Cobb Tuning dyno pull
 

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Enjoy!! Great numbers, imo. :)

Looking forward to seeing more out of Cobb in the coming months.

Sorry for a noob question...but why are the front tires spinning?

Damn! I went to the auto show instead of this...

You didn't hear yet? Subaru snuck AWD into the car without letting Toyota know. Profit.

Summary 164whp/142 ft-lbs

Nice, get about 140TQ under 3.5RPM range. I'm really liking the torque curve.

This dyno test sucks. Its a RWD car and they mount rear wheels up in the air? :bs:

I was expecting 170hp 140tq, so that's pretty much what i was expecting. I'm not expecting huge gains from cobb tuning either as they mostly deal with FI, and without changing anything about the engine I'm not sure tuning will yield much more than a few hp. If they can get it to 175hp stock I'll be surprised.

kind of a guess here, but maybe it's a resistance simulation. On the street, your rear wheels will haveto push the front wheels into motion, which adds some rolling resistance to the car overall, so maybe this dyno simulates this by making the rear wheels push the rollers on the front (so simulate pavement more closely).

I'm guessing it is an awd dyno and the front and rear rollers are mechanically connected. any time the rear rollers spin it will cause the fronts to spin

Say what?

oh good, I wasn't the only one that scratched my head at that comment. whew

HUH?

It's been awhile since I stopped caring about absolute numbers these dynos produce. It's a tuning tool. Hope they tested at least something, like air filters....

It was mounted correctly. The drive wheels are supposed to be on top (and slightly to the front) of the roller.

The straps at the rear of the car keep the car on the roller.

Same, I, like you, just decided not to reply lol

I bet tuning can improve the 3500-4500 torque dip and the torque drop off at high RPM.

Is anyone else concerned with the 20lbft dip in torque from 3k-4.5k? Why would it do that? Direct injection issues?

I ignored as well. Wasn't even sure how to approach that.

either that or variable cam timing issues. Not sure if this engine has a variable acoustic intake, but that would be another culprit.

If you want some reading material, there is some good info and speculation in this thread about it.

http://www.ft86club.com/forums/showthread.php?t=3583

Good. Cobb is gonna need testers who are certain ;)

For the lazy people:

Hmm. Runs pig rich up top.

That 20 wtq drop has got to go. That's just awful.

Wrong cobb :P

I believe that it's typical for a Subaru to have that dip. I remember reading about it NASIOC. I don't know why though. Sorry.

Dyno numbers are within acceptable range to the FRS numbers but unlike the rumor they are not more than the FRS. Odd.

hey not bad numbers....I also was thinking 170hp...but its all good...:thumbsup:

I wonder what Cobb will be able to pull out of this engine by tuning it. Definitely curious to see what results they can yield.

:popcorn:

AWD dyno's have front rollers that are linked with the rear. Thus the rear wheels are spinning both. It costs a bit of power, so it's not always entirely accurate. A single-axle dyno would be a bit better to test with.

What are you talking about?

Jeff

Good, I wanna spit flames on the upshifts with an exhaust. :thumbup:

I though Subaru showed these numbers 200/151...At flywheel? vs 164/142 real world?

http://www.ft86club.com/forums/attac...7&d=1328422528

Having all the wheels spin is more relevant than a single axle. Ideally you'd know transmission efficiency, effective moment of inertia of the drivetrain, rolling resistance, and power at the crank.

When you drive on the street, you lose power due to transmission loss, but the effect of moment of inertia will vary on how fast you want to accelerate, and isn't a true loss of power.

If you have one set of wheels spinning, you're ignoring the rotational inertia of the front wheels/brakes, which is silly because if you're going to include the rotational inertia of the rear wheels, you might as well include the rotational inertia of the front wheels, as on the road, you drive with 4 wheels contacting the pavement :P This way it gives you an idea of approximately how much power is going into moving the static (by this I mean non rotational) mass of the car, including rolling resistance.

Anyways, I'm surprised at this test because they're seeing much more low end torque than the HKS? run, or the Subaru published chart. I wonder if fuel has anything to do with this.

The midrange dip is I believe due to intake acoustics, not sure though.

Testing at the wheels is always less than that the flywheel. The engine has to turn the transmission, drive shaft, differential, axles, wheels, etc so that reading will always be less than at the flywheel.

also, don't forget that every brand of wheel dynomometer will read a bit different, so don't take specific numbers to heart. The main purpose of them is to get a baseline reading (what we just witnessed), make some changes, test again, and see if there is an improvement.

Pig rich? Pig rich is 9:1...:P As it is, you want mid 12s for power.

As for the dropoff, there's speculation that the throttle plate begins to close near redline to reduce strain on the engine. That would also explain the richening of the AFR. I wish someone would log the throttle plate.

200/151 is at the flywheel. The 164/142 is at the wheels. It takes power to turn the driveline (gears, driveshaft, rear diff, axles, wheels) so wheel hp is always lower. In this case it's about 18%, but this might be a low-reading dyno.

Ack - whoops thought there was a unit conversion problem. carry on.

They sold so few Si/350Z/RX8 (and other NA) APs that it was not worth making them...so they stopped.

I said it before and I'll say it again: COBB is out of the NA tuning game...IF they decide to make an AP for this car I will be [pleasantly] surprised. But IF they do, how much are you going to be willing to spend on an AP that nets you 5-15hp? I doubt many would spend the $595 COBB gets for their FI APs and what they would sell this one for.

great numbers?!!!!!!!! :lol:
:thumbdown:

Pretty sure Cobb (or any other) will be able to work something out... For the Mustang V6 2011+, Bama has made a flash tune that gives 18 RWHP and 22 ft-lb by pretty much only ajusting fuel/timing.

No need to be a jerk about it not being a dyno queen, like that's a surprise anyway. The numbers are correlative to advertised power, and torque is greater than expected.

That said, that mid-range torque dip is a massive canyon. I can only deduce it's the magic "efficiency zone" for highway fuel economy, and they chose to tune the engine to give up torque in that band to get better fuel economy. But, since the advertised fuel economy isn't that good, I'm out of ideas there other than "oops" tuning.

The torque also falls off much quicker at high RPM than the advertised engine plot, starting to give up at 6,200 instead of 7k.

Also, did everyone notice they stopped the pull at 6,800 instead of going to redline? It's likely there's no more power after that, but still, you'd think they'd want the data. Well, I'd want the data; Cobb may not care.

The stock AFR is a bit thick most everywhere. I can't think of a good reason this N/A GDI engine needs to be rich beyond peak-torque. E10 peak torque should be around 12.4:1, anything richer is just being wasteful unless this engine has a knock problem, which would be very strange considering it's direct injection and moderate BMEP.

Time will tell the story, hopefully.