-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
ATT info
- Thread starter dixiepc
- Start date
Will L.
Well-Known Member
ak diesel driver
6.5 driver
He tested against the hx40w2 which is slightly different and a Chinese built turbo
FellowTraveler
Well-Known Member
Mitsubishi Industrial turbos TDO7 series is what that turbo is based on and came in several configurations and unless you have access to tech on measurements you are SOL. Here is a link but few if any specs.
www.turbomaster.info
Since the specs are not published on the A-- that is the very reason I would not buy one myself simply because you "do not know what you have." I do seem too remember the starting place was a Mitsubishi TDO7-22.......
As for HX40w full size you always have access to the specs be it Holset or CKO both of which are generally made in CHINA however; the Holset can be made in England America or even other countries.
OH and the HX40w will spool faster than any comparable Mitsubishi.
From what I have gathered; that A-- turbo is a CKO too if it does not have Mitsubishi cast into it....
TDO7 - Mitsubishi - Catalog - TurboMaster
Mitsubishi Catalog TDO7 series Turbomaster sl, Spain's official distributor for Garrett and Holset Turbocompressors and TiAL accessories
Since the specs are not published on the A-- that is the very reason I would not buy one myself simply because you "do not know what you have." I do seem too remember the starting place was a Mitsubishi TDO7-22.......
As for HX40w full size you always have access to the specs be it Holset or CKO both of which are generally made in CHINA however; the Holset can be made in England America or even other countries.
OH and the HX40w will spool faster than any comparable Mitsubishi.
From what I have gathered; that A-- turbo is a CKO too if it does not have Mitsubishi cast into it....
Last edited:
ak diesel driver
6.5 driver
The hx40w2 has been known to come with a couple of different wheels and no info regarding which one you're buying. To my knowledge the ATT, other than a few problem child ones that slim fixed, are all the same. IIRC the specs are available over at the place as someone measured one.
FellowTraveler
Well-Known Member
From what I have gathered the CKO HX40w2 is the step "down" child of the full sized HX40 (w).
So what are the specs?
Will L.
Well-Known Member
Akdieseldriver is correct on the hx40w2 being what he had similar results with. Sorry about that.
The reason he never put out his specs in ATT and why almost no one measured and put it out there was he spent a lot of time and money in researching, and rather than putting out the info to have people undercut his sells to save $100, it was kept quiet.
Almost all his customers simply appreciated someone willing to pour money and time into researching an important upgrade for the 6.5 and if everyone always undercuts the few that do it, no one will invest into the availability of upgraded components.
Same reason Bill Heath wont release info on any of his stuff, or Kennedy wont release info on his things like fanclutch, peninsular never released their centermount turbo info, etc.
The reason he never put out his specs in ATT and why almost no one measured and put it out there was he spent a lot of time and money in researching, and rather than putting out the info to have people undercut his sells to save $100, it was kept quiet.
Almost all his customers simply appreciated someone willing to pour money and time into researching an important upgrade for the 6.5 and if everyone always undercuts the few that do it, no one will invest into the availability of upgraded components.
Same reason Bill Heath wont release info on any of his stuff, or Kennedy wont release info on his things like fanclutch, peninsular never released their centermount turbo info, etc.
Last edited:
FellowTraveler
Well-Known Member
If I'm going to drop $1.1+ k on a turbo it had better come with the specs.......
I seem to remember a Merlin IP that was pricey and w/o specs I would not spend a penny on such pie in the sky item.
I seem to remember a Merlin IP that was pricey and w/o specs I would not spend a penny on such pie in the sky item.
Will L.
Well-Known Member
I understand wanting to know the specs ahead of time. I don’t blame anyone for not buying something that doesn’t give the specs. I was just saying why they didn’t.
1999gmc
Active Member
That's a shame. You'll miss out on a good turbo. Been running mine for about 10 years now with no complaints. Heath redid my tune to more match the ATT and it runs really well. My only issue is it smokes pretty good at higher elevation and if I really get on it. But Heath reflashed it for me for $50 vs $400 for the KOJO. So recently I decided i had had enough of the smoke and had an extra computer so I sent it in to have a KOJO tune burned. Was not impressed at all. Sent it back because my Heath tune put it to shame. So I just got my computer back a week ago that they made a few tweeks I guess but still haven't installed it.
FellowTraveler
Well-Known Member
Interesting thoughts however; the tuner not knowing the specs tuning becomes a shot in the dark however; diesels are more forgiving so you just enjoy that turbo..........and I'll stick to Holsets or a HOLSET spec CKO.
- Staff
- #13
I just gotta say... if this turns into an ATT Vs whoever's pissing match I'm gonna SCREAM!!!!
That is all...carry on...
That is all...carry on...
1999gmc
Active Member
No. No pissing match here. Just letting him know I've been happy with it for about 10 years. No problems with it at all. I was hesitant to buy it because it's a chinese turbo and I really don't like most chinese made stuff. But turbine Doc was in on this as well with slim shady so I figured what the hell, I'll give it a shot.
1999gmc
Active Member
Well Bill Heath knew relatively close what it was and gave me a sweet tune other than the smoke at higher elevation. I can't believe how it woke the truck up after his reflash. Good luck with whatever turbo you decide. It seems more turbo's became available since I did the ATT. Or I guess I should say more people have tried other turbo's. There's a lot more info on the different 6.5 turbo's now than there was 10 years ago.
Since the Dark Ages are over and a bunch of people are now "WOKE"... Finally: It took them long enough. The ONLY answer used to be put a turbomaster on the GMx turbo and wind it up to the choke point.
Since then others have experimented with other turbos. In context to the rigs we drive most CHOKE on a grand cost of a turbo let alone twin turbos, or pass out at TWO GRAND cost to get a huge turbo to have more range like a Spool Valve or stall it. The fuel savings while towing from swapping the ATT on paid for itself and then some.
Some other turbos have been suggested and some even tried out.
You really can't go much bigger as a design change during a production run did so and that batch of turbo's smoked badly. More or less replaced after they found it.
So let me sum the huge ATT up for you: unless your are going to spin the engine over 2000 RPM simply don't expect any boost below that. It ain't lag, nothing spools faster, it simply will or will not generate boost at X RPM. A huge turbo simply doesn't hit/light off/spool until you have enough RPM. The back pressure is lower with 15 - 18 PSI. In effect it pulls like a freight train from 2000 RPM till redline. The GMx would light off while the starter is still spinning the engine and choke the engine with high back pressure over 2200 RPM.
Similar turbo? No complete "Kits"... But the HX40II is similar in dyno performance. When I was adjusting the WG on a random blade count HX40II... At one point the WG popped open early and it felt like I hit a brick wall from the sudden loss of power. Yeah, had to crank the nut to keep the back pressure up on the HX40II. The RPM range of the HX40II is similar, but, lower. It wasn't much lower and the dyno pulls I did (vs. ATT) were really close for HP TQ. One had higher TQ and the other higher HP. The biggest difference was the ATT was doing similar power with 15 PSI that the HX40II was doing with 24 PSI of boost. (Offhand from memory numbers here.) Making the HX40 "fit" as it wasn't a bolt on kit had two problems: blowing the boot off the turbo and loss of boost because it didn't fit all that well and soot leak from the downpipe. (Funny as hell when the elbow blew off on the dyno at 24 PSI and people watching on the dyno pull day were running away... Not funny when on the road and loose power.)
At 2500 RPM no throttle I had like 6 PSI off the GM3 turbo. Same with ATT was 0 PSI. Slap the throttle and instant boost from the ATT. Of course the parasitic GM3 just speed up for more boost and choke the hell out of the engine. AT 2500 RPM towing the ATT would accelerate while the GM3 just burned fuel.
I also ran a 6.2 pump that limited the smoke simply due to limited fuel from small plungers. (I ran a DS4 and 6.5 DB2 as well and eliminating smoke with NA small precups was why I got a high stall Yank after trying a BD spool valve.)
FellowTraveler
Well-Known Member
I Cummins now & A-- is but a moot issue.............
JayTheCPA
Well-Known Member
The selling points for me on an ATT were:
- it developed much less psi (low teens) to deliver the same power as other brands which needed much higher psi (low to mid twenties).
- it was less complex with no wastegate.
The sum of those two was cost avoidance during install (did not need to consider head studs or other internal motor mods just for the turbo) and lower risk of a moving part failure.
One thing I learned since the ATT conversion was that post-compressor to pre-turbine pressures need to have as close to a 1:1 ratio as possible no matter what turbo and tune was in use. To date, I have only seen one person start to tread into that water for the 6.5. Point is, if anybody is going to seriously look at a turbo and cast dispersions about any brand for lack of published spec's, the credibility factor goes down if only focusing on boost numbers or where in the RPM curve the turbo comes to life. Just say-in
- it developed much less psi (low teens) to deliver the same power as other brands which needed much higher psi (low to mid twenties).
- it was less complex with no wastegate.
The sum of those two was cost avoidance during install (did not need to consider head studs or other internal motor mods just for the turbo) and lower risk of a moving part failure.
One thing I learned since the ATT conversion was that post-compressor to pre-turbine pressures need to have as close to a 1:1 ratio as possible no matter what turbo and tune was in use. To date, I have only seen one person start to tread into that water for the 6.5. Point is, if anybody is going to seriously look at a turbo and cast dispersions about any brand for lack of published spec's, the credibility factor goes down if only focusing on boost numbers or where in the RPM curve the turbo comes to life. Just say-in
FellowTraveler
Well-Known Member
Beating a dead horse here.The selling points for me on an ATT were:
- it developed much less psi (low teens) to deliver the same power as other brands which needed much higher psi (low to mid twenties).
- it was less complex with no wastegate.
The sum of those two was cost avoidance during install (did not need to consider head studs or other internal motor mods just for the turbo) and lower risk of a moving part failure.
One thing I learned since the ATT conversion was that post-compressor to pre-turbine pressures need to have as close to a 1:1 ratio as possible no matter what turbo and tune was in use. To date, I have only seen one person start to tread into that water for the 6.5. Point is, if anybody is going to seriously look at a turbo and cast dispersions about any brand for lack of published spec's, the credibility factor goes down if only focusing on boost numbers or where in the RPM curve the turbo comes to life. Just say-in
DieselSlug
Well-Known Member
I have never driven a ATT equipped truck, nor even ridden in one but back in college I wanted one (as it was the rave back then as others have hinted to here). I couldn't afford the price of the ATT so I piecemeal-ed my Holset WH1C kit together. Performed very well with a tune. This whole swap cost me around $500.
The gains with any of these turbos mentioned above will impress from a stock GMx.
The gains with any of these turbos mentioned above will impress from a stock GMx.