Build Advice - Turbo/Injector Sizing?

[Cdiesel288]

So, my fuel economy dropped markedly; I noticed exhaust smoke and could smell fuel, aka I've got at least one bad injector. Long story short, I've spent a few days looking at turbo/compressor maps, nozzle flows in ml/min, and total fuel vs. air, and I just fell down the rabbit hole.

What does any average person do as I am starting to look at upgrading everything.

The truck is 2017 with a 5" exhaust, S&B intake, RaceME, and ARP studs.

Daily driver, but I do tow/haul monthly.

We are looking to make around 800HP and keep EGTs low while towing.

So far, I've come up with this list, and any advice/feedback is appreciated:

165gph lift pump, Exergy 12mm stroked CP3, Exergy 150 or 200% over injectors, replace the stock Holset with a drop in BD screamer 64mm turbo, S480 atmospheric turbo (was looking at the Pusher high mount compound turbo system), Hamilton springs and pushrods, and then a custom tune to tie it all in.

I am debating o-rings and a head gasket; I've heard fire rings get eaten over time, 100k miles or so, but not sure if either is necessary.

I like my exhaust brake, so I was looking at the screamer.

I know 150% over injectors will do the trick, I think 100% may be running too close to complete the duty cycle, but the 200% leaves room for more air in the future without being too large for the 64mm/S480 compound setup.

I baby my 68RFE, never push hard above 4th, and even then, I try to ensure the converter is locked before I put my foot down.

I know it won't last, and I've budgeted a trans and converter replacement for 2023.

I have 295/70/R18s, so I'm not actively trying to grenade the trans with 38's.

If I go all in, I want to do it right, and I want to do it once, so thanks for any advice.

Also, in watching a few videos, it seems no one wants to pull the front right quarter panel for ease of access to the turbos & exhaust.

Am I missing something here?

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[Muzzy]

Are you still running the stock exhaust manifold?

That will be an issue for EGTs.

If you push more air/fuel in, it has to get out without causing excessive drive pressure.

150-200% over injectors with a 12mm CP3 will be more than enough to get 800HP with proper tuning.

If your goal is 800HP, I might even look at a 100% over-injector.

The 100% are good for 900-950.

Going too large of an injector can cause some drivability issues.

The trans will be a weak point until it is upgraded.

Regarding the head gasket, I think you would be in good shape with ARP 625s.

If your goal is 800HP and you will never push past that, then just the studs will be ok (with proper tuning).

If you are going to get that itch to add more, then I would ring the heads.

That's why I have stayed just below 800.

750-800 seems to be the magic number for the 6.7 before considering some pretty costly upgrades (rotating assembly, valve train, ringed heads, etc.).

I just removed the inner fender liner to access the side of the engine.

-Muzzy

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[Cdiesel288]

Good catch on the exhaust manifold; I assumed the Pusher setup would come with one, but it does not.

I wanted 150% over injectors, but I can't find any in stock, so I mentioned the 200%.

But for daily driving, you're probably right that 100% would have the flow needed without affecting drivability.

I have ARP 2000 (425) studs installed. I know there is a lot of debate with the 425 vs. 625, and I've read so many different articles and opinions I feel like it's similar to the age-old 9mm vs. 45 arguments.

The short-term tensile stress and creep associated with martensitic stainless steel vs. austenitic stainless steel isn't that different.

Austenitic stainless wins for prolonged exposure to high tensile stress conditions, but we're talking power plant steam generators or nuclear RPV components.

I only say this because it's my career field.

If I planned on sled pulls, racing, or some other high-stress hobby, I would go with the 625.

Still, I would be willing to bet that throughout 200k miles, the average daily driver/towing rig would see less than 200 seconds at >70psi boost and>3000rpm, which IMO would qualify as short-term stresses.

I could have flawed logic, though.

I appreciate the feedback; I have seen too many builds with too much air or fuel, which ends up with problems down the road.

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[Muzzy]

I assumed you didn't purchase the studs yet.

If not, I would have recommended the 625s (if I had the extra $$ when I bought mine, that's the route I would have gone).

Since you already have the 425s, I would stick with those.

I am running ARP 425s on mine and around 50 PSI max boost (+/- PSI based on air density) on my most aggressive tune.

I never had an issue (about 90K miles since installed).

I am also reasonably conservative with the timing in my tunes to help avoid head gasket problems.

When I stress "with proper tuning," it is a crucial ingredient.

You can destroy a stock engine head gasket (or worse) with no additional fueling with wrong timing parameters.

-Muzzy

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[Cdiesel288]

100% the tune will be the most crucial part.

That's next on the list.

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[Bpbertolacini]

Steed speed T4i and a 363SXE are what I got with 475.

I love it; been through 3 transmissions and don't love that.

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[AK Bob]

Good catch on the exhaust manifold; I assumed the Pusher setup would come with one, but it does not.

I wanted 150% over injectors, but I can't find any in stock, so I mentioned the 200%.

But for daily driving, you're probably right that 100% would have the flow needed without affecting drivability.

I have ARP 2000 (425) studs installed. I know there is a lot of debate with the 425 vs. 625, and I've read so many different articles and opinions I feel like it's similar to the age-old 9mm vs. 45 arguments.

The short-term tensile stress and creep associated with martensitic stainless steel vs. austenitic stainless steel isn't that different.

Austenitic stainless wins for prolonged exposure to high tensile stress conditions, but we're talking power plant steam generators or nuclear RPV components.

I only say this because it's my career field.

If I planned on sled pulls, racing, or some other high-stress hobby, I would go with the 625.

Still, I would be willing to bet that throughout 200k miles, the average daily driver/towing rig would see less than 200 seconds at >70psi boost and>3000rpm, which IMO would qualify as short-term stresses.

I could have flawed logic, though.

I appreciate the feedback; I have seen too many builds with too much air or fuel, which ends up with problems down the road.

@DDP do you have 150% or 100% injectors in stock?

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[DDP]

Thanks for the tag! @AK Bob we can get him set up with whatever he needs from his list.

We have a holiday special; depending on what is ordered, we can send a big old steak package to the customer. : )

Holler at me anytime! Email or a call is generally the fastest way to get ahold of us. @Cdiesel288

sales@ddpmotorsports.com

866-895-3833

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[Palladium]

Great setup; the pusher compounds kit is a great product.

I ran it for about 40k miles with a steed speed T4i and had no complaints, EGT's were always in check.

My only advice will be to get yourself some Fleece AC lines; they give you the extra length to move it away from your downpipes.

While you're at it, go ahead and heat-wrap them.

They tend to move around, and it cost me a set.

Moving this much air/fuel through the motor, maybe consider an aftermarket valve cover and vent it to the atmosphere using a universal breather/catch can.

Plug up that oil return on the side of the block just behind your CP3.

This will make that engine bay pop and keep your seals in place.

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[Cdiesel288]

Thanks for all the advice.

I got parts ordered last night and emailed Ray this morning.

He had a tune ready in about an hour!

I've been looking at valve covers, and nothing has caught my eye yet.

I was thinking about getting everything powder coated in Cummins Red.

A buddy of mine runs a shop and got me in touch with a guy who does incredible custom aluminum work, he said he'd get back to me about the valve cover.

If the price is right, I may go that way.

Who knows.

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