Engine/Transmission (1998.5 - 2002) Hx 40 Question

[csevers]

Is the hx40 that some people upgrade to, normally found on an ISC and if so is it a direct bolt up to the exhaust manifold. I can see that the out let is different and have heard of the need for different down pipe. The reason I am asking is that I think have acess to a good used hx40 turbo for $300. 00 that I could use some day way down the road, I have direct mount pacbrake now so I would not change for some time.



Thanks for any info provided

Craig

 

[BFC]

Yep that's it. Stock HX-40 have tendency to blow up on out trucks. I'd buy that used one and send it to Piers and let him go throught it an do some of his magic. Only exhaust brake compatible with 40 are remote mounted ones.



Glenn

 

[csevers]

O K

What are the bennifits of an hx40 over the hx35 on our trucks if piesrified?





Thanks

Craig

 

[Diesel Freak]

A Piersified HX40 is more reliable and spools slightly faster than an OEM holset HX40



A HX40 can move 33% more air than a HX35 when both turbos are making 30 psi of boost.



a HX35 goes off the map at . 375 Kg/sec at 30 psi of boost

a HX40 goes off the map at . 5 Kg/sec at 30 psi of boost



The HX40 has a physicly larger turbine that flows more, and it also has a 4" band clamp outlet on the housing for a true 4" downpipe.

 

[Steve Campbell]

Question....Diesel Freak

Myself... . being "turbo Illiterate", I do not understand... .



a HX35 goes off the map at . 375 Kg/sec at 30 psi of boost

a HX40 goes off the map at . 5 Kg/sec at 30 psi of boost





Are these numbers the same irregardless of exhaust housing?

 

[Diesel Freak]

Re: Question....Diesel Freak

Originally posted by Steve Campbell

Are these numbers the same irregardless of exhaust housing?

Yes, they represent the mass flow rate of air the respective turbo is capable of moving at 30 psi of boost.



EDIT: the "map" I used is off the Holset Data Sheets... the maps are incomplete to say the least, but they give a rough idea of what the turbos are capable of when you are comparing Holset HX series turbos.

 

[Steve Campbell]

@290 RWHP.....

is the... . a HX35 goes off the map at . 375 Kg/sec at 30 psi of boost ..... at the edge of the map?

 

[Diesel Freak]

csevers

the HX40 has two different flanges where it bolts to the exhaust manifold... . make sure the one you have will fit.

 

[Diesel Freak]

Re: @290 RWHP.....

Originally posted by Steve Campbell

is the... . a HX35 goes off the map at . 375 Kg/sec at 30 psi of boost ..... at the edge of the map?

yes... it is the furthest to the right you can go on the datasheet.



one more thing.



Both turbos can make 45 PSI of boost, but the HX35 can only flow . 275 KG/sec at that pressure where the HX40 can flow . 4KG/sec... ... which is one of the reasons the HX40 works better at Higher rpms... . it just does not have to work as hard as the HX35 does to move the same ammount of air.



forgot one thing... the boost pressures I am stating are at the turbo discharge... not the intake manifold.

 

[Steve Campbell]

Let me get this straight....

"... the boost pressures I am stating are at the turbo discharge... "



So anything above 30 psi drive pressure puts the HX35 "off the map"????



I posted in a diff thread that at 20 psi/boost on my stock HX35/12 I have 30psi drive pressure. At 30 psi/boost I have 45 lbs drive pressure. We are talking inefficency here???

 

[Diesel Freak]

Re: Let me get this straight....

Originally posted by Steve Campbell

"... the boost pressures I am stating are at the turbo discharge... "



So anything above 30 psi drive pressure puts the HX35 "off the map"????

not quite.



on a stock ETH the wastgate is set to limit boost at the turbo discharge to 26 psi. This comes to about 20 psi at the manifold... if you want 30 psi at the manifold... the turbo has to crank out closer to 38 psi at it's discharge



I have the data sheets here if you want to take a look at them. Hopefully they will help clear up some of your questions.

 

[KLockliear]

Be careful with that. There are 20 different part numbers for HX-40's in the Holset catalog. Some have different size exhaust housings, some have different compressor housings, others have different compressor wheels which have different maps. Most are more prone to blow up than 1 or 2 specific part numbers in the application at hand.



Not all have a wastegate actuator that will fit the truck due to clearance issues with the oil filter.

 

[csevers]

maybe I will forget about it

I don't have to have this turbo it just so happens it got taken off a running unit do to someones missjudgement nothing wrong with it and I remembered hearing on the tdr that an hx40 was used and I figured that maybe I could get a cheap "deal" out of it by paying the core charge and putting it on my truck probably a bad idea from the start but ya gotta look for the deals when you can. I guess I will let it go back for core and wait for the right deal on the right turbo when I need one later.



Thanks for the info



Craig

 

[BigYellowIron]

How much HP will a hx 40 support at 40 psi of boost. I don't care about towing just short bursts not over 15 seconds.



Adam

 

[jwilliams3]

Adam,

At 40PSI of boost a Piers HX40 is probably supporting about 500-530hp.



--Justin

 

[C. Harlan]

GO FOR IT!!!! I LOVE MY PIERSIFIED HX40!!! I pulled a fully loaded 3 horse slant up a 6% grade, 2 miles long, with cruise at 78 MPH. Only got up to 1000° post turbo(See Siggy for mods). I think the HX40 is the BEST investment I have made for this truck! Just make sure you go with an AFE for the cleaner, as it flows more air than a BHAF... Plus it sounds better. . that 40 sounds like a jet turbine, and when you spool it up from 20-43 psi, it sounds like a siren! Thats how people know they are about to get killed racing!:-laf :-laf . . Just my $. 02 worth! PM me if you have any questions about the HX40.





-Chris-