I GUESS MY M1008'S Turbocharger is too small

als804

Member
33
6
8
Location
kimcheon, ROK
hello
first of all sorry my English. ( i - just learning English at google )
a few days ago i installed the turbo on my m1008
the turbo exhaust outlet diameter is just 2.5 inch. and i heard that the turbo is for 3l gasline egnine ( i know gm8 turbo or hx35w 's one is 3inch, now my exhaust line is 2.5 inch diameter and 1meter straight pipe )

my setting : you can see

symptom :
1. even pushing gently the pedal makes the turbine to whistle (~ whisiiiiiii~ ), also turbo boost is rising rapidly to 7psi ( it could make me scared "head gasket" )
2. i feel like shifting is more later than being with my no-turbo m1008 ( shifting point 30 km -> 45 km , vaccum hose is exactly installed as "before" )
3. i could not feel the difference of the power ( my efforts is useless ? :( )
4. egt temp is between 400 and 500 celcius temp at high way with 60mph & 37 inch tire

my guess:
my turbo is too small for 6.2 diesel

you guys how do you think of it ?
 
Last edited:

eric67camino

Active member
Steel Soldiers Supporter
207
126
43
Location
Kansas
The 6.2L was replaced with the 6.5L. The 6.5 came with a GM-8 turbo.

As I understand it, the turbo, intake, etc from a 6.5L will bolt onto the 6.2L. That is how I would try to do it.
 

als804

Member
33
6
8
Location
kimcheon, ROK
hello
first of all sorry my English. ( i - just learning English at google )
a few days ago i installed the turbo on my m1008
the turbo exhaust outlet diameter is just 2.5 inch. and i heard that the turbo is for 3l gasline egnine ( i know gm8 turbo or hx35w 's one is 3inch, now my exhaust line is 2.5 inch diameter and 1meter straight pipe )

my setting : you can see

symptom :
1. even pushing gently the pedal makes the turbine to whistle (~ whisiiiiiii~ ), also turbo boost is rising rapidly to 7psi ( it could make me scared "head gasket" )
2. i feel like shifting is more later than being with my no-turbo m1008 ( shifting point 30 km -> 45 km , vaccum hose is exactly installed as "before" )
3. i could not feel the difference of the power ( my efforts is useless ? :( )
4. egt temp is between 400 and 500 celcius temp at high way with 60mph & 37 inch tire

my guess:
my turbo is too small for 6.2 diesel

you guys how do you think of it ?

My conclusion is that i need to install more bigger turbo hx35w. Ok let’s goooo

i found some info regarding EGT with 60MPH CRUISE
No turbo(N.A) cruise 600-650F
Turbo crusie 400F
My poor turbo cuise 750-930F

My turbo is definitely self restricting
 
Last edited:

frank8003

Well-known member
Steel Soldiers Supporter
5,659
2,716
113
Location
Ft. Lauderdale, Florida
hello
first of all sorry my English. ( i - just learning English at google ) brevity ~
you guys how do you think of it ?
I think You are doing a fine job. You are a sticktoitniffness kind of guy, You will get what you want.
And I see you write in English, not your home language, better than millions where English is the
home language. You get a definitive "Hats off"!
 

cucvmule

collector of stuff
Steel Soldiers Supporter
991
278
63
Location
Crystal City Mo
Hello, there is nothing wrong with 7 psi of boost. Have you increased amount of fuel at the injector pump? Is your waste gate staying closed?

What kind of goal are you expecting to achieve? 25 to 30 more horsepower and and the same increase in torque? Did you have on the 37 inch tires before turbo or after?

Can you get access to a 6.5 turbo setup, or another turbo like the one you have now and have two?
 

Keith_J

Well-known member
3,120
195
63
Location
Schertz TX
What is the engine speed when you are getting 7 PSI of boost? A turbo for a 3 liter gasoline engine that can do 6000 RPM is about right for a 6.2 liter engine turning over at 3600 RPM. Why? Diesel engines cannot have valve overlap, both valves must be closed before top dead center so volumetric efficiency falls off very fast after 2400 RPM. Gasoline engines can have significant valve overlap where both valves are open because inertia of gases in manifolds significantly helps volumetric efficiency.

Exhaust gas temperature in a diesel increases with decreasing volumetric efficiency. If the turbo is too small, this could be the case. The real measure of turbo sizing is drive pressure to boost pressure. In optimum cases, turbine pressure is less than boost. Equal pressure is adequate. Turbine drive pressure more than 1.5 boost is bad as it overloads the CHRA thrust bearing surfaces.

Mass flow is the correct sizing measure, both turbine and compressor sides. But if you installed a scrapyard turbo and cannot find any mass flow maps, you should add a pressure gauge to the exhaust and compare pressures. A six inch section of stainless steel tube from the thermocouple port is enough insulation to protect silicone rubber hose, then another boost gauge will work.
 

Ilikemtb999

Member
655
14
18
Location
Denver, CO
Any specs on this turbo that you’ve installed?

500c* isn’t bad, 7psi is also not bad.

I see about 900*F and 10-12psi on my stock head gasket 6.2 with a gm4 turbo. I’m right in the middle of installing an hx35w and the factory outlet on that turbo is only 2.5” (I’ve replaced it with an aftermarket piece and will be 3” downpipe to 4” exhaust).
 

frank8003

Well-known member
Steel Soldiers Supporter
5,659
2,716
113
Location
Ft. Lauderdale, Florida
Maybe you just need a bigger engine......................... how about a 702

V-12


or one can now get a "new one" Thunder V12

thunder



The 702 V-12 was used in trucks grossing 120,000 lbs. and more. It had tremendous torque and would out pull an 8v71 (318) Detroit Diesel. It was often coupled to a Spicer 8125, 12 speed (6 reverse) fully synchronized transmission. It had a dual distributor and oil operated governor (had to drop the oil pan to adjust it) The spark plugs were in the valley, underneath the intakes and you had to watch not to drop anything down the holes when changing them! It used the same hydraulic lifters as a ’53 Chevy Bel Air
Trucking Co.’s loved them; they’d go 400-500,000 miles. A well tuned one would do 4 mpg. but gas was 40-50 cents a gal!
GM quit making them in 1965 but, by popular demand, tooled up again to make a bunch more for Canadian Trucking Co.’s. in 1966.

6.2L is 378 cubic inches 700 pounds?
11.5L is 702 cubic inches 1485 pounds?

 
Last edited:

als804

Member
33
6
8
Location
kimcheon, ROK
Hello, there is nothing wrong with 7 psi of boost. Have you increased amount of fuel at the injector pump? Is your waste gate staying closed?

What kind of goal are you expecting to achieve? 25 to 30 more horsepower and and the same increase in torque? Did you have on the 37 inch tires before turbo or after?

Can you get access to a 6.5 turbo setup, or another turbo like the one you have now and have two?
I know the 7 psi is the safety maximum. But my this turbo easily make 7 psi even when no load with light putting the pedal. I just wanna keep the speed at the ramp highway. But after test, there was no change.
I already had been with 37inch before having installed. And no change in fuel adjustment
 
Last edited:

als804

Member
33
6
8
Location
kimcheon, ROK
What is the engine speed when you are getting 7 PSI of boost? A turbo for a 3 liter gasoline engine that can do 6000 RPM is about right for a 6.2 liter engine turning over at 3600 RPM. Why? Diesel engines cannot have valve overlap, both valves must be closed before top dead center so volumetric efficiency falls off very fast after 2400 RPM. Gasoline engines can have significant valve overlap where both valves are open because inertia of gases in manifolds significantly helps volumetric efficiency.

Exhaust gas temperature in a diesel increases with decreasing volumetric efficiency. If the turbo is too small, this could be the case. The real measure of turbo sizing is drive pressure to boost pressure. In optimum cases, turbine pressure is less than boost. Equal pressure is adequate. Turbine drive pressure more than 1.5 boost is bad as it overloads the CHRA thrust bearing surfaces.

Mass flow is the correct sizing measure, both turbine and compressor sides. But if you installed a scrapyard turbo and cannot find any mass flow maps, you should add a pressure gauge to the exhaust and compare pressures. A six inch section of stainless steel tube from the thermocouple port is enough insulation to protect silicone rubber hose, then another boost gauge will work.
Thanks for info about dynamics of the engine.

I feel like my engine lost the power at high rpm range after installing turbo. i found a few oil in exhaust pipe so i guess my thrust bearing was already damaged after the first test drive Due to high rpm turbin in my opinion.

Ok i will do install the pressure sensor in turbin side. Also I already made an order of Hx35W.
You mean the same pressure between turbin inlet and compressor outlet is right?

I will share the results after installing hx35w
 
Last edited:

als804

Member
33
6
8
Location
kimcheon, ROK
Any specs on this turbo that you’ve installed?

500c* isn’t bad, 7psi is also not bad.

I see about 900*F and 10-12psi on my stock head gasket 6.2 with a gm4 turbo. I’m right in the middle of installing an hx35w and the factory outlet on that turbo is only 2.5” (I’ve replaced it with an aftermarket piece and will be 3” downpipe to 4” exhaust).
My turbo is the below. I chose for cheap price. Acutally my total expense from now on is just 280$. But due to my bad selection of the turbo i made more more$$$ :)

US $130.30 17% Off | T3 T4 Universal Turbo Turbocharger 0.63A/R V Band Flange Oil Cold 420HP 2.0-3.5L for Stage III Wastegate

Haha i am scared with even 7 psi. Oh my god. Factory is only 2.5.......

do you also makes 7psi with 1st gear 15-20mph and no load ? Mine always makes 7 psi and whistle sound with no .
I hear that gently pushing the pedal with N shift can’t make turbo boost pressure. But mine even makes 2-3psi with light pushing the pedal .
 
Last edited:

als804

Member
33
6
8
Location
kimcheon, ROK
Maybe you just need a bigger engine......................... how about a 702

V-12


or one can now get a "new one" Thunder V12

thunder



The 702 V-12 was used in trucks grossing 120,000 lbs. and more. It had tremendous torque and would out pull an 8v71 (318) Detroit Diesel. It was often coupled to a Spicer 8125, 12 speed (6 reverse) fully synchronized transmission. It had a dual distributor and oil operated governor (had to drop the oil pan to adjust it) The spark plugs were in the valley, underneath the intakes and you had to watch not to drop anything down the holes when changing them! It used the same hydraulic lifters as a ’53 Chevy Bel Air
Trucking Co.’s loved them; they’d go 400-500,000 miles. A well tuned one would do 4 mpg. but gas was 40-50 cents a gal!
GM quit making them in 1965 but, by popular demand, tooled up again to make a bunch more for Canadian Trucking Co.’s. in 1966.

6.2L is 378 cubic inches 700 pounds?
11.5L is 702 cubic inches 1485 pounds?

Lol nice engine
my frame may be distorted with light hitting the pedal.
 

Keith_J

Well-known member
3,120
195
63
Location
Schertz TX
What did you expect for 130 doll hairs? I've heard of Wuhan War Whistles for twice that off of Wish but dang did you dredge low on that price.
 

Keith_J

Well-known member
3,120
195
63
Location
Schertz TX
Wuhan War Whistles are good for one thing, mock up to make certain it will fit. AeroCharger charges more for their mockup kit but it is refunded when you pay the 25 hundred clams for their turbo. Not a bad deal, it's an interesting variable geometry design too.
 

als804

Member
33
6
8
Location
kimcheon, ROK
i assumed my installed turbocharger was toooo small for 6.2 liter diesel on the basis of higher EGT than stock at the same drive condition.
days ago hx35w arrived. today i get my small chinese turbocharger out and let them put on the ground.
i can see evident size difference. i know hx35w is the exact size or a bit lager turbo. in this respect my old turbo's turbine housing is definitely smaller.
that's why the old turbo was doing self-restricting.
i will put hx35w on. i will be back

IMG_0140.jpg
IMG_0145.jpg
IMG_0146.jpg
 
Last edited:
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks