GMx turbo upgrades for towing heavy, worth it?

[WarWagon]

My bad I assumed auto...

Yeah the NV4500 is a gear short of a 6 pack. Have you thought about a different MT shoved in there with some better ratios to use a narrow powerband? Not saying a NV5600, but, splitting the awful big RPM drop on the NV4500 is why it left the drawing board into production.

 

[red]

My bad I assumed auto...

Yeah the NV4500 is a gear short of a 6 pack. Have you thought about a different MT shoved in there with some better ratios to use a narrow powerband? Not saying a NV5600, but, splitting the awful big RPM drop on the NV4500 is why it left the drawing board into production.

Paid $2400 for the truck, a trans swap isn't really in the plans for it haha.

 

[Will L.]

I am planning a holset cko because $.

You can buy the hx40wii cko for under 300 fleabay.

With piping going to a cac (you can get junkyard dodge unit) not just to cool but catch a turbo impeller jic it blows and save the engine. Also thinking scatter shield around the turbo incase it goes full grenade to protect the vehicle occupants and engine parts. (Mine sits 11” away from me and the wife).

I know this is probably overkill, many folks run cko turbos without issues. Just something to think of incase thats why you shy away from them.

 

[1999gmc]

Contrary to popular belief a charge air cooler will help cool the air a gm turbo is pushing , all be it not as good as another snail but it would help cool the charge...

I did a write up on the Dieselplace back in the day. I bought my 99 and towed my toy hauler up through the Sierra Nevada mountains quite a bit and lost power. Hooked up my scanner and found that my IAT's would get to 304 degrees and I would lose power. Fabbed up a CAC and no more losing power and IAT's never went over 215 degrees.

 

[1999gmc]

I agree. Hummers run gm6 or gm7 and when they add a cac it helps. There is a about 150 rpm lag more, but worth it.

who would think a cac wont help a gm x turbo?
I know a couple people did a cac on the ATT and didn’t get good results, but that’s because boost (turbine compression) is so low. But if it were done here or Phoenix- it might in the summer.

Odd. I've run my charge air cooler with the stock GM8 and left it on since I already made it with my ATT and it's been great. Summer or winter.

 

[Will L.]

Odd. I've run my charge air cooler with the stock GM8 and left it on since I already made it with my ATT and it's been great. Summer or winter.

Have you ever bypassed the cac to the ATT to see how it is without it?
I can’t remember who it was on here that tried w/ and w/out cac and preferred w/ out.

There was a guy that is an avid reader here but will never post because his tinfoil hat is too tight (haha hi John, call me tomorrow) that lives in Vegas, I helped him install his ATT and he already had the cac also. He ended up removing his cac after comparison testing.

Using the cac adds to lag. It also in an obstruction to air for the radiator. When you compress air, it gets hotter. The higher the psi the more heat there is. The ATT works by moving more air at lower psi. So it does not generate nearly the heat most turbos do. There seems to be “tipping points” of iat that affect the 6.5. 200 seams to be one for the 6.5. Above 200 iat the power and mpg loss hits noticeably and left unattended will begin to drive the ect up. The higher the iat the faster it happens. Maybe it’s simple higher heat than the engine therefore it is adding heat rather than if under the thermostat temp the air being cooler absorbs heat helping. Set that theory aside...

The benifit of the air being colder- how many folks monitor iat and have noticed power/mpg gains when the iat goes from 180 to100? Going to guess none. The air density gain just isn’t enough to overcome having to charge and push through the plumbing and cac then show any benifits. If you could drop from. 180 to 30, yes. That you will notice. But a cac getting you from 180 to 30 means you need ambient of -10 or colder.
The a/c chilled evaporator at the intake where no pumping distance is lost - that could make it happen.

So the disadvantage of cac on ATT is lag added- small but on a turbo that is not helping that much at the stop light...
Also blocking airflow to radiator and any heat removed from iat gets dumped into the airstream of the radiator means the radiator isn’t cooling as well. If you are running down the hiway- so what no biggie. Running in traffic in the summer heat of Las Vegas -biggie. The ect lowered numbers from removing iat heat when the iat is below 200 it just doesn’t help enough to overcome. If John had a super radiator and coated his cac, maybe the temp drop of iac would be enough to compensate for it, but currently it isn’t.
He drives in traffic a bit- not gridlock stuff just stoplight to stoplight and freeway use. Only tows on a once a month basis. So if you tow hiway alot, it may be better results. Or if the cac doesn’t affect you because of weather in the summer...

 

[Chewy1576]

John from Quadstar has a Banks iDash with a whole grip of sensors for it. I'm sure we will be seeing a bunch of this data in the near future

 

[1999gmc]

Have you ever bypassed the cac to the ATT to see how it is without it?
I can’t remember who it was on here that tried w/ and w/out cac and preferred w/ out.

There was a guy that is an avid reader here but will never post because his tinfoil hat is too tight (haha hi John, call me tomorrow) that lives in Vegas, I helped him install his ATT and he already had the cac also. He ended up removing his cac after comparison testing.

Using the cac adds to lag. It also in an obstruction to air for the radiator. When you compress air, it gets hotter. The higher the psi the more heat there is. The ATT works by moving more air at lower psi. So it does not generate nearly the heat most turbos do. There seems to be “tipping points” of iat that affect the 6.5. 200 seams to be one for the 6.5. Above 200 iat the power and mpg loss hits noticeably and left unattended will begin to drive the ect up. The higher the iat the faster it happens. Maybe it’s simple higher heat than the engine therefore it is adding heat rather than if under the thermostat temp the air being cooler absorbs heat helping. Set that theory aside...

The benifit of the air being colder- how many folks monitor iat and have noticed power/mpg gains when the iat goes from 180 to100? Going to guess none. The air density gain just isn’t enough to overcome having to charge and push through the plumbing and cac then show any benifits. If you could drop from. 180 to 30, yes. That you will notice. But a cac getting you from 180 to 30 means you need ambient of -10 or colder.
The a/c chilled evaporator at the intake where no pumping distance is lost - that could make it happen.

So the disadvantage of cac on ATT is lag added- small but on a turbo that is not helping that much at the stop light...
Also blocking airflow to radiator and any heat removed from iat gets dumped into the airstream of the radiator means the radiator isn’t cooling as well. If you are running down the hiway- so what no biggie. Running in traffic in the summer heat of Las Vegas -biggie. The ect lowered numbers from removing iat heat when the iat is below 200 it just doesn’t help enough to overcome. If John had a super radiator and coated his cac, maybe the temp drop of iac would be enough to compensate for it, but currently it isn’t.
He drives in traffic a bit- not gridlock stuff just stoplight to stoplight and freeway use. Only tows on a once a month basis. So if you tow hiway alot, it may be better results. Or if the cac doesn’t affect you because of weather in the summer...

Not really the case for me. My ATT with CAC and ATT makes more power from idle all the way through the power band than the GM8 ever did. My CAC is mounted where the plastic skid plate thing was mounted stock so not causing any heat issues with radiator. Been there for 15 years and never had a problem puncturing it. I run 3" aluminum tubing the whole way. And I averaged 1-2 MPG better than I do without it. On a 100 degree day going down the freeway my IAT's are 105-110. Ford felt that the OBS Powerstrokes didn't need a CAC also. After I did mine on my 6.5 my buddy did one on his 96 Powerstroke. A little better mileage and way better sustained towing power is what he noticed also with his all stock engine,tuning, and fuel delivery. They only do about 15-20 psi of boost also. Pulling the sierras I get about 18lbs of boost with my ATT. If I was experiencing severe lag, I would remove it maybe and see what my IAT's do when towing, but lag has never been a problem for me.

 

[MrMarty51]

Not really the case for me. My ATT with CAC and ATT makes more power from idle all the way through the power band than the GM8 ever did. My CAC is mounted where the plastic skid plate thing was mounted stock so not causing any heat issues with radiator. Been there for 15 years and never had a problem puncturing it. I run 3" aluminum tubing the whole way. And I averaged 1-2 MPG better than I do without it. On a 100 degree day going down the freeway my IAT's are 105-110. Ford felt that the OBS Powerstrokes didn't need a CAC also. After I did mine on my 6.5 my buddy did one on his 96 Powerstroke. A little better mileage and way better sustained towing power is what he noticed also with his all stock engine,tuning, and fuel delivery. They only do about 15-20 psi of boost also. Pulling the sierras I get about 18lbs of boost with my ATT. If I was experiencing severe lag, I would remove it maybe and see what my IAT's do when towing, but lag has never been a problem for me.

That looks to be a nice clean setup. I had the thoughts of installing a CAC under My 2000 K3500, I just imagined it would hang a lot lower than that.
I guess I`ll really not be needing a device to improve boost and drop EGTs so much now. The boy child went and bought a brand new Dodge one ton diesel. I imagine if there is any heavy pulling to do the Dodge will be used.

 

[Will L.]

@1999gmc That is awesome to hear. And love the set up. Being the offroad addict and theorizing I should always be able to knock down walls and blast through hills, your location would scare me- but obviously using the truck like a truck instead of a battering ram it has worked great for a long time.
He called me to tell me to read what you posted and respond -his (And my) opinion that location and possibly cac quality is probably the reason. He is already considering the a/c method, and said if he doesn’t do it, he will copy your method. He will put the second condenser down there if he does the a/c method. Awesome news, thanks for sharing.
Oh yeah, he also had quite a bit of flex hose in his which could account for more contracting/ expanding and therefore more lag in boost. He has a Heath tune also.

Everyone else out there without a tune- My friend John ran the gm turbo then the ATT both factory and a tune. The tune makes a big difference in both. Power improvements, mpg improvements and cleaner emissions tests. The emissions tests here can be done by obd2 port and on the dyno. He did both just to learn. Both had improvements at all levels.
The tune can pay for itself, and the harder you work the truck the sooner it will was his experience. The tune is one of the two real advantages a ds4 has on a db pump. The other is better wmi control.

Personally-
If i could get the bottom end spool with a db pump on the ATT ... I would post pics of WarWagons ATT on my hummer...
Still trying hard to justify a way to do it, just cant find an affordable qsv I trust that I can fit.

 

[ak diesel driver]

I'm thinking altitude has about as much to do with the various experiences people have as anything.

 

[ak diesel driver]

I live at about 250' above sea level

 

[Will L.]

His truck was the one we tried the ATT on and experimented with first a little, so Vegas is 2,000-3,000. But quick trip to mnt charleson ski area is like 11.300, so driving up the mountain is like 10,000’ easy. Only snow from like late Nov-early Feb usually, so in summer it gets hot up there too.
So we’ve seen the difference of altitude and yes it makes a big difference. Longer spool times, loss of power, etc. There are some flat spots up there to tell compared to flat road here, not all climbing.

Lower altitude, colder temps, higher humidity are all the desired attributes for any diesel n/a or turbo for power and mpg. Gas afaik also

 

[Twisted Steel Performance]

From my observations over the time the said turbo has been used on these motors is that if you aren't running the motor at close to 3k rpm's it doesn't perform, slow spool up, lag, smokey, etc... is that the definition of a well matched turbo? I guess it's true a cac isn't needed with it, maybe because it isn't building boost..

I'm not bashing it or anyone that likes it, but if it were to be put up head to head with a 35/40 pro hybrid their would be no comparison for our all around rpm band...

 

[Will L.]

I want SOOO BAD to see heads up comparison on db2. The high rpm really is given to the ATT, and the bottom end definitely the 35/40. I wonder at what rpm they cross. Definitely smoke advantage to 35/40 (unless someone is infected with the rcdad- rolling coal dumb a** disease). So happy WarWagon did the hx40wii/ATT only skewed by 6.2 precups. And the smaller precups should lean favor to the wastegated turbo which lost slightly in the fuel end. Soo. If anyone can PLEASE teach me and others with the math.

My theory comparing them- 35/40- the 35 hot side will spool faster than 40wii but the 40wii should flow better high rpm. If the exact “perfect” size 40 inducer is determinable, it obviously can be put on both. I can do twin scroll, knife edged, or open on flange. T3 or T4. So all that seems a tie. Ive been super impressed with all 3, but only seen the heads up from WarWagon.

Auto trans obviously different than manual, and rpm used affects it too. The wider range I need is why I lean to the 35/40 after having driven the ATT db2 again after years. Planning for cko 35/40 or cko hx40wii at this point. I need to find a bucket-o-money and buy one of each! Haha.

 

[1999gmc]

My son just ordered the HX40II from PTwiring solutions today for his K5 that we put a 2001 6.5 in last year. It has the 4911 pump on it with a GM8 now. So at some point I am going to pull my ATT and try his turbo.

From my observations over the time the said turbo has been used on these motors is that if you aren't running the motor at close to 3k rpm's it doesn't perform, slow spool up, lag, smokey, etc... is that the definition of a well matched turbo? I guess it's true a cac isn't needed with it, maybe because it isn't building boost..

I'm not bashing it or anyone that likes it, but if it were to be put up head to head with a 35/40 pro hybrid their would be no comparison for our all around rpm band...

Tuning is huge. High elevation I get quite a bit of smoke with Heaths tune at low rpms pulling the trailer. But I paid Patrick for a KOJO tune and it's not even close to the power or mileage I get with Heaths tune. Sent it back to them and I have gotten it back but haven't tried it again because the first one was so disappointing I'm really not to excited about trying it. But that being said. If my truck just shifts into 2nd gear say in traffic and I get on it to go or pass someone it puffs out some smoke and lags a little(But hell my buddies stock 6.0L Ford does the same thing). A second or 2 then pulls good. If I'm around 2000 rpm or give it say 1/4 throttle from the start in 1st gear it pulls hard.

 

[GM Guy]

Ya'll missing the "budget" part of this.

IMO find a good GM8 for cheap, put the wicked wheel on, and retain the vacuum wastegate control.

For extreme budget, just keep what you have and keep vac control.

I might be the only one that feels this, but if a guy is running the GM turbo, the vac control does the best it can to keep drive pressures respectable.

Like the OP said, big turbo is the better/ smarter solution, but sometimes $ dictates doing something else.

 

[Will L.]

Thats why I mentioned the cko stuff on ebay. Wont post a link, but copy
HX40WII-T3 4050036 Diesel Turbo for 89-01 Dodge RAM 2500/3500 Diesel 6CTAA
$235.99 free shipping

just need to add $50-75 in steel to make a scatter shield/ box (and heat trap) from scrap AR plate if paranoid like me.

 

[93detroit]

I get what the OP is asking, and I understand why. My experience with gm-x turbos (a 1 and an 8) was not good. My first 6.5 was in a 93 c2500 with 3.42 gears. I tow heavier than most with a 6.5. With the fuel cranked up and a homemade TM set at 10-11psi, I spit a head gasket in about 8k miles (and bent 2 rods). There were two causes in my opinion. First, I would lug the motor when towing (1800-2100) because that is where the motor worked best due to the gm-8. Second, the small turbo was able to build that 10psi by 1,500rpm. Blocks and head gaskets do not like being under combustion pressure for long periods of time (you don't see NASCAR motors loaded under 5k EVER).

I bought an HX40WII and over time modified it to where I almost love it. It has a real deal Holset 56mm wheel and compressor housing (no advantage that I can tell), the exhaust exducer housing is bored 2mm to lower drive pressure, I bored the wastegate port from .5625” to .875”, and I loosened the wastegate (it's Loose!) to give no more than 15psi of boost. It still spools well even through a CAC (a little slower than stock to be sure). It will not build 10psi until 2k rpm and I will not run the engine under 23-2400rpm when towing. This turbo would seem even better if my stock db2 didn't give up on fuel before 3k rpm. I DO wish drive pressure was a little less as I still run 4-6psi at 65mph unloaded.
This works very well in my k2500 with a 4l80e and 4.10s.

 

[red]

Thats why I mentioned the cko stuff on ebay. Wont post a link, but copy
HX40WII-T3 4050036 Diesel Turbo for 89-01 Dodge RAM 2500/3500 Diesel 6CTAA
$235.99 free shipping

just need to add $50-75 in steel to make a scatter shield/ box (and heat trap) from scrap AR plate if paranoid like me.

Forgetting the oil drain/supply parts, intake/exhaust plumbing mods. So around $500-800 total. There's a CKO hx35w on my 82 crew cab with the Isuzu 4bd1t engine for testing purposes.

Ya'll missing the "budget" part of this.

IMO find a good GM8 for cheap, put the wicked wheel on, and retain the vacuum wastegate control.

For extreme budget, just keep what you have and keep vac control.

I might be the only one that feels this, but if a guy is running the GM turbo, the vac control does the best it can to keep drive pressures respectable.

Like the OP said, big turbo is the better/ smarter solution, but sometimes $ dictates doing something else.

I get what the OP is asking, and I understand why. My experience with gm-x turbos (a 1 and an 8) was not good. My first 6.5 was in a 93 c2500 with 3.42 gears. I tow heavier than most with a 6.5. With the fuel cranked up and a homemade TM set at 10-11psi, I spit a head gasket in about 8k miles (and bent 2 rods). There were two causes in my opinion. First, I would lug the motor when towing (1800-2100) because that is where the motor worked best due to the gm-8. Second, the small turbo was able to build that 10psi by 1,500rpm. Blocks and head gaskets do not like being under combustion pressure for long periods of time (you don't see NASCAR motors loaded under 5k EVER).

I bought an HX40WII and over time modified it to where I almost love it. It has a real deal Holset 56mm wheel and compressor housing (no advantage that I can tell), the exhaust exducer housing is bored 2mm to lower drive pressure, I bored the wastegate port from .5625” to .875”, and I loosened the wastegate (it's Loose!) to give no more than 15psi of boost. It still spools well even through a CAC (a little slower than stock to be sure). It will not build 10psi until 2k rpm and I will not run the engine under 23-2400rpm when towing. This turbo would seem even better if my stock db2 didn't give up on fuel before 3k rpm. I DO wish drive pressure was a little less as I still run 4-6psi at 65mph unloaded.
This works very well in my k2500 with a 4l80e and 4.10s.

Yea we did get off on the usual tangent with better turbos haha.

There is 1 nice thing, which is also a bad thing, about the GM turbos when towing. It's so restrictive it actually makes it a decent exhaust brake. Hurts performance of course but going down 3-4% grades at 15-18k combined weight maintaining 60mph without even considering the brake pedal has it's benefits.

So based on the experience of others, turbo master (and other manufacturers versions) is not recommended for heavy towing. Wonder if just the new wheel is a viable option like GM Guy mentioned. Claims lower drive pressures and temps.