Engine/Transmission (1994 - 1998) Turbo Pressure...

[MRandall]

I have a 1995 Dodge 2500 Cummins. It has an aftermarket turbo that boosts about 40lbs. What does a completely stock truck around this year boost? Also, is there any potential danger of boosting 40lbs?

 

[CumminsPower98]

I'm not sure for a '95 but my '98 I think was supposed to max out at 23 psi stock. I blew my gasket at about 38 psi while towing in sub-zero temps. I now have the waist gate adjusted to 30 while I'm making my money with the truck to be on the safe side since I run lots of stained high boost. Some people get away with big boost numbers on stock gaskets and bolts and others don't. I put studs back in mine. 35 psi seems to be a good number to live by in general for a stock engine.

 

[CumminsPower98]

I'm not sure for a '95 but my '98 I think was supposed to max out at 23 psi stock. I blew my gasket at about 38 psi while towing in sub-zero temps (247k at the time). I now have the waist gate adjusted to 30 while I'm making my money with the truck to be on the safe side since I run lots of sustained high boost. Some people get away with big boost numbers on stock gaskets and bolts and others don't. I put studs back in mine. 35 psi seems to be a good number to live by in general for a stock engine.

 

[Vaughn MacKenzie]

I have a 1995 Dodge 2500 Cummins. It has an aftermarket turbo that boosts about 40lbs. What does a completely stock truck around this year boost? Also, is there any potential danger of boosting 40lbs?

You are less likely to blow the gasket running 40psi on an bigger turbo than a stock one. Engine timing plays into max boost too. . . the more advanced it is the more likely you'll pop it. You're OK to a max of 15. 5 degrees running that much boost, but bear in mind every time you cranking 40 psi you're flirting with danger.

Another important thing is to not boost it that much until the engine is completely warmed up, otherwise you'll kiss it goodbye in a hurry.

 

[JacobsD]

hmmm, I've seen 41 PSI out of my stock HX35, of course with the wastegate blocked off. Is that abnormal? The truck just has an 8 plate in it. This was on a cold day (about 10* outside) wide open in 5th up hill.

 

[tp0d]

JacobsD: if that little hx35 is moving 41psi, it isnt gonna last too long. about 35psi is the absolute max.

MRandall: If the previous owner installed an aftermarket turbo, I would bet they installed a new headgasket and/or head studs. You can check by removing one of the valve covers, if the bolts in there are almost the size of the interior of the cover, they're probably aftermarket.

Just dont boost it high in the extreme cold, or below 160 engine temp, and you`ll be fine.

-j

 

[PKemp]

If your engine is still in one piece, its not stock and definitely not the original turbo. 8 to 10lbs boost is normal on a 1995 with a 165hp pump and an automatic, 9 to 12 on a 175hp pump an a manual.

Is there any danger of running 40lbs boost? Yes... .

You seriously need to look into what is in this truck before you do anything else. Do you have gauges? Sorry. you must if you can read boost... ... What kind of "egts" are you running loaded and unloaded? Do you have any idea what your timing is set at? Or what injectors you have? We need lots more info.....

 

[JacobsD]

My timing is stock, and my injectors are stock. Haven't had any trouble with mine yet. But if I do, that just means its time for more power

 

[CumminsPower98]

I should note that I set my timing to 16 so I know that had some affect on my HG blowing.

 

[AWray]

18 psi was the max in stock form for a '95 automatic. The manual was similar.

 

[Ahopper]

my 97 with the stock hx-35 and stock head gasket has seen past 35psi. (my guage only goes to 35psi and it keeps going) i can not hold it ther for very long bc my egt start getting a little hot. if the temp outside is colder than 80* i can peg it forever and not see over 1300* egt. i know that i shouldnt boost more than 35psi though so i try not to. on a stock hx-35 its only good to around 32psi i belive and anything after that u are just creating extra heat. someone correct me if im wrong.

 

[Ahopper]

also i have 16. 4* timing.

did u disable your waste gate?

 

[pwerwagn]

If your engine is still in one piece, its not stock and definitely not the original turbo. 8 to 10lbs boost is normal on a 1995 with a 165hp pump and an automatic, 9 to 12 on a 175hp pump an a manual.

They all acutally made about 18psi stock, except the 215 trucks and they made about 21psi stock. roughly.



Boost and headgaskets are a very subjective matter. Ive ran mine as high as 50psi a few times, stock head gasket and bolts, 200K miles, with a 35/40. And thats at 5200' altitude, so that little 35 shaft was a spinnin!!! It wasnt on purpose though, it was an accident.

on a stock hx-35 its only good to around 32psi i belive and anything after that u are just creating extra heat. someone correct me if im wrong.

thats pretty correct, depending on altitude. 32psi out of a 35 is a good rule to live by. It will live a long happy life that way. Any more than that creates so much drive pressure its a waste of time and a waste of turbo life.



Just remember, PSI does not always equal power. There is one truck now making well over 1,000hp at the rear wheels with only 60psi of cool air...



--Jeff