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Discussion Starter #1
My 4BT does not have motor tags (so no clue about 105 or 120hp) but it does have tags on the Holset H1C the assembly number is 3525699 which after researching shows it has a 46cm intake and 16cm exhaust. I have a couple questions about upgrades if anyone has time to weigh in.

Goals: 150ish hp

I was reading the hy35 sticky and I saw where lots of folks upgrade to a 12cm exhaust housing for the H1C which seems viable
After talking to Gillett Diesel they instead recommended changing my INtake from 46 to a 50 or even 52cm and retaining the 16cm exhaust. Their point being that I could always upgrade exhaust side later. (all of these parts would bolt right up meaning staying at 2.5" piping and possibly making intercooling harder at a later date [which would use 3"])

I'm kind of overwhelmed with which direction to go.... I'm still considering a HY35 as well but know that I will have to change more plumbing if I go that route. As I stated I'm really only wanting to chase about 150 hp in a 5,000lb pickup truck (zf-5 transmission)

Can anyone who is much smarter than poor me weigh in with advice?

Sincerely,
Brandon
 

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Don't go with an hy35.

-vr4oaks
 

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Oversizing the compressor side won't help at all. You need a smaller and more efficient turbine. Which is easiest to find in a better sized turbo. The 46mm compressor is plenty big enough.
 

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Discussion Starter #5
so would retaining the stock 46cm intake compressor and replacing the 16cm exhaust with a 12 cm be my best bet? I was told that a 9cm housing didn't exist except for wastegated
 

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Discussion Starter #6
I've been real happy with my super hx 30 lots of good low end power and decent top end
I have heard wonderful things about this turbo... I've read the moonshine thread and seen how to set it up. My question would be if everything is stock right now what would it take to adjust fueling levels in order to use that much turbo (Boost/Power)?

IE: does the stock ve pump strong enough? fuel screw adjustments? etc?
 

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is this why folks are raving about the super hx30?
Yes. Plus more modern turbos have better turbine blade shapes which make them more efficient. A more efficient turbo boosts sooner, produces more boost from the same drive pressure or less drive pressure for the same boost.

The HE221 is another excellent sized turbo.
 

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Discussion Starter #10
Do we have input on how a he221 or super hx30 might compare to a hx35 with a 14 or 9cm housing?

So many folks with different thoughts of what to use lol
 

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so would retaining the stock 46cm intake compressor and replacing the 16cm exhaust with a 12 cm be my best bet? I was told that a 9cm housing didn't exist except for wastegated
You might make a decent sort of a turbo with an 8cm housing - I think there is a company that makes them.

Do we have input on how a he221 or super hx30 might compare to a hx35 with a 14 or 9cm housing?

So many folks with different thoughts of what to use lol
Hy/Hx 35 don't work well at all.
 

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Do we have input on how a he221 or super hx30 might compare to a hx35 with a 14 or 9cm housing?

So many folks with different thoughts of what to use lol
I started with a HX35 with a 12 cm it was hot smokey and gutless then i put a 8cm housing on it and it was hotter still very smokey on the bottom/mid and a bit more responsive went to the HE221 and it was smokless LOTS more usable power and EGT's well within the safe range!The 221 was the single best thing i have done to my 4BT it makes good boost below the rpm's you would ever want to run it at under a good load i can see 20 lbs at 1500 rpm I have run mine from sea level to 8,000' with no issues makes the most of the 4bt's strong points>
 

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Super HX30w all the way man!! I saw 37psi with stock wastegate settings the other day on the highway, up a grade, in 4th gear.
 

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Unless you're really strapped for cash don't waste your time and money on a H1C, Been there, done that. Super HX30 or HE221. The 221 will need an adapter to fit on your exhaust manifold (T3 to T2/T25) or T2 manifolds are available. I choose a the 221 and have no regrets. Just finished a trip that included going over Wold Creek pass (10500') in Colorado with a combined weight of around 8000lbs, the 221 didn't smoke at all, performed like it was at sea level.
 

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Discussion Starter #16
I haven't done anything to my motor... do I need to change fuel plate? turn screws? etc before I fire this motor off if I pick either a super hx30 or he221? I will be doing all that stuff and more over time trying to get to 150ish hp but can these turbos run happily on a stock motor?
 

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When i had my VE IP calibrated it was returned to the factory 105HP settings and the motor ran fine with the HE221 and was much more responsive at low rpm's.All it took to "wake it up" was to adjust the AFC spring/pin and add full power fuel to bring it to the 175HP range>
 

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A guy does make a 6cm and 9cm housing for the h1c if you are dead set on it.
The one thing that would concern me (would take some maths to check) is blade speeds vs air speeds. There is an ideal speed ratio between the exhaust coming into the turbine wheel and the speed of the turbine wheel tips. If you go too much faster or slower the efficiency starts to suck. I'm pretty sure this is why my fuel economy took a ~10% hit when I hybridised one of my turbos a few years back. I suspect the blade speed ratios were wrong and while I didn't measure turbine drive pressure (I lost the gauge for a while) I suspect it would have been comparatively high.

So you need to carefully consider the operating points of the engine, the rpm you need on the compressor and see what size turbine housing is required to get the right gas speed at the turbine tips. It may be to get a good result you need to change the turbine wheel diameter as well as the turbine housing to match the compressor.

The great thing about stock turbochargers is this hard work has already been done for you by the turbo manufacturer.
 
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