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I installed my Magnaflow cat back and AEM CAI this weekend. Install was very easy for both, only taking about 3 hours for everything. I reset the computer to get a "fresh start" on learning the new air flow. I have no dyno numbers, but here's my observations.

- Spoolup: MUCH sooner. I didn't think this car could spool up any faster than stock but its easily hitting boost 300-500rpms sooner. It also goes from 0psi to full boost much faster. My boost gauge is a blur now.
- Exhaust Sound: The exhaust is surprisingly quiet. It has a much deeper sound, but is VERY quiet. I can easily add a test pipe without any worry about it being too loud.
- AEM Sound: Holy cow. You really hear the turbo when you get on it. The BOV is very prominent when you let off. I can't imagine having the BOV VTA knowing how clearly you can hear it with the CAI.
- Maximum Boost: The boost now spikes about 1psi higher before settling to its normal 15.5psi. I now spikes at about 18psi. Overall though, the computer still clamps down the boost at 15.5psi.
- Boost Curve: Along with the boost coming in 500rpms sooner, the boost stays at 15.5psi a little longer. Now to about 5700rpm.
- Power Increase: Definately noticable. It really shines in two spots. First when you hit the gas, the earlier spoolup gives you even more torque at the bottom end. Second, above 5000rpms the car pulls harder and farther towards redline.


Overall. Very happy
 

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I installed my Magnaflow cat back and AEM CAI this weekend. Install was very easy for both, only taking about 3 hours for everything. I reset the computer to get a "fresh start" on learning the new air flow. I have no dyno numbers, but here's my observations.

- Spoolup: MUCH sooner. I didn't think this car could spool up any faster than stock but its easily hitting boost 300-500rpms sooner. It also goes from 0psi to full boost much faster. My boost gauge is a blur now.
- Exhaust Sound: The exhaust is surprisingly quiet. It has a much deeper sound, but is VERY quiet. I can easily add a test pipe without any worry about it being too loud.
- AEM Sound: Holy cow. You really hear the turbo when you get on it. The BOV is very prominent when you let off. I can't imagine having the BOV VTA knowing how clearly you can hear it with the CAI.
- Maximum Boost: The boost now spikes about 1psi higher before settling to its normal 15.5psi. I now spikes at about 18psi. Overall though, the computer still clamps down the boost at 15.5psi.
- Boost Curve: Along with the boost coming in 500rpms sooner, the boost stays at 15.5psi a little longer. Now to about 5700rpm.
- Power Increase: Definately noticable. It really shines in two spots. First when you hit the gas, the earlier spoolup gives you even more torque at the bottom end. Second, above 5000rpms the car pulls harder and farther towards redline.
Overall. Very happy
[/b]
Good writeup. I'm sure you'll get flamed for things you stated as you have AEM not CPE, but some of us aren't biased.

Now just imagine how much sooner the boost will come on once you remove that cat in the down pipe.

:thumbup:

Jason
 

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Good writeup. I'm sure you'll get flamed for things you stated as you have AEM not CPE, but some of us aren't biased.

Now just imagine how much sooner the boost will come on once you remove that cat in the down pipe.

:thumbup:

Jason
[/b]
I think before the CAT is removed, the IC should be either cooled down by blankets over the piping or a new FMIC system. This will leave the vehicle is Legal status and increase the " Less than efficient " Top Mount.
The Charge will help ALOT with the pwr and the spool.
As the stock IC creates more heat than we want, we loose the charge which in turn makes the spool up of the Turbo at higher RPM, as you know.
Hence the cooler the air through the IC, the better the charge and the more pressure to push the blades at a lower RPM. Not even bringing into account the lower cylinder temps and fuel mixture.
 

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I think before the CAT is removed, the IC should be either cooled down by blankets over the piping or a new FMIC system. This will leave the vehicle is Legal status and increase the " Less than efficient " Top Mount.
The Charge will help ALOT with the pwr and the spool.
As the stock IC creates more heat than we want, we loose the charge which in turn makes the spool up of the Turbo at higher RPM, as you know.
Hence the cooler the air through the IC, the better the charge and the more pressure to push the blades at a lower RPM. Not even bringing into account the lower cylinder temps and fuel mixture.
[/b]
huh? u lost me.

how will cooler air help the spool up? you do realize that the IC is after the compressor right? lets dont forget that anything moving through the IC and IC pipes is hotter than ambient air. so blankets around the piping will not help with cooling. i dont think you're understanding the basics here.

as for turbine spinning, its not pressure pushing the blades, but rather velocity created across the turbine by pressure change. the greater the pressure at entrance, the faster the velocity at the exit. Bernoulli's law of compressible flow. you want the exhaust gases to be hot. more heat = more pressure = more exit velocity. without a CAT restricting the flow, the pressure change is theoretically from post-turbine to atmosphere.
 

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Good write up and I'm not gonna flame AEM, but I will say it is NOT possible that the power drop off comes later... as the power drop off occurs because the turbo runs out of steam, and no bolt on other than a turbo is going to change that....
 

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I think before the CAT is removed, the IC should be either cooled down by blankets over the piping or a new FMIC system. This will leave the vehicle is Legal status and increase the " Less than efficient " Top Mount.
The Charge will help ALOT with the pwr and the spool.
As the stock IC creates more heat than we want, we loose the charge which in turn makes the spool up of the Turbo at higher RPM, as you know.
Hence the cooler the air through the IC, the better the charge and the more pressure to push the blades at a lower RPM. Not even bringing into account the lower cylinder temps and fuel mixture.
[/b]
Wow am I confused..
 

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Good write up and I'm not gonna flame AEM, but I will say it is NOT possible that the power drop off comes later... as the power drop off occurs because the turbo runs out of steam, and no bolt on other than a turbo is going to change that....
[/b]
So even though he's watching it on boost gauge, you're still calling him a liar?
 

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Discussion Starter #8
Good write up and I'm not gonna flame AEM, but I will say it is NOT possible that the power drop off comes later... as the power drop off occurs because the turbo runs out of steam, and no bolt on other than a turbo is going to change that....
[/b]
Incorrect. Pull the vacuum hose off your wastegate actuator and watch it make 21psi to redline. Its been done.
 

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As for potential. The turbo is tapped. I posted an efficency analysis of the turbo a while back. The Turbo intakes 366 CFM. To make more horsepower you need more CFM. I dont care what your displacement is or how efficent the turbo will act as a restriction.

Mathmatically, if you look at a VE analysis the more efficent a motor is the more the turbo acts as a restriction as if you go past a certain point you cross a compressor choke line in which the compressor cannot compress more air.

http://www.turbodriven.com/en/turbofacts/d..._compressor.asp

If you plot a K04 map on stock MS6 boost the turbo is already godawful close to the choke line. A few psi more and you will stall the compressor. The turbo will create buttloads of turbulence and heat and you will most likely loose horsepower.

ACTUAL compressor map for a K04 turbo.

IPB Image


Pressure ratio is calclulated by Absolute pressure/Atmospheric Pressure or 15.7 PSI+ 14.7 PSI/14.7 PSI

CFM need is...

CFM = (L x RPM x VE x Pr)/5660

CFM= (2.3 x 6500 x 90 x 2.068)/ 5660

CFM= 491.6

This is the minimum the turbo must flow with an engine with a 90% VE to HOLD 15.7 PSI to 6500 RPM.


As you can see at a pressure ratio of 2.068 the turbo is RIGHT on the edge of its efficency.

The MAXIMUM this turbo can flow at a pressure ratio of 2.068 is at the right hand upper edge of the map. Which just happens to be... 0.175 cubic meters a second. This converts into around 371 CFM.

Now we have already calculated the CFM needed to hold 15.7 PSI to redline. Thats 491.6 CFM at a 90% VE. This converts to 0.2320 cubic meters a second. This happens to be COMPLETELY off the chart and unattinable for this particular turbo.

This turbo is what we term Maxed Out. It is pretty close to being maxed out from the factory... No matter what you do it will NEVER efficently support 15.7 PSI at 6500 RPM.

This is PRECISELY why boost and power drops in the upper RPM band.

http://www.turbos.bwauto.com/en/products/passenger_gas.asp

0.21 kg/ sec of flow equals about 366.67 CFM at STP.

Taken from this thread

IT CAN'T BE DONE!
 

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yes, and we all know....or should know there are different K04 turbos with different flow capabilities...you are assuming on the turbo that is in the MS6 is the current one on the manufactures website...correct? Can you prove the flow of the turbo in the MS6? probably not....just assumptions. I have no proof either to say you are wrong, but you are saying it is a definite fact that this turbo will not boost above 17 psi or so....which I dont believe is true....yet..... anyway. Time will tell however.
 

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a turbo is measured in cfm not psi. the boost gauge is measuring the pressure within the pipes post throttle body in this case. if the psi moves up, the turbo is not necessarily working harder. in order to pressurize the air charge, the cfm of the turbo must be greater than the cfm allowed into the cylinders. in other words, u put more air into a given space than it can be taken away and thus, pressure rises.
 

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and CFM means... centrifugal....????
 

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yes, and we all know....or should know there are different K04 turbos with different flow capabilities...you are assuming on the turbo that is in the MS6 is the current one on the manufactures website...correct? Can you prove the flow of the turbo in the MS6? probably not....just assumptions. I have no proof either to say you are wrong, but you are saying it is a definite fact that this turbo will not boost above 17 psi or so....which I dont believe is true....yet..... anyway. Time will tell however.
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If you read the end of the thread I called APR performance, hands down the largest company in the 1.8T world, and talked to one of the engineers...

He confirmed that the K04-022 from the AudiTT was the exact same turbo as all of the other K04's with a different mounting system. When i told him what we were pushing out of the turbo he was suprised, and said I can't believe Mazda would use such a small turbo...
 

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If you read the end of the thread I called APR performance, hands down the largest company in the 1.8T world, and talked to one of the engineers...

He confirmed that the K04-022 from the AudiTT was the exact same turbo as all of the other K04's with a different mounting system. When i told him what we were pushing out of the turbo he was suprised, and said I can't believe Mazda would use such a small turbo...
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Usually the K16 is the next step up, K03 -> K04 -> K16 Should be close to bolt on. The other thing that the S4 guys are doing is hybrid turbos because there isn't any room in the B5 S4. KO4/K16 and K04/K24 hybrids are solid options as well.
 

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Yes.... there are also other companies (think AGP is one of them)... that put Garret insides into a BorgWarner housing making it an easy bolt on...

If I decide to ever use a larger turbocharger I will wait and see what Perrin does... hopefully something GT35R or larger...
 

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Any tips on the AEM install?
 

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Discussion Starter #19
Any tips on the AEM install?
[/b]
The AEM kit comes with step by step instructions with pictures of every step. They are very simple to follow. No special tools are needed, so pretty much anyone can do the install.
 

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Good write up and I'm not gonna flame AEM, but I will say it is NOT possible that the power drop off comes later... as the power drop off occurs because the turbo runs out of steam, and no bolt on other than a turbo is going to change that....
[/b]
Actually, I just put on my AEM CAI and it DOES pull much harder above 5500. As to the exact explanation, we can all argue about it but the power drop off is definitely and markedly curtailed....
 
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