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Just a quick post, I've seen some interest regarding the LSX-B15 engine. I purchased a long block and spent the past year building it with many custom upgrades, nothing crazy, and zero porting anywhere! I kept a build journal, parts, vendors, etc... Just a few things: The PWM fuel system works excellent, no need for a booster or return system. Need DW300c pumps, 80-90psi PRV, and 1050x injectors. The important thing is to make sure and update the tables in both the engine ECM and FPCM. My fuel pressure is set to 40psi min and 55psi max. I tuned a safe MAF tune, still working on a few fuel points. Latest numbers are 1250lbs at 5600rpm with 16lbs of boost. Stock blower with brick upgrade, ZL1 lid w/ 1/2" lid spacer, 2.5" upper, 15% lower. Pretty impressive numbers I say, stock LS7 cam is smooth, idle set to 850rpm. When tuning it is important to enter correct data, cam timing values, throttle body values, cold air inlet diameter, to name a few. Ask your tuner what values they entered for your throttle body upgrade, or better yet, did they tune your FPCM, update the injector data? There are many tables that need to be properly updated and street calibrated. If the fuel is not dialed in, air not dialed in, calibrated, you will have poor performance, knock, and zero benefits from mods. The B15 iron block has no flex, .2" thick siamese cylinder walls, priority main oiling, additional bolt pattern for the heads, etc... It is a monster from the factory right out of the crate, no need to do anything internal! If you are familiar with numbers, you can see just looking at mine running on 92 at 10.07 AFR WOT there are no magic tricks, just huge power. I don't get around to posting very often, but I will be happy to try and answer questions relating to LSX swap.
PS: 1000hp is a cake walk for these engines, current oil pressure 30psi normal, around 50psi WOT, dual Spal 1360 fans set for constant at 90% duty, track temps 190 engine 190 oil. tr6060 stock, Creative Steel engine mounts, one piece Gulf Coast shaft, Mcleod clutch, ATI Super Damper, need to re-scale the spark tables from 1.36 to 3.0, current WOT cylinder air mass is 2.63.
kittyboy
 

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1250 ft lbs with ls7 cam and stock blower… on pump 92?

Wait for it!
 

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Just a quick post, I've seen some interest regarding the LSX-B15 engine. I purchased a long block and spent the past year building it with many custom upgrades, nothing crazy, and zero porting anywhere! I kept a build journal, parts, vendors, etc... Just a few things: The PWM fuel system works excellent, no need for a booster or return system. Need DW300c pumps, 80-90psi PRV, and 1050x injectors. The important thing is to make sure and update the tables in both the engine ECM and FPCM. My fuel pressure is set to 40psi min and 55psi max. I tuned a safe MAF tune, still working on a few fuel points. Latest numbers are 1250lbs torque at 5600rpm with 16lbs of boost. Stock blower with brick upgrade, ZL1 lid w/ 1/2" lid spacer, 2.5" upper, 15% lower. Pretty impressive numbers I say, stock LS7 cam is smooth, idle set to 850rpm. When tuning it is important to enter correct data, cam timing values, throttle body values, cold air inlet diameter, to name a few. Ask your tuner what values they entered for your throttle body upgrade, or better yet, did they tune your FPCM, update the injector data? There are many tables that need to be properly updated and street calibrated. If the fuel is not dialed in, air not dialed in, calibrated, you will have poor performance, knock, and zero benefits from mods. The B15 iron block has no flex, .2" thick siamese cylinder walls, priority main oiling, additional bolt pattern for the heads, etc... It is a monster from the factory right out of the crate, no need to do anything internal! If you are familiar with numbers, you can see just looking at mine running on 92 at 10.07 AFR WOT there are no magic tricks, just huge power. I don't get around to posting very often, but I will be happy to try and answer questions relating to LSX swap.
PS: 1000hp is a cake walk for these engines, current oil pressure 30psi normal, around 50psi WOT, dual Spal 1360 fans set for constant at 90% duty, track temps 190 engine 190 oil. tr6060 stock, Creative Steel engine mounts, one piece Gulf Coast shaft, Mcleod clutch, ATI Super Damper, need to re-scale the spark tables from 1.36 to 3.0, current WOT cylinder air mass is 2.63.
kittyboy
To produce 1000 hp assuming the engine is efficisn’t, the engine will require 1500 CFM.

Nothing happens until the piston moves.
Once the piston moves it generates a CFM demand.

Piston CFM demand is linked to engine RPM.

Have you calculated what engine RPM would be required to generate sufficient piston speed to produce the required piston CFM demand?
 
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Just in case your wondering, that is a rhetorical question. Bruce already knows that answer! Haha
 

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Just in case your wondering, that is a rhetorical question. Bruce already knows that answer! Haha
We also have not yet discussed the no porting required statement… Lol
 
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That's got to be a computer reading. Not a dyno #.
I think somewhere someone has assumed that if one doubles the air pressure in the intake manifold one will double the horsepower…’NOT’!
 
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Must still be calculating…
 
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See attached image, CFM was not my point, I was primarily sharing that expanding the spark table will help to more accurately adjust timing based on increased cylinder air mass, and yes there is a good amount of enrichment at this level.
Most of us who have been on this forum since its about the
time of its inception, have answered many of the same
questions, many times.

Today it helps us to add a little well meaning humor to our posts..;)
So some of us have just bee 'Bustin Your Balls' in good spirit ..lol

The GM lsX Iron Block is a good engine for most on this forum to upgrade to.
There are better alternatives, but for the most that block will serve one very well.

-back to your statement-
You wrote:
"PS: 1000hp is a cake walk for these engines"

That statement inferred that one can easily make 1000 HP.
I am not inferring that is not what you meant, but it still came across that way.

We have many members on this forum who never post, but
read every post in an attempt to learn.

If a post is confusing, then its best to clarify it.. ;)

So let's go over the math that will give us the engine rpm required to inhale 1500 cfm, which is the value required of an 'Efficient Engine' to generate ~1000fwHP.

Assuming the engine is an NA 376 cid. . .
=> (1500 * 3456)= 5,184,000
=> (5,184,000 / 376)=13,787 rpm required of an NA_Engine.

-what about an FI Engine-
That value would be reduced by the 'Density Ratio' of the blower.

For simple roots blowers:
Typically one uses the square root of the absolute pressure ratio to solve for density ratio.

So then, assuming the absolute pr is 2.0;
=> (2.0^0.5)= 1.41
***Raising the value of 2.0 by ^0.5 is the same as taking
the square root of a value on your calculator.

If the above is true, then we can assume the following:
=> (13,787 / 1.41)= 9,749 rpm required_FI Engine..

The above is simply an example of the math used to solve for
the required engine rpm, assuming the density ratio is 1.41.

If one's engine is equipped with an highly efficient mass flow
recovery system, then a percentage of the 59% lost to heat
due to the adiabatic process can be recovered.

Let's assume the mass flow recovery system recovered
half of the 59%, or 29.5%.

If we add the value of 29.5 to the value of 1.41 we arrive at a sum of 1.71.

We would then have a requirement that the engine be spun to. ..
=> (13,787 / 1.71)= 8,086 rpm.


-regarding simple dd / pd roots blowers-
Finally, if one desires to double the hp using forced induction, then
one would be required to inhale 4-Times the air. . ..

This is because the square root of four (4) equals 2.0. .. .

Cheers
 

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Just a quick post, I've seen some interest regarding the LSX-B15 engine. I purchased a long block and spent the past year building it with many custom upgrades, nothing crazy, and zero porting anywhere! I kept a build journal, parts, vendors, etc... Just a few things: The PWM fuel system works excellent, no need for a booster or return system. Need DW300c pumps, 80-90psi PRV, and 1050x injectors. The important thing is to make sure and update the tables in both the engine ECM and FPCM. My fuel pressure is set to 40psi min and 55psi max. I tuned a safe MAF tune, still working on a few fuel points. Latest numbers are (Correction IS 1150lbs NOT 1250lbs) at 5600rpm with 16lbs of boost. Stock blower with brick upgrade, ZL1 lid w/ 1/2" lid spacer, 2.5" upper, 15% lower. Pretty impressive numbers I say, stock LS7 cam is smooth, idle set to 850rpm. When tuning it is important to enter correct data, cam timing values, throttle body values, cold air inlet diameter, to name a few. Ask your tuner what values they entered for your throttle body upgrade, or better yet, did they tune your FPCM, update the injector data? There are many tables that need to be properly updated and street calibrated. If the fuel is not dialed in, air not dialed in, calibrated, you will have poor performance, knock, and zero benefits from mods. The B15 iron block has no flex, .2" thick siamese cylinder walls, priority main oiling, additional bolt pattern for the heads, etc... It is a monster from the factory right out of the crate, no need to do anything internal! If you are familiar with numbers, you can see just looking at mine running on 92 at 10.07 AFR WOT there are no magic tricks, just huge power. I don't get around to posting very often, but I will be happy to try and answer questions relating to LSX swap.
PS: 1000hp is a cake walk for these engines, current oil pressure 30psi normal, around 50psi WOT, dual Spal 1360 fans set for constant at 90% duty, track temps 190 engine 190 oil. tr6060 stock, Creative Steel engine mounts, one piece Gulf Coast shaft, Mcleod clutch, ATI Super Damper, need to re-scale the spark tables from 1.36 to 3.0, current WOT cylinder air mass is 2.63.
kittyboy
You wrote:
"Just a quick post, I've seen some interest regarding the LSX-B15 engine. I purchased a long block and spent the past year building it with many custom upgrades, nothing crazy, and zero porting anywhere! "

Just a few comments on porting requirements:

How large the port / port area needs to be will
be determined by one's HP Requirements.

The HP Requirements begins with the relationship
between the engine size versus engine rpm.

It is most important that the area of the port be normalized for both the flow, as well as the velocity, as both are determined by the engine size and peak hp engine rpm.

This then will determine which cylinder head one will purchase, as some cylinder heads will flow more, but the velocity is down. Others will flow less, but the velocity will be too high. The above comments once again are related to any given engine combo and engine rpm.

Flow benches are a good start.
But 'Area versus Shape' of the port, play a large role in the performance of the cylinder head on a 'Live Engine' going down the track.

But more importantly is maintaining the correct balance of flow to velocity, determined by the size of the engine, the engine rpm, which then relates to a 'Non-Linear flow demands, at different piston speeds / piston motion, as found at various crank pin angles.

Then all of the above must be matched to the camshafts lobe profile.

So then; the cylinder heads flow profile, as well as the velocity profile,
must then be related to the lobe profile.

This is not a 'Custom Cam' put together by someone looking at lobe intensities within some cam manufacturers catalog.

This is a 'Custom Lobe' ground on a computer controlled cnc grinder, where the lobe has been defined within the computer via complex algorithms, and the computer then tells the cnc grinder what lobe profile to grind for . . . . .

'Your' cylinder head flow and velocity profile
. . . .As related to the crank pin angle.


While the above serves here to inform forum members what can be done, most on this forum will not need to deal with such an expensive camshaft. So now we move back to a knowledgeable person who has much experience with these engine platforms, and one who has gained empirical info from much dyno testing, as well as cataloging many runs down the track.

An individual like this is much better than reading advertisements from large companies who do much advertising in many magazines each month.

Rant Over..:rolleyes:
 
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