Replacement turbo

[skypilotj]

Can the ATT be had with Gamma Titanium Alumina turbine wheel and shaft?

 

[Slim Shady]

The turbine wheel and shaft are not Gamma titanium. Once again I am sure cost would be prohibitive. The turbine wheel on the A-Team Turbo is a high temp alloy capable of withstanding high exhaust gas temps for extended periods of time without degradation to the metallic structure of the turbine wheel. I know War Wagon has consistently had 1500 degree temps for periods of time. I have run mine at 1300 degree for ten plus minutes and no damage at all.

All turbine wheels and compressors wheels are investment cast parts balanced separately then put together and balanced as an assembly. Industrial fail safes are built into the turbo to stop catastrophic failure of the compressor wheel. Thus sending metal pieces into the engine. The design of the compressor wheel and the way the pieces are assembled make this feature possible. Just one of the little things that are not apparent. This does not mean the compressor wheel will not be damaged and need replacement along with the compressor housing. Both will be damaged however the compressor wheel in most instances will not shed metal pieces into the engine before turbo failure is apparent to the operator.

 

[skypilotj]

Good post and excellent link. I like the section on machining Gamma TI.

 

[WarWagon]

1550 sustained during a mountain grade towing while testing tunes. The ATT was recently pulled, 5000 miles later, and is fine. (It was pulled to test/dyno a HX40II clone.) The turbo blanket was scorched after that 1550 EGT run on the inside. The engine still runs and I feel EGT is just one of many variables. Myth = busted that your engine will 100% for sure melt down over 1150 degrees EGT. It can melt down if other factors are different like higher ECT, more advance, lower RPM, etc.

I have the downpipe, crossover, and manifolds wrapped. The downpipe is wrapped past the passenger floor pan firewall bend. It keeps stuff from melting or catching fire. :rolleyes5:

 

[NVW]

That temp is scary, makes me wonder what I could tow if I let it get over 1050?

 

[Slim Shady]

NVW I have consistently run mine at 1100 for more than a half hour straight, no issues. matter of fact the truck ran great after that, cleaned out the exhaust manifolds. LOL 1200 shouldn't really be an issue either, After that I wouldn't take any bets, depends on the truck and the exhaust set up, as long as that heat isn't staying in the exhaust manifold for very long I wouldn't think we are going to do to much damage to anything. I think with the GM turbo though it is a big problem because of the latent heat build up because of the restriction. That is only my opinion though and I don't recommend anyone running their motor at any temp they feel is unsafe.

 

[NVW]

Slim, if my engine was newer I'd do it, but at it's mileage I don't want to push it. I already have one 6.5 to rebuild with no time to do it.

 

[JayTheCPA]

Ok, so I worked through this entire post (well, mostly, skimmed the physics section :bigeyes: ) and not clear on whether there is a specific ECM (OBDII) tune that optimizes for the ATT. So, for somebody like myself with a stock tune, is there one that will take advantage of the ATT's capabilities or just go with one of the preset packages from KOJO / Heath / Kennedy / etc? It looks like KOJO has a tune (presumably specific for the ATT), but what about the others? Did the conversations with Heath ever go anywhere?

 

[Slim Shady]

Ok, so I worked through this entire post (well, mostly, skimmed the physics section :bigeyes: ) and not clear on whether there is a specific ECM (OBDII) tune that optimizes for the ATT. So, for somebody like myself with a stock tune, is there one that will take advantage of the ATT's capabilities or just go with one of the preset packages from KOJO / Heath / Kennedy / etc? It looks like KOJO has a tune (presumably specific for the ATT), but what about the others? Did the conversations with Heath ever go anywhere?

As far as I am aware KOJO tuned specifically for the OBD II while owning and driving a OBDII vehicle equipped with a A Team Turbo. As far as Bill, he and I discussed it at great length and we could not get past one stumbling block, almost but not quite.

PM me if you would like to discuss this in greater detail.

 

[JayTheCPA]

Perfect, this closed the loop as I just did not track where the question over ECM tunes was ever settled. Now it is

 

[Paveltolz]

Bill Heath did a couple of great tunes for my ATT. One performance and another for economy. Coincidently, the tunes worked very well when I went back to my GM-5 too (ah the fun of experimentation). The first tune (towing) I had that initially improved my GM-5 from it's OEM tune wasn't sufficient to what the ATT needed. It's a matter of experimentation and communication with the tuner. Fortunately, I was able to make the improvements while traveling through the neighborhood on business.

 

[Brooklyn Tow]

Bill Heath did a couple of great tunes for my ATT. One performance and another for economy. Coincidently, the tunes worked very well when I went back to my GM-5 too (ah the fun of experimentation). The first tune (towing) I had that initially improved my GM-5 from it's OEM tune wasn't sufficient to what the ATT needed. It's a matter of experimentation and communication with the tuner. Fortunately, I was able to make the improvements while traveling through the neighborhood on business.

Good to know........Just ask for "Paul's ATT Tune?" :arf:

 

[NoDak]

I feel there is a miscommunication here on what terms mean what. Lag is the time it takes from when you romp on it until the boost comes up. It seems to me some are confusing "lag", with a raised power band. GM chose there turbo to basically optimise power in the cruise area as the 6.5 was never meant to be a powerhouse. It seems from what I have read that the ATT is not very laggy, but it DOES raise up the powerband a few hundred RPM's. I know my LB7 doesn't have much boost below about 2K RPM's, yet I don't feel it is laggy in the slightest. The ATT powered truck I rode in was anything but laggy I thought, but it did have a higher powerband than a stock GM-8 turbo'd truck had. There is NO perfect turbo. They will all have tradeoffs in them. Even VVT's have there weakness's to them. For the cost, and what it does, the ATT is an excellent replacement though I feel, and if I had a 6.5 powered vehicle it would be sporting one.

The English language is a wonderful tool because it is very flexilble, but for the same reason it can be difficult to communicate and easy for same the text to have several different meanings.

Here are my two "sense"... lol....

Who really cares about turbo lag or even turbo boost pressure response time? "Turbo boost pressure response time" would be the "affirmitive" description if one adhered to Roberts Rules of Order right? I think a more meaningful measure is torque response time. For example, if we cruised down the highway at about 300 or 500 rpm above torque peak speed at full throttle, then go to "no pedel" and coast until things cooled off a bit and the engine speed slowed to torque peak engine speed, then go to wide open throttle... then record the time it takes to reach 80 or 90 percent of peak torque. I know, we don't have a "torque gauge" on the old dash. But, my point is torque response is a more meaningful description of the package don't you think?

I believe the all around performance of my ATT on my '95 with a 4L80E and 3.42 ring gear and pinion is alot of fun. I've improved mileage as advertised, all the while I can't stop driving it harder because it is more fun and sounds alot like a 454 rat. Others have commented on how they like the drive by or launch sound too (take note I have a noise attenuatining cat in addition to the see-thru muffler). Perhaps Kennedy has the things dialed in to give the right amount of initial "launch" fueling, then ramping it up appropriately from there?

I can make a little bit of smoke, but I have really give'er the onion from a cold or slow speed.

Another point I should add... If I'm cruising around town or pulling a trailer... I make sure I shift it down to 3rd to stay out of overdrive and avoid lugging a pretty good load down at 1500 or 1600 rpm.

 

[NoDak]

The ATT on the '95 has 57,000 miles on it.

Who has the best suggestion for a new crossover tube? Where to order? Part numbers? The goods????

 

[guybb3]

The ATT on the '95 has 57,000 miles on it.

Who has the best suggestion for a new crossover tube? Where to order? Part numbers? The goods????

I bought mine from SS Diesel simply because I was having trouble getting a stainless one anywhere else.

 

[sshewins]

I too have an ss diesel item. It is stainless, but a low grade stainless. Still, IMHO, its better than no stainless.

 

[Slim Shady]

I to bought a SS stainless it was the only stainless one at the time. I knew it was lo grade stainless when I got it to braze together. It was two piece and I don't like clamps.

 

[Slim Shady]

The English language is a wonderful tool because it is very flexilble, but for the same reason it can be difficult to communicate and easy for same the text to have several different meanings.

Here are my two "sense"... lol....

Who really cares about turbo lag or even turbo boost pressure response time? "Turbo boost pressure response time" would be the "affirmitive" description if one adhered to Roberts Rules of Order right? I think a more meaningful measure is torque response time. For example, if we cruised down the highway at about 300 or 500 rpm above torque peak speed at full throttle, then go to "no pedel" and coast until things cooled off a bit and the engine speed slowed to torque peak engine speed, then go to wide open throttle... then record the time it takes to reach 80 or 90 percent of peak torque. I know, we don't have a "torque gauge" on the old dash. But, my point is torque response is a more meaningful description of the package don't you think?

I believe the all around performance of my ATT on my '95 with a 4L80E and 3.42 ring gear and pinion is alot of fun. I've improved mileage as advertised, all the while I can't stop driving it harder because it is more fun and sounds alot like a 454 rat. Others have commented on how they like the drive by or launch sound too (take note I have a noise attenuatining cat in addition to the see-thru muffler). Perhaps Kennedy has the things dialed in to give the right amount of initial "launch" fueling, then ramping it up appropriately from there?

I can make a little bit of smoke, but I have really give'er the onion from a cold or slow speed.

Another point I should add... If I'm cruising around town or pulling a trailer... I make sure I shift it down to 3rd to stay out of overdrive and avoid lugging a pretty good load down at 1500 or 1600 rpm.

NO DAK I like your post and yes I believe the tuner can make or break a turbo or truck by how knowledgeable they are about tuning. 57000 miles, he he, no grass under that truck. How is the fuel mileage truck doing? I like the way you post details and clear up points, never considered Roberts Rules of Order, but it fits. Good point.

 

[NoDak]

I bought mine from SS Diesel simply because I was having trouble getting a stainless one anywhere else.

Just to be sure, I was talking about the hose between turbo and upper intake manifold. As supplied with ATT, the orange corrigated hose.

I called "http://www.ssdieselsupply.com" at 716-874-6900, and the fella claimed they have never had anything like that?

Are we talking about a different part, or a different vendor?

 

[NVW]

PM Slim, I believe he has a silicon replacement now.

Just to be sure, I was talking about the hose between turbo and upper intake manifold. As supplied with ATT, the orange corrigated hose.

I called "http://www.ssdieselsupply.com" at 716-874-6900, and the fella claimed they have never had anything like that?

Are we talking about a different part, or a different vendor?

sshewins would have been referring to the exh manifold xover.