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I know this subject has been beaten to death but after 100s of posts and hours upon hours of research I still feel like i need a more directed answer. So here's the Details....

Truck is a 2000.5 2500 24v with 6spd and original s.o vp44, Fass 95(18psi idle 14psi WOT), South bend Con Fe (or Ofe not sure) clutch with 13in flywheel and HD Hydraulics, S&B cold air and intake horn, XDP 3pc manifold, hx35/40 hybrid(60/60/14), 4in downpipe-5in exit, old style vacuum pacbrake, EJWA cts2 w/ hot unlock, stage 2 water/meth controller and dual nozzles, 150hp DAP injectors, 210k miles, 3.54 gears and 35s.

The original hx35 blew the oil seals a while back so i figured I would swap it for something else. Ended up finding the hx35/40 im running now for a good price and figured I'd try it out. Turns out I hate it... Really didn't feel much of a power gain over the hx35 w/12cm. Got more lag and smoke and the 14cm housing didn't help with egts at all.. On a hard pull or 3rd gear launch i can see 1700 degrees QUICK! Im constantly driving by the pyro. And to top it off it lights around 1700 rpm and falls on its face super fast. Prolly dies about 2400 rpm or so (haven't gotten a solid rpm). Sold the hx35 to recover some of my cost (which i regret) so i cant even swap back..

I don't pull everyday but I do pull often. Anywhere from 5k up to 15k. I never go to the strip or sled pull. Just like to have fun more often than not.

So my question is what turbo would you guys recommend for my application? I am going to go to compounds but i cannot afford that at this time and after 15k miles with this turbo im just done with it so i would like a turbo that could be used in compounds down the road but for now , as a single, would cool things down, cut the turbo lag down to maybe 1500 rpm or better, have a broader operating range and have a quick spooling compound setup down the road

I've basically got the idea of something like 62/65/12 62/68/12 or maybe 14cm housings or a 63/68/13ss but im looking for input from someone that has experience with one, all or other turbos that would work great. Any info or input would be greatly appreciated! Thanks in advance.
 

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As for towing I would sell your hx35/40 and replace it with a s300 57/65/14 since you want to go twins later down the road and tow often an s400 72/84/1.10 with 150s would get you the best of both worlds. 150 are the max limit on the skinny pedal for the s300 but with the compounds its a balance of power and egt's for towing.

Hit up crazy carl he knows his stuff pretty good. Mr compounds with whipple super.
 
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Discussion Starter #3
Would the 57mm wheel help with spool up or what would the purpose of going to a smaller compressor wheel be? Im fine with the 150s being the max for now cuz in all reality they seem to be the max with the 60/60 so i would assume the 65mm turbine would help egts somewhat.

I will definitely hit up Crazy Carl. Been looking at his twin/compound kit for a while now and almost wondering if i could somehow cough up more cash to just go compounds straight of the back..
 

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Another ??.. Being that i have never run a twin/compound truck out has left me to wonder how would compounding say a 62/65/12 with an s472 or s475 affect spool up? Like if the 62/65 spooled at 1600rpm as a single would it spool faster or slower after compounding or would it spool the same? Just curious cuz ive never seen or heard it mentioned before
 

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compounds spool slower than a single assuming the turbo is the same.

more mass more air volume more path for exhaust gasses to flow through.
 

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Discussion Starter #6
Is there a big difference in spool up or is it like the difference between a 12cm and 14cm housing so to speak?
 

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With towing and a larger turbo, and definitely with compounds later on, I would STRONGLY suggest regearing the truck. The OE 3.54 gearing is fine for a stock setup, but 4.10's makes a whole new experience out of a VP44 truck with large injectors.
 

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Discussion Starter #8
Ive considered regearing before especially with my 35s. The only downside i found (for me) is i tend to drive 80-85 mph (Ik ik thats speeding but i always tend to) and with my current set up @75 im running 2000 rpms and 2200 @85 in 6th gear. When i haul i hold 5th gear around 60-65 and puts me between 22-2300 rpm. Always thought that 410s would be a little low for me however I do like the idea of going with 3.73s. Ive always had good luck with those. I've never been in a modded 410 truck tho. They have all been basically stock duallys and running 235s or whatever the stock tire size is supposed to be so i cant knock the idea of 410s just yet
 

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If you're running in 5th gear, and the rpm's seem high for you, shift to 6th. You need rpm to keep the turbo happy, which will keep your EGT's down.

I would not bother with the small jump to 3.73's. We gear 35's with 4.10's, and 37's/38's with 4.30's. This is especially true with the 6.7's and 68RFE's. Gearing is SO important to the overall performance of your entire setup.
 

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Discussion Starter #10
Okay well thats good to know. Thanks for that info. Do you have an idea of what change in rpms 410s would make? I would assume about 200-300 rpm difference but idk
 

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Is there a big difference in spool up or is it like the difference between a 12cm and 14cm housing so to speak?
I beleive the 12cm on the s300 is not gated where the 14cm is gated. The point for compounds is to use a small guy to light at low rpm and the big guy to keep the air flow at high end when outside of the little guys map.

Okay well thats good to know. Thanks for that info. Do you have an idea of what change in rpms 410s would make? I would assume about 200-300 rpm difference but idk
there is a gearing calculator ling somewhere on these forums I have it at home they have it for all the transmissions and gears.
 

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Discussion Starter #12
So from what im gathering Lower gears (4.10) would make an auto spool slower due to a high stall TC and not loading the engine but they would make a manual spool faster since its a more direct drive. Is that right?
 

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Changing the gearing for gearing is keeping the drive line from having stress points and premature failure. Also depends on tire sizing because this will also alter the RPM in which gear you are towing to keep your turbo within its specs. Dynamite Diesel did a nice video on it and why its important to change gearing when your changing tire size and upgrading power. I would link it but I am at work and youtube is blocked.
 

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Discussion Starter #14
I will have to look it up when i get a chance later today.

A bit off subject but where in the hp/tq range would anyone suggest adding track bars to the rear axle? Never had an issue with axle wrap but I don't want it to start either. Have heard these trucks can be notorious for that
 

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Discussion Starter #15
I will have to look it up when i get a chance later today.

A bit off subject but where in the hp/tq range would anyone suggest adding track bars to the rear axle? Never had an issue with axle wrap but I don't want it to start either. Have heard these trucks can be not
 

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Depends on your suspension. If you have a a huge lift block for your rear suspension you might want track bars to help with the wrap. I did a rear shackle flip which only raised my back by 3/4" at lowest and 2 3/4" at max and it eliminates the need for track bars due to the high hinge point of lift blocks. Unless you really need them fix track bars are done incorrectly they will bind and cause more issues if you do any thing off road.
 
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Dynamite Diesel did a nice video on it and why its important to change gearing when your changing tire size and upgrading power.
I do a lot of stuff with/for Dynomite. Lenny Reed is a good friend of mine, and knows what's up. We definitely see eye to eye on this issue. Another really important topic is stall speed. I see some guys completely ruin their setup with the wrong stall speed choice.
 

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Discussion Starter #18
Sorry for the delayed response. Took a last minute invite to hike/camp up at Horseshoe lake in the Jicarita here in NM.

Ive been interested in track bars for some time. I don't do a whole lot of frame twisting kinda off roading on this truck but most of the roads are dirt and it is what i take for wood and hunting so binding could be of concern to me.

Dynamic what kinda of issues do you see with the wrong stall speeds? Just interested so i can get a better knowledge of what to look for in any future builds for me or any buddies
 

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Dynamic what kinda of issues do you see with the wrong stall speeds? Just interested so i can get a better knowledge of what to look for in any future builds for me or any buddies
Gearing too tall, stall speed too low. Happens all the time...
 
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