B2/12 develops power much more smoothly than the DZ, which felt flat on the bottom and had a "hook" when the turbo lit off. The 'B2/12 just smoothly starts pushing as you add throttle. And if you give it the fuel, it will light off hard and keep pulling.



On the top end I was pleasantly surprised. The HTB2/12 runs 100-150* cooler than the DZ/14. That's not so much the surprise, but the fact that it did it at 30-32 psi (10 psi less than the DZ) was. I have yet to break 1300* with the box on kill (thats' 465hp - but keep in mind, I do have a cam that's good for about 100* decrease). So I have a little bit of growing room, considering the HTB2/12 combo will still make quality boost to the mid 40's.



For towing, I was not happy with the DZ/14 combo at all. That turbo needs a lot of exhaust to drive it, which means either heavy throttle or rpms over 2k, neither of which make for comfortable towing. The 12cm housing helped, but I wasn't to wild about running the crappy Holset wastegate with that much airflow (it only 'gates the back 3 cylinders). I haven't towed with the 'B2 yet, but with its improved low end response I don't think it will be as bad as the DZ.



As far as 12cm vs. 14cm, just because you used the word "towing" I'd reccomend the 12cm housing. The only time you'll see a decrease in egts from a 14 cm housing is in the upper rpm range (say, 2200+rpm) and with heavy throttle. Anytime other than that and you'll probably see higher egts (as well as more smoke and less response at lower rpms). The 12cm will run cooler with the trailer in tow and will give you more power down low where you need it. And since these turbos wastegate all six, you don't have to worry about the drive pressures and temps in 1/2 the cylinders when you're running against the wastegate. So, unless you're sled pulling or dragracing, I'd say stick with the 12cm. In fact, I'd say that if you need a 14cm housing with this turbo, you probably need a larger compressor, too.



Can ya tell I like the HTB2/12?

 

[darkhorse]

What are the pro's and con's of each turbo? 12cm or 14 cm?



Iwill be running them in conjunction with mach 4's. I will be towing from time to time 14000# at the most.



Any other turbo's i should consider?

I experienced none of PC 12's problems with my DZ 14. It spools quickly for me with very little smoke. I'm totally in love with my Banks Brake & that's one reason I didn't consider other options. The DZ also has an attractive price.

 

[PC12Driver]

What are you pulling?

 

[NoSeeUm]

I experienced none of PC 12's problems with my DZ 14. It spools quickly for me with very little smoke. I'm totally in love with my Banks Brake & that's one reason I didn't consider other options. The DZ also has an attractive price.

Darkhorse,



I have been looking primarily at the DZ, I also want to keep my brake. One question though.



Does the DZ exhaust all six cylinders through the waste gate or do you have to do exhaust manifold modifications / install a plate?



Thanks;

Jim

 

[NoSeeUm]

What are you pulling?

PC;



Darkhorse runs a CaTCHer, might be the difference there?



Jim

 

[zstroken]

HTB2 the y are bulletproof. I have one with a set of supermentals and no heat issues. Shop around you can get some pretty good prices on the HTT stuff(hint hint). You can PM me if you ahve any questions.

 

[darkhorse]

Darkhorse,



I have been looking primarily at the DZ, I also want to keep my brake. One question though.



Does the DZ exhaust all six cylinders through the waste gate or do you have to do exhaust manifold modifications / install a plate?



Thanks;

Jim

The DZ has the usual Holset turbine housing. The wastegate is only in the back scroll segment but relief there leaves less pressure on the front segment. I did open the hole & radius it a bit with my Dremel & I use the Banks Break which has a larger & smoother passage for WG gasses. Yes I'm using CaTCHER programs that do make a difference in performance. Actually, I'm not running any thing right now, as I rolled my truck & won't be abel to drive my replacement until I'm out of my Halo Brace. So come May, I get to go through the BOMBing process all over again.

 

[NoSeeUm]

The DZ has the usual Holset turbine housing. The wastegate is only in the back scroll segment but relief there leaves less pressure on the front segment. I did open the hole & radius it a bit with my Dremel & I use the Banks Break which has a larger & smoother passage for WG gasses. Yes I'm using CaTCHER programs that do make a difference in performance. Actually, I'm not running any thing right now, as I rolled my truck & won't be abel to drive my replacement until I'm out of my Halo Brace. So come May, I get to go through the BOMBing process all over again.

OK thanks. The idea of installing a spacer plate seems more attractive to me when I install the DZ. I was thinking of going with a 1/4" or possibly as much as 3/8" plate. Do you think that would be adequate or too much?



Yes, the Banks Brake is quite a bit larger elbow than stock. I believe that stock elbow is 3" and the Banks Brake elbow is 4", but not positive. I am still running the stock HX35 turbine casing.



I am aware of your injuries and truck problems from following the Smarty thread. Gods help with your speedy healing and happy (re)bombing to you.



Jim

 

[darkhorse]

Thanks Jim! Bones heal slowly but my poor truck isn't healing at all. :{ The good news there is that no running gear was damaged so at least I don't have to buy new BOMBs, jest move them.



I'm curious if the spacer would rally make much difference. It seems to me the real bottle neck is the wategate hole & passage. I any event, my set up worked well to control EGT's & boost levels. I have the Banks Big Head actuator. On WOT tests, the boost would rise fast to 40 psi then drop back to the rated 38 psi. I would only see a thin haze in the exhaust & I've never seen 1200* egt. When I tow, it's with horses in the trailer(about 8K lb. ) & I don't push it with my precious live load. . I can see that things might get to hot with heavier loads & at higher altitudes up mountain passes.

 

[PC12Driver]

PC;



Darkhorse runs a CaTCHer, might be the difference there?



Jim

Nah. Extra fueling only helps light the turbo when you're accelerating. If you're trying to maintain a speed going up a hill with the trailer in tow, you're not using the extra fueling that the enhancements would provide. You need a turbo that is efficient at the rpms you're running at, and since the DZ/14 would light off at about 1,900-2,000 rpm (while partial throttle towing, I'm not talking full throttle racing), that's about 200-300 rpm too high. More fuel isn't always what you need to match a turbo to your engine.



I'd say the difference is in how we tow. I'm pulling a high profile 10k lbs fifth wheel on my vacations. A hot day in the rolling hills of Iowa on 80 was a pain with the DZ/14, and once I hit the mountains it really sucked. On the other hand, when I pulled an 8,000 pound boat across Michigan the DZ was no problem. The heavier the load, the more the turbo's characteristics stand out. So, considering that AHire tows about 4k more than I do and lives in a fairly hilly part of the country (if I remember correctly), I can't recommend the DZ/14. Not even a little.



These turbos are really in two different classes. If the extra $ isn't an issue (about $200-300 more for the HTB2) and having a turbo-mounted exhaust brake isn't mandatory (mine was worth taking off for the HTB2, and now I'm looking forward to a PacBrake PRXB), there really is no question. The performance difference on the top and especially on the bottom is night and day.

 

[darkhorse]

I'm not trying to be argumentative, but my DZ lights off at 1400 rpm with no problem. I'm not sure how much difference is due to my porting job. but I did not experience the higher cruise temperatures that I was told I might have. I have no doubt the HTB2 is a better choice for heavy towing. I'm only curious why Iamb not experiencing the problems others have reported with the DZ.

 

[AHire]

What are you pulling?

Mainly 20' landscaping trailer w/3 john deere 72" mowers or a skid steer loader. I do pull farm tractors from time to time that weigh 12000# alone so add that to a gooseneck trailor and it gets pretty heavy.



Basicly i want (dont need) mach 4's but want to keep my truck "usable" for towing and smokin some strokers at the same time

 

[Rebel Ram]

I cannot answer with experience regarding the Zilla, But as for the HTB2? I am thrilled with mine. I finally got my fueling problem fixed yesterday and went for a test drive and the boost went to 50 PSI in about 1. 5 seconds. I have never gotten more than 35 PSI from any of the Holset based turbos I've tried. That is not to say that many are having good results with them.

My Banks Brake is in a box right now and like PC12Driver, I am so glad that I didnt let my brake criple my truck by limiting my choices.

 

[PC12Driver]

I'm not trying to be argumentative, but my DZ lights off at 1400 rpm with no problem.

Shoot, argue away! I wish there was a discussion like this when I bought my first turbo. Gotta give you something to do while you're healing...



Is that 1,400 rpm light-off on a heavy throttle acceleration run? I know that wouldn't be a problem with the DZ. A big shot of fuel would get 'er turning just fine. It was the constant speed/increasing grade that would get me. If I didn't charge the hill or really jab the throttle I couldn't get on top of the turbo; power would sag, and egts would climb.

 

[Dual EE]

My DZ starts coming on strong around 10-15#s. Not quite sure of the exact rpm, but probably around 1500. With my driving habits, the stock turbo was no match w/the 370's. The DZ w/12 housing is adequate, but I would not add any more fuel then I have. I have not towed anything heavier then about 4k so far. The egt's were controllable, but have to be watched. I have my boost limited to max of 35#'s.

 

[Matthug]

Do you guys realize that you are comparing schwitzer and holset turbine housings as if they are the same? The schwitzer 12 flows more exhaust than a holset 14 and has a larger A/R, plus the 4'' outlet keeps restriction down even more. The HTB2's 14 housing also flows more than a holset 16.

With the power you want and towing I would also recommend an HTB2 with the 12 housing. The HX40 style downpipe with help keep EGT's down while towing. If you actually take an HX35 elbow off and measure it internally it's smaller than 2. 75''!!!

 

[PC12Driver]

Do you guys realize that you are comparing schwitzer and holset turbine housings as if they are the same?

We were? I didn't think things had gotten housing specific yet... But you are 100% correct: there's more to the exhaust housing than the cm2 measurement. Just setting the two side-by-side on the bench you can tell the Schwitzer (HTB2)'s housing is smoother and will probably flow more than the Holset's (subjective, I know). The Schwitzer's wastegate makes the Holset's look silly. And the 4" coming off the back of the turbo gives ya a good feeling, too (and the sound rocks). Good stuff all around. The only time I'll put another Holset back on my truck is when it's time to sell it.



Did I mention that I like my HTB2/12?

 

[AHire]

The htb2 sounds like the best turbo for my needs. Money would matter if it was 500 to 1000 dollar difference. From what i come up with the dz would be close to its max with m4's correct? But the htb2 can efficiently handle more fuel if i wanted to go bigger injectors, tst comp and so on?



I could also use the htb2 in a twins setup! Oo.

 

[darkhorse]

Shoot, argue away! I wish there was a discussion like this when I bought my first turbo. Gotta give you something to do while you're healing...



Is that 1,400 rpm light-off on a heavy throttle acceleration run? I know that wouldn't be a problem with the DZ. A big shot of fuel would get 'er turning just fine. It was the constant speed/increasing grade that would get me. If I didn't charge the hill or really jab the throttle I couldn't get on top of the turbo; power would sag, and egts would climb.

My DZ lights off at the slightest throttle movement & the boost literally shoots up in relation to the throttle movement. I really think the CaTCHER program has something to do with that. I have no doubt the HTB2 has more potential than the DZ, but my point is, in my application, the DZ is good enough for the job. Even in the few WOT test runs I've made, I haven't over run the wastegate's capacity as it hold a steady 38 psi to red line. Consider that I'm running Mach 3. 8's & an APB often turned up all the way. On the other hand, with that level of fueling I almost never use more than 2/3 throttle. Hay, maybe it's my High Ram that's responsible for my DZ's good performance. :-laf