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ATT run vs. HX40II

This gave me a good chuckle.

Yes, now that I see that sentence it does make me laugh!! My girl sleeps on my left the turbo was sitting on a table to my right, when we "get it on" I'd look over at my turbo. So I don't know what was making me excited, maybe both??? All kidding aside the turbo is breaking in nicely have to say I give it good 2800 rpm just to hear that rush of air and the power surge. No more black smoke.
 
This thread could go for ever discussing the effects and sheer pleasure of your power surge at 2800 rpm. I think we need a Dyno run data sheet from your girl, just to settle this debate.

Anyway, glad to here the ATT is all that for you. It's been good on my truck.
 
I was thinking of installing an intercooler. It seems most people who have an ATT remove there intercoolers. Anyone have advice? The manufacturer says I don't need it?
 
Ok so an intercooler is always good. Can I fab one up with the same effectiveness as the one sold for $1800.00? I think I could do it for a fraction of that with all the generic stuff available. What makes those 1800 intercoolers worth it?
 
It isn't necessary, in my opinion, but if you do, do an intercooler make sure it is sufficient to flow enough cfm that it will not be restrictive. It may be more benifi
 
I was just looking at water to air intercoolers, I think this type will be worth the time and money.
 
The ATT runs cool enough and low enough boost not to need the extra lag from the IC volume. Under 275 on a hot day. Factory turbo is over 300 degrees.
 
Ok so I'm getting mixed reviews about running an intercooler with my ATT. But ill ask again, what about water/methanol injection? Getting off the subject a bit, the compressor side of my turbo and the coupler to the intake are really cold. How does the ATT pull that off? I've been around trucks and heavy equipment since I was a boy I don't think I've ever seen that.
 
Ok so I'm getting mixed reviews about running an intercooler with my ATT. But ill ask again, what about water/methanol injection? Getting off the subject a bit, the compressor side of my turbo and the coupler to the intake are really cold. How does the ATT pull that off? I've been around trucks and heavy equipment since I was a boy I don't think I've ever seen that.

The ATT isn't always providing boost. No compression of boost = no heat. No heat means fuel saved, cooler IAT's, less cooling system use and lower NOX. For example at cruise the ATT is at 0 PSI on my 1995 and a couple psi on other rigs. Not much heat at 2 PSI. At 105 degrees out the IAT is 240 degrees at WOT last time I measured it unloaded. Not hot enough to justify cooling if this is the peak temp. Towing and sustained boost up 7% grades for miles maybe. But my MPG doing that is close to an inter cooled Duramax so why waste the money? My peak boost is around 18 PSI vs. the 30 PSI+ of modern inter cooled DI engines.

Trucks and heavy equipment work harder more % of the time so the engine is at a steady speed with boost. Thus the intake past the turbo is hot from constant boost, heat from compression.
 
Ok so I'm getting mixed reviews about running an intercooler with my ATT. But ill ask again, what about water/methanol injection? Getting off the subject a bit, the compressor side of my turbo and the coupler to the intake are really cold. How does the ATT pull that off? I've been around trucks and heavy equipment since I was a boy I don't think I've ever seen that.
I have an ATT and w/m injection and zero complaints. About the only time I use w/m is in hot weather towing a trailer up a long or steep hill.
 
THANKS WW !

Good test, WW ... gotta love it when somebody brings data to the table! We've heard a bunch of guys talk about how the ATT pulls, and how it gets better mileage, now we can see why.

What he said... and a few others too.:thumbsup:

I am SO grateful for the money and effort expended by you and those like you. Y'all have hepled me and others with your time, experience, and patience.:agreed:

Is there a thread on your 6 switchable tunes?

I hope someday to be able to afford an ATT. Who would you recomend as seller? (blatant request for vendor pitch)
 
I hate all this turbo bashing, it doesn't do anyone any good, I don't really care who runs what but facts are facts, it seems some setups prefer the ATT, others the HX40II and the HX40. Between both sites, some really great info, hats off to anyone who has taken the time to dyno, test, fab etc to bring the results to the table.

OP, you keep saying your setup is different than anyone elses, what's so different about it? Thanks.
 
Wasn't the HX40 designed for the Cummins 6BT marine engine? That engine is a much lower revving engine than the 6.5, which would explain why WarWagon was seeing 23 lbs of boost in his test. I think the Cummins 6BT runs at 15 psi sustained with the HX40.
 
Wasn't the HX40 designed for the Cummins 6BT marine engine? That engine is a much lower revving engine than the 6.5, which would explain why WarWagon was seeing 23 lbs of boost in his test. I think the Cummins 6BT runs at 15 psi sustained with the HX40.

Not sure but Subclatter on the other site used an HX40, compared to others who use the HX40II, which is a smaller turbo than the HX40 and aren't the HX40II and the ATT close in size? SB saw lower boost at the same load vs the ATT with his HX40.
 
Not sure but Subclatter on the other site used an HX40, compared to others who use the HX40II, which is a smaller turbo than the HX40 and aren't the HX40II and the ATT close in size? SB saw lower boost at the same load vs the ATT with his HX40.

Certainly size is a factor, but I was thinking that the greater factor was the designed boost at specific compressor speed and that is based on the engine speed and its exhaust output. The Cummins is a long stroke in line 6, which means it will move more air at lower rpm than the shorter stroke 6.5. That's what my focus was on.
 
I hate all this turbo bashing, it doesn't do anyone any good, I don't really care who runs what but facts are facts, it seems some setups prefer the ATT, others the HX40II and the HX40. Between both sites, some really great info, hats off to anyone who has taken the time to dyno, test, fab etc to bring the results to the table.

OP, you keep saying your setup is different than anyone elses, what's so different about it? Thanks.

The engine was built on near zero budget. The ATT went on because I HAD to replace the turbo with the blown engine. So to save money I got a 1986 6.2 NA military engine with under 30K on it. It got head studs and a new timing chain. I used the 6.2 NA precups in it. Looking at the pics below it is the smallest precup with the original precups from a 1995 TD sitting on the heads. The other head is on the 1993 and are 6.5 NA precups. The 1995 TD precups were cracked and one had a bunch of piston aluminum melted to it.

The precups limit the amount of fuel I can burn. Buddy has tried everything to stuff more in with timing etc. More fuel just raises EGT and smokes black. So even the tune for this engine is a one off just to work around the precups. There is more power available, but, not without pulling the engine to change the precups out. I didn't know better when I dropped the engine in...

I don't know of anyone else running NA precups with larger than factory turbo's. Even so, it isn't common. The ATT equipped 1993 with 6.5 NA precups, that are bigger, get better results than the 1995 with it's smaller precups. Better power and no smoke.

Military engines do not have emissions so the 6.2 NA military precups are different and run dirtier than the civilian ones.

precups.jpg


As far as turbo size, the HX40II is in the center.
largemedsmall2.jpglargemedsmall.jpg
 
It's hard to say what application tht the HX40 or HX-40II that is bought on ebay was meant for. CUMMINS has used the hybrid HX40(HX-35 center and exhaust with an HX-40 compressor housing) on the 5.9L in the 2500/3500 trucks in 00-01(it was abandoned quickly as it was a total MESS), then the 5.9L with a true HX-40, there was 2 or 3 variations of it used on the 8.3L by CUMMINS for the 250-325HP version, and quite a few other applications for other engines and manufacturers. It was never used in the marine enviroment that I know of as most marine turbos are non wastegated turbos like the ATT(wastegates tend to freeze up and or rot out in a marine saltwater enviroment). My biggest issue with the whole turbo bashing debacle has been to much but dyno thrown out there(and to much obsession with boost numbers) with to little actual dyno numbers to back it up. It is nice to see actual back to back tests run on both turbos and true results of both.
 
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