CM871 Turbo on CM2250

[Lonestar10]

boost pressure is resistance to flow the sensor is only a few inches from the intake valves they are the restriction at that point not the turbo. the he561 if you wanted to make stupid horsepower would be better but if your looking for efficiency the he400 is better.

more air = more fuel. the 561 flows more air then what is needed on a 2250-2350 for normal horsepower ranges.

the 561 will be much less efficient when first getting into the throttle as it needs to spool up its bigger impellors.

the only thing that can improve on he400 for 2250-2350 would be impellor design that would focus on requiring less exhaust pressure to spool and create the same boost pressures.

i have a YTS stage 2 he400 its hogged out a bit on the suction side with a different impellor i dont really see a difference in fuel economy but i did have to open the exhaust side up some in the computer so that it would not overboost about 5% was the adjustment to the turbo actuator. which brought it back from making 40psi boost to 32 for my 450HP/1750 rating that walks most of these cats and detroits up hill

[Rawze]

-- Depends on what someone is trying to achieve. - If they want to sacrifice fuel efficiency for better heat flow because your pulling a road train at 60+ tonnes and are averaging 80+% output power for hours on end day after day... The 500 series would be an improvement while the engine is enduring such tortures, but otherwise, a waste of time.


-- If your not sure what your average engine loads are, look in insite at the usage graph and see where the average engine loads sit most of the time. If the average engine load is 45% or less for the lifetime, like most trucks I see .. You will only be spending money and wasting your time and it will serve absolutely no purpose to do such a thing except to drain your wallet.

- The bigger turbo may be able to move more heat thru the enguine, but at a cost of ...

* less overall response.

* provide no advantages for producing any power levels below about 620 HP.

* less fuel efficiency.

-- and if someone is pulling loads that are actually that heavy ... BETTER GEARING always prevail any ways... why someone would want to mod the most expensive drive-line component (the engine itself) is beyond me when it is far cheaper to re-gear the truck for the application.

[Aleeex]

Anyone have a way to get a hold of unilevers?


Or who else is trustworthy in tuning these red things?

I am trying to reach out to YTS to see if I can do something with my turbo. Im at 560k and previous owner replaced the turbo (I got the truck with 439k). Theres no play, its just leaking a little oil. I presume behind the compressor wheel.

I need to get this boost under control asap

[tree98]

Mr hag is your only option, Uni isn't around here anymore.

[Waterloo]

As Tree stated, Uni is retired, doing other things. I spoke with him around a month or so ago, both him and Mommaburt are doing something different.

[Aleeex]

Well I did the best I can to clean things up, I think the bolts behind the compressor wheel are leaking. They have those little washers with rubber inside and I’m guessing they aren’t sealing. Cleaned them up and put some gasket maker on both sides of the little washers and put it all back for now. Those little bolts are m5X.8 if anyone is wondering.

I dont recommend anyone to be doing what I am doing.


Going to be ordering a turbo.. maybe the yts stage 2..

[Rawze]

(09-07-2020 )Aleeex Wrote:  Well I did the best I can to clean things up, I think the bolts behind the compressor wheel are leaking. They have those little washers with rubber inside and I’m guessing they aren’t sealing. Cleaned them up and put some gasket maker on both sides of the little washers and put it all back for now. Those little bolts are m5X.8 if anyone is wondering.

I dont recommend anyone to be doing what I am doing.


Going to be ordering a turbo.. maybe the yts stage 2..

If you removed the impeller ... (first pic) ... unless you precision marked not only the nut install but the exact original impeller position, etc.. AND the exact amount of torque it was held on by ... then, if you don;t get it exactly back in exactly the same position... impeller AND NUT.... then your turbo is now out of balance and it can fly apart at high speeds without any warning whatsoever.

That could be very, very bad and cause you to destroy your entire engine without any warning.


so ... NO... I do not recommend anyone even attempt to remove, loosen, or even adjust on the impeller(s) on a turbocharger on their own.

[Magard]

I did this 871 turbo on a 2250 deal. Not really worth the effort You can pm me about it. I’m always driving so I can’t type much

[Aleeex]

(09-07-2020 )Rawze Wrote:  

(09-07-2020 )Aleeex Wrote:  Well I did the best I can to clean things up, I think the bolts behind the compressor wheel are leaking. They have those little washers with rubber inside and I’m guessing they aren’t sealing. Cleaned them up and put some gasket maker on both sides of the little washers and put it all back for now. Those little bolts are m5X.8 if anyone is wondering.

I dont recommend anyone to be doing what I am doing.


Going to be ordering a turbo.. maybe the yts stage 2..

If you removed the impeller ... (first pic) ... unless you precision marked not only the nut install but the exact original impeller position, etc.. AND the exact amount of torque it was held on by ... then, if you don;t get it exactly back in exactly the same position... impeller AND NUT.... then your turbo is now out of balance and it can fly apart at high speeds without any warning whatsoever.

That could be very, very bad and cause you to destroy your entire engine without any warning.


so ... NO... I do not recommend anyone even attempt to remove, loosen, or even adjust on the impeller(s) on a turbocharger on their own.

Yes, anyone reading this must understand the risk. And shouldn’t do it.