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Discussion Starter #1
I am starting this thread to make sure I am doing this right (as there are ppl on here that know a heck of a lot more than I do), and for those that don't want to take someone's word for how much fuel they are gonna need to produce a certain amount of power.

I am trying to nail down the cc/1000 shots that I need to turn my pump to for my desired horsepower. On the way to this, we can also find how many lb/min of fuel we will need though out the RPM range, which, with your A/F ratio, will give your lb/min of air for turbo sizing (not factoring VE).

I am going to use the 4BTA CPL tag 1963 which is pretty much the same as my 1839 tag as far as the p pump goes. These tags max out at 2500 RPM, so I will interpolate the data at higher RPM.

The BSFC (Brake Specific Fuel Consumption) is the rate of fuel consumption divided by the power produced. On the EPA tag it is given for us as:

lb/(HP*hr)
and
g/(kW*hr)

I will be using imperial for this example.

I want 300 HP out of my 4BTA @ 3200 RPM

On the EPA tag, we can follow the BSFC curve up and approximate it at .42 lb/(HP*hr), which is the fuel consumption at full load at that RPM. So now let's find the lb/hr of fuel:

300 HP * .42 lb/(HP*hr) = 126 lb/hr of fuel (divide that by 60 min and multiply your A/F ratio and you got your tentative airflow)

126/4 cylinders = 31.5 lb/hr per cylinder

31.5 lb/hr * (1 liter/1.834 lb) * (1000 cc/ 1 liter) * (1 hr/ 60 min) = 286 cc/min assuming 1 liter of diesel weighs 1.834 lbs

286 cc/min * (1 min/ 1600 shots) * (1000) = 179 cc/ 1000 shots 4 stroke engines inject fuel every other stroke 1600 = 3200/2

That is how much fuel needed to get 300 HP with those conditions. Now let's look at max torque. I am aiming for 600+ ft*lbs @ around 1800 RPM.

Formula for HP from RPM: HP = Torque*RPM/5252 = 600*1800/5252 = 205 HP

205 HP * .334 lb/(HP*hr) / 4 cylinders = 17.1 lb/hr per cyl

17.1 lb/hr * (1 liter/1.834 lb) * (1000cc/1 liter) * (1hr/ 60 min) = 155 cc/min

155cc/min * (1 min/ 900 shots) * (1000) = 172 cc/ 1000 shots

So I will need 172 cc/ 1000 shots to get 600 ft*lbs of torque at 1800 RPM.

This is pretty simple, a couple weeks back I thought there was some secret to get the cc/1000 shots, but someone smarter than I am pointed me in the right direction (i.e. the EPA tag) and this is what I got. Let me know if I am missing anything here.

-Ryan
 

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Alrighty then.

cc/1000 shots is about fuel delivery.
Engine efficiency (BSFC) determines how much of that fuel gets turned into usable shaft torque.
Power is torque x rpm (with correction for units used)

The EPA tags give you rpm, cc/1000 shots and power.
So you can crunch the power and rpm down to torque.
The cc/1000 shots then gives you the efficiency.
But first we must crunch some numbers. I work in metric. It's easier.

You're using 0.42lb/hp/hr. In metric that is 257g/kwh. The numbers I've previously been using at ~3,200rpm are within a few percent of that.
I'm using VE (volumetric efficiency) of 0.74 at that rpm.
300hp = 212kw
Take 257g/kwh of diesel, multiply it by 212kw and we get 54.48kg of diesel per hour or 908g/min
Using an A/F ratio of 18 then we need 54.48 x 18 = 980.7kg of air per hour or 16.34 kg/min.

Fuel

At 3,200rpm in a 4 cyl 4 stroke diesel you've got 6400 bangs per minute.
So into each cylinder we have 908/6400 = 0.142g of diesel and 2.55g of air.

I use 0.85 g/cc for diesel, so that's 0.167cc per bang or 167cc/1000 shots.
That's within a few percent of yours. So all good there.

Air

We need to fit ~2.55g of air into a cylinder of 0.95 litres volume.
Air at 20C and 101.3kPa has a density of 1.205kg/m^3 or 1.2g per litre.

With no compression we would only have 1.205x0.95 = 1.145 grams of air in the cylinder.
To fit in our 2.55 grams we need to increase the density by 2.55/1.145= 2.22 times.

But it's far worse than that. No engine can fill it's cylinders perfectly at all rpm. In this case (2 valve diesel) I think the VE can be as bad as 74%. So each stroke only gets 0.74 of the air it should.
So we actually need to increase the density by 2.55/(1.145x0.74) = 3 times.

To get 3 times as much air in, we need to compress it at least 3 times and then cool it (intercooling) as much as we can.
Using an 80% effective intercooler and a 70% efficient turbo compressor I get numbers like 33.5psi of boost required.
The air out of the turbo compressor will be around 190C. The air out of the intercooler will be around 54C. Airflow is ~36 lb/min.

Turbo
To run the turbo compressor to compress that much air to that much pressure takes ~46.2kw (62.5hp) worth of shaft power. Your intercooler is shedding 37kw of that as waste heat.
I figure your EGT at this point will be somewhere around 700C. I'm using 715C for this example.
Now a perfect sized turbine of 70% efficiency to extract just the right amount of power from the exhaust gas would be running at an expansion ratio of ~2.7:1 and a corrected mass-flow of ~24 lb/min. Now this is a little bit smaller than a HX35-12cm turbine.

So if you were to only run an engine at this power rating, you could bolt on a 12cm HX35 turbine and you'd be almost good. But of course the HX35 doesn't do much the rest of the time on a 4BT.
Turbine drive pressure would be around 31psi, just a shade below required boost.

I'm out of time tonight. I'll have a dig around for more suitable turbos tomorrow and see if I can map one out.
 

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Discussion Starter #4 (Edited)
Alrighty then.

cc/1000 shots is about fuel delivery.
Engine efficiency (BSFC) determines how much of that fuel gets turned into usable shaft torque.
Power is torque x rpm (with correction for units used)

The EPA tags give you rpm, cc/1000 shots and power.
So you can crunch the power and rpm down to torque.
The cc/1000 shots then gives you the efficiency.
But first we must crunch some numbers. I work in metric. It's easier.

You're using 0.42lb/hp/hr. In metric that is 257g/kwh. The numbers I've previously been using at ~3,200rpm are within a few percent of that.
I'm using VE (volumetric efficiency) of 0.74 at that rpm.
300hp = 212kw
Take 257g/kwh of diesel, multiply it by 212kw and we get 54.48kg of diesel per hour or 908g/min
Using an A/F ratio of 18 then we need 54.48 x 18 = 980.7kg of air per hour or 16.34 kg/min.

Fuel

At 3,200rpm in a 4 cyl 4 stroke diesel you've got 6400 bangs per minute.
So into each cylinder we have 908/6400 = 0.142g of diesel and 2.55g of air.

I use 0.85 g/cc for diesel, so that's 0.167cc per bang or 167cc/1000 shots.
That's within a few percent of yours. So all good there.
I definitely agree. Metric is easier, but not as useful for me since I live in the States. So I was recrunching your numbers to see why we didn't end up at the same cc/1000. Turns out your fuel weighs just a little bit more than mine, but even with that correction we were still a little off. Just went through and converted all the numbers again and it looks like 300hp is 223 kW, not 212 kW. So using 223 kW instead and if we both use the same weight for fuel, we end up at the same answer of cc/1000.
 

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Discussion Starter #5
^ This makes it all the more clear why compound turbos are the deal for diesels.
Right you are, ashville! That's exactly what I will be doing. Just need to continue calculating and try to understand the flow and the PR of the LP turbo compared to the HP turbo through the RPM range. I want to maintain turbo efficiency at high RPM and at cruise if I can. This post is just one step in the process to get there. Hence, me, picking everyone's brain on their experience AND knowledge.
 

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I definitely agree. Metric is easier, but not as useful for me since I live in the States. So I was recrunching your numbers to see why we didn't end up at the same cc/1000. Turns out your fuel weighs just a little bit more than mine, but even with that correction we were still a little off. Just went through and converted all the numbers again and it looks like 300hp is 223 kW, not 212 kW. So using 223 kW instead and if we both use the same weight for fuel, we end up at the same answer of cc/1000.
Good catch, I did this in a hurry last night and that was the one number I did in my head. 300x0.74 =/=212.

I plan to recalculate later on using the same fuelling at 2000rpm and picking a turbo that can burn all of that. Seeing how close we can get to 2000rpm max torque and 300hp with a single turbo.
 

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This is all good but what are the options for the low budget people that can't send a pump to the shop to have set at a specific cc? Not every one has down time or money to have their pump set to these settings.
 

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This is all good but what are the options for the low budget people that can't send a pump to the shop to have set at a specific cc? Not every one has down time or money to have their pump set to these settings.
You don't need to send the pump anywhere.
Once we've worked out the fuel and boost required, you can set the boost, check your IC is working well, tune in your EGT or A/F ratio and you'll be in the ballpark. Go for a dyno run if you want to do a live final tune and check.

We already know that a VE pump maxed out can deliver ~180cc/1000 shots. This is looking like plenty for 300hp.
 

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Still not every one is running A/F gauges and everything else you guys are using. Now if you were to use total fuel plate movement (ppump) Afc pressure setting, depth of pre boost screw, and if the Afc is set all the way forwards or towards the rear of the engine. That's what everyone would be able to work with.
 

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Discussion Starter #10
This is all good but what are the options for the low budget people that can't send a pump to the shop to have set at a specific cc? Not every one has down time or money to have their pump set to these settings.
I don't plan on sending the pump out at all. I have a p pump and we know that it can pump well over 200cc/1000 shots. I just plan on tuning it (fuel plate, afc screw adjustments) until I get my EGTs and A/F ratio where I want them. Then yeah do as Dougal suggests and do a Dyno run.
 

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Still not every one is running A/F gauges and everything else you guys are using. Now if you were to use total fuel plate movement (ppump) Afc pressure setting, depth of pre boost screw, and if the Afc is set all the way forwards or towards the rear of the engine. That's what everyone would be able to work with.
Fuel plate movements will vary too much from pump to pump and have no relevance to other pumps. Where cc/1000 shots is good across the board.

But with the trifecta known of cc/1000 shots, boost and EGT, you can simply set boost with EGT and you're good enough. If you don't have at least a boost and EGT gauge, then you can't really play this game.
 

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Discussion Starter #12
Still not every one is running A/F gauges and everything else you guys are using. Now if you were to use total fuel plate movement (ppump) Afc pressure setting, depth of pre boost screw, and if the Afc is set all the way forwards or towards the rear of the engine. That's what everyone would be able to work with.
No A/F gauges. I plan on tuning the A/F using some of the info on this thread:

http://www.4btswaps.com/forum/showthread.php?28841-Diesel-Tuning.-A-F-Ratios-etc.

Lots of good stuff there and elsewhere.
 

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Fuel plate movements will vary too much from pump to pump and have no relevance to other pumps. Where cc/1000 shots is good across the board.

But with the trifecta known of cc/1000 shots, boost and EGT, you can simply set boost with EGT and you're good enough. If you don't have at least a boost and EGT gauge, then you can't really play this game.
Exactly and the fuel plate controls rack movement which controls amount of fuel and the curve it's delivered in. Regardless of the Afc the plate will determine the amount of fuel in the end. You can set the Afc to full fuel at 30 psi but if the plate is mid way or rearward then you will be short on fuel.

What I am trying to get at is even though you say 175cc and 30 psi to get X amount of hp. There will be some excited people and disappointed people when they try to mock this and the results are nit what they expected.

Instead of trying to tell everyone to make their pump push x amount of cc take the pump your going to use to prove your equations and set a base setup.

Specify the fuel plate, fuel plate location, pre boost, Afc location, psi setting for max fuel, is the Mack plug used, what DVs are used, fuel pressure, and then you could get even more in depth with the turbo setup.

If you look at everything in the past on the performance side. Someone tried a setup, tuned it, and ran it on the dyno. No one cared about the cc or a/f. They found a set up that ran good and clean and now people use that as a base line across the board.

Sometimes it's good to go into depth on some things, but other times it's just complicates things and confuses people.
 

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Discussion Starter #14
Instead of trying to tell everyone to make their pump push x amount of cc take the pump your going to use to prove your equations and set a base setup.

Specify the fuel plate, fuel plate location, pre boost, Afc location, psi setting for max fuel, is the Mack plug used, what DVs are used, fuel pressure, and then you could get even more in depth with the turbo setup.

If you look at everything in the past on the performance side. Someone tried a setup, tuned it, and ran it on the dyno. No one cared about the cc or a/f. They found a set up that ran good and clean and now people use that as a base line across the board.

Sometimes it's good to go into depth on some things, but other times it's just complicates things and confuses people.
Patience, my friend, I am getting there. I totally understand what you mean, it's really hard to measure cc/1000 when you don't have a shop and the tools necessary. But on paper it will tell me what mass air flow I need, and that I will be able to measure with my boost gauge to validate. Knowing VE, mass air flow, and EGTs, I can get my cc/1000 shots pretty close to where I calculate them by burning clean. But you are right, I don't necessarily need to know them (unless you are getting close to the limits of your pump). The purpose of this thread is to understand what exactly is going on with the fuel flow and how to get there. Who knows... Someone may use this thread if they send their pump off to a shop.

I have been planning to do what you just suggested. I will record my settings/tune for my pump and post the results so that if someone wants to use it as a baseline, they can. But before I do, I want to understand everything I can about the system.
 

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Exactly and the fuel plate controls rack movement which controls amount of fuel and the curve it's delivered in. Regardless of the Afc the plate will determine the amount of fuel in the end. You can set the Afc to full fuel at 30 psi but if the plate is mid way or rearward then you will be short on fuel.

What I am trying to get at is even though you say 175cc and 30 psi to get X amount of hp. There will be some excited people and disappointed people when they try to mock this and the results are nit what they expected.
I get that you want a recipie where anyone can throw the ingredients in the oven and get a good enough result. But You're talking about the instructions at the fertiliser level rather than " 2.5 inch onion" level.

As we all know, the same amount of fertiliser is going to give different people quite different size onions. But if we specify the size of the onions and the size of the steak during the cooking there's a higher chance that people are going to come out satisfied with the meal. Regardless of the type of fertiliser they are using.

Sometimes it's good to go into depth on some things, but other times it's just complicates things and confuses people.
Hang about and keep reading. It'll start to make a lot more sense. I appreciate that this is working at tuning from the completely different end to most people.
 

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So step 1 for tonights work is to change the power to 222kw (300hp at 740 watts per hp = 222kw).

Results are:
Fuel:
175 cc/1000 shots (getting near the limits of a VE pump).
Air
0.285kg/s (37.7 lb/min).
Boost and Turbo Compressor
36psi.
Turbo compressor PR is 3.45 (getting high for a single).
Air out is 198C
Intercooler air out is 56C.
Turbo shaft power is 50.9kw.
Intercooler heat shed is 40.8kw.
Turbine
Corrected choke flow (this number is basically the size of the turbine) 22.1 lb/min
EGT around 717C.
Turbine PR of 2.89
Drive pressure of 34.4psi (including exhaust outlet pressure of 117Kpa or 17psi giving 2.3psi exhaust restriction).

So from here I want to apply the same fuelling at 2000rpm and see what turbo is capable of that.

2000 rpm investigation:
Variables.
VE I'm using 0.87.
BSFC I'm using 214g/kwh.
Turbo compressor is 70% efficient.
Intercooler is removing 80% of the heat (80% effective).

Results are:
Torque & Power:
797Nm & 167kW.
Fuel:
175 cc/1000 shots (intentionally the same as before).
Air
0.179kg/s (23.6 lb/min).
Boost and Turbo Compressor
27.7psi. (lower due to better VE at lower rpm.
Turbo compressor PR is 2.88
Air out is 168C
Intercooler air out is 50C.
Turbo shaft power is 26.5kw.
Intercooler heat shed is 21.2kw.
Turbine
Corrected choke flow (this number is basically the size of the turbine) 17.7 lb/min
EGT around 710C.
Turbine PR of 2.38
Drive pressure of 23.6psi (including exhaust outlet pressure of 111Kpa or 16psi giving 1.3psi exhaust restriction).

So, at 2000rpm to burn all the fuel we need a smaller turbine on our turbo than the ideal size for max power at 3,200rpm.
The usual way around this is to fit the turbine that gives the required boost at 2000rpm and use a wastegate to bypass some exhaust at higher rpm. This works quite well, the one downside is the smaller turbine has to produce the same power from less flow at 3200rpm (because some flow is diverted around it via the wastegate). This gives higher drive pressures which can cost some power.

Fitting the smaller turbine
So what happens if we put a turbine of the ideal size for 2000rpm max torque on and run it at 3,200rpm?
My calculations show about 9% of the total exhaust needs to be bypassed around the turbine by the wastegate. The turine pressure ratio rises from the 2.89 earlier (giving 34.4psi drive) to 3.28 (41psi drive).
So now our drive pressure is about 5psi higher than boost. This is perfectly acceptable, but it does cost some power. It takes ~8.2kw of power (9hp) to make up for the extra flow restriction. So now our engine likely won't quite make 300hp without some extra boost and fuel. Where with the bigger (but laggier) turbo it would do 300hp.
 

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I threw the above numbers in the Borg Warner Matchbot. It's a great way to check your work, particularly on turbine sizing:
http://www.turbos.bwauto.com//aftermarket/matchbot/index.html#version=1.3&displacement=3.9&CID=237.978&altitude=0&baro=14.706&aat=68&turboconfig=1&compressor=62k80&pt1_rpm=1500&pt1_ve=90&pt1_boost=10&pt1_ie=80&pt1_filres=0.08&pt1_ipd=0.2&pt1_mbp=0.5&pt1_ce=64&pt1_te=70&pt1_egt=1320&pt1_ter=1.46&pt1_pw=NaN&pt1_bsfc=0.35&pt1_afr=18&pt1_wts=300&pt1_wd=83&pt1_wd2=74&pt1_wrsin=69033&pt2_rpm=1800&pt2_ve=88&pt2_boost=15.5&pt2_ie=80&pt2_filres=0.1&pt2_ipd=0.2&pt2_mbp=1&pt2_ce=65&pt2_te=70&pt2_egt=1320&pt2_ter=1.71&pt2_pw=1.1&pt2_bsfc=0.35&pt2_afr=18&pt2_wts=320&pt2_wd=83&pt2_wd2=74&pt2_wrsin=73635&pt3_rpm=2000&pt3_ve=86&pt3_boost=27.7&pt3_ie=80&pt3_filres=0.12&pt3_ipd=0.3&pt3_mbp=1.3&pt3_ce=70&pt3_te=65&pt3_egt=1320&pt3_ter=2.34&pt3_pw=0.05&pt3_bsfc=0.35&pt3_afr=18&pt3_wts=340&pt3_wd=83&pt3_wd2=74&pt3_wrsin=78238&pt4_rpm=2500&pt4_ve=83&pt4_boost=32&pt4_ie=80&pt4_filres=0.15&pt4_ipd=0.3&pt4_mbp=1.5&pt4_ce=68&pt4_te=70&pt4_egt=1320&pt4_ter=2.69&pt4_pw=7.55&pt4_bsfc=0.37&pt4_afr=18&pt4_wts=368&pt4_wd=83&pt4_wd2=74&pt4_wrsin=84681&pt5_rpm=2800&pt5_ve=80&pt5_boost=35&pt5_ie=80&pt5_filres=0.18&pt5_ipd=0.3&pt5_mbp=1.8&pt5_ce=68&pt5_te=70&pt5_egt=1320&pt5_ter=2.96&pt5_pw=9.2&pt5_bsfc=0.38&pt5_afr=18&pt5_wts=400&pt5_wd=83&pt5_wd2=74&pt5_wrsin=92044&pt6_rpm=3200&pt6_ve=74&pt6_boost=36&pt6_ie=80&pt6_filres=0.2&pt6_ipd=0.3&pt6_mbp=2&pt6_ce=70&pt6_te=65&pt6_egt=1320&pt6_ter=3.18&pt6_pw=8.29&pt6_bsfc=0.42&pt6_afr=18&pt6_wts=400&pt6_wd=83&pt6_wd2=74&pt6_wrsin=92044&

Turns out 17.7lb/min is the size of the turbine on the EFR6258 with the 0.8 A/R turbine housing. What is quite interesting is 3200rpm appears past max power. Matchbot is showing slightly more power at 2800rpm. The exact point will depend largely on the engines air consumption and VE.
Port and polish work will move your max power to slightly higher rpm.
 

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Are you figuring in anything for elevation? I know that to run similar sized turbos someone at sea level can use larger turbines and housings where someone in Colorado in the mountains needs smaller housings and wheels. The s472 that was on my 24v ran great in Texas but when I got it to Missouri it was a Smokey pig, and that was roughly 2000ft difference in elevation
 

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Discussion Starter #19
Excellent point Ppump. I am in Utah. That's 4500ft. So yes, I will factor that in, eventually. But it is easier for people to go from standard pressure to their local pressure, than to go from my local pressure to someone else's. We're just creating a baseline for people to work from.
 

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I threw the above numbers in the Borg Warner Matchbot. It's a great way to check your work, particularly on turbine sizing:
http://www.turbos.bwauto.com//aftermarket/matchbot/index.html#version=1.3&displacement=3.9&CID=237.978&altitude=0&baro=14.706&aat=68&turboconfig=1&compressor=62k80&pt1_rpm=1500&pt1_ve=90&pt1_boost=10&pt1_ie=80&pt1_filres=0.08&pt1_ipd=0.2&pt1_mbp=0.5&pt1_ce=64&pt1_te=70&pt1_egt=1320&pt1_ter=1.46&pt1_pw=NaN&pt1_bsfc=0.35&pt1_afr=18&pt1_wts=300&pt1_wd=83&pt1_wd2=74&pt1_wrsin=69033&pt2_rpm=1800&pt2_ve=88&pt2_boost=15.5&pt2_ie=80&pt2_filres=0.1&pt2_ipd=0.2&pt2_mbp=1&pt2_ce=65&pt2_te=70&pt2_egt=1320&pt2_ter=1.71&pt2_pw=1.1&pt2_bsfc=0.35&pt2_afr=18&pt2_wts=320&pt2_wd=83&pt2_wd2=74&pt2_wrsin=73635&pt3_rpm=2000&pt3_ve=86&pt3_boost=27.7&pt3_ie=80&pt3_filres=0.12&pt3_ipd=0.3&pt3_mbp=1.3&pt3_ce=70&pt3_te=65&pt3_egt=1320&pt3_ter=2.34&pt3_pw=0.05&pt3_bsfc=0.35&pt3_afr=18&pt3_wts=340&pt3_wd=83&pt3_wd2=74&pt3_wrsin=78238&pt4_rpm=2500&pt4_ve=83&pt4_boost=32&pt4_ie=80&pt4_filres=0.15&pt4_ipd=0.3&pt4_mbp=1.5&pt4_ce=68&pt4_te=70&pt4_egt=1320&pt4_ter=2.69&pt4_pw=7.55&pt4_bsfc=0.37&pt4_afr=18&pt4_wts=368&pt4_wd=83&pt4_wd2=74&pt4_wrsin=84681&pt5_rpm=2800&pt5_ve=80&pt5_boost=35&pt5_ie=80&pt5_filres=0.18&pt5_ipd=0.3&pt5_mbp=1.8&pt5_ce=68&pt5_te=70&pt5_egt=1320&pt5_ter=2.96&pt5_pw=9.2&pt5_bsfc=0.38&pt5_afr=18&pt5_wts=400&pt5_wd=83&pt5_wd2=74&pt5_wrsin=92044&pt6_rpm=3200&pt6_ve=74&pt6_boost=36&pt6_ie=80&pt6_filres=0.2&pt6_ipd=0.3&pt6_mbp=2&pt6_ce=70&pt6_te=65&pt6_egt=1320&pt6_ter=3.18&pt6_pw=8.29&pt6_bsfc=0.42&pt6_afr=18&pt6_wts=400&pt6_wd=83&pt6_wd2=74&pt6_wrsin=92044&

Turns out 17.7lb/min is the size of the turbine on the EFR6258 with the 0.8 A/R turbine housing. What is quite interesting is 3200rpm appears past max power. Matchbot is showing slightly more power at 2800rpm. The exact point will depend largely on the engines air consumption and VE.
Port and polish work will move your max power to slightly higher rpm.

I should be able to put Dyno numbers to Dougal’s theatrical numbers soon, I’m in the process of building this exact engine with a P-pump and Borg Warner EFR6258, the pump is at the shop now and they will set it for 178 cc/1000 shots.
 
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