OK general question is what turbo for a remote mount setup in a high GVWR setup?

SBC, manual transmission, maximum 4500-5000RPM. Truck will tow around 10,000lbs
Goal is only 500-600 ft/lbs at the wheels but that is through a big heavy NV4500 transmission/clutch and with 35” tires.
I’d like to see 450ft/lbs at the wheels by 3,000 or so RPM.
I don’t care so much about the HP…My build won’t have much because it’ll be choked a bit with a LONG runner TPI intake setup and mostly stock Vortec heads

On the exhaust would I want a smaller exhaust diameter to improve turbo response or larger exhaust pipes and a smaller turbo charger?

On the exhaust pipe I could use a heavy wall tubing to help hold in heat because weight isn’t as big a concern on this vehicle like it would be on others.

A single exhaust pipe would help with packaging

 

Exhaust: Run stock manifolds and 2" crossover. You could definitely go 14ga for the tubing and not hurt anything, thicker even is fine pre-turbo. The more heat you keep in the system the more responsive the turbo will be Then after turbo go 1.25x the exducer wheel diameter, bigger is better. You can heat shield everything in the bay. I had great luck with heatshield products: https://www.summitracing.com/parts/hsp-170105.

 

i was going to be remote mounting

 

I'm curious why a remote setup? You should have a good bit of room up front.

I think if you search through the archives a lot of people have used Holset HX35 turbos off 5.9 cummins trucks. I'm not sure what the modern possibly chinese equivalent would be though.

 

To keep heat out of underhood and maintain AC
Between a 34” core radiator, intercooler, oil cooler and power steering cooler I’d like to keep things cool under the hood
And I’ll be able to use the headers I have instead of going back to stock manifolds

 

Hx35 would be pretty small, its for a 5.9l that runs half the RPM and makes 245hp. 2 of them... just right.

Sorry about the crossover confusion, just run the stock exhaust back to the turbo, then run the dump side bigger. I would think something like an s362 would be pretty good for this. I think you want to keep a pretty high drive ratio to help keep exhaust pressure and heat lower.

I think you are asking for trouble trying to make a gasser produce a ton of torque for a towing app. This has been discussed to death, so feel free to read one of the other threads: https://www.theturboforums.com/search/376223/?q=towing&o=relevance&c[node]=236.

You would be much better off running the engine a thousand RPM higher to make power and using the driveline to make the torque (gearing), you are going to be putting a lot of cylinder pressure and heat into that engine, for sustained periods. An SBC is not designed for this.

I am not saying it isn't possible to make a gas engine make good torque with boost, the OEM are doing it right now... but the SBC is not designed to do it.

 

I should clarify that @3000 RPM the power plant should have close to 400 RWTQ at the wheels even N/A. The tuned port runner length really shifts the power band lower.

I’ll do some reading for sure. I’ve seen some recommendations for some really small exhaust pipes and I really don’t think that’s a good idea with this kind of setup.

Thanks for the feedback I appreciate it!!

 

What compression? What fuel? How much does the motor make NA? Budget?

Shouldn't need much boost to get to 450ftlb. Def. want the smallest unit possible. Hard to size it not knowing the engine specifics. If its for towing, you don't really need to worry about the turbo running out of steam, or even its performance at 5k rpm. The HX35's HX40 stuff have huge exhaust housings and won't work well IMO. Id look at something in the 60mm range with a smallish T4. Hard to be more specific without more details.

I agree with what's said above. Headers will likely slow you down and do the opposite of what you want. (slow exh velocity) Also, aftermarket headers are generally not very stout and tend to crack when subjected to turbo heat cycles in my experience. Esp. when wrapped.

You'd be better off with some big clunky cast manifolds that hold a ton of heat with 2" off each. Merged into a single 2" back to turbo. I get that may be more trouble than its worth if its already together. But it would be more ideal.

Hope you post pics and more details. I'm considering something similar myself.

 

I've done a couple of rear mounts for customers.
Regular headers to a y single exhaust back. The temp drops the further the turbo is from the heads so size pipe accordingly.
The charge pipe was smaller than normal also to a intercooler. Waste gate tied back into tail pipe 2 feet from turbo back out the rear.
Made a sump for turbo drain and had a remote oil pump the sump to the valve cover or pan if you can.
They all spooled suprisingly well and made 8 pounds on spring with a small turbo.
For towing I'd upgrade the radiator and exhaust valves aND the biggest intercooler you can fit. All these were efi.

 

Compression is going to be close to 9.1. I’d run 87 if I could get away with it but I assume I’ll have to run 93.
Most of the combos I’ve seen like what I’m planning make 500+lb/ft but those are flywheel numbers. I expect I’ll lose 100lb/ft due to the heavy clutch/flywheel, trans, wheels/tires

In any event torque will be close to if not more than 500lb/ft with 400@ 3,000 RPM flywheel
The intake system is the primary driver of the torque/rpm characteristics

 

Power is easily changed, just up the boost if its not meeting your needs. Detonation will be your limit w 87 octane, 9:1 SCR, and small turbo. I'd start really low timing/boost wise and check plugs making baby steps. Something in a 60/65 with a .68-9x T4 would be my pick. S300 series 60mm if you want a real turbo. Or a cheap ebay GT4582. ($150ish)

 

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Are supporting oiling mods a good idea?
I was eyeballing a 7qt pan, high volume pump, and remote high capacity filters and additional cooler

 

Doesn't hurt. I think all modern pickups (1/2 ton+) have oil coolers.

 

Feel like guys have proven it's almost easier to run a remote oiling system. Gravity drain into a 1 gal reservoir, then pressurize the feed through an oil/trans cooler to supply turbo bearing. Something just rubs me the wrong way sending engine oil all the way back and pumping drain oil all the way forward.

 

If you have a oil cooler allready, IMO I wouldn't add the extra cooler or filters. The sump and line help cool the oil on return from turbo.
A bigger pan almost always helps.
On trucks I mount turbo just past the cab , the oil scavenge pump doesn't have far to go. Make sure it turns on with ignition switch.
The smallest turbo was a 60 something precision, it spooled quick.
I should have added, I V band all exhaust.
Your power goals are reasonable enough, but you will need to upgrade your clutch for sure.
Want to add. You are still going to have to upgrade stuff as a normal hp build would need. All the builds werent just slap a turbo on, just to be clear. Haha

 

Yeah this one does have a factory cooler

 

I really need this to be reliable
Most of its miles will be multiple hours from home trips per year
I like the idea of separating the oil supply from the engine

 

So for management:
First I’m on a budget because this is a complete teuck build. And shit is adding up already

I’m looking at a Dynamic EFI flash 2 system and HP tuners
The other route is a modified 5.7 Vortec harness, Vortec crank and cam position sensors and a 0411 PCM from an Express van with a 5.7 Vortec.

Tuning is going to be difficult for me I believe as I have zilch experience. My original plan of using the flash 2 system included installing it this winter on the TBI setup and get setup and used to basic tuning.

Now I’m looking at the Vortec/0411 pcm setup because I have all those parts too

I need to try and find some info on the Vortec setup but my googling is turning up some really old stuff

 

Hptuners can be tough, you will need time to get it really dialed in. There are a lot of parameters and it isn't always clear how to adjust things to get what you want. It will take some learning time. The good thing is, once you are into it you can tune multiple vehicles off the same interface, and most of the tuning is similar year to year within each manufacturer. One of the holley units would be easier on you, Holley HP 550-601 is for the TPI system, it is not as budget minded but fewer headaches.

Just to play devils advocate, is there a reason you aren't considering an LS? A basic head/cam/intake 6.0 will do everything you are asking, without the heat concerns.

 

Yeah I think the $2k initial may be too rich for me
I’ve seen a FAST EZ EFI system for TPI that is inexpensive but fuel only and still batch fire.
The Dynamic EFI flash EBL is also batch fire.

I’m leaning towards the 0411 swap and Vortec harness.
I’m hearing that even with a stock tune and MAF the 0411 will run port injection. I need to look into this more.

For torque below 3500 RPM nothing is better per C.I. than a SBC with a TPI intake.
Check out this dyno from Holdener of a 383 with stock TPI base and plenum (ported) and aftermarket runners (comparison is to bone stock lower/plenum/runners)
And this is with a bigger cam than I would be using so I’d lose some HP for sure but gain torque below 3500
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