Another PMR hp question

So I've been looking for some newer threads regarding safe Hp for a 7.3 with PMR's, I can't find any recent ones so I figured i'd ask. What seems to be the best PMR setup lately? Ideally I want to build mine with 238/100 injectors, srp1 hpop and g38r turbo and land right around 450 hp, can this be tuned safely? I'd be having beans tune it when the time comes, is this really pushing it for a PMR? Thanks in advance.

How much faith do you have in your tuner?

Beans is pretty good with PMR safe tunes from what i've heard, I know it mainly comes down to tuning, if someone has had sucess with a similiar setup then i'd love to know who tuned it.

At the end of the day, you still have pmr's no matter who tunes it....

238/100s should put you in the 500+ hp range, Jonathon (currently Dyno-proven who wrote and am asumming beans still sells his tunes) got 490 something HP just out of 175/80s

I've already been down this road. I'm personally going with 180/100's and that's my limit because of liability. And I could be pushing it with those injectors. I have all the supporting mods to run them. My truck has pmr's but it really doesn't matter cause forged can go through the block just as well. 450 hp is a lot of horsepower in my book but a concern would be your transmission. At 450 hp, your transmission probably won't hold. So if you want that horsepower you better be looking for a more beefy converter and tranny. My opinion are pis 175/80, fullforce 160/100 or powerstrucks 180/100 and you'll have all the horsepower you will ever need. Good luck!

dadada said:

I've already been down this road. I'm personally going with 180/100's and that's my limit because of liability. And I could be pushing it with those injectors. I have all the supporting mods to run them. My truck has pmr's but it really doesn't matter cause forged can go through the block just as well. 450 hp is a lot of horsepower in my book but a concern would be your transmission. At 450 hp, your transmission probably won't hold. So if you want that horsepower you better be looking for a more beefy converter and tranny. My opinion are pis 175/80, fullforce 160/100 or powerstrucks 180/100 and you'll have all the horsepower you will ever need. Good luck!

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It does matter actually. Forged rods are much stronger than pmr.

It doesn't matter what injector. You can run 400/400's on PMR's. Never mind the max hp that an injector is capable of. Everyone just get that out of your collective heads and throw it out the window when it comes to PMR tuning. The idea of "this particular injector is capable of X amount of horsepower". Toss it away.

What matters is how much fuel at what time and duration. That will be mainly up to your tuner, and partly what you want him to do. The injectors you choose will determine what your tuner has to work with. After that it's supporting mods being able to make the power time and time again with good performance and manageable EGT's.

First, stop looking at horsepower. Look at torque and set a limit. For PMR's, make it under 900 lb/ft if you want it to live as long as possible. Go higher and good luck, you're going to need it.

Why torque? Because that's your best indication of cylinder pressure without having an actual tool to measure the cylinder pressure in real time. High cylinder pressure is what is going to pop a rod, and PMR's just love to jump out of the block when cylinder pressures spike. You can have 400 hp and 1200 lb/ft of torque, or you can have 500 hp and 900 lb/ft of torque. Which one has the higher cylinder pressure? I bet you can guess at this point.

As for the injectors, larger nozzles will give you more horsepower with less torque, because they have a smaller injection window that they can work with and you can continue to make good power at higher RPM's while keeping EGT's nice and low. But at the same time they are harder to tune for many, and require some refinements to achieve a nice daily driver that you are truly happy with. On the flip side smaller nozzles are easier to work with in regards to making your truck a pleasant daily driver, but require a much longer injection event duration. This longer injection event can increase EGT's and limits your upper RPM power as that injection window shrinks.

Pick a tuner you are comfortable with and talk to him about your goals and what components you plan to toss under the hood. The two of you will be working close together until that truck is running as you want it, so both of you better be speaking the same language before you open your wallet.

Is this going to push the limits of the PMR's. Uhhhhhhhhh, yeah. Of course. You're going to gamble, just know that here and now. Understand what can possibly happen, prepare yourself for it, and don't be surprised if it happens.

For my own truck I've been very happy with it. The thing is a work beast and nothing out tows it up a mountain pass. Period. It's been alive in it's current configuration and power level for several years and tons of miles, and it hasn't skipped a beat. Knock on wood it keeps this up for many many years to come.

*Your experience may differ.

what turbo are you running Curtis ?

Not going to quote Curtis' long post. But you better listen to him.


Sent from my truck while eating, adjusting the radio and passing a Mustang sideways.

Spatel23 said:

what turbo are you running Curtis ?

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Just a 38R.

I personally would run 175/80's if you have or plan on upgrading your hpop. If not run 200/80's. Both go these can get you to your goal. I would not push a 38r with more than these.

Tim @ P.I.S. said:

I personally would run 175/80's if you have or plan on upgrading your hpop. If not run 200/80's. Both go these can get you to your goal. I would not push a 38r with more than these.

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Push it more than what??? Tuning????

Like I said before, forget everything about what an injector can possibly make. Instead, it's all about how much fuel, at what time, and at what duration. Guess what controls that?

450 hp on 175/80's with an HPOP? Ok, what are the EGT's at 450hp vs my 250/200's on a bone stock HPOP? I'll give you a hint, I'll run up a mountain towing at full capacity with 450hp on tap and struggling to reach 1200 EGT's while those 175/80's are capped at 350hp and reaching 1300+. And I'll do it while breaking the speed limit. Get a set of 175/80's to keep up. It hasn't happened yet, and it won't.

Seen it already.

Folks, start thinking outside the box. riest:

And this isn't a pissing contest, so don't take it that way Tim. It's just going against what has been preached time and time again since these trucks rolled off the assembly line. Smaller injectors doesn't mean greater reliability. That's the point I'm trying to drive home. It's all in the tuning.

There is far more potential then what people have been trained to believe.

Curtis, I know very little about tuning, but my limited experience parallels yours to a t.
Just going from stock to a 100% nozzle is a big improvement in a) power available, and b) egt.
When people say that's what these should have came with from the factory, this is what they are talking about.
I'm not sure that a 200% nozzle is even better, I've personally not ran one yet. I think the limiting factor will be time to fine-tune idle and off-idle characteristics as the nozzle gets bigger. Having said that, it's obviously doable.
Maybe you would be willing to post a couple off video again, curtis, of your idle? :toast:

CurtisF said:

Push it more than what??? Tuning????

Like I said before, forget everything about what an injector can possibly make. Instead, it's all about how much fuel, at what time, and at what duration. Guess what controls that?

450 hp on 175/80's with an HPOP? Ok, what are the EGT's at 450hp vs my 250/200's on a bone stock HPOP? I'll give you a hint, I'll run up a mountain towing at full capacity with 450hp on tap and struggling to reach 1200 EGT's while those 175/80's are capped at 350hp and reaching 1300+. And I'll do it while breaking the speed limit. Get a set of 175/80's to keep up. It hasn't happened yet, and it won't.

Seen it already.

Folks, start thinking outside the box. riest:

And this isn't a pissing contest, so don't take it that way Tim. It's just going against what has been preached time and time again since these trucks rolled off the assembly line. Smaller injectors doesn't mean greater reliability. That's the point I'm trying to drive home. It's all in the tuning.

There is far more potential then what people have been trained to believe.

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You are correct with a tow tune 350 is where you would be. BUT how much fuel do you think you are really injecting in your scenario? No where near the. 250cc. Promise. The difference is with the 175's you still mostly get the. 175 even while towing. It's all in how it comes in. The 250's prolly less than. 200cc. And depending on the brand way under 200. I have seen 250's that under normal conditions seen in everyday driving a bench flow test reveled any where from. 125-195 max output. Yet they are sold and marketed as. 250.

Tim @ P.I.S. said:

You are correct with a tow tune 350 is where you would be. BUT how much fuel do you think you are really injecting in your scenario? No where near the. 250cc. Promise. The difference is with the 175's you still mostly get the. 175 even while towing. It's all in how it comes in. The 250's prolly less than. 200cc. And depending on the brand way under 200. I have seen 250's that under normal conditions seen in everyday driving a bench flow test reveled any where from. 125-195 max output. Yet they are sold and marketed as. 250.

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I think that is curtis' s whole point.
Body size has nothing to do with power, at least until the tuner calls for enough po to empty the injector. That's going to be hard to do most bodies over say 180 cc, on a stock to 30% nozzle.
100% nozzle may get you close, as I understand it.
I'm no tuner or injector builder, just how I understand the heui system. Charles has repeatedly said exactly the same as curtis, in past threads, if that matters.
Both of these guys have been around, and documented the abilities and limitations of these setups, fwiw.

What about politics??

But yeah, he knows a thing or two about the 7.3.

Start with this statement right here.

CurtisF said:

Like I said before, forget everything about what an injector can possibly make. Instead, it's all about how much fuel, at what time, and at what duration. Guess what controls that?

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Simplified version, at 1 rpm you have a huge window to inject fuel. At say 3000 rpm a much, much smaller window to inject fuel.

This is how you spec an injector. Find what you want to do with your truck. Example #1 - Heavy Tow. Spend majority of your time at lower RPM band? select a 30% nozzle because it CAN move a good amount of fuel, yet make for a nice clean burn. 160cc of fuel can easily make in the mid-high 300HP. Perfect for towing and maintaining nice cool EGT's.

Example #2 - sled pulling. Spend majority of your time at higher RPM band? select 400% nozzle because it WILL move a lot of fuel, nothing else matters. 300cc of fuel can easily make in anywhere from 650-850HP depending upon the setup. Anything more that much over 300cc will not inject within the RPM band a lot of pullers are trying to be in. That takes you back to the whole theory of why have 1000cc injector if you can only inject 100cc.

Now you have to also throw into this equation that you really have a set of injectors that REALLY do inject what they claim in a realistic usable time frame.

And then you have to have a tune that is capable of making use of the fuel that is available.

I will say i agree with Curtis on the nozzle deal. I ran 175/100%'s with a 17* on my truck, loved it, great all around set-up. I then bumped up to 250/200%'s with a 15* HPOP. OBS with a stock turbo, non-intercooled. I'll be the first to admit that the 250's aren't really making anymore power than the smaller injectors, as i'm limited by air and oil. Its making the same power cleaner and with slightly lower EGT's. Plus my timing is pretty conservative, and definitely seems quieter than when i had the smaller injectors/nozzles which would be good for PMR's. BUT i can see trying to tune these injectors over e-mail being a pain. Thats why i bought Minotaur once i put the hybrids in.

Myself, including a few friends all ran 38r's on our PMR setups with 250/100's. And with that said we also all broke rods eventually. Mine ran for 40k miles before it let go. Others weren't so lucky.

If I could do it all over again, I'd go with a 200% nozzle. The way I understand it is a 200% nozzle empties faster thus making the injection event faster and thus lowering cylinder pressure.