A2A Supercharged Intake Options

turtle64b · 12-20-2019, 09:13 AM

Quote:

Originally Posted by Senna-F1

So Eugene says boost should continue to climb even past 15 psi at 6600. Might be something going on. It slowly drops after that instead. So, anyone ever seen a stock pulley setup continue on past 15? It looks like it could just be this SC running out of steam and not being able to supply a continuous 15 psi as revs increase past 6600 on the stock pulley. But Eugene doesn’t think so. Thoughts?

BTW, Does the rate of pressure loss, as seen in the video below, seem reasonable? I had read this rate of loss is OK. I addressed any obvious leaks, except for a bit coming from the MAF sensors.

https://youtu.be/-7ZPmLl_7xI

In my opinion, I think that you lose efficiency and may have air escaping once you get past a certain speed. I see the same thing in my logs, where boost peaks and then tapers off at top end, around 7kish RPM

Senna-F1 · 01-27-2020, 04:59 PM

Quote:

Originally Posted by Senna-F1

So Eugene says boost should continue to climb even past 15 psi at 6600. Might be something going on. It slowly drops after that instead. So, anyone ever seen a stock pulley setup continue on past 15? It looks like it could just be this SC running out of steam and not being able to supply a continuous 15 psi as revs increase past 6600 on the stock pulley. But Eugene doesn’t think so. Thoughts?

BTW, Does the rate of pressure loss, as seen in the video below, seem reasonable? I had read this rate of loss is OK. I addressed any obvious leaks, except for a bit coming from the MAF sensors.

https://youtu.be/-7ZPmLl_7xI

SOHO tightened my belt, even though at first they thought it was fine. Up until they tightened it, boost was still dropping up top, just a tad. So to those who are losing even a small amount of boost, might just need a tighter belt. Posting log data showing boost till redline. Boost gauge read 15.2 psi which is even a bit lower than the ECUTEK log data of 30.2 psi absolute pressure.

Rusty · 01-27-2020, 10:10 PM

Quote:

Originally Posted by Senna-F1

SOHO tightened my belt, even though at first they thought it was fine. Up until they tightened it, boost was still dropping up top, just a tad. So to those who are losing even a small amount of boost, might just need a tighter belt. Posting log data showing boost till redline. Boost gauge read 15.2 psi which is even a bit lower than the ECUTEK log data of 30.2 psi absolute pressure.

Gauge pressure is different then absolute pressure. They will never read the same.

The simplest way to explain the difference between the two is that absolute pressure uses absolute zero as its zero point, while gauge pressure uses atmospheric pressure as its zero point. Due to varying atmospheric pressure, gauge pressure measurement is not precise, while absolute pressure is always definite

turtle64b · 01-28-2020, 07:16 AM

Quote:

Originally Posted by Rusty

Gauge pressure is different then absolute pressure. They will never read the same.

The simplest way to explain the difference between the two is that absolute pressure uses absolute zero as its zero point, while gauge pressure uses atmospheric pressure as its zero point. Due to varying atmospheric pressure, gauge pressure measurement is not precise, while absolute pressure is always definite

Agree here. Your gauge/meter is probably off by maybe .2/.3 psi, depending on height above sea level. At sea level, atmospheric pressure is 14.7 psi.

DrBacon · 01-28-2020, 12:47 PM

Quote:

Originally Posted by Senna-F1

SOHO tightened my belt, even though at first they thought it was fine. Up until they tightened it, boost was still dropping up top, just a tad. So to those who are losing even a small amount of boost, might just need a tighter belt. Posting log data showing boost till redline. Boost gauge read 15.2 psi which is even a bit lower than the ECUTEK log data of 30.2 psi absolute pressure.

Is that timing on pump gas or ethanol? That's some insane timing advance

redondoaveb · 01-28-2020, 01:41 PM

Quote:

Originally Posted by DrBacon

Is that timing on pump gas or ethanol? That's some insane timing advance

It must be on pump. I know at least with mine (I have 91 octane) it had to be timed for pump or it would get bad knock if timing was set for e85. That's why I did the wastegate set up.

Senna-F1 · 01-28-2020, 01:50 PM

Quote:

Originally Posted by redondoaveb

It must be on pump. I know at least with mine (I have 91 octane) it had to be timed for pump or it would get bad knock if timing was set for e85. That's why I did the wastegate set up.

I have a flex fuel tune. I’m pretty sure timing and fuel are set for pump and e85, and then interpolated for whatever mix you end up using. Obviously fuel has to work this way, and I assume timing works the same way. Tune for best and worst fuel case and interpolate the points for the mixtures of each fuel type.

Senna-F1 · 12-20-2019, 07:37 PM

Yeah, mine used to taper, or not rise as fast. But now after 15 psi, it very slowly drops. Given my boost pressure test to 20 psi, I’m probably not leaking much. There really isn’t anything that could collapse. I’m already at 80 duty cycle and I over purchased for all my fuel components. 485 pump, S1.SE with the new rails, and 1050x that was supposed to be good for well over 600 WHP. Should have gone for 1300s, but no one indicated I’d need that. In fact I have the same components as the Topgunz ACE kit car. I’m on pump and have already hit 80%. It breathes very easily now with a 4” intake I guess.

turtle64b · 12-22-2019, 09:11 AM

Since no one wants to buy the fuel pump assembly that I accidentally bought back at the beginning of the year, I am toying with making a custom harness and putting an OEM (maybe upgrade the pump later) fuel pump assembly behind the driver's seat. This would both combat the fuel starvation issue as well as provide more flow. But that's for a different thread haha. I'm currently with CJM S1-SE with an Aeromotive 340lph and ID1050x.

I definitely think that you are going to get maximum flow with the 4" intake. The reason I didn't go higher than 3.5" is because the manifold pressure with the 3.5 setup is so closely resembled the filterless datalogging that I did earlier in the year after initial installation on this car. I should research the science behind velocity stacking, since that may aid in suction efficiency, which led to the higher pressures you see.

Senna-F1 · 12-22-2019, 11:31 AM

Here is the science behind the velocity stack.

http://www.profblairandassociates.co...mouth_Sept.pdf

I was going to model my own custom stack based on this article. Still may, but I already had the 6” to 4” stack sitting in my MR2 so I used that one instead.

This issue I see with doing anything larger than about 3” is the rectangular section just doesn’t allow for a large round shape. At this point my 3D part through that section is right at the equivalent of a 3.9” dia pipe.

Here is a graph showing how small increases in pipe diameter have a large effect on square area. So every little bit helps. Also the model I created.

"Z"en · 12-22-2019, 12:41 PM

Quote:

Originally Posted by Senna-F1

Here is the science behind the velocity stack.

http://www.profblairandassociates.co...mouth_Sept.pdf

I was going to model my own custom stack based on this article. Still may, but I already had the 6” to 4” stack sitting in my MR2 so I used that one instead.

This issue I see with doing anything larger than about 3” is the rectangular section just doesn’t allow for a large round shape. At this point my 3D part through that section is right at the equivalent of a 3.9” dia pipe.

Here is a graph showing how small increases in pipe diameter have a large effect on square area. So every little bit helps. Also the model I created.

I like what you did and are doing. Please keep us posted. I did similar sims before but didn't take too much time to look at the underlying principle. What inspired me was the Vortech bellmouth, but just for fun frankly as I was already satisfied with the power I was having. Anyway, always glad to see more engineering inventions. Interesting. ^_^

takemorepills · 12-22-2019, 07:18 PM

Quote:

Originally Posted by Senna-F1

Here is the science behind the velocity stack.

http://www.profblairandassociates.co...mouth_Sept.pdf

I was going to model my own custom stack based on this article. Still may, but I already had the 6” to 4” stack sitting in my MR2 so I used that one instead.

This issue I see with doing anything larger than about 3” is the rectangular section just doesn’t allow for a large round shape. At this point my 3D part through that section is right at the equivalent of a 3.9” dia pipe.

Here is a graph showing how small increases in pipe diameter have a large effect on square area. So every little bit helps. Also the model I created.

What software are you using for 3D modeling?

Senna-F1 · 12-22-2019, 02:21 PM

I seem to be having fuel pressure issues. On a 10 psi run and taking video of fuel pressure gauge it didn’t rise more than 5 psi, if that. This is probably my duty cycle issue.

Here’s a 15.2 peak psi boost gauge photo.

Senna-F1 · 12-22-2019, 07:25 PM

Autodesk Fusion 360. It’s a pain in the butt!!

Sent from my iPhone using Tapatalk

TBatt · 12-31-2019, 03:42 PM

Quote:

Originally Posted by Senna-F1

Autodesk Fusion 360. It’s a pain in the butt!!

Sent from my iPhone using Tapatalk

Would you be interested in sharing your design file or at least an STL of the design? I have a spool of carbon fiber nylon that I would like to make the part with.

12-20-2019, 07:37 PM	#8 (permalink)
Senna-F1 Enthusiast Member Join Date: Jun 2016 Location: Cary, NC Age: 54 Posts: 425 Drives: 370SC,EliseSC,MR2T Rep Power: 50	Yeah, mine used to taper, or not rise as fast. But now after 15 psi, it very slowly drops. Given my boost pressure test to 20 psi, I’m probably not leaking much. There really isn’t anything that could collapse. I’m already at 80 duty cycle and I over purchased for all my fuel components. 485 pump, S1.SE with the new rails, and 1050x that was supposed to be good for well over 600 WHP. Should have gone for 1300s, but no one indicated I’d need that. In fact I have the same components as the Topgunz ACE kit car. I’m on pump and have already hit 80%. It breathes very easily now with a 4” intake I guess. TBatt and turtle64b like this.

12-22-2019, 09:11 AM	#9 (permalink)
turtle64b Track Member Join Date: Jun 2015 Location: Granbury, TX Posts: 550 Drives: '11 SC Blue 7AT Rep Power: 3366	Since no one wants to buy the fuel pump assembly that I accidentally bought back at the beginning of the year, I am toying with making a custom harness and putting an OEM (maybe upgrade the pump later) fuel pump assembly behind the driver's seat. This would both combat the fuel starvation issue as well as provide more flow. But that's for a different thread haha. I'm currently with CJM S1-SE with an Aeromotive 340lph and ID1050x. I definitely think that you are going to get maximum flow with the 4" intake. The reason I didn't go higher than 3.5" is because the manifold pressure with the 3.5 setup is so closely resembled the filterless datalogging that I did earlier in the year after initial installation on this car. I should research the science behind velocity stacking, since that may aid in suction efficiency, which led to the higher pressures you see. "Z"en likes this.

12-22-2019, 07:25 PM	#14 (permalink)
Senna-F1 Enthusiast Member Join Date: Jun 2016 Location: Cary, NC Age: 54 Posts: 425 Drives: 370SC,EliseSC,MR2T Rep Power: 50	Autodesk Fusion 360. It’s a pain in the butt!! Sent from my iPhone using Tapatalk TBatt likes this. __________________ 618 WHP.452 WTQ.4" Python Intake.15 psi.e50.Topgunz SC.SOHO Tune.S1SE.STG 4 Clutch.Motordyne LTH/Test Pipes/Exhaust.485 Pump.1050x

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