Times thru the stock airbox.

[Turbo1dr]

I'd like to see a test done of the entire stock air intake system up to the turbo.

This consists of a:

stock plastic inlet piece (the piece that bolts to the rad support)
stock air cleaner housing
any air filter inside housing
stock plastic elbow with air temp sensor
stock MAF
3" inlet tube (doesn't have to be the stock one hose)
stock inlet bell

BUT this time attach a vacuum gauge in the 3" pipe and read the vacuum it pulls. I'd like to see what kind of vacuum it pulls instead of using just CFM. I would think you can still have a lot of CFM even while the system is pulling a vacuum...which would mean it's still restrictive.


Do this same test with only a 3" pipe and a 9" & 14" K&N cone filter with and without MAF's installed. NO TURBO INLET BELL INSTALLED
Do this same test with only a 4" pipe and a 9" $ 14" K&N cone filter with and without MAF's installed. NO TURBO INLET BELL INSTALLED

Would like to know actual vacuum on the gauge along with CFM.


This would be like measuring exhaust system backpressure using a pressure gauge. But instead of it being pressure... it's vacuum. Pressure on a exhaust system is bad and vacuum in the inlet tube is also bad....meaning something is restrictive.

 

[SloGN]

fired up the flowbench tonight-------i was encouraged by how many folks seemed to be interested in the stock airbox-------some numbers to ponder--------and some test conditions--------all measurements are CFM of flow at 28 inches of water------
stock elbow with temp sensor- 793
empty airbox and elbow no snorkel- 475
empty airbox and elbow with snorkel- 572
empty airbox and elbow with kirban lower plate no snorkle- 799
empty airbox and elbow with kirban lower plate with snorkle- 781
full airbox and elbow with purolator filter w/o snorkle- 454
full airbox and elbow with purolator filter with snorkle- 534
stock inlet bell with open vent- 589
stock inlet bell with vent capped with rubber cup- 620
stock inlet bell smoothed (flashing removed) and vent filled flush with epoxy- 629

note:these figures are not corrected for hum/temp so they are only useful for relative values

let me know what you would like to see and i will do it in the next few days...........................RC

Richard

i done a similair tests a few yrs ago on the exhaust cut-off on the exhaust cut outs but everyone told me i was crazy.


here is the test that i done back in 2005.


talking about flows on the exhaust and how the cut-out messes with the flows.

Hey guys


i dug this post up from the grave. I done some testing on the SloGN today on backpressure.


Mods to the engine/exhaust/turbo is in the sig. well here goes.


All the pressure reading were taken from the EGR port.

RUN 1 20 psi of boost in third gear i showed a BP of 33 psi made two runs to verify consistesy. this was thru the exhaust

RUN2 Next i proceeded to open the collecter on my test pipe. with the dump open @ the same 20 psi the BP was @ 36 psi Again to runs were made to show consistesy.

RUN3 i took the Test pipe competely off the car and ran just a open DWN pipe the boost went to 22 psi with 35 Psi of BP

Run4 i corrected the boost back down to 20 psi with the Dwn pipe and got 31.5 Psi of BP.

So from what i have noticed on my car just opening the dump on my test pipe yeilds no gains at all.


next. i'm going to check the Back pressure @ the o2 sensor location to see if there is an actual diffrence in pressure there than at the egr port. i doubt there will be any difference since the EGR port is tied in witht he rest of the exhaust system pre-turbo.

so 31.5psi/20 psi= 1.57 ratio just a open dwn pipe.

20psi/33psi= 1.65 ratio thru the exhaust

20psi/36psi= 1.8 ratio with the dump open on the test pipe.


The only thing that i can think of why the Backpressure went up by just opening the test pipe is that it is creating turbulence in the pipe by the air having turn and exit the dump collector. thus having to have more pressure to get the air to flow out or maybe not more pressure bu more engery to push the air out even tho it's a shorter way out.


The only thing that i can see that would make the Backpressure lower by opening the dump collector is the fact that the car has a real restrictive exhaust.


how this makes for some interesting info guys.





note i had the stock exhaust manifolds on the car at that time with a stock cam with the GT61-52 turbo.

 

[A2000RICH]

What does the Kirban lower plate with a Filter flow? It appears you flowed it without a filter. Did you flow it with a filter?

Flow numbers are highly dependent on the input and output. The Elbow flowed 793, but was this with a bellmouthed venturi inlet or just straight hooked up to the machine? If a bellmouth wasn't used, the elbow might actually flow 1000 CFM since it is a middle component of a system and not acting as an inlet or an outlet.

Similarly, if you flow a stock MAF, you will conclude "this thing sucks", but if you put a 4" to 3" bellmouth on the front of it, it will flow almost 1000 CFM with no other changes. The bellmouth would simulate the airflow the MAF would actually see in the system, since very few of us run an open MAF.

i agree that a bell will increase what might flow but even thats not the same as a long straight pipe with minimal turbulence--------i will do a few comparisons this weekend and publish them

 

[A2000RICH]

I'd like to see a test done of the entire stock air intake system up to the turbo.

This consists of a:

stock plastic inlet piece (the piece that bolts to the rad support)
stock air cleaner housing
any air filter inside housing
stock plastic elbow with air temp sensor
stock MAF
3" inlet tube (doesn't have to be the stock one hose)
stock inlet bell

BUT this time attach a vacuum gauge in the 3" pipe and read the vacuum it pulls. I'd like to see what kind of vacuum it pulls instead of using just CFM. I would think you can still have a lot of CFM even while the system is pulling a vacuum...which would mean it's still restrictive.


Do this same test with only a 3" pipe and a 9" & 14" K&N cone filter with and without MAF's installed. NO TURBO INLET BELL INSTALLED
Do this same test with only a 4" pipe and a 9" $ 14" K&N cone filter with and without MAF's installed. NO TURBO INLET BELL INSTALLED

Would like to know actual vacuum on the gauge along with CFM.


This would be like measuring exhaust system backpressure using a pressure gauge. But instead of it being pressure... it's vacuum. Pressure on a exhaust system is bad and vacuum in the inlet tube is also bad....meaning something is restrictive.

this weekend i'll do the tests you asked about---------BUT do you understand that there is a vaccum number in my tests--------if you are not familiar with flow benches one of the parameters that you set is the pressure drop for a given flow--------in many engine measurements 28" of water is sort of a "standard" and that is why i use it most of the time--------that is the pressure drop stated in inches of water across the device with the stated flow-------for any value of flow (CFM) it will always increase if the drop in pressure (ie vaccum) is allowed to increase-------am i clear on this???.......................RC

 

[Turbo6Smackdown]

1. Could you test a BONE stock system, as it came from the factory (im sure you have a ton of that stuff layin around)

2. Then, test the same system with a kirbans billet inlet bell, and a bellmouthed compressor housing, as was shown earlier in this post. if you dont have a kirbans inlet bell, just use a fully ported and polished stocker, with the hole filled.

Next, test the standards, that everyone here pretty much runs. 3. Test the system (bellmouthed compressor, with modified inlet bell) with the typical 3" aluminum maf pipe, with a 3" K&N filter stuck onto the end of it.

4. And lastly, test the same system, but with a tin man, or big mouth cold air kit, stuck onto the end of the 3" aluminum maf pipe. (stock maf on every test)

I want to see, in steps, the increase (or decrease) in numbers, as the mods get 'better'... or what was commonly thought of as better. I want to see, how much the latter 2 designs outflow the 2nd design, to see how much of a loss I will be at. (im thinkin of puttin some of the stock stuff back on. IF im not at much of a loss that is) Thanks

 

[UNGN]

The bellmouth of the turbo inlet is not going to be the bottleneck in the system even if it only flows 500 CFM and the Airbox flows 600 CFM.

The compressor impeller is lowering the pressure at the throat of the bellmouth so comparing the CFM flow here to upstream values is kind of an apples to oranges comparison.

Also, the bellmouth isn't really the bottleneck of a turbo. If you put a TA61 Bellmouth on a stock turbo, it will flow less than if you have a well matched stock bell, because 1.) the throat of the turbo is at the leading edge of the impeller and not at the outlet of the bellmouth and 2.) the flowpath of air with the stock bellmouth will be smoother than with the TA61 bell, where the air will run into the face of the turbo and around a square corner into the turbo inlet.

Again, the throat area of a turbo is determined by the impeller size and not by the Inlet bell size.

A "ported turbo" inlet (smoothed stock bell matched to slightly ported inlet housing) will make more HP than an unported turbo inlet, but we are not talking a night/day difference, maybe 1/2 a .1 on a timeslip. Matching a stock bell to the turbo is worth about the same as matching to a larger bell. You may notice a difference from stock, but I serously doubt you will notice a difference between each. Matching too large a bell may actually be worse than a matched stock bell, because the ideal bell shape is lost.

The airbox is a huge restriction vs. a K&N. Ram air devices may show up as more restrictive than an open K&N on a flow bench, because the flow bench isn't going down a track at 100 mph.

In practice, I have seen little gain with Ram air or cold air at the track, because I cool the the hell out of my motor/intercooler between runs, the the stock intercooler scoop does a pretty good job "pressurizing" the air under the hood, so it's like ram air without all the wind.

 

[Turbo6Smackdown]

ahh yea. forgot about that. without goin down a track, the numbers will be different. thanks for reminding me that.