Small towing twins on 6.7

getblown5.9

Ceritified Kleenex Dealer
My 5.9 gave up on me at 305k miles, so I found a good 6.7 motor to put in its place running 5.9 electronics and fueling. Got the swap underway but I need to decide on turbo set up for towing my puller around. I am trailer and pull truck weighing in around 14k maybe 16k if I buy a bigger trailer soon.

I have almost all the parts to use a stock 24v manifold, with my stock 5.9 HE351CW turbo on top, and a box stock 475 under it. This option is the cheapest and I know these twins worked great towing heavy on a 5.9 motor my buddy had. I am just concerned how restrictive that turbine on the 351 will be for a 6.7 motor. it will have stock cam, and then for fueling it will be stock or 50hp injectors, stock CP3 and EFI Live tuning.

Do you think the small turbine and wastegate will be enough to let the 6.7 breathe with this level fueling? Truck is an automatic, and my daily driver when not towing, and I drive like grandpa for the most part, not going to be trying to squeeze every ounce of power out of it. A cool reliable 425-450hp for towing will work for me.

My other options for this level is going to be a 2gen swap with one of the various s400 charger, but I worry about the lag and egt's for towing the pull truck around. Anyone have any experience to share?
 
Aren't they dual/compound turbos? :)

I would think the HE351/475 setup would be just fine. Are you able to do some massage work on the HE351 to make it flow a little better?
 
I'd have to do some digging again but IIRC way back when it was determined that 6.7s will easily spool a charger a that 5.9s struggle with. Meaning something like a single 66mm charger made a great towing setup as a single on the 6.7
 
I plan on drilling out the waste gate opening to as big as the plunger will cover. If I have to change housings or anything, or swap to a manifold with an external gate setup it negates my savings and I will just build a complete new set with s362 over a s475 or put a single on it.

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I think you'll be fine, it's pretty ridiculous how small the outlet is on the factory 6.7 VGT turbos. With that being said, I'd probably go with a T4 manifold and a single box S366 or S463
 
ran few with the 369SXE and they were awesome. Currently a 465 single and Holy crap!!
That stock turbo is just gonna be a choke point.
 
You're towing right? Not hot rodding it?

I would think a 351 with some wastegate mods would flow enough, since you're only talking about 425-450hp...

However, there a singles that will do it too, and nothing even close to a 66 is necessary IMHO. Best towing charger I EVER ran on a 425hp 12v was an S360 Extended tip wheel, with a 68 turbine in a 14 housing. Spooled like crazy on a cammed 5.9 and would keep it just under 1300* towing upwards of 40K gross weight.


Twins are fun to tow with, but with the turbo technology we have now, the simplicity of singles is nice too....however, I have seen a large tendency on this sight for people to recommend LARGE singles to tow with...and while you can, it doesn't mean everyone will enjoy it.

Again, all my opinion.
Chris
 
Sig600 I've seen you talk about that turbo before. Where did you get it or who has them now at least?

I got them from Engineered Diesel...I'm sure they are still around somewhere, or any of the real turbo houses can get it or something very similar for you.

Chris
 
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