MS3 Dyno'd with Cobb SF Intake....a little disappointed

ZooZoom

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Mazdaspeed3 Sport Cosmic Blue
Went back to Yimi Sport Tuning in Santa Clarita today. I've dynoed my Speed3 there before. I wanted to see the results after putting on the Cobb SF short-ram air intake. No other mods since my last dyno runs.

I was hoping to see about 10-15 whp gain plus a bit more torque. Technically speaking, I did gain about 10 horsepower. But I lost nearly 10 wheel torque in the process.

The most telling results are examining the AFR's from before & after putting on the Cobb SF intake. Clearly, the ECU needs tuning to support the full potential gains from the intake. It leans out (or holds higher AFR's) between 3K to 4K rpm. The AFR trend with the stock airbox is much more desirable.

Now this doesn't mean the Cobb SF intake is a bad mod. It just highlights the need to have a tool like the Cobb AccessPort and ProTuning (custom dyno tuned) ECU management in order to take advantage of the greater air flow. The ECU does not seem to do enough adapting to flow more fuel as the air flow rises. This risks detonation under conditions of poor quality gas. And of course, in California, 91 octane is as sweet as it comes from the pump. Except at the tracks where you can get 100 octane fuel.

So here's the dyno plot comparing the before & after installing the Cobb SF Intake:

kevinstockairboxvsCobbSRI.jpg



The +10 hp gain is found only at the higher rpm's and that makes sense because it takes more air flow to make power at high rpms.


At least my ETS 3.25" thk TMIC proved damned consistent on the dyno. It helped having the fan box secured directly against the TMIC to force flow without the hood duct work. Look how repetitive all 3 dyno runs were.

KevinGiesyCobbSRI.jpg



Here are a couple pics plus a short camera vid of the first pull.

PICT0001.jpg


PICT0002.jpg


PICT0006.jpg


PICT0004.jpg


 
Nice numbers..They are pretty close to mine.I know mine is running super lean also.I really need a a/f gauge to see where Im at.
 
I would have expected a little more horsepower and torque from that mod...
How does the dyno butt feel? Does it pull harder, spool up quicker, throttle response better?
 
what other mods do you already have?
is it possible that the combination of all of the mods can throw off the a/f ratio?

Also, remember that once you get more and more mods, you wont get as big of a jump as you would think based on the numbers manufacturers give oyu.
 
if they just stuck a sniffer in ur tail pipe to get the AFR's its not accurate at all......it has to be b4 any of the cats.
 
I read about the Yimi dyno day, and almost went. I was hoping to meet Paul and his crew as their shop is right down the street from where I work. I slept in though, and missed the window to see your MS3 on the dyno.

10hp on top of what you got from the TMIC sounds pretty good to me, since mods are not addative in gains.

I agree that a really good tune can unleash the 'wild child'.
 
im guessing in a drag race where you are in the high rpms the cobb intake would stomp the stock box. This is the exact same thing I saw with the sri I made for my car. leaned it down low and just about right up top. The bottom end gains were none but significant in the topend. Close to 10whp, Id say the intake is a for sure mod especially for the fact how it makes for less wheel spin down low yet pulls better up top. I will be getting this same intake. Thanks for the info.
 
thanks for the comment guys. you are basically on target with your statements. the butt dyno did feel like the car was more lively especially above 4,500 rpms. in fact, it felt like it finally pulled all the way to redline but the actual dyno graph tells otherwise.

I don't have any other engine performance mod than the ETS TMIC. Unless you count a Forge BPV (rlaugh)

Still have 100% stock exhaust.


I do have Mazdaspeed springs & camber kit riding on Koni Yellows.

And just put on Rota P1s 18 x 8 Hyperblack with Kuhmo Ecsta SPTs
 
thanks for the comment guys. you are basically on target with your statements. the butt dyno did feel like the car was more lively especially above 4,500 rpms. in fact, it felt like it finally pulled all the way to redline but the actual dyno graph tells otherwise.

I don't have any other engine performance mod than the ETS TMIC. Unless you count a Forge BPV (rlaugh)

Still have 100% stock exhaust.


I do have Mazdaspeed springs & camber kit riding on Koni Yellows.

And just put on Rota P1s 18 x 8 Hyperblack with Kuhmo Ecsta SPTs


stock boost too?
 
I wouldn't worry about it. There are a lot of variables, and by looking at the graph, by the fact that your initial torque curve was higher than with the cobb sri, explains a lot. Because there is no way a freer flowing intake on a turbocharged engine with all other things equal, will produce less power down low than a more restrictive intake.

I wouldn't blame a lower curve on the intake, rather it is likely that another variable came into play.
 
just dynoed mine only mazdaspeed intake got 263 hp on the first run then 259 then 253 i think bad heat soak got worst every time . get the results tonight post later when I get the email . Isn't there an official dyno thread ?
 
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