The stock turbo on my 4BT is an H1C, Assy #3528918, Serial H347462, Type H1C. Exhaust housing is marked 352193 & 16 27 12. Can't tell if it's 12cm or or 16cm or what. Non-wastegated near as I can see.

I will be using this rig for towing and want to upgrade to best turbo, thinking 12cm wastegated or HTT Stage III or Stage IV. Their turbo kits listed are non-wastegate if I read it right, and run from $200 for the III to $285 for IV.

What's best for my use: a non-wastegated Stage III, or Stage IV, or changing to a used wastegated 12cm housing [if I can find one...]? I plan to turn the fuel up some and probably run water/meth inj. and use my stock 3" exhaust.

Thanks for your help guys....

JimmieD

 

The HTT upgrades are different from the 12cm exhaust housing upgrades. The HTT kits upgrade the turbo's compressor side while the 12cm housing upgrades the turbo's exhaust/turbine side. You can get the HTT kits and use them together with the 12cm exhaust housing to make one sweet turbo.

 

Thanks, j/r. I wonder which would be the better upgrade if a guy only chose 1 like either-or? Don't know where to get a 12cm exhaust right off hand. Engine is out now so it's the best time, but can't wait long to get the parts....

 

If you really want to crank the fuel up at some point, I think the HTT kit will help you more. It will give you more boost and cooler boost than the stock compressor wheel/housing and allow you to turn the fuel up more (creating more power overall).

Changing the exhaust housing to a 12cm will make the turbo spool much faster and that's about it. If you turn the fuel way up the 12cm could even become too restrictive for you.

If I had to choose one, I would choose the HTT upgrade. Then just keep your eye out for an old 12cm WG housing (came stock on 2nd gens) for a cheap price and add that on later.

 

THANKS J/R !!! That's EXACTLY what I needed to know! I can't do this all at once due to money issues so a practical step-by-step build is best for me. I can afford the HTT unit, plus a water/meth, and some injectors and exhaust brake and then wait til later if any more is even needed [after pump tweaks]. Also want to get some of the harder stuff done while the engine is out of the truck......

JimmieD

 

Jimmie, look on Ebay for an HY-35. They came stock on the later 2nd gens with automatics. You can usually find them pretty cheap because they are not upgradeable like the HX-35's. Those have a 9cm wastegated housing and are too restrictive on the 5.9's, but they will work awesome on a 4bt.

If you choose to upgrade the H1C, keep it on the small side. Their Stage II should be plenty of air, and you will need a 12 cm housing to get good spoolup.

 

Hmmm....the plot thickens! Off to e-Bay, and thanks Dave!!!

 

Its kind of interesting. I love the 16 CM housing on my 6BT.
This whole converstion is about a 4BT. When the 6 is at 3000 RPM and the 4 is at 3000 rpm, the 4 is pumping a lot less air. Im guessing the 12 CM housing would be really good and possibly like Wannadiesel said maybe the HY with the 9 CM would be good.
This is all speculation. most of us deal with a 6 cylinder but now we are talking 4 cylinder.
Maybe Jimmie will be the 4BT guru. Let us know what you decide and what works.

 

Yes, it is interesting. Too bad I don't have the money and the time for some serious experimentation! Also I'm still diesel challenged and haven't learned too much about theory yet.

A 3.9 4BT with your 5.9 6BT mods in your sig that gave you 329 hp and 948 torque would yield 219 hp and 632 torque, plus some really decent mileage! I'd like to hit somewhere around 175-200 hp, and maybe 500 torque or better for best mileage with some pulling power. I'm putting the Cummins in a 60's Dodge with NV 4500 and Dana 60HD rear and HD suspension for an RV hauler. Should work fine once it's tweaked some? Need to do some of the major work while the engine is out....hopefully.

 

Should do well. I'd run it with just the turbo and pump tweaks and see how it goes before you go spending money on injectors. Frostie's setup (and mine, too) is not tow-friendly. We can make a lot of power for short bursts, but we can't use it to pull a heavy trailer up a 5 mile grade or we'll aluminize the exhaust system from the inside.

The truck sounds like a sweet setup. You should end up with the towing performance of a late 12 valve with slightly better fuel economy. A 4bt cranked up to make the same power as a stock 5.9 is not going to have a lot better fuel economy. It still takes fuel to make power, so your only savings are in mechanical losses and weight reduction.

What gears will you be running?

 

Yea, I'm leaning to the conservative side on mods! I want long haul dependability but with enough power to stay out of my own way. With an older truck, without discs [yet], and with less sophisticated suspension I feel it's best to take it a little slower too.

I'm running 2WD with a 4.1 Dana 60HD, and about 31.5"-32" tires. New steering box, sway bar, stabilizer & springs in front, and a sway bar in rear with coil-over shocks, 3/4T springs and maybe add some leaves. Using an exhaust brake [probably D-Celerator electric] and maybe the Cooling Mist injection system plus pump tweaks, with injectors later. All I need is moderate big block performance out of it and I'll be a happy guy....

 

Lets see some pics if you have them. Sounds cool

 

Thanks hertz! This is a LARGE project for me but I'm doing a photo album as I go. Truck was rear-ended [totalled] so I have to rebuild that, plus some rust issues like cab mounts and all new floors, plus complete suspension swap front and rear, plus the changeover from gas to diesel power of engine, trans, drivetrain etc. etc. but when it's semi-done I'll get pictures up. Probably bit off a little more than I can chew but have some good help on it including right here, so it will happen one way or the other!

JimmieD

 

The gears will help with towing performance, I think that's a good choice for you.

Sounds like a big project. Have you thought of a hauler bed instead of fixing the pickup bed?

 

No, not really, 'cause it would kind of make a mess of things: it's a '67 Dodge Town Wagon, somewhat similar to the old Chevy Carryall or IH Travelall. Ya don't see them every day, but it's a station wagon, or panel truck with windows. Therefore it's bumper tow or no-go! Truck weighs about 4,100 or so empty so a 3.9 4BT should do the towing fairly well with some tweaks....