Is it worth the AMS VSR over the Magnus SMIM?

[hks-gst]

No. That would only hold true in a situation where ALL cylinders were open at the same time. However, our plenums work in a pulse format. The pulses from the cylinders closest to the turbo disrupt the airflow to #1 causing it to run richer from air starvation. The taper only increases this by causing a restriction for the air to reach #1.

Have you done any test to prove this?

 

[JWoodley]

This is turning into quite an interesting debate. Let's keep this going and it might make for a good sticky.

 

[wishihadatalon]

http://forums.evolutionm.net/showthread.php?t=196546&page=1&pp=15 I figured some of you would like to read this.

 

[daren_p]

No. That would only hold true in a situation where ALL cylinders were open at the same time. However, our plenums work in a pulse format. The pulses from the cylinders closest to the turbo disrupt the airflow to #1 causing it to run richer from air starvation. The taper only increases this by causing a restriction for the air to reach #1.

Sounds interesting, could you explain in more depth/more info? The part that makes me curious is you say the pulses closest to the turbo disrupt the airflow to #1 causing it to run rich, if this is the case how come most tapp the #1 cylinder for egt as it is supposed to run the leanest, which is the opposite of what you just stated?

 

[wishihadatalon]

Sounds interesting, could you explain in more depth/more info? The part that makes me curious is you say the pulses closest to the turbo disrupt the airflow to #1 causing it to run rich, if this is the case how come most tapp the #1 cylinder for egt as it is supposed to run the leanest, which is the opposite of what you just stated?

That is because of fuel starvation. It is the last cylinder in line. JOn at TRE was telling me something else that is interesting. The knock sensor is on no. 2 cylinder because of the way air bounces off of the back of the intake manifold and ends up going to the no. 2 cylinder which would lead me to believe that no.2 is actually the leanest.

 

[daren_p]

That is because of fuel starvation. It is the last cylinder in line. JOn at TRE was telling me something else that is interesting. The knock sensor is on no. 2 cylinder because of the way air bounces off of the back of the intake manifold and ends up going to the no. 2 cylinder which would lead me to believe that no.2 is actually the leanest.

I too have heard some say that infact the #2 cylinder runs leaners. About the #1 cylinder being last in the fuel rail, I wouldn't have thought this would make much difference as the rail is under high pressure, which I would have thought would distribute the fuel equally.

 

[Boosted98gsx]

It's at a pressure at the end of the rail, meaning the pressure at #4 would be higher.

 

[snox135]

It's at a pressure at the end of the rail, meaning the pressure at #4 would be higher.

And how do you firgue that is happening?

 

[daren_p]

It's at a pressure at the end of the rail, meaning the pressure at #4 would be higher.

Well correct me if Im wrong but the FPR is what controls the pressure in the rail, obviously this is after the rail so the rail itself whould have equal pressure throughout. Whats the pressure law? basically in a sealed vessel pressure is equal in every direction. How would the pressure at 4 be higher?

 

[JeanDSM]

Ive allways heard that the #1 cylinder is the leanest one beacuse of the design of the intake manifold and the direction of the air makes the #1 runner the leanest one.

about the guy who was talking about throttle bodys for this setup when i decide what manifold to buy, i will be spending more than $650 i will go 3in t/b all the way, i also have 3in intercooler pipes. The only problem i have is that i still havent found information about conecting a 2g 4wires tps harness to a ford style tps.

 

[wishihadatalon]

Well correct me if Im wrong but the FPR is what controls the pressure in the rail, obviously this is after the rail so the rail itself whould have equal pressure throughout. Whats the pressure law? basically in a sealed vessel pressure is equal in every direction. How would the pressure at 4 be higher?

Think on more of a stock system though. I thing in a upgraded system where fuel pressure is higher and you are pushing more fuel from a larger fuel pump it isn't as much of a concern.

 

[daren_p]

Think on more of a stock system though. I thing in a upgraded system where fuel pressure is higher and you are pushing more fuel from a larger fuel pump it isn't as much of a concern.

Hmmm, I don't think the pump or the flow will make a difference in this situation. Pressure is pressure & it is always equal thoughout the whole system regardless of the flow. Sure the stock pump flows alot less then a 255 but if their both set to a base pressure of 43 psi, then the pressure acting everywhere in each system should be the exact same. The only thing that may change this is the system isn't completely sealed in that fuel is continuously running through the loop & also gets ejected from the system via the injectors, so Im not 100% sure what role this would play on things. If anyone knows exactly the effects of everything, post it up, I'm just throwing out what seems logical to me

 

[~laser_craver~]

Correct me if i am wrong but if the fuel rail is equally pressurized which it should be because it is sealed. And the #1 runner is the runner with the least amount of air due to it being furthest away from tb. Wouldnt the #1 be richer?

 

[DarthBulk]

Hmmm, I don't think the pump or the flow will make a difference in this situation. Pressure is pressure & it is always equal thoughout the whole system regardless of the flow. Sure the stock pump flows alot less then a 255 but if their both set to a base pressure of 43 psi, then the pressure acting everywhere in each system should be the exact same. The only thing that may change this is the system isn't completely sealed in that fuel is continuously running through the loop & also gets ejected from the system via the injectors, so Im not 100% sure what role this would play on things. If anyone knows exactly the effects of everything, post it up, I'm just throwing out what seems logical to me

You are definitely on the right track. There are actually 3 pressures at play here, all of them related. There is Total Pressure, Static Pressure, and Dynamic Pressure. The pressure that stays the same in a fluid system is the Total Pressure. If everything were static, the Total Pressure would equal the Static Pressure. As soon as the fluid starts to flow, however, you exchange some static pressure for dynamic pressure. This means your static pressure drops, and is why the pressure is not the same everywhere in your fuel system even though a fuel pressure gauge seems to show a constant pressure. It is all dependent on the velocity (and pipe diameter, etc.) at the location you wish to know the pressure.
Fluid flow is a fun topic, but involves a lot of complicated equations. I work with it a lot in my profession

 

[wishihadatalon]

You are definitely on the right track. There are actually 3 pressures at play here, all of them related. There is Total Pressure, Static Pressure, and Dynamic Pressure. The pressure that stays the same in a fluid system is the Total Pressure. If everything were static, the Total Pressure would equal the Static Pressure. As soon as the fluid starts to flow, however, you exchange some static pressure for dynamic pressure. This means your static pressure drops, and is why the pressure is not the same everywhere in your fuel system even though a fuel pressure gauge seems to show a constant pressure. It is all dependent on the velocity (and pipe diameter, etc.) at the location you wish to know the pressure.
Fluid flow is a fun topic, but involves a lot of complicated equations. I work with it a lot in my profession

And what might that be? I am looking for something to go to school for and fluid dynamics has always been interesting to me

 

[Blizz]

And what might that be? I am looking for something to go to school for and fluid dynamics has always been interesting to me

Mechanical or Aerospace Engineering, then from there you can specialize in fluids if you like.

 

[definitiveno]

I'm a Firefighter and we use alot of pressure loss equations regarding fluid as well. One would have to know the coefficient of the diameter lines that we were using and I could figure it all out for you guys.

Generally we can determine what the nozzle pressure is at a hose by starting with PDP (pump discharge pressure) and using a formula CQ(2)L=TPL

C = coefficient
Q = quantity or volume
L = length of lay
TPL = totoal pressure loss


It can be reversed though if we have a coefficient and a pressure indication at the end of the source (a pressure guage at the end of the fuel rail for instance)

You guys wouldn't believe how inefficient small lines/hose can be. I wouldn't be suprised if there was 20 psi pressure drop from the pump to the fpr gauge, if not more.

 

[Boosted98gsx]

You guys wouldn't believe how inefficient small lines/hose can be. I wouldn't be suprised if there was 20 psi pressure drop from the pump to the fpr gauge, if not more.

Yay for no linear flow in pipes!

 

[DarthBulk]

And what might that be? I am looking for something to go to school for and fluid dynamics has always been interesting to me

It is Aerospace Engineering. I designed vacuum pumps and the equipment to test the vacuum pump systems for small aircraft at our company. I also designed a fuel pump test cell, and started to build it (100 gallon fuel tank that is rotatable about 3 axes, with variable altitude and temperature, and all the test equipment for measuring pressure drops, flow rates, temperature rise, etc. We even have to deliberately try to explode the fuel pump by discharging sparks inside the pump during operation) I took several courses in aerodynamics and fluids, and I also took a graduate level course on experimental aerodynamics. To tell the truth, that was more fun than anything else.
definitiveno is right, small lines and hoses are very inefficient. Consider that the flow velocity is always zero at the wall of a tube or hose, and then ramps up to the maximum velocity at a certain distance from the wall. In a small tube or hose, you might have a very small area that actually is flowing the maximum velocity.

 

[wishihadatalon]

It is Aerospace Engineering. I designed vacuum pumps and the equipment to test the vacuum pump systems for small aircraft at our company. I also designed a fuel pump test cell, and started to build it (100 gallon fuel tank that is rotatable about 3 axes, with variable altitude and temperature, and all the test equipment for measuring pressure drops, flow rates, temperature rise, etc. We even have to deliberately try to explode the fuel pump by discharging sparks inside the pump during operation) I took several courses in aerodynamics and fluids, and I also took a graduate level course on experimental aerodynamics. To tell the truth, that was more fun than anything else.
definitiveno is right, small lines and hoses are very inefficient. Consider that the flow velocity is always zero at the wall of a tube or hose, and then ramps up to the maximum velocity at a certain distance from the wall. In a small tube or hose, you might have a very small area that actually is flowing the maximum velocity.

What about friction and heating the fuel? I read a post about having to large of a fuel line and having the fuel heat up by returning it and feeding it so much.

Thanks for the info too

 

[RipperXX]

Im not sure how many of you know about the manifold that was under development on Evolution.net, I was very sad to see it come to a halt with a finished rendering, and just not haveing the 12k needed to make the prototype. Looked good too.

And after seeing it's development I really think vendors should at least test there products in a CFD type program.

 

[wishihadatalon]

Im not sure how many of you know about the manifold that was under development on Evolution.net, I was very sad to see it come to a halt with a finished rendering, and just not haveing the 12k needed to make the prototype. Looked good too.

And after seeing it's development I really think vendors should at least test there products in a CFD type program.

Well the thing is HKS had a manifold that looked exactly like that on a drag 4g63 motor way back in the day. I will try to find pics.

 

[wishihadatalon]

http://users.techline.com/hceline/wrx/115-1596_IMG.JPG
http://users.techline.com/hceline/wrx/115-1598_IMG.JPG

 

[Boosted98gsx]

http://users.techline.com/hceline/wrx/115-1596_IMG.JPG
http://users.techline.com/hceline/wrx/115-1598_IMG.JPG

Is that an Evo motor? If it is, that manifold is backwards.

 

[NewTurboTuner]

WOW!
It's something funky!
It has a TB for each runner!