[ExpensiveTaste]

Originally Posted by Joshboody

No, volume is correct... volumetric efficiency curve will change. How much air can flow. basically follows the torque curve and we'll see if this increases or just moves right as others have mentioned. pressure and temperature is mass.

I'm no expert, but I don't think you are correct. Without modifying cam timing, porting the head, using bigger valves, or increasing incoming air pressure, volumetric efficiency will not change...I could be wrong but this is how I understand it.

[OpenFlash]

Originally Posted by ExpensiveTaste

I'm no expert, but I don't think you are correct. Without modifying cam timing, porting the head, using bigger valves, or increasing incoming air pressure, volumetric efficiency will not change...I could be wrong but this is how I understand it.

When viewed as a working system (engine+turbo+induction+exhaust), VE will change. The lower exhaust back pressure (afforded mainly by the big turbine housing) will improve the pumping efficiency of the engine. If the VE of the engine alone will not change of course but that isn't really worth discussing since the engine is just one part of the system.

Shiv

[ETS Michael]

Originally Posted by Jeff@topgearsolutions

With all this talk about spool up and lost torque down low I think that is just what this car needs. I'd sacrifice some lag for some brute power on the top end. It may also give us the chance to actually hook the tires.

The torque down low is necessary for 4 wheeling and your grandpas Ford taurus

Best thing we could have is a shift in the power-band. I'm not saying 10 second turbo lag like your Evo 9's on gt35 but somewhere in the middle.

+1

[Q4P]

So the question remains... is it possible to safely run 18 psi on a larger turbo on pump gas (without blowing anything) and make more power when compared to 18 psi on the stockers with meth? I am not sure myself unless this power was made at a lower rpm or boost level... someone please explain this in laymans terms and how the curves would/should look on a larger turbo.

[ExpensiveTaste]

Originally Posted by shiv@vishnu

When viewed as a working system (engine+turbo+induction+exhaust), VE will change. The lower exhaust back pressure (afforded mainly by the big turbine housing) will improve the pumping efficiency of the engine. If the VE of the engine alone will not change of course but that isn't really worth discussing since the engine is just one part of the system.

Shiv

Ah, gotcha. I didn't think about the fact that it will take less exhaust pressure to push the same turbine at a lower speed that will produce the same amount of boost. I'm not sure how much this would increase VE, though. Does this engine have any overlap while in boost? I would think not...

[AYF80]

All I have to say is that My car sounds brutal and revs SOO Fast its a little shocking. The engine response on what is still a basic tune is astounding. The Engine revs and comes back down to idle so quickly, I can't help but think that we won't loose any low end TQ at all. You will see what i mean shortly.

As stated by chris, we just need to fabricate a new V brace due to the motor mount being relocated. the OE V Brace will not be strong enough due to the relocation.

[ExpensiveTaste]

Originally Posted by HPF 335i #1

All I have to say is that My car sounds brutal and revs SOO Fast its a little shocking. The engine response on what is still a basic tune is astounding. The Engine revs and comes back down to idle so quickly, I can't help but think that we won't loose any low end TQ at all. You will see what i mean shortly.

As stated by chris, we just need to fabricate a new V brace due to the motor mount being relocated. the OE V Brace will not be strong enough due to the relocation.

I would like to know if HPF is continuing to keep the wastegate closed at idle to help improve low end (factory only closes 1 of the 2 wastegates at idle). That alone, would most likely make it rev happy.

[AYF80]

I didn't ask, I can though. But it must be.

[bmwe82]

Originally Posted by HPF 335i #1

All I have to say is that My car sounds brutal and revs SOO Fast its a little shocking. The engine response on what is still a basic tune is astounding. The Engine revs and comes back down to idle so quickly, I can't help but think that we won't loose any low end TQ at all. You will see what i mean shortly.

As stated by chris, we just need to fabricate a new V brace due to the motor mount being relocated. the OE V Brace will not be strong enough due to the relocation.

What is considered a basic tune?

[AYF80]

Shivs Base Single Turbo tune, so far its only been plugged in. Still needs to be tuned this week.

[bmwe82]

Originally Posted by HPF 335i #1

Shivs Base Single Turbo tune, so far its only been plugged in. Still needs to be tuned this week.

Have you street driven on it?

[AYF80]

No i was just in the shop, Chris didn't want to TQ the engine without the Brace. Im driving it on the 25th.

[AYF80]

Whats also cool is that it fired right up with no CELs, or anything bad. Its just ready to Rock... Its Nasty, you can tell its going to be a Beast.

[Brey335i]

Originally Posted by HPF 335i #1

Whats also cool is that it fired right up with no CELs, or anything bad. Its just ready to Rock... Its Nasty, you can tell its going to be a Beast.

Congratulations man. Long time in the making but it seems like you'll have the most awesome N54 for a while.

[bmwe82]

Originally Posted by HPF 335i #1

Whats also cool is that it fired right up with no CELs, or anything bad. Its just ready to Rock... Its Nasty, you can tell its going to be a Beast.

well it was born on friday the 13th, so no surprise there

[bryce]

Originally Posted by ExpensiveTaste

PV=nRT

Pressure * Volume = a constant * a constant * Temperature

So if the Pressure remains the same and the volume remains the same (stock cylinder head intake ports don't change in size), then it only leaves temperature. Just saying...

That formula is correct, your logic isn't. What I've been saying in multiple posts, and what you're not grasping, is that the volume (or air mass) increases with a larger turbo at the same boost pressure

[blisstik]

Regarding the motor mount relocation, does it require welding the new mounts on the frame?

Originally Posted by HPF 335i #1

No i was just in the shop, Chris didn't want to TQ the engine without the Brace. Im driving it on the 25th.

[ExpensiveTaste]

Originally Posted by bryce

That formula is correct, your logic isn't. What I've been saying in multiple posts, and what you're not grasping, is that the volume (or air mass) increases with a larger turbo at the same boost pressure

Lol, disregard the size of the turbocharger. The volume in the intake manifold/cylinder head ports remains the same. So the only way to get more mass is to increase pressure or decrease temperature (very likely the main piece that adds power if pressure remains the same). You may get more flow from the compressor but you are still forcing the air into the same amount of space (volume).

[AYF80]

Originally Posted by blisstik

Regarding the motor mount relocation, does it require welding the new mounts on the frame?

No

[OpenFlash]

Originally Posted by ExpensiveTaste

Ah, gotcha. I didn't think about the fact that it will take less exhaust pressure to push the same turbine at a lower speed that will produce the same amount of boost. I'm not sure how much this would increase VE, though. Does this engine have any overlap while in boost? I would think not...

The more exhaust back pressure there is between the exhaust port and the turbine inlet, the lower the engines effective VE. When this pressure gets excessive, you will get exhaust gas reversion (where the exhaust creeps back into the combustion chamber during even the smallest amount of overlap). On top of that, this pressure will have the same effect as a shoving a tennis ball into one of the tailpipes. Boost and IAT is only half the equation. Better way to look at the boost is the amount of air NOT getting into an engine. Instead it's just cramming up in the manifold because the engine isn't gulping it down quickly enough. What you want is the engine to gulp it down at a high rate (high HP!) and NOT have it accumulate/back-up in the manifold. The needle position on the boost gauges doesn't make the car go fast. Airflow rate through the engine does.

shiv

[bryce]

Originally Posted by ExpensiveTaste

Lol, disregard the size of the turbocharger. The volume in the intake manifold/cylinder head ports remains the same. So the only way to get more mass is to increase pressure or decrease temperature (very likely the main piece that adds power if pressure remains the same). You may get more flow from the compressor but you are still forcing the air into the same amount of space (volume).

The volume of the intake mani, fly head, etc isn't changing. The volume of air being introduced by the larger turbo has increased. IDK why you're still arguing, a few different people (Inc. Shiv) have told you otherwise. If you're still not convinced, call hpf, full-race, Cobb tuning, or any shop that fits larger turbo's. They'll explain it to you.

One last piece of proof:

Acura rsx type S
greddy turbo kit @ 15PSI will make 300whp
full-race turbo (gt35 turbo) @ 15psi will make 500+ whp

Only variable is the turbo, manifold

[bryce]

One other way to look at it, then I'm done. Piccture a small balloon filled with 15psi or air. Then consider a gigantic balloon filled with 15psi of air. The large balloon has the same pressure, but a much larger mass or volume of air. Same is true for a small vs. Large turbo. If you still don't get it with that metaphor, fuck off and do more research on your own.