Bosch 044 fuel pump bhp limit?

[Hellstrom]

But this isn't a BMW, it's a Toyota Supra and that speaks for itself.

 

if you ever saw a BMW s50b32 head you would wish that you put boost in that instead of the supra head its totally porn. with the intake stremas angeled as a sportbike.

[hodge]

So are you saying I've built a freak of a car that defys the laws of displacement, or are you saying my Dyno results are a load of shizzle.

[JamieP]

Density is getting the air cold, that is done via an intercooler. when compressing air it also produce heat, heat makes the air get less density. afaik there is not other way of getting higher air density then getting it colder. now we are talking about turbo and how effective the turbo is. obviously you need pressure to stuff the Air in to the cylinders. the higher the pressure the more air gets in. a bigger turbo can maintain flow and not heating up the air more then nessesary. however its still the pressure thats push the air into the cylinders. more pressure more air.

 

its abit hard to explain but afaik addin 1bar of boost can never really produce more then 100% more power (yeah like ive said new turbos are incredible good and might actually get 102-105% of power) iam not saying that a small turbo will produce equally as a big one at the same power iam just saying that adding 1bar of boost will not make your eninge more then ca 100% more effective in the best of worlds that is obviosly. some energy will get drained due to heat.

 

Just to get this straight, lets say a TT engine is 200bhp with no turbos, sound about right? you are saying with 1 bar of boost and a GT55-91 it wont make more than 400bhp?

[Hellstrom]

first of the supra tubos are 20year old design and they are no where near as effective as a new turbo. yes that would be the case given that you would use the same exhaust,same intake piping,same intercooler same evertyhing and that that air is the same temprature as with the TT setup.

[Scott]

Density is getting the air cold, that is done via an intercooler. when compressing air it also produce heat, heat makes the air get less density. afaik there is not other way of getting higher air density then getting it colder. now we are talking about turbo and how effective the turbo is. obviously you need pressure to stuff the Air in to the cylinders. the higher the pressure the more air gets in. a bigger turbo can maintain flow and not heating up the air more then nessesary. however its still the pressure thats push the air into the cylinders. more pressure more air.

 

its abit hard to explain but afaik addin 1bar of boost can never really produce more then 100% more power (yeah like ive said new turbos are incredible good and might actually get 102-105% of power) iam not saying that a small turbo will produce equally as a big one at the same power iam just saying that adding 1bar of boost will not make your eninge more then ca 100% more effective in the best of worlds that is obviosly. some energy will get drained due to heat.

 

I started replying to this but the post would end up silly long trying to explain everything.

 

You are correct in saying that the intercooler cools the air. However, that has nothing to do with the efficiency of the initial charge from the turbo. The bigger the compressor wheel the more lag you will get but the more efficent the turbo will be at a certain boost level. If the intake charge pre-intercooler is 100 degrees and the intercooler manages to drop that by 10% then the intake charge will be 90 degrees. If the turbo is less efficient and the intake charge pre-intercooler is 130 degrees with the intercooler only managing 10% the intake charge post intercooler will be 117 degrees... far hotter. The hotter the air, the less oxygen in the volume of air being flowed and the less fuel can be mixed with it.

 

I could go on all night to be honest. It's actually fairly simple once you grasp the basics but it's hard to get that grasp

[Scott]

first of the supra tubos are 20year old design and they are no where near as effective as a new turbo. yes that would be the case given that you would use the same exhaust,same intake piping,same intercooler same evertyhing and that that air is the same temprature as with the TT setup.

 

It wouldn't be the same temperature though as the turbo is far more efficient

[Hellstrom]

So are you saying I've built a freak of a car that defys the laws of displacement, or are you saying my Dyno results are a load of shizzle.

 

honestly hodge i dont know what. iam not trying to shout out that its somting that is bollox here but i honestly dont really see how you can get 900+hp with 1.5 bar using stock valves and using a supra head that is not bad but is not really known for good flow.

 

adding 1bar of boost increase the air with 100% obviously you cool down the air but still getting more then 100% i just dont sound right

[Scott]

honestly hodge i dont know what. iam not trying to shout out that its somting that is bollox here but i honestly dont really see how you can get 900+hp with 1.5 bar using stock valves and using a supra head that is not bad but is not really known for good flow.

 

adding 1bar of boost increase the air with 100% obviously you cool down the air but still getting more then 100% i just dont sound right

 

Your logic for coming up with this theory has no basis though. It just seems like an idea plucked out of the sky.

[Hellstrom]

yeah ofc, but again the turbo cant be more then 100% efficient. iam saying in the best of worlds 1bar will add 100% increase in power. iam not saying that any turbo will do it.

[Scott]

yeah ofc, but again the turbo cant be more then 100% efficient. iam saying in the best of worlds 1bar will add 100% increase in power. iam not saying that any turbo will do it.

 

But you know that isn't true, or at least you should. I don't get what you are saying here? Have a think about it for more than 2 seconds...

 

If you put a GT45 on a toyota supra (180hp as an N/A) it will make WAY more than 360hp at 1.0bar. The stock turbo's make around 100% more power and that's on a set of turbo's built by noah.!

 

I've seen Supras on the stock turbos making around 380hp at 1.0bar, that's an increase of 111%. At 1.2bar the max I have seen is around 430hp.

 

Edit: According to your logic, in order to hit the 600% (and then some) increase that JP has on his car he would need to run 6 bar. Can you not see how mental that logic is?

Edited September 21, 2011 by Scott (see edit history)

[hodge]

honestly hodge i dont know what. iam not trying to shout out that its somting that is bollox here but i honestly dont really see how you can get 900+hp with 1.5 bar using stock valves and using a supra head that is not bad but is not really known for good flow.

 

adding 1bar of boost increase the air with 100% obviously you cool down the air but still getting more then 100% i just dont sound right

 

Please read through my engine spec again, the head has been gas flowed.

Also as a point of interest Suprafan72 made 975hp with a totally stock head and 264 cams.

[Scott]

Please read through my engine spec again, the head has been gas flowed.

Also as a point of interest Suprafan72 made 975hp with a totally stock head and 264 cams.

 

That was at 8bar though

[hodge]

Just to chuck another spanner in the works my Blue supra when running hybrids at 1.5 bar made 450hp ish.

 

Here's a simple equation to work it out.

 

3lt engine + big turbo + lots of fuel = pull your face off SIMPLES.

 

 

I would just like to add to this ermmm discussion that Jamie is running the same sized turbo as mine but the billet version. When my car was dyno'd his boost curve was put on top of mine to compare, and it made my car look like an N/A.

[Hellstrom]

lol you got me thinking. i will try to sorce this in the best possible way and ill come back with a reply tomorrow and well see if i have become any smarter.

[JamieP]

well see if i have become any smarter.

 

Im not holding my breath dude

[CanisLupus]

flow is noting without pressure.

 

with you asumptions a 200mm turbo would produce 1000hp at 0.1bar.

 

Clearly it isn't because flow depends on pressure... Same turbine wheel + higher pressure = more flow. Same pressure + bigger wheel = more flow.

 

Like scott said theoretically it would. Honestly i don't know where you get your linear power figure from 1bar=100% more power that's the first time i hear something like that. In the end everything depends how much air and fuel you get in the cylinder to be exact the more air molecules you get in there the better and stronger the combustion will be and more power is developed.

 

It isn't that easy saying "2bars will get you xxxbhp and that's it" there are to many other things in the equation.

 

 

 

EDIT that many posts while writing this one ^^

[Hellstrom]

dubble post

[Scott]

Clearly it isn't because flow depends on pressure... Same turbine wheel + higher pressure = more flow. Same pressure + bigger wheel = more flow.

 

That's not entirely true as, for a comparison, the volume between the turbo outlet and the head intake would remain constant so the same pressure with a bigger wheel would actually create the same flow only at a lower temperature (the difference being that the larger wheel would be turning much slower and working nowhere near as hard). If you increased the flow of the head and the size of the intake, intercooler, intercooler piping etc then the flow would be greatly increased at the same pressure.

 

That's getting far to complicated for a Wednesday night though.

Edited September 21, 2011 by Scott (see edit history)

[CanisLupus]

That's not entirely true as, for a comparison, the volume between the turbo outlet and the head intake would remain constant so the same pressure with a bigger wheel would actually create the same flow only at a lower temperature (the difference being that the larger wheel would be turning much slower and working nowhere near as hard). If you increased the flow of the head and the size of the intake, intercooler, intercooler piping etc then the flow would be greatly increased at the same pressure.

 

That's getting far to complicated for a Wednesday night though.

 

Rethinking it you're right... but with the lower temps for the same flow density rises and with it power

[Scott]

Rethinking it you're right... but with the lower temps for the same flow density rises and with it power

 

Bingo

[Hellstrom]

You can see pressure is part of the equation but you don't understand

that for a given engine it's peak power rpm is the critical factor deciding how much power it makes.

 

HP equals: torque in ft/lbs X RPM divided by 5252

 

The engine running the bigger turbo will have more airflow: it makes it's torque peak higher and makes more horse power at high rpm. One of the turbo setups is not fully servicing the engine, the other is doing better. If you had detailed info you would see that the higher powered set up was revving a lot harder.

The same factors that limit na HP also limit turbo hp. There is no magic pudding; that is why the 150 hp per litre F1 engines still needed to rev to over 10000 rpm with 60 psi in the intake to make their grunt.

 

You can increase an engines power by increasing the torque at the same rpm or increasing the rpm and maintaining the torque.

 

You can increase the peak hp of an engine dramatically but lower the rpm at which the peak is made by turbocharging it. That is in fact what most manufacturers do when they turbo. Garden variety engines like 2jz's are boosted so that they behave like a bigger engine- a 4.5 or 5 litre type torque output. An OE factory turbo 2j makes more than 50% of the torque and peak horse power of the engine it is based on despite reductions in comp ratio and manifolding efficiency. It makes this extra power at lower rpm.

 

A std NA 2jz according to Wiki makes about 220 hp at 6000 rpm and requires 192 lb/ft to do it:

 

192 lb/ft x 6000 rpm divided by 5252 = 219.3 hp

 

 

If that engine was boosted to 20 psi (1.38 bar) or 34.7 psi absolute, at 100% efficiency it would be good for 220 + 1.38 x 220 = 303.6

so 523 hp at 6000 rpm and 457 lb/ft.

 

If turbocharging the engine 'uncorked' it by reducing exhaust back pressure, improving inlet flow and fuel quality then the increases at 20 lb boost would be greater. It might make the equivalent 250 NA hp at slightly higher rpm. Boosted to 20 psi, and at a theoretical, unachievable 100% efficiency, it would be good for 595 hp.

 

To get the output you are claiming, 650 rwhp, or using my 15% transmission allowance, 747.5 hp at the crank implies a na output of over 105 hp per litre. Highly unlikely.

[Scott]

You can see pressure is part of the equation but you don't understand

that for a given engine it's peak power rpm is the critical factor deciding how much power it makes.

 

HP equals: torque in ft/lbs X RPM divided by 5252

 

The engine running the bigger turbo will have more airflow: it makes it's torque peak higher and makes more horse power at high rpm. One of the turbo setups is not fully servicing the engine, the other is doing better. If you had detailed info you would see that the higher powered set up was revving a lot harder.

The same factors that limit na HP also limit turbo hp. There is no magic pudding; that is why the 150 hp per litre F1 engines still needed to rev to over 10000 rpm with 60 psi in the intake to make their grunt.

 

You can increase an engines power by increasing the torque at the same rpm or increasing the rpm and maintaining the torque.

 

You can increase the peak hp of an engine dramatically but lower the rpm at which the peak is made by turbocharging it. That is in fact what most manufacturers do when they turbo. Garden variety engines like 2jz's are boosted so that they behave like a bigger engine- a 4.5 or 5 litre type torque output. An OE factory turbo 2j makes more than 50% of the torque and peak horse power of the engine it is based on despite reductions in comp ratio and manifolding efficiency. It makes this extra power at lower rpm.

 

A std NA 2jz according to Wiki makes about 220 hp at 6000 rpm and requires 192 lb/ft to do it:

 

192 lb/ft x 6000 rpm divided by 5252 = 219.3 hp

 

 

If that engine was boosted to 20 psi (1.38 bar) or 34.7 psi absolute, at 100% efficiency it would be good for 220 + 1.38 x 220 = 303.6

so 523 hp at 6000 rpm and 457 lb/ft.

 

If turbocharging the engine 'uncorked' it by reducing exhaust back pressure, improving inlet flow and fuel quality then the increases at 20 lb boost would be greater. It might make the equivalent 250 NA hp at slightly higher rpm. Boosted to 20 psi, and at a theoretical, unachievable 100% efficiency, it would be good for 595 hp.

 

To get the output you are claiming, 650 rwhp, or using my 15% transmission allowance, 747.5 hp at the crank implies a na output of over 105 hp per litre. Highly unlikely.

 

What is the N/A output of JPs car given that equation you have? What about the 2000hp white Supra?

 

It makes no sense bud.

 

An N/A running 20psi wouldn't make anywhere near 595hp on a GT35r, but it would make way more on a GT45.

 

How are you not getting this?

Edited September 21, 2011 by Scott (see edit history)

[Hellstrom]

Estimating Required Air Mass Flow and Boost Pressures to reach a Horsepower target.

 

· Things you need to know:

· Horsepower Target

· Engine displacement

· Maximum RPM

· Ambient conditions (temperature and barometric pressure. Barometric pressure is usually given as inches of mercury and can be converted to psi by dividing by 2)

 

· Things you need to estimate: · Engine Volumetric Efficiency. Typical numbers for peak Volumetric Efficiency (VE) range in the 95%-99% for modern 4-valve heads, to 88% - 95% for 2-valve designs. If you have a torque curve for your engine, you can use this to estimate VE at various engine speeds. On a well-tuned engine, the VE will peak at the torque peak, and this number can be used to scale the VE at other engine speeds. A 4-valve engine will typically have higher VE over more of its rev range than a two-valve engine.

 

· Intake Manifold Temperature. Compressors with higher efficiency give lower manifold temperatures. Manifold temperatures of intercooled setups are typically 100 - 130 degrees F, while non-intercooled values can reach from 175-300 degrees F.

 

· Brake Specific Fuel Consumption (BSFC). BSFC describes the fuel flow rate required to generate each horsepower. General values of BSFC for turbocharged gasoline engines range from 0.50 to 0.60 and higher. The units of BSFC are

Lower BSFC means that the engine requires less fuel to generate a given horsepower. Race fuels and aggressive tuning are required to reach the low end of the BSFC range described above.

 

For the equations below, we will divide BSFC by 60 to convert from hours to minutes.

 

To plot the compressor operating point, first calculate airflow:

 

 

 

 

Where:

· Wa = Airflowactual (lb/min)

· HP = Horsepower Target (flywheel)

· = Air/Fuel Ratio

· = Brake Specific Fuel Consumption ( ) ÷ 60 (to convert from hours to minutes)

 

 

EXAMPLE:

 

I have an engine that I would like to use to make 400Hp, I want to choose an air/fuel ratio of 12 and use a BSFC of 0.55. Plugging these numbers into the formula from above:

 

of air.

 

Thus, a compressor map that has the capability of at least 44 pounds per minute of airflow capacity is a good starting point.

 

Note that nowhere in this calculation did we enter any engine displacement or RPM numbers. This means that for any engine, in order to make 400 Hp, it needs to flow about 44 lb/min (this assumes that BSFC remains constant across all engine types).

 

Naturally, a smaller displacement engine will require more boost or higher engine speed to meet this target than a larger engine will. So how much boost pressure would be required?

 

◊ Calculate required manifold pressure required to meet the horsepower, or flow target:

 

 

 

 

Where:

 

· MAPreq = Manifold Absolute Pressure (psia) required to meet the horsepower target

· Wa = Airflowactual(lb/min)

· R = Gas Constant = 639.6

· Tm = Intake Manifold Temperature (degrees F)

· VE = Volumetric Efficiency

· N = Engine speed (RPM)

· Vd = engine displacement (Cubic Inches, convert from liters to CI by multiplying by 61.02, ex. 2.0 liters * 61.02 = 122 CI)

 

EXAMPLE:

 

To continue the example above, let’s consider a 2.0 liter engine with the following description:

 

· Wa = 44 lb/min as previously calculated

· Tm = 130 degrees F

· VE = 92% at peak power

· N = 7200 RPM

· Vd = 2.0 liters * 61.02 = 122 CI

 

 

 

= 41.1 psia (remember, this is absolute pressure. Subtract atmospheric pressure to get gauge pressure (aka boost):

 

41.1 psia – 14.7 psia (at sea level) = 26.4 psig boost

 

As a comparison let’s repeat the calculation for a larger displacement 5.0L (4942 cc/302 CI) engine.

 

Where:

 

· Wa = 44 lb/min as previously calculated

· Tm = 130 degrees F

· VE = 85% at peak power (it is a pushrod V-8)

· N = 6000 RPM

· Vd = 4.942*61.02= 302 CI

 

 

= 21.6 psia (or 6.9 psig boost)

 

This example illustrates in order to reach the horsepower target of 400 hp, a larger engine requires lower manifold pressure but still needs 44lb/min of airflow. This can have a very significant effect on choosing the correct compressor.

 

With Mass Flow and Manifold Pressure, we are nearly ready to plot the data on the compressor map. The next step is to determine how much pressure loss exists between the compressor and the manifold. The best way to do this is to measure the pressure drop with a data acquisition system, but many times that is not practical.

 

Depending upon flow rate, charge air cooler characteristics, piping size, number/quality of the bends, throttle body restriction, etc., the plumbing pressure drop can be estimated. This can be 1 psi or less for a very well designed system. On certain restrictive OEM setups, especially those that have now higher-than-stock airflow levels, the pressure drop can be 4 psi or greater.

 

For our examples we will assume that there is a 2 psi loss. So to determine the Compressor Discharge Pressure (P2c), 2 psi will be added to the manifold pressure calculated above.

 

 

 

 

Where:

 

· P2c = Compressor Discharge Pressure (psia)

· MAP = Manifold Absolute Pressure (psia)

· ΔPloss = Pressure Loss Between the Compressor and the Manifold (psi)

 

For the 2.0 L engine:

 

 

= 43.1 psia

 

For the 5.0 L engine:

 

 

= 23.6 psia

 

Remember our discussion on inlet depression in the Pressure Ratio discussion earlier, we said that a typical value might be 1 psi, so that is what will be used in this calculation. For this example, assume that we are at sea level, so ambient pressure is 14.7 psia.

 

We will need to subtract the 1 psi pressure loss from the ambient pressure to determine the Compressor Inlet Pressure (P1).

 

 

 

 

Where:

 

· P1c = Compressor Inlet Pressure (psia)

· Pamb = Ambient Air pressure (psia)

· ΔPloss = Pressure Loss due to Air Filter/Piping (psi)

 

 

P1c = 14.7 - 1

 

= 13.7 psia

 

With this, we can calculate Pressure Ratio () using the equation.

 

 

 

For the 2.0 L engine:

 

 

 

= 3.14

 

For the 5.0 L engine:

 

 

 

= 1.72

 

We now have enough information to plot these operating points on the compressor map. First we will try a GT2860RS. This turbo has a 60mm, 60 trim compressor wheel.

[Hellstrom]

sorry for the wall of text, Taken from Garrets homepage. Iam enjoying reading this myself iam not trying to make a statement here. iam just intrested myself as how this actually work as i might actually learn somthing from this myself.

[Scott]

I don't see answers to my questions bud, back up what you are furiously googling by putting it into practice. How much N/A power is JPs car running?