[jeep cummins]

I have a 4bt with a ppump in an old 50s dodge that has one ton running gear, I'm currently running with a super hx30w. I have a hx35w that I was planning on running as the atmospheric turbo but im wondering if it would end up being too small. Its a 14cm housing with a 56mm wheel. What size compressor/exducer should I be looking for if the hx35 isn't up to snuff? I assume the hx40 is too large so maybe a hybrid hx35 with a 60-62mm compressor or should I be looking at something completely different?

Truck weighs 5k and it will just be a daily driver not towing or running up and down mountains regularly. I'm not looking for the most hp ever just want to make sure I'm not sizing the turbos so they complement each other before I go through all of the work to mount them and do the plumbing.

 

[char1355]

Well, the ideal setup is generally the HX30W 44mm with the HX35W with the 14cm turbine housing. The Super 30 should do OK with the HX35W. Any twin system is a mater of fine tuning to get the balance just where you want it. An HX40W is not too large but is normally more for guys going all out in the performance area. The preferred unit is the Super HX40W which has a billet 7 blade compressor wheel and a special turbine wheel and a 16cm housing. There are lots of Super 40 turbos out there but few if any are the true super model. I would recommend having twin boost gauges to monitor what the 2 turbos are doing. Another gauge to consider would be a back pressure gauge. How much power are you planning on? A P pump 4bt with a Super 30 can do around 225 HP with stock 5x.010 injectors. You'd want a #10 torque plate in the injection pump and set the pump timing advance to around 16 deg. With twins, you will need to change injectors to 5x.012 which can take you past 300 HP. The factory 250 HP 4bt used those. Are you running a manual or automatic transmission? A stock manual transmission clutch will not hold the torque of a 300 HP 4b Member Eggman can advise you on that one. He's on his 3rd transmission to get to the right size clutch. Also, any boost above 40 PSI will likely need the head O ringed. Stock gasket can only hold so much. Hope you have a good intercooler. Some cheaper units won't hold 40 PSI or more.

 

[jeep cummins]

Thanks for the reply Charles.

Which super 40 wheel sizes should I be looking for? There's a decent of info about 40/44 hx30s but not much on sizing with a super.

I'm planning on having both boost gauges as well as back pressure hooked up for awhile while tuning. I just want to make sure everything will be complimentary to the other upgrades before tuning and chasing my tail.

I don't really have a planned power number just want it to be reliable/non smoky once dialed figure something around 3-350 but if its 275 I'm not going to lose any sleep.

I already have a 10 plate and timing is set at 15.5 and I have 5x12s.

Its mated to a nv4500 with a np205 and it has a 13 inch 500hp clutch. Dont really want to dual disk it id probably turn down the power before doing that.

Don't really want to oring the head either but I can if I'm blowing head gaskets all the time. My intercooler is custom inordinate to fit where it does. Its roughly 2 x 3 x 2.5 thick. Can't really get much bigger without drastically cutting sheetmetal. Its already going to be a challenge to get both turbos piping and an adequate air filter in the space that I have.

 

[char1355]

OK. The Super HX40W has a 60x86 billet compressor wheel with 7 blades. Wheels came in 8, 7, and 6 blades but the Super is a 7. There are also 7 blade models with cast wheels. On the turbine side it has a 76x64 10 blade turbine wheel in a 16cm2 housing. The 10 blade is unique to the Super. Standard models are the same size but 12 blades. I believe the part number for that turbo is 4033666H or maybe 4044662D. The genuine item is not cheap. Around $1500-1800. Not positive on the turbine housing flange, but it may have come in T3 or T4. Another thing is the HX40W is not small and requires a 4" exhaust. It's a big puppy. On the compressor outlet elbows, they come in sizes of 3"-4". The 4" would be ideal since the intake on the Super 30 is 4". That same elbow will also fit the HX35W. It is part 3884977. Sounds like your other equipment is in proper order. You'll have to figure out which exhaust manifold to use. Space on a 4bt is kind of cramped. If hood clearance isn't a problem, one of the top mounted manifolds would be better. Will have to work out bracing to support the primary turbo. Oh, and don't forget you'll need a big air filter.

 

[jeep cummins]

Thanks for all the information Charles, greatly appreciated. I'll update the thread when I have a few miles on the truck.

 

[Thegreengoblin]

so your hx30 super and hx35 will "work", but it's not exactly the best set of turbos to be combined. They are too closely sized. Your not going to get the advantage of the fast spooling small turbo as the hx30 super sacrifices spool up speed to gain higher hp. Id get a hx30 40 or 44 and run that with your hx35. You have a good hx35, hx30's are cheap.
I'm running a hx30 44 and hx35 12cm, runs great, nice fat power band off idle to 3k and hit's 40 psi.

 

[eggman918]

IMO early boost trumps later bigger boost, my 42mm 30 and wh1c will be making good boost well before it's useful so even at 1,300-1,400 rpm when loaded I will see over 20psi allowing me to cleanly fuel at a pretty high level and a couple of hundred RPM of useable early really helps seeing as the B series only has about a 500 RPM spread of "happy" revs. so a 20% increase in useful power band does make a big difference...$.02.

 

[jeep cummins]

I have the stock hx30 ill have to measure it and see what size it is. I'm still not convinced ill be able to fit twins its really tight under the hood being that its really only 'underhood' space and don't have any room above the fenders.

This is the truck im trying to shoehorn them into.

 

[edpruss]

How is your running gear going to stand up to the increase in torque? Have you gotten the higher diff. ratios available for those axles?
Ed in CO

 

[Dougal]

HX30 Super isn't any different in a compound situation to a 44mm HX30 as you don't need the extra air-flow or surge capacity. It's also physically bigger so you may run out of room.

HX35-12cm works for compounding, 14cm is better, HX40-16 is better again. I mapped it all out here:

Possible 500hp 4BTT Power Recipie.

So Fnnissan asked me which turbos would be needed to get 500hp from a 4BT. He piqued my interest so I ran some calcs. First a disclaimer. I am working on severely limited data and don't even have a 4BT to test this on. But I'm confident my numbers will give results within 10% or so. I have...

www.4btswaps.com

The HX40 I used for the calcs was the 64/76mm turbine with 16cm housing.
The HX35 I used was a 60/70mm turbine with 12cm housing.

But. Start with your power goals and work backwards. Compounds are always an excellent idea if you can fit them. Especially if you drive at altitude.

 

[char1355]

The HX30W standard models came in 40mm, 42mm, and 44mm inducer. The Super is a 46mm. All came with a 6cm2 turbine housing with the one exception being the 42mm which also came in a 12cm2 version. That one was used on an industrial 6bt and is not a good match for the 4bt. The 40mm was used on industrial engines and we rarely see it used. The 42mm came on the P pump 4bt as well as some industrial engines. The 44mm is an import only item which is probably on some of the later built 4bt's. The 46mm Super came on a Deutz 6 cylinder and is also an import only item. Most guys tend to use the 44mm mainly due to availability and cost. Same goes for the 46mm Super. The 40mm and 42mm units can be had but since they were mainly built in the USA or UK they tend to be more expensive. On the primary side, most have used the HX35W with the 12cm2 turbine simply because its easy to find and used ones are cheap. The 14cm2 version is kind of scarce and buying that turbine housing to change one is kind of pricey. That housing can be had in both gated and non gated. Not sure that a gated housing is necessary on a 4bt primary. Unless you're running some extreme power level I doubt the primary would ever reach 20 PSI. By the time the exhaust gases have gone through the smaller secondary they have lost some of their energy. That's one of the reasons for having good insulation on the exhaust manifold and turbine housings. That heat is the energy that spools the turbos.

 

[jeep cummins]

How is your running gear going to stand up to the increase in torque? Have you gotten the higher diff. ratios available for those axles?
Ed in CO

Its running a Dana 60/10.5 with 4.10s and 37s. Should be fine, its what is in every 6bt pickup ever produced.

That picture isn't my actual truck but same truck, didn't change them at all besides a fre creature comfort options from 46-68, buts its a blue with black fender wm300.

Thanks for the input everyone. I'll measure my old hx30 this weekend, it going to need a rebuild kit at a minimum, it had a decent about of shaft play and it had some broke off bolts in the exhaust housing, one of the reasons I got the super. From Charles I'm assuming its the 42 but ill double check. It looks like turbo lab has hx40 60/83 wheel/compressor and bearing housing and that would work for the hx35 I have.

I guess I'll use my super hx30/hx35, is the compressor housing any larger on the 40 with the bigger wheel? I was hoping to do some mock up next week when I'm home to see if I can even fit twins or I'm just getting my hopes up to be dashed.

 

[Thegreengoblin]

HX30 Super isn't any different in a compound situation to a 44mm HX30 as you don't need the extra air-flow or surge capacity. It's also physically bigger so you may run out of room.

super has a bigger comp wheel does it not? It will spool a tad slower as as eggman said, earlier spool the better with a 4bt, im in agreement with him.
Super will work but you have to hx35 or 40 to do the mid to top end work, 30 doesn't need to do that. Might as well get the small 30 and spool right in the basement if your gonna bother with compounds, if not just run the super as a single as it was intended. My 2c

 

[Dougal]

super has a bigger comp wheel does it not? It will spool a tad slower as as eggman said, earlier spool the better with a 4bt, im in agreement with him.
Super will work but you have to hx35 or 40 to do the mid to top end work, 30 doesn't need to do that. Might as well get the small 30 and spool right in the basement if your gonna bother with compounds, if not just run the super as a single as it was intended. My 2c

I think lag between the two will be minimal. Super has a bigger wheel with more inertia, but bigger wheels also produce boost at lower turbo rpm (it's all about blade tip speed).

I'm in full agreement with the HX30 44 being the pick for compounds and Super being the pick for a grunty single. I also like to point out the Super can do a lot more boost than most people have them set for. 250hp will not be a problem, 300hp will be a challenge

250hp needs 30psi boost: 250hp 4BT Recipie

300hp needs ~36psi boost but it's hard to find the perfect turbo. I haven't fully mapped out the Super at this point: Calculating 300hp using cc/ 1000 shots and turbo sizing
BW EFR6258 was looking promising but the wheels were falling off those.

 

[char1355]

Dougal, If 250 HP only needs 30 PSI then the 42mm and 44mm can readily do that. May be a little less stressful on the 46mm Super. To do 250 HP will need one size up in injectors. The 250 HP 4bt used 5x.012. You can get that size for both VE or P pumps. 36 PSI for 300 HP ain't going to happen on a single. Above 250 HP you need twins.

Jeep, not all Cummins 6bts came with the Dana 60 4.10. They also came with a 3.55 and the early automatics had a Dana 61 with a 3.07 ratio. You ask about the size of the HX40 vs the HX35. Holset shows the dimensions for the HX35 as L224mm x W250mm x H169mm. Weight 9-11 Kg. The HX40 dimensions are L231mm x W250mm x H169mm. Weight 11-14 Kg. Main issue would be the exhaust. The HX35W will generally use a 3" where the HX40W requires a 4". Both turbos have 4" air intake and both use the same compressor outlet elbows ranging in size from 3" to 4". What exhaust manifold are you working with. If you have adequate hood clearance, you can put the small turbo up top and the big one down low. There are 2 top manifolds that can work. One is 3901635 which puts the top turbo in the center and the other is 4934697 which puts the small turbo to the front. See photos below. Also, have to keep an eye on the oil filter in relation to the big turbo intake. You can get a cobra head intake that can help some on clearance issues. And, on the HX40W there is a cobra head exhaust Cummins part 3927862.

 

[SUBRUTUS]

Dougal, If 250 HP only needs 30 PSI then the 42mm and 44mm can readily do that. May be a little less stressful on the 46mm Super. To do 250 HP will need one size up in injectors. The 250 HP 4bt used 5x.012. You can get that size for both VE or P pumps. 36 PSI for 300 HP ain't going to happen on a single. Above 250 HP you need twins.

Jeep, not all Cummins 6bts came with the Dana 60 4.10. They also came with a 3.55 and the early automatics had a Dana 61 with a 3.07 ratio. You ask about the size of the HX40 vs the HX35. Holset shows the dimensions for the HX35 as L224mm x W250mm x H169mm. Weight 9-11 Kg. The HX40 dimensions are L231mm x W250mm x H169mm. Weight 11-14 Kg. Main issue would be the exhaust. The HX35W will generally use a 3" where the HX40W requires a 4". Both turbos have 4" air intake and both use the same compressor outlet elbows ranging in size from 3" to 4". What exhaust manifold are you working with. If you have adequate hood clearance, you can put the small turbo up top and the big one down low. There are 2 top manifolds that can work. One is 3901635 which puts the top turbo in the center and the other is 4934697 which puts the small turbo to the front. See photos below. Also, have to keep an eye on the oil filter in relation to the big turbo intake. You can get a cobra head intake that can help some on clearance issues. And, on the HX40W there is a cobra head exhaust Cummins part 3927862.

Turbo Labs makes the HX40w w/3" exhaust out...

 

[dieseldude]

I have the stock hx30 ill have to measure it and see what size it is. I'm still not convinced ill be able to fit twins its really tight under the hood being that its really only 'underhood' space and don't have any room above the fenders.

This is the truck im trying to shoehorn them into. View attachment 134636

You have room but every thing is tight.

 

[Dougal]

Dougal, If 250 HP only needs 30 PSI then the 42mm and 44mm can readily do that. May be a little less stressful on the 46mm Super. To do 250 HP will need one size up in injectors. The 250 HP 4bt used 5x.012. You can get that size for both VE or P pumps. 36 PSI for 300 HP ain't going to happen on a single. Above 250 HP you need twins.

Check this out, I ran some numbers: 300hp Single Power Recipe

HX30 Super will be tapped out at ~285hp. We need either more fuel, better VE or better efficiency to make 300hp.
A P pump and bigger turbo would eat it, but trying to find the right turbo is difficult.

 

[GLTHFJ60]

Super HX30 with HE351CW upgraded with an HX40 turbine wheel has been an absolute ripper in my truck. Love how quickly the HE spools up. Tons more power over the SuperHX30 as a single. Have a restriction in the way I fabricated my interstage charge pipe which I've yet to correct which I think is limiting my top end, but it's clean with 5x.012 injectors on my VE pump 4BT.

Still need to dyno it.

HE351cw turbine upgrade:

HE351 Exhaust Housing Upgrade - Turbo Lab

HE341 HE351 Exhaust Housing Upgrade Details: HE351 HE351CW HE341 Turbine Housing Upgrade 67mm x 76mm HX40 Turbine Wheel + Turbine Housing Reduce EGTs Lower Drive Pressure Increase Spool Up (because of 76mm exducer of turbine) Brand New Turbine Housing Direct Replacement of HE341 HE351 HE351...

turbolabofamerica.com

 

[Thegreengoblin]

Super HX30 with HE351CW upgraded with an HX40 turbine wheel has been an absolute ripper in my truck. Love how quickly the HE spools up. Tons more power over the SuperHX30 as a single. Have a restriction in the way I fabricated my interstage charge pipe which I've yet to correct which I think is limiting my top end, but it's clean with 5x.012 injectors on my VE pump 4BT.

Still need to dyno it.

HE351cw turbine upgrade:

HE351 Exhaust Housing Upgrade - Turbo Lab

HE341 HE351 Exhaust Housing Upgrade Details: HE351 HE351CW HE341 Turbine Housing Upgrade 67mm x 76mm HX40 Turbine Wheel + Turbine Housing Reduce EGTs Lower Drive Pressure Increase Spool Up (because of 76mm exducer of turbine) Brand New Turbine Housing Direct Replacement of HE341 HE351 HE351...

turbolabofamerica.com

It would be awesome to see a hx30 compound set up dyno'd. No one has dyno'd hx30 over hx35 or any other turbo and posted results. I've got hx30 over hx35 and curious about actual whp and wtq it's capable of