Engine/Transmission (1998.5 - 2002) Turbo Choices with Jacobs Exhaust Brake

[isb360]

Hi All,



My buddy has an '01 ETH truck, NV5600, 4. 10 gears w/ dealer-installed Jacobs Exhaust Brake. He's already put dual stacks on the truck, but it is still fed from the stock HX35 turbo.



Looking around he sees the Aurora2000 as an option, but has gotten no response from ATS to several emails regarding his questions.



Any other turbo choices out there for folks running Jacobs brake with stock 3" downpipe?



He's looking at Mach IV's + Smarty + TST + xxxxx turbo for towing a 13. 5k 5-er.



Thanks in advance for everyone's input.



Tim

 

[Boondocker]

I too would like the answer to this exact question as I feel very close to buying a turbo. I haven't looked into ATS, but am considering a PDR HX35. The Dodgezilla is the same concept, an HX35 with an HX40 compressor (I think that's how it goes), known as a hybrid.

 

[NoSeeUm]

I called ATS once some time ago. The A2000 or a better choice (maybe) the A3000 will not fit to a HX35 exhaust flange.



My next best option was a Dodgezilla (Hx35/Hx40 hybrid), or so I thought. The DZ spools very fast, in my case too fast. In the 1800-2100 RPM 15-20 boost range I had some surge issues. Not surge in the ussual sense, just a chh-chh-chh noise. Looking at City Diesels compressor map I was just running very close to the surge line at those RPM's / boost. The DZ was just making boost a little to fast for my truck. I was re-assured by City Diesel (several times ) that the surging noise was not damaging the compressor. I just never got used to the noise nor got past eliminating the surge completely.



I also had barking issues with the DZ that were non-existent with the Hx35. The 3rd to 4th and 4th to 5th were the problem shifts. I learned to drive around the barking and became a matter of letting off the diesel peddle more gingerly.



The DZ did reduce my maximum EGT's though. I could hit 1600F plus with the HX35 and it reduced to them to the low 1400F's. The spool RPM I would guess was 100-200 higher.



If I had to do it again, I think that I might have tried just mating a 14cm WG turbine housing to an OEM HX35 first. I can not give opinions on how it would work, but I think the EGT relief might only be moderate. But I also think most the problems I had would not be an issue. The difference in drive pressure from the 12cm to the 14cm is very noticeably lower. You will likey need a 14cm WG turbine housing with any hybrid, if you decide to go that route so it would not be stranded dollars.



NWBomber Thread is where I asked for some advice.



In the end, I just said "UNCLE". I bought some twins and ditched the direct mount brake, then I installed some onboard air and a remote mount brake.



EGT's are good. Brake works good. Truck is happy. I am happy! My wife wonders if I am sane.



Jim

 

[isb360]

Jim,

Thanks for the feedback. The TDR is a wide and diverse audience and I have to think there are lots of folks that fall into this category and will hopefully be able to chime in.



20/20 hindsight would have my friend not getting the factory Jake, rather just wait and get a Banks or something compatible with 4" downpipe.



Tim

 

[JFlagg]

I don't know for sure if there are any that fit, but when I changed over to a HX40, I had to remove my factory Jacobs brake. I couldn't find any aftermarket turbos that fit either. I think I'll end up getting a inline PacBrake when I get around to it. Though, I talked to them a few months back they said they were working on a brake that would fit the back of a 40(clamp type coupler) and work on a second gen(vaccum operated) truck. Haven't called them back to check on the status lately though. They told me in Dec to check after the first of the year.

 

[Allnew2Me]

I recently went through the same thing. My truck has the BanksBrake on it and I really did not want to buy another brake so I went with the PDR35/14 which retains the same exhaust outlet. It is similar to the dodgezilla in that it is a hybrid 35/40 turbo. A lot of the popular turbos now are based on the S300 which uses an HX40 outlet. I went with the 14 housing and I"m glad I did, the 12 would have been small, especially when I replace my injectors.

The downside of keeping my brake and going with the PDR35 is that I am about at the max for air now and if in the future I want more HP I will have to lose the brake for an inline model. The good news is that my PDR35 is perfect for a set of twins.

 

[Boondocker]

HX35 hybrid options?

Jim,



The NW Bomber thread was educational right up to the point where I got confused all over again What I managed to learn was that setting the wastegate to open sooner, rather than holding it closed longer, was better... at helping to equalize drive pressure. So some kind of adjustable wastegate is preferable. What size compressor housing was best, 12cm or 14cm?



I think that your helix cam is a variable here that no one can seem to account for. I've had some surge on rare occassions with my stock HX35, more so when my wife drives (towing), but then her approach to throttle control is kind of binary (geek humor).



BTW your wife thinks you're not sane. I was going to say something in your defense, but couldn't think of anything :-laf



Neil

 

[NoSeeUm]

Jim,



.....



BTW your wife thinks you're not sane. I was going to say something in your defense, but couldn't think of anything :-laf



Neil

LOL These days she just looks at me and smiles that knowing smile... .



Having the wastegate set tighter makes it spool faster. For me the DZ would not really work well using a boost elbow. I was relying on drive pressure to creep the wastegate open and slow the boost response. I have thought a 6 bladed vice the 8 bladed compressor wheel I had might have been better in that application, but at this point I am not certain. Most people want fast spool and the DZ is certainly in its zone for doing that, but sometimes it can lead to problems.



Like you say, in the end I had to realize not everything fits the way you want it to. I was just asking the DZ to do something that it was not able to really do effectively. It works very well in my twins.



Jim

 

[NoSeeUm]

Jim,

Thanks for the feedback. The TDR is a wide and diverse audience and I have to think there are lots of folks that fall into this category and will hopefully be able to chime in.



20/20 hindsight would have my friend not getting the factory Jake, rather just wait and get a Banks or something compatible with 4" downpipe.



Tim

Any type of brake that mounts directly to the turbine outlet, and fulfills the function of the exhaust elbow will limit turbo options severly.



FWIW I had a Banks Brake, it was a direct mount. The type of brake that is most BOMB friendly is a 4 inch remote (in-line) brake. I have a PacBrake. It was easy to install, but it requires an on-board air system.



Jim