Just another 450whp Turbo FT86 -- and NOW 530hp

[Jaden]

Originally Posted by Ross

In what bizaro world is 550hp worth of air 800hp? Also you apparently read right past my statement about other brands, or maybe I should have been more clear. By other brands I am referring to other automotive manufacturer based engines. You made a blanket statement in regard to 2.0l not just the fa20.

As I previously stated the exhaust side of the head and camshaft selection, ect are the limitations of this engine. The cost to develop the parts needed to make the fa20 comparable to other brand engines is just not justifiable. If I want to go after a 1k hp 4cyl I will choose a better starting option then a subaru based engine.

Also for a good flowing 6.2l engine I would look more to 75mm to 80mm turbo. Typicall 72mm based turbo exhaust wheels cam become a point of restriction with something like the ls3. It's turbo so it is only a mac valve away from more boost.

At sea level CFM = lbs per minute / .069. edit, this is to find cfm then Horsepower = CFM X .73

There are some variance but very little and obviously, it changes the higher in elevation you get where the air is thinner.

If you want to find the boost ratio, you add boost to 14.7 and divide by 14.7. Then you can look at a compressor map to find the flow rate at the boost ratio.

Flow rate is a REALLY good indicator of hp. IF you want to find the hp a turbo is capable of at a given boost ratio, you find the boost ratio on the compressor map, that will give you the flow rate and then divide the flow rate in lbs/min by .069 for sea level or raise it a bit if you're at a higher elevation to find CFM and use Horsepower = (cfm × .73)

That's just what the compressor of the turbo/SC is CAPABLE of though. The engine has to be capable of flowing that much air at the boost level.

Figure out the boost level that you want to run and understand that the boost level provides however much more air over ambient the boost is. 14.7 is ambient at sea level so a boost of 7 psi is ~48% more air than ambient.

If the engine flows enough air N/A to make 200 whp, then at 7 psi it should flow approximately 48% more than that.

Guess what... if you look at real world examples, you'll find that 7 lbs of boost typically means 40-60% more power. The only time that compressor flow rates come into play is when the compressor flows LESS than the engine can at THAT boost level. Then a bigger turbo will increase power UP TO the level that the engine can process. The up to 60% is because boosted air is flowing faster so with the same duration and lift as when it was N/A it will get a little more air than the charge might suggest, but that doesn't change the finite nature of the displacement.

Jaden

p.s. at 3500ft ambient is ~12.9psi so 7psi of boost becomes ~55% more... Now this doesn't allow for higher velocity air compared to N/A and or smaller turbos that are less efficient, but you are still dealing with a finite volume of cylinder and stroke, so you are not going to get 125% more air at 7 psi of boost, I don't care HOW efficient all of your components are...and your baseline at 3500ft should be lower because of less dense air and less oxygen.

edited to reflect conversion to hp from CFM...

[Ross]

That is funny, every car I tune is typically 1lb a min = 10hp. Give or take a hp or so. Calculated airflow 42 lb a min, dyno power 420 hp, calculated airflow 80lb a min, dyno 800hp. I am also at sea level. There is more to making power then assuming 100% efficient engine. But I have to run, this twin turbo ls will not finish it self. You may want to look further into your math.

[EAGLE5]

Originally Posted by Jaden

I'll GIVE VIT $100 if he makes 500hp on 7 psi on an FA20...without grenading the motor with stock heads and not stroked or bored.
Jaden

Should he have the stock exhaust, stock fuel system, and stock map too? 87 octane only? How about the stock turbo?

[Jaden]

Originally Posted by jsimon7777

Should he have the stock exhaust, stock fuel system, and stock map too? 87 octane only? How about the stock turbo?

I thought that these heads flow like a V8? LOL, obviously more displacement means more flow...

He argued that nothing matters but a higher flowing turbo...I'm not the one changing shit...

Jaden

I explained how it really works... and no he's not going to get 500 hp on 7 psi even on a stroker 2.1 with the highest flowing heads he can imagine. There is simply NOT ENOUGH DISPLACEMENT.. I don't know how much more plain this can be made... The engine's volume simply doesn't allow for 500 hp on 7 lbs of boost...If you're not making 300+hp N/A, you're NOT going to make 500hp on 7 psi of boost...sorry...

[Jaden]

Originally Posted by Ross

That is funny, every car I tune is typically 1lb a min = 10hp. Give or take a hp or so. Calculated airflow 42 lb a min, dyno power 420 hp, calculated airflow 80lb a min, dyno 800hp. I am also at sea level. There is more to making power then assuming 100% efficient engine. But I have to run, this twin turbo ls will not finish it self. You may want to look further into your math.

sorry I was leaving off conversion from CFM to hp, that's to get CFM from lbs/min..

regardless, change it to 80 lbs/min, doesn't make a difference. enough flow to make 800 hp.

Jaden

[VitViper]

Originally Posted by Jaden

In order for this engine or ANY 2.0l engine for that matter, to make 500hp at 7 psi of boost, it would need to have the flow N/A to make 320hp, because no matter WHAT you do, you will only be able to increase the amount of air that fits in the given volume ~48 % at 7 psi of boost.

You'll find that an otherwise stock ls3 will make about 525-530 whp at 7psi because it makes about 360whp n/a.

That is the reality, you want more, you increase the static flow or you increase the boost, those are your ONLY options. Bigger turbo will NOT add more than 48% additional airflow at 7 psi of boost. That's pretty much the DEFINITION of boost...

Jaden

You really did miss the whole point of comment, it's actually quite amusing. But I'll spell it out for you.

Boost. Is. Irrelevant.

20psi vs 7psi, who cares what the boost level is if they both make 500hp and the motor "breaks" at 500hp? Does the "boost" break the motor, or does the power? Which one is it? LOL


But for you talking in absolutes -- I made ~490whp on ~9-10psi on a 67mm turbo not too long ago. On a 2.0L motor. On E75 at that. What do you think this motor would make if I dropped it on straight methanol?

You have a very poor understanding of turbos, engines & power production, from what I can tell.

[Jaden]

Originally Posted by VitViper

You really did miss the whole point of comment, it's actually quite amusing. But I'll spell it out for you.

Boost. Is. Irrelevant.

20psi vs 7psi, who cares what the boost level is if they both make 500hp and the motor "breaks" at 500hp? Does the "boost" break the motor, or does the power? Which one is it? LOL


But for you talking in absolutes -- I made ~490whp on ~9-10psi on a 67mm turbo not too long ago. On a 2.0L motor. On E75 at that. What do you think this motor would make if I dropped it on straight methanol?

You have a very poor understanding of turbos, engines & power production, from what I can tell.

I didn't miss shit. You people are missing the fact that you have to be able to fit the oxygen in the fucking chamber to make as much power as you want.
Power production is all about oxygen content. If you add more oxygen it will make more power. If the internals can take it you can add a500 shot of nitrous along with 200 nA and make 700hp but even then only if there's enough displacement to fit 200hp of air and 500hp worth of no...lol

If you made 490 hp on 10 psi then your car was capable of making aprox. 260hp na.


But if you don't understand there is a finite amount of oxygen you can fit at a given boost level without other power adders, you just don't understand engines at all.
Jaden

[Spartarus]

Originally Posted by VitViper

What if I told you... boost is irrelevant?

I can drop a 72mm turbo on the car and make 500hp on 7psi.

What then?

OK. I've watched pedantic people argue over this, and try and fail to understand it for too many pages.

I'm going to say a few things. If you want to argue about it, we'll do some math together. It's going to be fun.

We get it, "boost is irrelevant" you took the red pill and woke up outside the matrix and you know Kung Fu.

"Boost is Irrelevant" is a neat statement. It's actually quite an interesting thought experiment in how turbos work. Contextually, it can even be a correct statement, but I take exception to it because it isn't universally true. We both know that.

That statement, alone, without an explanation is misleading at best.

Proof positive that several people have spent pages arguing that it is relevant, and they're not completely wrong, they just don't understand it well enough to tell you why.

Boost is a dependent variable, and thus, cannot be divorced from the rest of the equation.

Period.

You can change the other variables (to a certain degree, within limits) independently of "boost" and create different amounts of horsepower. But to say unconditionally that it's irrelevant is as callous as saying RPM's are irrelevant in relation to speed. The contexts in which those two statements are correct are similarly narrow.

We can bust out the math if you like.

[Jaden]

Originally Posted by Spartarus

OK. I've watched pedantic people argue over this, and try and fail to understand it for too many pages.

I'm going to say a few things. If you want to argue about it, we'll do some math together. It's going to be fun.

We get it, "boost is irrelevant" you took the red pill and woke up outside the matrix and you know Kung Fu.

"Boost is Irrelevant" is a neat statement. It's actually quite an interesting thought experiment in how turbos work. Contextually, it can even be a correct statement, but I take exception to it because it isn't universally true. We both know that.

That statement, alone, without an explanation is misleading at best.

Proof positive that several people have spent pages arguing that it is relevant, and they're not completely wrong, they just don't understand it well enough to tell you why.

Boost is a dependent variable.

Period.

We can bust out the math if you like.

I explained how boost works and gave the math to explain it and volumetric efficiency but people are so fucking stuck on bigger turbo more power, they look right past it all.

I even explained the damn circumstances where a bigger turbo WILL make more power and how much more it should make.

7psi will never make more than 65 percent more power give or take a small amount because of volumetric efficiency. It simply doesn't matter how big a turbo you use the displacement won't allow it. The way a bigger turbo makes more power is by having a cooler more dense air charge by more efficient boost, by having a faster airflow to get it into the chamber faster with the same duration of valve opening and WITHIN the limits of the displacement. Anything beyond the limits of displacement requires higher boost to make more power or a different type of oxygen enrichment that is even more dense and can fit better in the same amount of displacement.

Jaden

[EAGLE5]

Spartarus puts it nicely. You can change rpm, fuel, temperature, air 02 %, the head, valves, the header, cams, timing, octane, impeller size, penis size, and so on. They'll all affect the HP. That said, the original claim was 500HP on a 72mm turbo with a 2.0 liter engine. I'd hazard a guess that with enough rpm, e85, good air temperatures, and timing, 500HP is completely doable at 7psi on an FA20.

[VitViper]

Originally Posted by Jaden

I didn't miss shit. You people are missing the fact that you have to be able to fit the oxygen in the fucking chamber to make as much power as you want.
Power production is all about oxygen content. If you add more oxygen it will make more power. If the internals can take it you can add a500 shot of nitrous along with 200 nA and make 700hp but even then only if there's enough displacement to fit 200hp of air and 500hp worth of no...lol

If you made 490 hp on 10 psi then your car was capable of making aprox. 260hp na.


But if you don't understand there is a finite amount of oxygen you can fit at a given boost level without other power adders, you just don't understand engines at all.
Jaden

Yes you did, my post was in context to arguing boost levels as a contributing factor to motors breaking. 500hp is 500hp regardless of how it was made. If that's the breaking point of a motor, it doesn't matter if your turbo was pushing 7psi or 20psi.


You also stated 500hp on 7psi is not possible on any 2L, which is completely false as it's been done for years on SFWD drag cars, they make 700hp on 15psi and don't even dyno any less as most of them can't make less "boost".

[VitViper]

Originally Posted by Spartarus

OK. I've watched pedantic people argue over this, and try and fail to understand it for too many pages.

I'm going to say a few things. If you want to argue about it, we'll do some math together. It's going to be fun.

We get it, "boost is irrelevant" you took the red pill and woke up outside the matrix and you know Kung Fu.

"Boost is Irrelevant" is a neat statement. It's actually quite an interesting thought experiment in how turbos work. Contextually, it can even be a correct statement, but I take exception to it because it isn't universally true. We both know that.

That statement, alone, without an explanation is misleading at best.

Proof positive that several people have spent pages arguing that it is relevant, and they're not completely wrong, they just don't understand it well enough to tell you why.

Boost is a dependent variable, and thus, cannot be divorced from the rest of the equation.

Period.

You can change the other variables (to a certain degree, within limits) independently of "boost" and create different amounts of horsepower. But to say unconditionally that it's irrelevant is as callous as saying RPM's are irrelevant in relation to speed. The contexts in which those two statements are correct are similarly narrow.

We can bust out the math if you like.

The argument was about engine breaking at X or Y Power level. My response was in this context and I can't fathom why anyone would take it any other way.

Now we can start talking shaft speeds to make it more interesting...

[Jaden]

Originally Posted by VitViper

Yes you did, my post was in context to arguing boost levels as a contributing factor to motors breaking. 500hp is 500hp regardless of how it was made. If that's the breaking point of a motor, it doesn't matter if your turbo was pushing 7psi or 20psi.


You also stated 500hp on 7psi is not possible on any 2L, which is completely false as it's been done for years on SFWD drag cars, they make 700hp on 15psi and don't even dyno any less as most of them can't make less "boost".

If you are talking about boost being the only oxygen adder, then no 500hp is not possible at 7psi.my response was in regards to a bigger turbo allowing an fa20 to make 500hp on 7psi.

Sure you can make 500na if you use nitro methane, but that wasn't what was stated. It was stated what if I told you I could throw a72mm turbo and make 500hp at 7si and I said id say that wasn't possible because just throwing a72mm or even a90mm turbo won't let you make 500hp on a2l motor at 7psi.there's just not enough displacement.

The only way to make that much power on a 2l motor is by adding more oxygen content than you can fit in the engine at 7psi.

I mean then I had someone come in and day they were making 490 at 10 psi,well that's not 500,and that's not 7 psi.

10 psi is more than 15-20 percent more oxygen than 7 psi.so duh you're going to make more power.

Jaden

[Spartarus]

Originally Posted by Jaden

I explained how boost works and gave the math to explain it and volumetric efficiency ...

Did you? Let's examine the statement.

Originally Posted by Jaden

At sea level CFM = lbs per minute / .069. edit, this is to find cfm then Horsepower = CFM X .73

There are some variance but very little and obviously, it changes the higher in elevation you get where the air is thinner.

If you want to find the boost ratio, you add boost to 14.7 and divide by 14.7. Then you can look at a compressor map to find the flow rate at the boost ratio.

Flow rate is a REALLY good indicator of hp. IF you want to find the hp a turbo is capable of at a given boost ratio, you find the boost ratio on the compressor map, that will give you the flow rate and then divide the flow rate in lbs/min by .069 for sea level or raise it a bit if you're at a higher elevation to find CFM and use Horsepower = (cfm × .73)

That's just what the compressor of the turbo/SC is CAPABLE of though. The engine has to be capable of flowing that much air at the boost level.

Figure out the boost level that you want to run and understand that the boost level provides however much more air over ambient the boost is. 14.7 is ambient at sea level so a boost of 7 psi is ~48% more air than ambient.

If the engine flows enough air N/A to make 200 whp, then at 7 psi it should flow approximately 48% more than that.

Guess what... if you look at real world examples, you'll find that 7 lbs of boost typically means 40-60% more power. The only time that compressor flow rates come into play is when the compressor flows LESS than the engine can at THAT boost level. Then a bigger turbo will increase power UP TO the level that the engine can process. The up to 60% is because boosted air is flowing faster so with the same duration and lift as when it was N/A it will get a little more air than the charge might suggest, but that doesn't change the finite nature of the displacement.

Jaden

p.s. at 3500ft ambient is ~12.9psi so 7psi of boost becomes ~55% more... Now this doesn't allow for higher velocity air compared to N/A and or smaller turbos that are less efficient, but you are still dealing with a finite volume of cylinder and stroke, so you are not going to get 125% more air at 7 psi of boost, I don't care HOW efficient all of your components are...and your baseline at 3500ft should be lower because of less dense air and less oxygen.

edited to reflect conversion to hp from CFM...

I'm going to offer some advice. Present statements beyond your experiential understanding as questions, not assertions, because they're a lot easier to eat when you're wrong.

I'm not going to pick apart every detail exhaustively, because even if anybody bothers to read it, it won't be informative. If people want the real equations, I'll post them separately.

Your mass flow to Volumetric flow equation is wrong, and lacks units. Air density at ISA is .765 Pounds per Cubic foot, not ".69...god knows what units".

Don't throw out numbers without units. It makes them meaningless.

Calculating horsepower from Volumetric flow by multiplying by a constant is not correct, not even as a "rule of thumb." It's missing too many variables to be accurate in any situation. To get anywhere close to HP from airflow we need to discuss Specific Fuel Consumption and how tuning affects that number.

"boost ratio" equation is only good at sea level. You can not simply look up flow rate for a given pressure ratio on a compressor map. It's a whole other axis. You need both points (pressure ratio and flow) to plot a point on a compressor map. It involves a lot more math.

Flow rate is NOT a really good indicator of HP. Period.

Your 48% argument assumes that Volumetric Efficiency does not change with turbocharging. This is perhaps one of the most interesting aspects of turbocharging, especially in the last few years as turbos have become efficient enough to where manifold absolute pressure is higher than turbine inlet pressure in certain cases..

We are not even ready to discuss altitude and shaft speed yet.

There is a lot more to tuning than the basic numbers.

Here's a thought to chew on. I used to own a 4-banger motorbike that made 205.1 Horsepower per liter.

Guess how much boost? ...The hell with it, it'll spoil the fun. It was naturally aspirated. And bone stock.

More thought-experiment material. Upsizing the valves on this car actually costs NA horsepower, but add a turbo and suddenly +1mm valves are enough to carry the powerband all the way to to 9000 RPM.

Originally Posted by Jaden

If you are talking about boost being the only oxygen adder, then no 500hp is not possible at 7psi

Of course 500 HP is possible on 7 PSI. Whether it's possible on the bone-stock engine is ... Going to be interesting.

"Big turbos" are my job. Except mine don't have a silly reciprocating engine shoe-horned in between the compressor and the turbine.