Hybrid Turbos - 2 Questions: Spool & Boost at Cruise

[PRout]

Under normal driving circumstances (empty truck - not hot rodding):

1. Which turbo will give the quickest spool up or response taking off from a stop?

a. Stock HX35
b. PDR35/12
c. Dodgezilla/12


2. Which turbo will give the highest average boost while cruising at a steady 65 MPH?

a. Stock HX35
b. PDR35/12
c. Dodgezilla/12


Ok, I lied. . Bonus question:

3. Which turbo will give the lowest average EGTs while cruising at a steady 65 MPH?

Same choices. .

:-{} #@$%! :-laf:-laf

 

[Fishin Guide]

Under normal driving circumstances (empty truck - not hot rodding):



1. Which turbo will give the quickest spool up or response taking off from a stop?



a. Stock HX35

b. PDR35/12

c. Dodgezilla/12



Stock or PDR35.





2. Which turbo will give the highest average boost while cruising at a steady 65 MPH?



a. Stock HX35

b. PDR35/12

c. Dodgezilla/12



Stock





Ok, I lied. . Bonus question:



3. Which turbo will give the lowest average EGTs while cruising at a steady 65 MPH?



Same choices. .



It depends. Stock and PDR were close for me. DZ temps were up around 100 degrees.





It really depends on your setup. But, the more speed in the exhaust, the harder the turbine is driven. The lighter the setup (wheels, shaft, turbine) the faster the spool. This is based on the same size compressor. Increase compressor size, spool slows. (More weight, larger diameter, less slip).



The PDR drove closest to stock for me. The DZ is much laggier compared to both, even with a 12cm housing.



:-{} #@$%! :-laf:-laf

JMO



Dave

 

[PC12Driver]

I'll second Dave's answer. For good towing performance below 350hp it's pretty tough to beat the stock 35/12.

 

[Hammer]

Hmm. .

How come you didn't include the Garrett GT37R's when you did your questions?..... Adny

 

[PRout]

Hmm. .
How come you didn't include the Garrett GT37R's when you did your questions?..... Adny

Hammer, sorry, Im not familiar with this turbo. . Ill look it up. Meanwhile, if you think it outperforms the above choices and a person can keep their existing exhaust brake from the 35 turbo, then please do list it on here. . Thanks. .

 

[PC12Driver]

Whoops, not sure where I got the towing-thing from in my previous post... probably answered that when the wife was talking to me. Anyway, I'll still second Dave's answer.



If you're looking at keeping your exhaust brake, then yeah, you'll be pretty limited on your turbo choices (HX35 exhaust housing-based). But on the other hand, I miss my Jacobs exhaust brake, but not bad enough to put a Holset back on my truck.



I guess the question that should be asked before anything: are you having trouble with egts now?

 

[PRout]

No problems with EGT's because I try to not push it hard on the climbs.

Actually what Im thinking is I would like to improve fuel mileage and was thinking that if you have a little quicker spool-up and more oxygen at cruise, you might have less wasted fuel (or smoke).

One thought would be to go down to the HY style turbo with the smaller housing even yet. But dont want to give up anymore on the top end (or EGT control for towing), so thats not looking like a viable option.

Was thinking the PDR/12 might be a way to go, but so far its looking like in this case, stock may truly be best.

What bugs me most is the claims of the DZ & PDR increasing fuel mileage, spooling up quick, more O2 - wider efficiency window, etc etc, but when the real user reports come back, the satisfaction comments are mixed at best. .

 

[Mundgyver]

Can you fit a variable-vane turbo or do they even make one that would work on our motors with some software tied to the injection pump and ECM. That would allow you to dial in some custom flows for a particular style of driving I would think.

 

[EricBu12]

Look up the Industrial Injection 35/40 w/14 housing. you are able to use stock elbow on the new turbo. I see max temp lower than before with stock, spools almost as fast as stock. . hardly notice it... gives a little higher boost at cruise... I tow heavy and this works pretty good.

 

[PRout]

Interesting, will look it up. . Thank you.

 

[icman95]

I just went through this exact setup with my truck. I have the stock Jacobs and love it. Getting rid of it was NOT an option, even for an aftermarket one. Best solution I found was to take off my stock turbo and send it to High Tech Turbo in Utah. They created a hybrid for me with the stock turbine wheel and housing (so that I can keep my Jake) and put on a 60mm compressor and housing. Rebuilt the whole thing with new bearings and seals, etc. $550 plus shipping. Can't beat that. Originally I was going to buy an Aurora 2000 because it said it fit the original exhaust elbow, but this isn't true. It only fits ones with band clamp attachments, not bolt on to the turbo style like with the Jake. Be carefull of the ones that say this. Ask specific questions first. I almost made a big mistake. Good luck

 

[PRout]

Alright Icman! Thats interesting input. .

How do you like its performance as compared to the stocker? Spool-up time, cruise boost & egt's?

You sound like your satisfied with it. .

 

[NoSeeUm]

Not sure I would worry too much about 50F of even 100F cooler or warmer cruise EGT.



The big concern is what rpm you want it to "spool and cool" when you are pulling. This will help out the most for managing EGT. IMO extremely fast spool up time matters the least, unless you like to hammer the throttle and don't want any smoke. I just want the turbo to get on top of the fuel and keep the EGT low so that I don't have to stare at the gauge for fear of wiping an engine.



The HX35 12cm wg tows pretty well all around, unless you over fuel it.



Any one tow much with a HX35 14 cm wg?



Jim

 

[San Felipe Bob]

Hx35/40

I have towed with both the HX35 /14 wg and the HX35-40/ 14 wg.



I prefer the 35-40.



Check out my sig. for the mods.



I've got plenty of fuel and need to control my EGT's with my right foot.

I would'nt change a thing except for maybe a set of towing twins... .



SFB

 

[icman95]

Sorry I didn't reply sooner. I posted my last message just as I was leaving for vacation. Towed my camper from CT to South Dakota with my new setup and all went extremely well! The whole rig weighed just over 21k pounds, so the truck was doing some work. The turbo spools up ever so slightly slower than the stock, but it's not a show stopper. I do have to watch my EGT's but I am pulling a heavy load! The most critical time to watch them is when I'm at cruising speed on the highway in top gear and need to put my foot in it to get up a hill, pass, etc. If I downshift, it's not so much of a problem, but if not, I catch the turbo at a lower rpm and it makes the egt's go up too much. Not a big problem, just a matter of learning a little different way of driving it. The rig pulled like there was no tomorrow. With a little bit of care paid towards the egt gauge, I could get the thing rolling up hill at 75 mph. Not bad compared to the stock power I had last year that barely could hold 60 and with a lighter load. I'll try to keep this short as possible. More q's? Let me know.

 

[PRout]

Iceman, Thanks for following up. Sounds like HTT did you right. And, for a good price too!

So how does the turbo work for you during normal driving while empty? Do you feel like you gave up much performance just taking off from a stop light normally?

 

[icman95]

Actually, empty is even better. Egt's aren't as big of a deal when empty, but when jamming on it hard you still have to watch a bit. This is especially true when I have the TST box on, but I assume that watching gauges is a normal part of working any motor. Whether it is a CTD or Mustang or rice burner tricked out, it's always a good idea. I get a little bit of smoke when getting on it hard empty and when pulling my trailer when I shift into (can't remember now) 3rd or 4th gear. Not bad, though. I had 110hp injectors in it before and it smoked like crazy. Egts were awful but I couldn't figure that out. A friend has 100 hp's on the stock turbo and otherwise the same setuwwwwwwwwwwwwwwdsp as me and he has a hard time getting them to smoke. The only difference is that he has a different brand of injector. I changed to 75's and all is well. Maybe a difference in manufacturing between suppliers or maybe the turbo wasn't big enough for 110's. The setup that HTT gave me is the biggest they can offer on the stock turbo, keeping the stock turbine housing, so the only downside to the whole deal is that if it isn't big enough for you, there is nothing more. You'd have to go with a whole new aftermarket turbo which kills the idea of keeping the factory Jake (the reason I went this route in the first place). I think empty performance at stoplights and such is actually pretty good, but everyone will have a different opinion on this. I wasn't out to build a dragster, but it takes off much better that stock. I can spin the wheels if I try. EGTS empty hwy cruising anywhere from 550-800 depending on terrain, the weight of my right foot, etc. I have gotten them higher, but going uphill, of course. I'm really very happy with the setup. The truck just took my wife and I on a 3800 mile round trip, in rather hot temps, pulling at the factory towing limits, and performed wonderfully. Out in MN and SD the speed limits are 70 and 75 and really everybody does 80. The truck kept up even uphill and I got the thing to 90 once or twice (shhh... don't tell the SD hwy patrol). At 75 mph on flat ground I was running between 1000-1200 egts. This may sound like a lot, but everyone I talked to said I could run at 1250 "all day" without hurting a thing. This seems like it's true. Downshift to go up a hill and all is well, too. Got 8. 5 mpg in the states with higher speed limits, but what do you want for pulling that much weight at those speeds? Flatter states with lower limits got me mid 10's mpg and once even 10. 99. Not too shabby.

 

[Boondocker]

Ken,



Thanks so much for the detailed follow-up. I track this subject with keen interest as my primary performance objective is towing, not smoking, and keeping my Jacobs e-brake Even though I don't tow a lot, that is when I stress the truck. Since you have adjustable fueling (Smarty and TST PM3), would you mind sharing your preferred settings - towing and empty?



Also, can you add to the specifications of your turbo. You mentioned a 60mm compressor wheel and housing. I typically hear of compressor housings sized and 12cm sq or 14cm sq. Does your turbo 'size' equate to that? Also, is yours wastegated or not? If so, did you have HTT set the wastegate to your spec?



Thanks,

Neil



Disclaimer: My turbo knowledge is questionable.

 

[icman95]

Neil,



I, too, was out to build just a towing vehicle, not a racer, so I got almost exactly what I was hoping for. As for the computer settings, I keep the Smarty on 3 and the TST either off or on 2 when towing. Here's why: The 3 on Smarty adds timing and a little bit of fuel, but not as much as on the catcher settings 5-9. The timing seems to lower EGT's a bit which is always a good thing and the amount of fuel added isn't enough to smoke or ruin the egt's. Also, the Smarty does boost fooling so that the ECM doesn't throw a code for the higher than stock boost. With this setting and the 75 hp injectors it's not really necessary to use the TST much. If I need a bit more go, like on an uphill on ramp etc. , I'll set it to 2 which gives about 30 more horse and 80 more tq according to the manufacturer. This seems to be enough and while it does raise temps a bit and make a little more smoke, it's tolerable. After the need has past, I set it back to 0 to save some fuel. At $3 a gallon I like to pull the trailer well, but not crazy. The truck's appetite has to be considered on long trips. Also, the TST does boost fooling, so even if it is set to 0 it will keep the ECM quite if you're not using the Smarty.

To be perfectly honest, I don't drive the truck much this time of year as a daily driver, simply because I use my Harley to go back and forth from work. Fun to ride and 40 mpg vs 16 mpg. I have bumped the smarty and TST up a bit just driving empty but where I am it's so hard to play with that kind of power and not get into trouble, so I haven't experimented with as many settings as you'd think. My friend (TDR member isb360) uses Smarty 7 or 9 and TST 6 as his daily driver settings, and seems to like it. He has 100 hp sticks and stock turbo, so not exactly the same comparision, but close.



I used the turbo number of 60 mm wheel because this is what it said on HTT's website. It didn't give a cm sq equivalent, but I'm sure there is one. Just call and ask. They are really knowledgeble and friendly. They have a hybrid section on their site and all the info is there, including pricing. My turbo was wastegated from the factory and it remains that way. The TST box came with a boost elbow that replaces the stock one and allows the wastegate to stay closed for a much longer period of time. HOWEVER, I did not install it. I had sent the turbo to HTT before I installed it and they sent it back with one of their own. I called them to see what to do and they said their's will do the job. It does. I get 25 lbs of boost rather that the stock 15 with the 75's. When I had the 110s in it was 30. While almost everyone will tell you that's not enough and more is better, the pressure doesn't have to be as high if the turbo is putting out more volume of air because of the bigger wheel. This is something that gets lost on most people. Just like a garden hose and water. If you have a smaller hose, a higher pressure is needed to put out a particular amount of water, but if the diameter of the hose is bigger the same amount of water will flow out with less pressure. Also, if I set the Smarty and the TST higher, the increase in fuel will drive the turbo faster, creating more boost. So it's there if I want it. Overall, I couldn't have asked for more from the truck and the setup. I will probably always find little things I might want to do to it, but as it stands now, I am as happy with it as I can be. We beat the snot out of it for the last ten days and it asked for nothing in return except vast quantities of diesel. By comparision, a friend of ours took his 31ft class "c" motorhome on the Ford 450chassis with the v-10 gasser on a very similiar trip the same week. It weighs a lot less and is smaller in length and width, but got worse mileage and he said he was afraid to come home a particular way because it almost couldn't make it up the mountain in one spot on his outbound trip. He isn't into trucks, etc so it suits his purposes, but this was reaffirming to a diesel nut like myself.



Once again to all who care-I'm sorry for a lengthy post, but when I was researching my setup, I was thirsty for towing specific info. Now that I have some to share, I'm happy to do so.

 

[Boondocker]

Neil,

I, too, was out to build just a towing vehicle, not a racer, so I got almost exactly what I was hoping for. ...

Once again to all who care-I'm sorry for a lengthy post, but when I was researching my setup, I was thirsty for towing specific info. Now that I have some to share, I'm happy to do so.

Well bless you for that! I've been studying this topic for a couple of years and yours is some of the most relevant info I've read. With my Mach 1. 6 injectors, Smarty #3 is the most appropriate towing setting as that gives me the most control and all the power I need to move 17K lbs quite respectably. Lately I've been running #4 on the street, still a bit too smokey. But Las Vegas in the summertime is hot air and hotter air. My stock HX-35 has a boost elbow from a previous Edge EZ, so it can easily make more boost than is worthwhile. I need more volume, not more pressure.

One more question. Do you still have the stock exhaust manifold?

I too haven't been driving much lately as I commute the VMax to work. Can you say power-to-weight-ratio! Oo.

Cheers,
Neil