Exhaust HP Gains

[Asterisked Accolade]

Exactly.

[Jason@Nameless]

Originally Posted by celica73

I'd really like to see that exhaust with a single muffler and single tip. It seems rather tortured to put the Y in there. It should be lighter and cheaper that way (and not suffer performance in the least).

We can easily put a tip and single 4" or 5" muffler into this:



Subaru BRZ Single Exit Track Axleback Muffler Delete

It's $99 as pictured and saves 23lbs. There is no performance loss to the Y from our experience comparing our STi Hatch vs. Sedan exhausts. We will verify this on the BRZ when we head back to the dyno this week running the track single exit axleback vs. the street dual exit. We do a stepped Y to minimize division loss at the Y and bias torque. On our WRX & STi catback, we make ~32ftlb of torque over a baseline of a Stage1 off the shelf tune. 19-22whp.

One other note regarding the layout of that Y on the BRZ & WRX/STi Hatch: we did a lot of testing on this and adding the additional bend required to run the Y vertically instead of horizontally certainly makes more of a beneficial difference than it does a detriment as it splits flow evenly between the two circuits rather than having the exhaust gas pile up in the outside of the preceding bend and bias the majority of flow into one of the two secondary circuits. Makes a major difference in the sound as well as the performance.

Dimman, I completely understand re: the dyno graph data. My goal usually is to post dynos that any customer can digest and understand, but like I said originally I have no problem sharing any and all data that we have. I probably was more irked than I should have been. I'd rather share as much data as possible rather than have a single person have questions.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

[Jason@Nameless]

Originally Posted by Tainen

yeah not a bad idea. They love to do custom setups with lots of options... so maybe stepped stages that get more aggressive/less DD friendly.

Our configurability is our secret weapon against overseas produced high inventory designs. It's impossible to do if you have to buy 50-100 units at a time from Taiwan/China/Korea. I think our 2011-2012 WRX/STi TurboBack exhaust has over 5184 possible configurations. And that's not counting recirculated vs. non recirculated external wastegate options.

Jason

[UncleFester]

The race pipe looks good. I'm curious how loud the car will be. Looking forward to the video and dyno results.

[Jason@Nameless]

Originally Posted by UncleFester

The race pipe looks good. I'm curious how loud the car will be. Looking forward to the video and dyno results.

Back to back dynos between the race pipe and the street axleback resulted in the same power up top and about 1ft lb loss at the bottom end but at that level I'd chalk it up to simple variation in pulls. I do have a video of this exhaust and need to post it asap. It's surprisingly quiet. If you want an example, just pull your factory axleback off and take a spin around the block on an open midpipe. Granted, putting the exhaust out the back reduces drone a bit in the cabin though.

J

[Jason@Nameless]

Originally Posted by Jason@Nameless

I think our 2011-2012 WRX/STi TurboBack exhaust has over 5184 possible configurations. And that's not counting recirculated vs. non recirculated external wastegate options.

I did the math on this, and including the EWG recirculation options we have
20412 available configurations of our 2011-2012 WRX/STi Sedan TurboBack Exhaust.

[Jason@Nameless]

Originally Posted by celica73

I'd really like to see that exhaust with a single muffler and single tip. It seems rather tortured to put the Y in there. It should be lighter and cheaper that way (and not suffer performance in the least).

Scott

We tested a single 2.5" straight pipe vs. that 'tortured' exhaust and the dual exhaust w/ twin 1.75" pipes made ~1hp/ft lb more than the straight pipe at peak rpm, but at that level we're talking standard deviation. Either way, the dual exhaust makes great power and there's not more to be had by changing the flow path.

Jason

[milenko11]

How safe is it to run the over pipe and axle back setup without a proper tune? I know ecu's can typically learn but I'm just hesitant on new platform. Ideally I'd like to have a tuning solution in place before mods but the sound of the nameless exhaust is very tempting.

[Tainen]

we ran it on the dyno, it maintained fairly safe AFRs. I drove the car in that form for a few weeks as well, felt solid, no CELs, no knocking. The 2nd cat is AFTER the last o2 sensor, so really, it doesn't change what the first and 2nd o2 sensor are seeing. I think it's safe, and I've bet my 30k car on it.

[Agnostik]

Do you guys test decibels on your designs and configurations? Would be good to get a general idea on the sound level to expect from something like this.

I am curious because, where I live, they are beginning to impose enforced decibel limits. Would be good to get something that sounds good and enriches that nice boxer growl but won't put me out of those specified limits.