• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Holset HX40 spooling

6.5L

6.5L

Old Iron Runner
Messages
1,177
Reaction score
433
Location
Northwest Wyoming
SO I picked up a Holset HX40 for dirt cheap, never spin. Got a 60mm wheel and 18cm housing. Was gonna make a 35/40 hybrid but was wondering if I ran it straight out, how bad the lag would be? My trucks is fairly decent at spooling a 12cm but any bigger and I think it would be a turd
 
Holset & CKO HX40W 18 cm2 spool without any issue or lag as compared to Garrett and Mitsu with same sized turbines many performance sites rave about this faster spooling of the Holset/CKO that being said others and I run 18 cm2 w/4L80e w/o issues because of the torque converter multiplication loading the drivetrain at stall speed a manual does not do that so you may have a problem with the 18 cm2 unless you are running the granny low NV4500. The HX40w 18 cm2 is perhaps the best mod I've done so far.

Dodge Ram Cummins ran Holset 18 cm2 turbines for a few years w/autos with mixed results and these days the Super 40 HX w 16/18 cm2 are popular with lots of performance minded types.

While it's claimed Holset and CKO really can't be compared the turbine housings are the same "Holset" design however with varied blade count, pitch etc. Keep in mind there are many Holset/CKO HX40w models w/fitments from the 5.9 ltr to 8.3 ltr. The Holset Super 40 HX w is commonly 16 cm2 w/18 cm2 being an option the comparable CKO Super Drag HX40w (not Hx40w ii) is 4" in/out w/18 cm2 turbine.

SEE: http://www.thetruckstop.us/forum/threads/holset-hx40w-non-gated-hx40-super-hx40.43524/
 
I know FellowTraveler did a lot of research on it and it was his results that made me go with the full HX40 vs the HX40wii. The deciding factors for me were that I was an auto and I had a computer controlled pump, so the tune could help get it spooling down low.

The only thing I have to compare mine to is the GM8 unfortunately. If I stomp on mine from a dead stop it'll be a smokey mess for a bit then we'll go, but if I drive it like a sane person and get into it after about 15 feet of moving then we're all good and off and away. In fact, I should try to document that distance for sure, that would be helpful. I know it doesn't take long.

I know you like experimenting 6.5L, so I think it would be really interesting to see what it runs like on your truck. Then you could make your 35/40 hybrid and report back on that. Of course I'm not wishing any extra work on you....it would just be fun to read how it works.

Either way I can't wait to see what you do!
 
n8in8or said:
The only thing I have to compare mine to is the GM8 unfortunately. If I stomp on mine from a dead stop it'll be a smokey mess for a bit then we'll go, but if I drive it like a sane person and get into it after about 15 feet of moving then we're all good and off and away. In fact, I should try to document that distance for sure, that would be helpful. I know it doesn't take long.
Click to expand...
Test after the timing is correct and TDCO is to your liking. I suspect down low any delay in spool is until torque converter multiplication is max and stall speed is reached.

From a standstill my Burb justs leaps forward instantly bellowing a cloud of black smoke that dissipates shortly thereafter. From a roll it does the same thing the Burb is much faster, smoother and IAT, EGT's cooler & ECT are normal even beating on it. However I'll need a new IP soon as I have a slight pump wear related miss.
 
FellowTraveler said:
Test after the timing is correct and TDCO is to your liking. I suspect down low any delay in spool is until torque converter multiplication is max and stall speed is reached.

From a standstill my Burb justs leaps forward instantly bellowing a cloud of black smoke that dissipates shortly thereafter. From a roll it does the same thing the Burb is much faster, smoother and IAT, EGT's cooler & ECT are normal even beating on it. However I'll need a new IP soon as I have a slight pump wear related miss.
Click to expand...
Good points. I should have noted that.
 
I was toying around with the idea of machining the 12cm HX35 housing to accept the turbine wheel out of the 40 since it flows better. Then all I would really have to do is swap turbine housings and would have kind of a unique hybrid. Might be worth a shot. I got the 6.34 low gear. I know somebody asked. I think it would be fun. I know a lot of people recommend the larger turbine housing, but for me....I really want to try this.
 
6.5L said:
I was toying around with the idea of machining the 12cm HX35 housing to accept the turbine wheel out of the 40 since it flows better. Then all I would really have to do is swap turbine housings and would have kind of a unique hybrid. Might be worth a shot. I got the 6.34 low gear. I know somebody asked. I think it would be fun. I know a lot of people recommend the larger turbine housing, but for me....I really want to try this.
Click to expand...
I think that sounds cool for your setup (the little I know about turbos anyway). Plus if you don't like it, I don't think it's too hard to find a replacement 12cm housing, is it?
 
Sounds like a neat plan.

Just to be curious, does the HX40 have the same outlet flange as your HX35? If so, then it's easy to try as-is since you wouldn't need a new adapter made. If it isn't the same, then that's one more reason to just go to the 35/40 hybrid rather than doing 2 separate modifications just for experimentation's sake.
 
I'm not sure. They look really similar as far as bolt pattern but I don't know. I measured it, and the turbo flange is T3, so thats one less thing. But I dont feel huge on wanting to fabricate a downpipe. I hope I can just swap back plates and be done.
 
The HX40 has a larger version of the flange on the HX35. It looks the same, but its much larger. I would be interested to see how the HX40 does if you just bolt it on. Don't change anything else.
 
I'm running a 18 cm housing with the hx40 10 blade turbine combined with the 54 mm hx35 compressor. The lags not too bad,will light around 1800-2000 and makes 20-25 psi . If yours is a 12 blade ,it might spool slightly quicker .
 
I would try it as is.

I was thinking of machining out a 12cm housing too but was told it wouldn't make too much difference, IIRC.

Are you sure its a 60mm? I didn't think they came 8 blade 60mm?
 
I just measured it with a caliper yesterday. Definitely a 60mm inducer. And I was told it would help if machining a 12cm housing to accept the HX40 turbine wheel but it just wouldnt flow as well at higher RPM but would flow really well at lower RPM.
 
You must log in or register to reply here.
Back
Top