Engine/Transmission (1998.5 - 2002) Need More Boost ...

[HookMeUp]

With everything installed, Van Aaken Smartbox, Jammer Stage 1's, and adjustable boost elbow I can only build 30-32 psi boost which is ok but my EGT's keep climbing and at 1250 I'll get out it. Is this limit of the boost I can build? I would like to have controllable EGT's. Do I need a bigger turbo? Looking at all of the posts on here this setup should be controllable. Lots of of others running bigger sticks and get lower EGT's.



Please help ...

 

[DCreed]

stock turbos dont like to go over 36psi and if youve got a stock hy (u should) the 9cm housing's the problem. then yes its turbo time

 

[AKAMAC]

He has the HX not the HY.

I can't see a reason for the high EGTs. Is the VA box a timing only box?

 

[Boondocker]

PMcBride probably has the HX35. More boost from this turbo is not the answer because the air will be super-heated by the time you get into the low 30's (PSI). You need more air... bigger turbo. There's a nice selection in the $1200-1500 range. Are you talking about a towing situation? Ocassional EGT spikes from spirited acceleration are no big deal, but constant high EGT from pulling a load down the highway are a problem.

 

[HookMeUp]

PMcBride probably has the HX35. More boost from this turbo is not the answer because the air will be super-heated by the time you get into the low 30's (PSI). You need more air... bigger turbo. There's a nice selection in the $12-15K range. Are you talking about a towing situation? Ocassional EGT spikes from spirited acceleration are no big deal, but constant high EGT from pulling a load down the highway are a problem.

I do have the HX35. I assume you mean $1200 - $1500 range and not whats stated above? Yes these readings are from spirited acceleration. I'm just concerned about EGT's while towing. We are looking at getting a 12k 5'er. If I was to upgrade turbo's which would be a good combination? The HTB2 62/12?

 

[Boondocker]

I still have the stock turbo, with similar power upgrades to you. I drive by the gauges though. HTB2 62/12 and Industrial Injection's SPS 62/12 would be highly recommended. Those require a larger downpipe.

Since I have an elbow-mounted exhaust brake that I don't feel like replacing, I'm considering a PDR HX35 (hybrid). If I didn't already have the ebrake, I'd get the better turbo and go with a different ebrake setup.

 

[Cummins724]

I do have the HX35. I assume you mean $1200 - $1500 range and not whats stated above? Yes these readings are from spirited acceleration. I'm just concerned about EGT's while towing. We are looking at getting a 12k 5'er. If I was to upgrade turbo's which would be a good combination? The HTB2 62/12?

If you don't plan on big injectors in the future... . the HTB2 62/12 is great for your current mods. If you are gonna go bigger... . a Super Stock 62 from HT is highly recommended!

 

[rubberneck]

I do have the HX35. I assume you mean $1200 - $1500 range and not whats stated above? Yes these readings are from spirited acceleration. I'm just concerned about EGT's while towing. We are looking at getting a 12k 5'er. If I was to upgrade turbo's which would be a good combination? The HTB2 62/12?

If you are going to be towing a 12k trailer, stick with the stock turbo, or one of the smaller hybrids (dodgezilla etc). Bigger is not always better when towing. There are going to be plenty of people get on here and say im wrong, but dont change a thing untill you tow it and see where you stand. Bottom line, you put gauges in for a reason, USE THEM. If you are running up a hill trailer in tow and things get hot, back out of the throttle, down shift if need be and slow down a bit. No you probably wont be able to flat foot the go peddle, but a bigger turbo is not going to let you do it either. Dont sweat higher egts on hard acceleration, that is not what you will be doing when towing. The smaller charger will build more boost in the lower RPMs which is where you want it for towing. I get higher EGTS when towing with my B1 than i do with a stock hx35. I ran my truck for many many miles with an edge EZ and DD'3 injectors, it was a great towing combo, and made about 36psi with an adjustable elbow on my 35.

32 psi seems a hair low, but may be correct. Double check all of your hose clamps on the intercooler boots and make sure you dont have any leaks in the intake manifold. (I have blown 2 intake manifold gaskets throughout the years. )

 

[hummincummins2]

i would throw in a new aftermarket turbo from II. i love the silver bullets!

 

[NoSeeUm]

PMcBride probably has the HX35. More boost from this turbo is not the answer because the air will be super-heated by the time you get into the low 30's (PSI). You need more air... bigger turbo. There's a nice selection in the $1200-1500 range. Are you talking about a towing situation? Ocassional EGT spikes from spirited acceleration are no big deal, but constant high EGT from pulling a load down the highway are a problem.

Well Hm... .



I am assuming you have tried adjusting the boost elbow?



From my experience a HX35 will likely have drive pressure around 60-65 psi at 32 psi boost. So I often wonder if it is really the high drive pressure not the compressor in-efficientcy that actually raises the EGT's. Probably both are the reason.



At best it is stop gap, like Boondocker says, running a HX35 to higher boost levels. A bigger turbo is likely a good choice. With it you will get a better drive to boost ratio and a more efficient compressor.



And...



You might just as likely get a whole new set of problems. For my experiences, the HX35 tows really nice especially if you keep boost in the mid 20 psi range.



I have read many times about trucks, switching turbo's and running the same boost then picking up 20-30 Hp. With that said, 1250F EGT is really a admirable target to achieve, and allot of people would not be unhappy at all with that.



Jim

 

[HookMeUp]

I think I will wait until we get the 5'er and tow it a few times before deciding if I need to do anything with the turbo. All the posts are great advice so lots to think about.

 

[HookMeUp]

Found My lost boost pressure.

Time to close this thread out. I found my lost boost, I retightened all of the intercooler boots. I can now hit 35psi and hold it with no problems. EGT's will hit 1250 and hold there. So hopefully they will be managable while towing. Thanks for all of the help everyone.

 

[hdtrukn]

Any thought to water injection ?

Cheaper than a turbo.

 

[icman95]

Sorry to beat a dead horse here, but I just finished my mods last week and over the long weekend towed my 5th about 800 miles round trip. Had tremendous EGT problems. Could't get enough boost (about 15-20psi) in 6th gear to keep temps down. Had to travel from CT to northern Maine and back almost always in 5th gear. This was the only way to keep temps reasonable-11-1200 climbing hills. Wasted a lot of fuel, though and smoked like crazy. The smoke blowing back onto the trailer actually lifted off two of the decals put on by the factory. Haven't put in the boost elbow that came w/ TST box because the tech at High Tech Turbo said not to, but I think I'll have to and see what happens. The bigger compressor wheel in the reworked turbo should give plenty of airflow, but somehow hasn't. I talked w/ the turbo and injector people before I bought either and got favorable responses on this setup from both. Any ideas? Considering water/meth injection, but would like to make this work on its own. Towing again in 2 weeks. I'll have to see what the elbow can accomplish for me.

 

[PC12Driver]

The bigger compressor wheel in the reworked turbo should give plenty of airflow, but somehow hasn't.

I went through this same thing when I bought my first turbo. Bigger does not always equal cooler egts. It's all about where in the rpm range do you want the power to be delivered.



The larger compressor can move more air than the stocker - but it needs more energy to do so. Think of a house fan. If all you do is put a larger diameter, more aggressive fan blade on it without upgrading the motor, you'll still move about the same amount of air (possibly even less) because the standard motor will turn slower because of the extra load from the larger fan. The fan just transfers energy from the motor to the air; if there isn't any more energy to transfer, the fan won't magically move more air.



Same with the turbo. The bigger compressor needs more energy, and that comes from the exhaust gas volume. So you'll need to keep the rpms up to move more air through the turbine side to drive the compressor (egts for the new turbo are probably quite controllable above 2000 rpm, aren't they?). Or a good healthy dose of throttle will provide enough gas expansion to light the turbo up (this would be the common "add more fuel" solution), but when you're under the turbo with skyrocketing egts and a trailer in tow, that's not the best solution as you know.



As you've found, larger turbos aren't always the best solution for towing. A turbo has about a 500 rpm effective range on our engines, and if you shift that window higher into the rpm band, then the bottom end will suffer.



What size compressor did you upgrade to? How about the exhaust housing size?

 

[icman95]

Your explanation is right on. I have a friend (and TDR member) who is a jet engine engineer and he explained it just as you have, but the part that puzzles us both is that the requirement for more fuel to drive the turbo should have been met with the 110hp injectors and the TST box. The compressor wheel was upgraded to a 60mm along with a new compressor housing. I couldn't change the exhaust housing due to the fact that I need it to bolt up to the Jacobs e-brake I have had for six years. If I wanted to change out the Jacobs for some aftermarket brake, I could have bought a whole new turbo, but this was the only option I could find that would let me keep the Jacobs.

 

[PC12Driver]

... the part that puzzles us both is that the requirement for more fuel to drive the turbo should have been met with the 110hp injectors and the TST box.

That's a common misconception in the online diesel world. That's not the case unless you pull at full throttle all the time.



The larger injectors and TST box allow for more fuel than stock to flow into the engine. And the only time that extra fuel is used is during heavy/full throttle. If you're just cruising along and encounter a slight to moderate hill, you're not going to use more fuel than stock. So therefore you still will have a stock level of energy driving the larger turbo. If you don't have the extra expansion from the extra fuel, then you have to rely on extra RPMs for enough volume to drive the larger compressor.



A smaller turbine housing will help extract a bit more energy from the exhaust and move the powerband down a couple hundred rpms, but if you still have the stock 12cm housing that's as small as you can get for the HX-35.

 

[icman95]

I know I'm in a bit of a pickle here. Next week I'm going on a 190 mile trip with my camper. Shouldn't be too traumatic. In August, though, we're going to South Dakota and I'll have to have the problem fixed by then. I'm considering sending the turbo back to High Tech and having them install a smaller compressor wheel, but yet bigger than stock. Something else I haven't done is check for leaks in the induction system. Maybe it is as simple as tightening some clamps, but with my luck I won't get off that easy.