Is this worth my time?

[john65td]

i am looking to upgrade my turbo. i dont have the cash for an att wish i did. any way i can get a hx35 with external adjustable wastegate 60k on it no play in great shape for $80 bucks the guy wrecked the truck and is hard up for cash. i know i have to turn the boost down and can't run high boost. but i'm concerened about the lag i have a friend with a 96 cummins and he is always complaing bout when towing he has to keep rpm's up cause it takes a while to spool up. i did some research and found banks offfers a quick spool exhaust housing to elimanate this problem. so my question is this is it worth it to get the hx35 and put it on then when taxes come splurge and get the quick spool housing? anyone with a hx35 alreary on their truck with results for me? what kind of lag do you have are you happy with the turbo?

 

[North Maine]

80 bucks for a turbo in good condition sounds like a no brainer to me, no matter what. You can't buy a GM-4 for that.

 

[bison]

lot cheaper than buying a kit for a GM-4.

 

[540s10]

the 6.5 has more cubic inches and more of an exhaust pulse than the inline, so it would only help spool up, also the operating rpm is a lil higher in a 6.5 too, so lag really shouldn't be a huge concern.

I've been reading about this and would also like to know a few things about this particular swap.

if the gm-x turbos are so horribly inefficient and IAT's soar when really pullin on em at 10-15lbs of boost why does everyone say you need an intercooler with the holset when its barely working to maintain those boost levels on a 6.5?

It obviously has a larger hotside than the GM turbo's so that would also mean less back pressure and better breathing no?

 

[SmithvilleD]

Holset rates the HX-35W w/ 12cm2 turbine housing to support up to 280 hp (flywheel) & they're really not a bad match unless you've got big hp goals & intend running above 3000 rpm to hit those goals. The HX-35W is a bit small if your goals are high, but still a quite notable upgrade from the GM-X series.

They've got a broad comp map (100 - 280 hp intended range) & I believe you've got a grasp of how to adjust/limit the boost levels to where you want. If you're actually running your GM-4 up to 18 psi, you'll definitely notice the 6.5 w/ Holset will run/feel "free-er" further up the rpm range

ChicagoTDP & Midniteplowboyy can give particulars on their setup's boost threshold. I've been checking out Holset setup options on a 6.5 for quite a while now - drove the first sorta crude example about 8 years ago.

The divided turbine housing (mates to the divided Cummins exh man) is intended to keep exhaust pulses (putts) segregated/organized 'til they impact the turbine wheel to enhance low speed response. Unless you fab a setup to keep each 4 cyls/bank segregated up to the turbine inlet, you loose that advantage. Practically speaking divided housings enhance low speed response, but as rpms rise/pulses get closer together, the divided housing benefit gradually turns into a slight restriction. Point being, I'd spend a bit of time matching the corners of the Holset's T3 housing opening, to the 6.5's T3 mounting pad.

Because they're a T3, they mount/fit cleanly. Need to adapt the oil supply (different fitting). Simplest exhaust/downpipe plan is buy a prefab'd endplate available on ebay, that come with a 3" hole - ready to slip fit & weld in a 3", tight 90 degree bend (4 or 5" radius, 4 clears the AC accumulator better if 'ya can find it). Will prolly need to weld it in canted a bit downward for bet clearance.

The stock Cummin's/HX-35W transient response often isn't that respresentative as they've got a fair bit of defueling/derating built into the fuel curve programming down low to limit drivetrain stress. The Cummins guy's with programmers that eliminate or lessen the drivetrain saving defueling see significant improvements in boost threshold.

Believe the Banks quick spool turbine goes up to a 14cm2 size so it may not lower the boost threshold rpm on a 6.5 application - check w/ Banks or somebody that's tried it before spending $. The turbine exit diameter is around 2.6" - if there's a way smoothly blend that to the 3" pipe as a diffuser, that would probably benefit transient response a bit. Like all turbines, response is about the pressure difference across the turbine, so the lowest restriction/least pressure in the exhaust system, the faster the spool.

 

[HighSierra86]

I too am very interested in this set up. The few people around who have done it seem to be very happy with the results. There was a thread on here a little while back with a member who was using both a hx35 and a hy35. He had stated better mpg results with one, but stated that they both worked nicely.

I plan on going this route when i have some cash to rebuild my 95. Nothing against the ATT, i would love to purchase one for my company truck used mainly for towing. But i feel there are other options out there for replacement turbos that we need to be open to.

 

[Slim Shady]

GO for it: and post

IAT : at boost levels. running at highway speed and towing
Turbine drive pressure to boost ratio,
EGT levels intercooled and non intercooled IAT,
Fuel mileage improvement.
Then a dyo chart,

that should get things started. :thumbsup:

 

[HighSierra86]

GO for it: and post

IAT : at boost levels. running at highway speed and towing
Turbine drive pressure to boost ratio,
EGT levels intercooled and non intercooled IAT,
Fuel mileage improvement.
Then a dyo chart,

that should get things started. :thumbsup:

speaking of which.......anyone ever get a dyno run with the ATT yet??

 

[NVW]

speaking of which.......anyone ever get a dyno run with the ATT yet??

Yes, there is a thread on it in the 6.5 performance section. Kane and Kojo have dyno #'s

Leo

 

[Slim Shady]

I think we have pretty well run the ATT A-Team Turbo through it's paces and recorded almost more data than is out there on most turbos.

So lets start getting data on the Blessed Holset: then we can make comparisons that mean something,

Other than just opinions, competition is good, facts are great. I personally am partial to the A-Team Turbo, GO FIGURE THAT!

Also have not seen many put out the money to get a working turbo kit out there for us. I hope to make back some of the R and D money some day. Have to sell a few more, or ??

 

[john65td]

ok ill have to get it put it on and post results. i need to update my sig i changed my waste gate spring cuz on cold morings it will go up to 21psi and after awhile i found that its just making more boost and not power and when it got colder boost was going a little to high for comfort but its still up there at 16 psi

 

[SmithvilleD]

The original post & responses weren't intended to be an affront to the ATT, just discussing if the HX-35W he found at a bargain price could be a solution that's easy on the budget. And it can.

I don't think it's likely folks trying different Holset combinations on 6.5's are gonna steal ATT sales. Simply because it does require a little fabrication. Same reason it would be tough to make a financial go of selling a kit to plug-n-play the HX-35W; because folks that don't mind (or maybe enjoy) a little fabrication could duplicate a kit.

Over the years, I've experimented w/ multiple turbos on most of the the turbo engine projects I've done. Whatever my working knowledge of the compromises/tradeoffs in sizing turbo's to a given engine/use is, it comes by experience. I doubt the majority of 6.5'rs are interested in experimenting & the stock turbo & ATT are well understood options. Some of my interest in a Holset turbo for the 6.5 relates to having turbine housing & compressor options widely/cheaply available from their widespread use.

The earliest 5.9 Cummins turbo's in the Dodge pickup were rated/underrated ~160 hp & common chassis dyno results show they're probably closer to 200 hp at the flywheel. Their turbos had proportionally larger turbine sections; they were tailored to be efficient highway haulers - the compromise was transient response (& emissions). As the Dodge truck 5.9's evolved, they moved towards smaller turbine housings to meet customer responsiveness expectations & emissions regs. My point here is, there's a range of truck use/owner expectations & turbo sizing is a compromise. As the cutting edge of turbo design evolves, the range of use a given turbo fits well is getting wider, but there's still a compromise.

Lots of HX-35 5.9's out there pushing the 300 hp mark. Heading beyond the HX-35's most efficient range to be sure, but also more fun to daily drive than the same truck/setup w/ an HX-40.

I'm all for collecting/presenting data as that's what builds a depth of understanding how things truly perform. Been investigating ways to do data acquisition on all the discussed parameters & more. Past projects where I've done this had cost effective, well coordinated data logging solutions available - whether simply logging parameters in association with a stock ECU, or an aftermarket, standalone ECU w/ built in logging capabilities.

I'm currently bucks down & deliberating on a cheap solution I've found that can log analog parameters in good time resolution (10 Hz). The rub is that it can't log frequency inputs so no easy way to tie/synchronize logs w/ rpm, which is important to better understand transient response of different turbos. There's a new acquistion system from PLX Devices that I'd like to try, & it appears to have the capabilities at a bit less cost than other established systems. Still, it would prolly take ~$1000 to log all the parameters I want - so I've got to have more excess spending $, before I'd do this as a hobby pursuit.

 

[dms4x4]

SmithvilleD.........The DM 100OBD is cool. Do you have to buy and hook up individual sensor modules for each sensor? I'm ignorant on diagnositc equipment, but isn't there something that would plug directly in to the main controller (assuming there is such a thing), and read directly off that, perhaps with a single data cable?

Question 2........ What exactly do you mean by "transient response" of a turbo charger?

You sound like a pretty savvy guy. Have you thought about getting a small PLC, the sensors you want to monitor, then writing a small program to record the data you're looking for?

 

[Acesneights1]

Funny you should post this. I was conteplating a Holset for my CUCV on top of the Banks Manifold. The Banks kit is way too expensive for what it is IMHO. I'd rather get my hands ona manifold and fab the rest, hence what turbo to use. Smithville you hit the nail right on the head. The Dodge's don't have a lag, it's in the programming so the cummins doesn't rip the truck apart or make it unsafe on slippery roads. I was already warned if I put a Smarty on mine b BE CAREFUL in the rain so obviusly it spools fine. Thing about my CUCV that I have over you guys is plenty of room for an ATA IC and much bigger Rad so I can get away with more I think temp wise. Time will tell. Nice thing is I have the Dodge in teh driveway to compare the turbo.
What I'm thinking is:
Banks Manifold
Custom fabbed exh.
6.5 F intake
Some sort of ATA. Plenty of room for one.
Reason I'm leaning Banks Manifold is because the 6.5 Mainfold will not clear any future A/C box I may want to add. Fat boy likes it cold....

 

[SmithvilleD]

SmithvilleD.........The DM 100OBD is cool. Do you have to buy and hook up individual sensor modules for each sensor? I'm ignorant on diagnositc equipment, but isn't there something that would plug directly in to the main controller (assuming there is such a thing), and read directly off that, perhaps with a single data cable?

Question 2........ What exactly do you mean by "transient response" of a turbo charger?

You sound like a pretty savvy guy. Have you thought about getting a small PLC, the sensors you want to monitor, then writing a small program to record the data you're looking for?

Q1 - On the OBDII trucks, it may be an option to collect stock sensor data from the OBDII port & incorporate it, along with adding the additional sensors/modules I'd like to have coordinated: EGT, turbine drive pressure, compressor outlet temps before IC, etc. Doubt it can interact w/ OBD1, but will certainly ask if going this route. A buddy of mine in Australia found an inexpensive 5 channel, 0-5V data acquisition card that laptop connects via USB - happy to share the info if anybody has interest.

Q2 - By transient response, I mean how the turbo goes from coasting/no load into boost. Looking at that transition in some detail & at different points in the rpm range.

I apologize in advance for going a bit beyond the scope of the original post question, but here's a little background on why I support folks wanting to experiment with different turbos on the 6.5. The attached pic is of one of the turbo engines I've experimented with. This is a few years back when a ~400 hp, 11 second AWD true street tired car was considered fast - things have continued to evolve far beyond this due to enthusiasts experimenting.

The DSM community is great example of folks sharing info & pushing their common hobby forward. Here is a link to just one thread on their results with different Holset combos:

http://www.dsmtuners.com/forums/tur...-results-only-complete-installed-systems.html

Some diesel folks may not give the DSM-ers much respect, but just glance thru some of their installs, fabrication skills, & data shared. You still have to sort thru who knows what, but's there's no denying how they make progress.

Slim, TD, & others are to be appreciated for all the data they've collected & parts/knowledge contributions to the 6.5 community. The link above shows some examples of the kind of data acquisition & discussions interpreting the data I'm suggesting could benefit 6.5-ers as well.

Kane & KOJO's dyno sheets are also good examples of what can be learned from studying the results. While the slipping torque converter & hinky rpm scaling add a little difficulty to the interpretation, the shape of each truck's torque curve is what you'd expect from these truck's notably different turbos. If their fuel curves are very similar, the torque curve differences are largely due to the different turbos. Eliminate the slipping torque converter & IC variables & I would fully expect the ATT torque curve to remain shaped just like the one KOJO submitted, but higher.

 

[chevyCowboy]

im working on an alternate turbo well smiithville is going to help once i get the mounting and fab work done its a he351ve with is a variable geometry turbo theses a tread about it and it may work and it may not but i wanted to give her a shot dont thik its ever been done before

all good things come from trial and error and whats leard in one project may help another guy in his so hell im intersted in anything anyone wants to try

 

[HighSierra86]

Smithville....thanks again for a very interesting read. Your knowlage in the turbocharging area goes right over my head. And as you stated in your first post, no one here is trying to challenge anything with the ATT. I think everyone here owes alot of respect to the guys who put in so much time and money making an affordable aftermarket turbo for the 6.5. Because as we all know, new advances and aftermarket performance parts are hard to come by with these trucks.

That being said, I liked the idea of trying the road less traveled, and im very curious to see if I can make use of the less comon built holset combo. And im sure as smithville stated before, you are not gonna find many people willing to fabricate and risk using one of these just because of the "unknown" factor. The ATT has obviously been proven to the six five community in both reliability and performance. I just feel the need to be different. Thus the reason i like driving and tinkering with the 6.5's. So as soon as i have some spare cash and some time, I would be happy to post all of my findings with a build such as this. I have access to an engine dyno, so i may even be able to get some numbers with different turbo combinations. So now i just need to make some money again

 

[SmithvilleD]

Thanks for the good word HighSierra. Part of why I make posts like the last one, is to show examples of how some of the sharpest turbo guys I've been around - got that way. They've got huge appetites for learning - both the science & practical applications. They've read every turbo book out there, they Hoover all the comp maps, turbine maps, any potentially useful data they can find & study the heck out of it. They look at what compromises the OEM Engineers made & try to understand why. And perhaps most importantly, they've got real world experience experimenting.

Another reason I pointed to the DSM tuners thread is as one example of folks that know a thing or two about the transient response of turbo's. Their discussions have progressed deeper than "a wastegated turbo is best" or "non-wastegated is best". Look at the mass airflow range they're dealing with. Those are 120-140 ci engines operating from idle to 600+ hp in some cases. A ways down that thread is a dyno chart done at RoadRace Engineering. There's a time synch'd plot of boost pressure just below the HP curve that gives an indication of that turbo's response. Some of these guys have that data down to 0.2 second intervals.

My point is: if 'ya wanna learn, don't let the common human nature tendency to "mock what we don't understand" get in the way of learning. Science guys, mechanics guys, gassers, diesel folks, & everybody in btwn have knowledge limits & this tendency. The more 'ya get past it, the more 'ya can learn.

Now - why couldn't our 6.2/6.5's have come stock with a (block/bottom end/heads) structure that routinely tolerates 2x stock hp/torque levels with few failures:sad: