Cummins turbo on 4.0


63'sprint

10+ Year Member

Joined
Oct 1, 2009
Messages
8
Points
3,001
Transmission
Automatic
Any body tried a HY35 Holset on a 4.0L:3gears:
 
i havent heard of it yet. be the first to do it. i run a he351 on a 2.3 and it's good, but definitely a peak power turbo (spools late but runs like a bat outta hell once it's up).

i have always thought it would be an excellent turbo on a mid-size (3-4 liter) motor.

so be the first and tell us about it.
 
If my plans come to fruition, a cummins turbo might find it's way onto the 4.9L in my F-150. Although I think it might be too big. I'm looking for full boost between 1500 and 3500 RPMs (it'll be a tow truck).
 
that would be pretty sick...i have a holset hx35 for my 2.3 turbo build. looking for aout 350rwhp..it shoud do the trick. with that hy35 on a 4.0....i hope your gonna out some money into forged internals because you are gonna need it!
 
Seems like a small engine for a big turbo to me. I doubt you'll get much satisfaction. A diesel has no throttle plate so there is always a good amount of air going through it even when it's not making power. With a 4.0 it doesn't seem like that wheel will be going much at idle or part throttle. Also, I think a diesel like that gets something 50% stoichemetric meaning the turbo might be good for twice the power on a gas motor as it is on a diesel. You probably can't spin it enough--it's probably good for 350hp and you could probably make 220hp with a pretty stock turbo 4.0, realistically. So you have a bunch of turbo that you can't use and it will cost you big on the bottom end. If it's worth doing, it's worth finding a turbo more closely matched. I would find a turbo for a gas motor in the 250hp range and use it.

Just my gut feeling on the issue. Nobody is even going to hear that thing on your 4.0 driving around town so what good is it?
 
I have seen them work pretty good on the "tiny" 2.3's Will. Granted they usually put down in excess of 400 HP, but it was only 2.3 liters pushing air through it. The 2.3s are good for it, but 400 HP might be a little much to expect a 4.0 to put up with on a routine basis. That and the trannies that attach to a 4.0 aren't exactly designed for that much power.
 
Not looking to go crazy, but it seemed the 2.3 turbos would be on the small side. If a 2.3 turbo is making full boost at 2000 RPM than anything above that rpm range is just a added exhaust restriction with no gain. Also there are enough different options on compressor and exhaust housing sizes that if it doesn't work as well as antisipated I think I can tune around it. Looking at forged pistons and good rod bolts, only plan on running 8-12psi boost with a fairly hefty aftercooler. Thanks for the input,any suggestions are appreciated... should I be worried about the rods
 
My 2.3 with a stock 2.3 turbo (Garrett T3 .48 A/R) Doesn't build full boost till about 2800 RPM. At 18 PSI it makes for a frighteningly fast Ranger.

My guess is that you'd have full boost at about 1800 RPM with this turbo on a 4.0. 4 liters don't really spin much faster than 4500 due to stroke length and camshaft so I'm not sure you'll need a turbo big enough for 5500 RPM.

I've only heard of a few people that have put 10+ PSI through a 4.0, but I don't remember hearing anything about failing rods. The cast pistons and lack of tunability of EEC-IV are the biggest problems with forced inducted 4.0s.
 
with my he351 at 28psi i did 0-60-0 in just over 1 city block :icon_surprised:
 
The HY35 has a small 9cm housing and shouldn't have any problem spooling on a 4.0 if anything you may want to go up to a 12cm housing. I've got a WH1C (older cousin of the HX35 and HY35) with a 21cm housing I'm going to be using on my Dakota.
 
Lets put some things in perspective:

8 blade hx35 (1995-1998 cummins manual pickups) - 52 lb/min - 500whp
7 blade hx35 (1999-2002 cummins manual pickups) - 60 lb/min - 600whp
hy35 (uses the same compressor as above mated to a different turbine wheel and housing)
8 blade hx40 - 60lb/min - 600whp
7 and 6 blade hx40 - 69lb/min
HX52 (Volvo Semi) - 88lb/min

I agree, it seems that the turbo is quite big for the application considering the compressor map for the smallest holset is capable of 500whp. On the other hand, holsets are known for being quick spooling in relation to other similar sized turbos. I guess someone has to be the first to try it...I wouldnt expect great results though.
 
Last edited:
holset maps are hard to come by. Most diesel turbos have smallish turbine housings for fast spool up as a diesel engine is geared torwards low rpm torque rather than max hp. I have a small .48 ar T3 on my 4.0 and its still going after 2 years now. Currentlyt still driving it daily.
 
You must log in or register to reply here.

Sponsored Ad

TRS Events & Gatherings

Where We Were in 2025 – The Ranger Station

Latest posts

Featured Rangers

Want to see your truck here? Share your photos and details in the forum.

TRS Latest Video

Official TRS Merchandise

Follow TRS On Instagram

Latest Album Photos

IMG_4690.JPEG
IMG_4689.JPEG
IMG_4688.JPEG
IMG_4679.JPEG
IMG_4656.JPEG
IMG_4625.JPEG
IMG_4562.JPEG
IMG_4561.JPEG
IMG_4560.JPEG
IMG_4559.JPEG
IMG_4558.JPEG
IMG_4445.JPEG

Product Suggestions

Back
Top