How much hp/boost can my slightly built engine take?

[flsupraguy]

I have a 6-bolt swap in my 95 tsi. It is a complete 1G Swap, using a 2G head. The head is ported and has crower valve springs and crower titanium retainers. The head is using ARP head studs. How much hp/boost do think this engine is capable of handling? (With proper tuning ofcourse).

 

[sweet95]

It will probibly with stand alot upwards around 500 or so, it just depends on your set up to make the power.
ERIC

 

[kpt4321]

Boost is irrelevant with regard to motor strength.

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=96631

Excerpt from my post:

In the end, I think that defining a motor's limits in general terms of horsepower, or maximum MASS flow, is the way to go.

The question is, how much power can a stock 6-bolt take, which is also something that has been asked about a million times.

500 whp is attainable, and then some.

 

[SpoOLxExO]

So, if boost is irrelevant to determine HP capibility, where does metalurgy come into play?

Surely a 7-bolt engine's connecting rods are weaker than a 6-bolt's, but that is because of the "Size" of the rod, in which i'm referring to the thickness of the beam. (7-bolt will "break" more easily when HP is raised to what is known as an aceptable 6-bolt HP level, or around 400-450WHP)

Does this mean you are theorizing that both engines can withstand the same amount of boost from the same turbo in discovering how much HP a stock 4g63 can "Take"?

And Vice versa on the Toyota 2jz-gte which has one of, if not THE highest content of high-strength metal in the rods, pistons, and block straight from the factory. These engines have "Handled" over 800hp w/o even lifting the head many times, as most of us know.



This is interesting...

 

[kpt4321]

Originally posted by SpoOLxExO So, if boost is irrelevant to determine HP capibility, where does metalurgy come into play?

Would you like to exlain how metalurgy is related to determining HOW to measure the limits of a motor?

Surely a 7-bolt engine's connecting rods are weaker than a 6-bolt's, but that is because of the "Size" of the rod, in which i'm referring to the thickness of the beam. (7-bolt will "break" more easily when HP is raised to what is known as an aceptable 6-bolt HP level, or around 400-450WHP)

Right. The 7-bolt rods are weaker, so they cannot take as much cylinder pressure.

The point?

Does this mean you are theorizing that both engines can withstand the same amount of boost from the same turbo in discovering how much HP a stock 4g63 can "Take"?

Huh? If they were both pulling the same boost from the same turbo with the same setup, they would both be making the same power. That means that either you're below the limits of both engines, one is vlowing up, or they're both blowing up.

They can't necessarily withstand the same amount of boost, no. However, that limit is not related to boost, it's related to cylinder pressure, torque, or horsepower.

Give me a "boost limit" for a motor, and I guarantee I can come up with a case where the motor would die with much less boost, and where the motor would be ok with much more.

Give me a cylinder pressure (which is very closely related to horsepower) and it doesn't matter what the shit you do, the motor is going to have problems (rods, rings, etc) once you exceed that pressure.

And Vice versa on the Toyota 2jz-gte which has one of, if not THE highest content of high-strength metal in the rods, pistons, and block straight from the factory. These engines have "Handled" over 800hp w/o even lifting the head many times, as most of us know.

Right, the 2JZ is strong. Are you going anywhere with that statement, or were you just letting us know?

 

[SpoOLxExO]

Unlike most of my responces to your posts, I'm not trying to be a dick.

I really do want to know were metalurgy comes in determining how much horsepower an engine can handle before it pops.

I was using the 7-bolt to 6-bolt reference to help with the answer on metalurgy, and stated the strength of a 2jz to make a comparison.

The Metal found in the rotating assemblyof the 4g63 is not as strong to what the 2jz is, other-wise we could make 600hp on stock engines, right?

You see, my brother is a machinist in the navy. I have been learning about the strength of certain metals, and was genuinely curious as to how it comes into play on a stock engine.

But I guess you can't answer a question that you don't know about right?

 

[NosLaser]

From now on, the official answer to any vague "how much boost" questions is going to be 7.

7 boost.

Regards,

 

[GTM]

Originally posted by kpt4321
...
Give me a "boost limit" for a motor, and I guarantee I can come up with a case where the motor would die with much less boost, and where the motor would be ok with much more.

Give me a cylinder pressure (which is very closely related to horsepower) and it doesn't matter what the shit you do, the motor is going to have problems (rods, rings, etc) once you exceed that pressure.
...

That's easy, advance retard ign and/or valve timing, overlap, change the air fuel mix. Just to see if you are on your toes... something else?

Cheers,
GTM

 

[kpt4321]

Originally posted by SpoOLxExO I really do want to know were metalurgy comes in determining how much horsepower an engine can handle before it pops.

I think that the problem is that you're not being specific enough. There are enough aspects to metalurgy, that not only could we not discuss them all here, but it's doubtful anyone could cover anything.

Things like material composition matters, but so does the proccess in which the parts were made (type of production), the quality control of that process, and on and one.

Also, keep in mind that we're not just talking about rods here. Depending on the motor and the conditions, there are other parts that could fail as well, some due to metallic weakness, and some not so much.

I was using the 7-bolt to 6-bolt reference to help with the answer on metalurgy, and stated the strength of a 2jz to make a comparison.

The 6-bolt's extra strength, and the strength of the 2JZ, don't necessarily have anything to do with composition. It could simply be that the 2JZ has bigger rods, and thicker ringlands....

The Metal found in the rotating assemblyof the 4g63 is not as strong to what the 2jz is, other-wise we could make 600hp on stock engines, right?

That's not a safe assumption. The 2JZ, first of all, distributes that power over 6 cylinders to the loads on the individual parts that have a tendency to break are reduced. Second of all, the metal doesn't necessarily have to be of a better composition in order to be stronger. A perfectly engineered toothpick will be weaker than a 3" diameter pipe, even if the pipe is crappier material.

Besides, the 4G63 can make 600 hp on stock internals.

You see, my brother is a machinist in the navy. I have been learning about the strength of certain metals, and was genuinely curious as to how it comes into play on a stock engine.

If you're looking for how strong the metal in the 4G63 is, I don't have an answer. That's a difficult question, how exacty do you rate such a thing? Rockwell hardness?

But I guess you can't answer a question that you don't know about right?

 

[kpt4321]

Originally posted by GTM
That's easy, advance retard ign and/or valve timing, overlap, change the air fuel mix. Just to see if you are on your toes... something else?

Cheers,
GTM

Were you speaking in reference to the first part of my statement, or the second part?

Those are the types of things I had in mind on the first section. There are also even simpler changes like fuel quality, charge temp...

 

[GTM]

Originally posted by kpt4321
Were you speaking in reference to the first part of my statement, or the second part?
Those are the types of things I had in mind on the first section. There are also even simpler changes like fuel quality, charge temp...

That which I quoted. I was thinking strictly in physics / mechanics and not chemical additives, more at temp in general: air, oil, water.
...........
And then a well designed windage baffled oil pan/crankcase is known to make a 10-15 hp improvement plus removing loads from the internal motive parts.

Cheers,
GTM

 

[kpt4321]

Originally posted by GTM
And then a well designed windage baffled oil pan/crankcase is known to make a 10-15 hp improvement plus removing loads from the internal motive parts.

Good example!

Changing that increases horsepower, but doesn't bring the motor any closer to breaking, really.

On the other hand, the whole reason it increases power is because it increases the ratio of the forces on both sides of the pistons. In this case, it probably saves stress on the motor though.

 

[GTM]

Originally posted by kpt4321
...
On the other hand, the whole reason it increases power is because it increases the ratio of the forces on both sides of the pistons. In this case, it probably saves stress on the motor though.

Yes, it is relieving stress caused by the air friction, oil in suspension, and turbulence. So all of this allows the engine to rev higher provided the cam gear and breathing can handle the rpm. By running cooler oil you can decrease viscosity index and gain more power provided it doesn't increase the pressure to force it through an oil cooler.

Cheers,
GTM