I just picked up a hx40 with a 16cm wastegated housing for a real good deal. It is about a week old and what I was wondering is if there would be any advantage of this turbo over my 35-40 hybrid with a 12cm housing on my 97. It does have a decent amount of fuel going to it(just broke the overdrive output shaft off this weekend ) and I am pushing up to 48 and sometimes 50 lbs. of boost on a hard run. Is the 40 a lot laggier than the hybrid. Thanks,Gary

 

Lag would depend on if it is an OEM 40, or a modified version. If your EGTs are OK, I'd probably go with a 14 housing on the hybrid, IF you can get the boost down more. 48+ is a lot for a 12.

Do you race it quite a bit or sled pull? The 40 has the same shaft as a HX-35. Could run the risk of snaping the shaft, since the 40 has bigger wheels (more mass).

With my setup (plate in stock position), I max out at 40# boost and 1250-1300* (pre-turbo).

 

The HX40 will perform like a dog unless it has been modified to handle lower exhaust pressures and rebalanced to handle the rpm they then can generate on a B series engine. They are OEM for the C series engine which moves a lot more air at lower engine speeds, so without an exhaust turbine and housing designed for the B series they will lag so bad as to not be worth installing, or your idle has to be set up to 1,200 to keep them pumping, and then you will blow your automatic transmission.

A properly tuned HX40 (such as the units Piers makes) will do very well, but only if you also use pulse manifold to keep the exhaust pressure uniform and to let #1 and #4 cylinders breathe better.

If you are running an OEM exhaust manifold, stick with the hybrid you have or some other modified 35 sized unit.

 

I think the turbo is stock but not sure. I think I'm going to try it just to see what it will do. The guy I got it from put it on just a week before he wrecked his truck. It was a 01 making a hair over 480 at the wheels. This is just my work truck and I kind of run it hard every now and then .

 

With a hx-40 I would think 480HP would be pretty hot. HX-40's arent that strong but are a good pu grade for a 350-400HP truck. I personally like J.R's built 35's I have one on my truck and it helped out with egt's and cut some smoke down. he put a $' stule flange on it so I coudl use a hx-40 Down pipe and not have to worrie about a adapter or anything.
DM01

 

you'll make more power at 40psi than at 50psi... if the wastegate on your hybrid is wide open and you're making 50psi, then yes, you need the HX40 and then some...

HX40's are plenty strong

Forrest

 

Is yours a stock 40 forrest and how does it spool?Yes, the hybrid is WFO and the old 12 v is still rolling lots of smoke. I need to do something before I tear up the turbo. Our trucks are close to the same except for timing and transmissions. I think I'm going to try the 40unless I sell it first , the hybrid ought to work real good on my wife's 02. How are the twins coming, about as fast as mine. Thanks,Gary

 

that little 12cm housing is killin' ya...

I have no problem controlling boost w/ my turbo... if I block the wastegate, I make 45psi, but it makes more power at 39psi.

does your HX40 look like it's got the same compressor wheel? you want to make sure you've got a good compressor wheel...

there will be a night and day difference in the spool up time... in the wrong direction! but it should pull way harder up top and EGT's will climb a good deal slower...

mine is a stock HX40. I've been sneezing it daily for ~25k miles and it's still as tight as the day I installed it. I think the HX40 weakness thing is over-hyped... back in the day the ones that fragged were the ones with lightened turbine wheels and Kurt's 12cm jobs (due to overspinning IMHO)

just keep the boost at 40 or less and don't hit it w/ nitrous, and it'll live a long life...

my twins are coming slower than yours I'm sure

Forrest

 

How can I tell if it has the right compressor wheel, ya think it should be the same as the wheel from HHT on the hybrid? This is a new turbo bought threw a diesel shop that hot rods trucks, surely they would know the best wheels to get. I will try to get ahold of them this week and see if they can remember. The little housing probably is hurting it but man it is fun with the quick spoolup on bottom end. I just got to get off before I blow it off.Thanks,Gary

 

there are a lot of different HX40 compressor wheels out there... I would at least get some measurements before you commit... you want at least a 60mm 6 blade wheel.

Forrest

 

I just looked at it and it is a six blade and then you can see six more on back in the housing. I'm taking it to get a pipe to fit it at the truck supply and do what you did,it already has 5 in up near the front. 60mm is the biggest wheel they made for a 40 right? Thanks,Gary

 

sounds about right... not sure what you mean by getting a pipe to fit it... I had a hard time finding a v-band flange for it. ended up buying one from Keith at Diesel Dynamics.

Forrest

 

I was just guessing they have a 4 in. outlet, I was going to a truck shop to get a stub pipe and a 90 to cut up and make the down pipe then go the the 5 in. at the last turn. It looks like 5 in. would be hard to weave up through by the frame and motor. The outlet has kind of a taper to it for a band type clamp it looks like. How did you adjust you're boost on the 40. We have used needle bleed valves on gas motors. Thanks for all the info Forrest.

 

you could make a 5" downpipe no problem... plenty of room...

big truck shop isn't going to have the HX40 rear flange... it's not a standard flare flange like one of the Schiwtzers... there's a company that sells a machined flange for the 6CT Cummins, but it's like $60-80... Keith sold me the flange I used for considerably less!

I've just got an adjustable boost elbow (bleeder valve) to adjust the boost

Forrest

 

Thanks