Nameless Performance Equal Length Stepped Header
 

We just wrapped up our first equal length stepped header for the BRZ, featuring mandrel bent T304 stainless construction and an optional high flow catalytic converter in the factory location for SCCA racing compliance. We're excited to take this and the next design or two we are working on to the dyno on Thursday.

http://sphotos.xx.fbcdn.net/hphotos-...98271447_n.jpg

So far this is what we have got to show - the first prototype system is a Tri-Y design featuring 1.625" equal length (within 0.8%/.125") primaries and equal length (within 8%/.5") 1.750" secondaries into a 200 cell high flow catalytic converter with a 2.5" outlet to the over-pipe (will be fabricating a 2.5" overpipe also). There are two secondaries at the bend that is facing left, they are stacked on top of each other, and the higher of the two is not visible in the photo. This header does fit in the factory skidtray and ceramic coating will be an option. We have also discussed a faceted sheet metal heat shield.

Our goal is to include our customers in our development process at every turn and we've got a fork in the road to determine which of the four other design ideas we should test first. So we'd like your input. According to our exhaust flow dynamics software the existing design is optimal with secondary runners being of a length that requires the removal of the catalytic converter. We were considering replicating this system exactly with long 1.75" secondaries in place of the catalytic converter. This would most likely require a jetted secondary oxygen sensor fooler to keep from throwing a check engine light.

Alternately, we can build out a torque biasing design using 1.5" primary pipes and 1.625" secondary tubing with a high flow catalytic converter like the first design. The other alternatives are to run a long tube stepped 4-1 design with or without a catalytic converter but utilizing one of the above primary/secondary sizes, or going up in size (not looking terribly favorable from our preliminary calculations).

So what would you like to see, we would love to have your feedback. All of the designs will probably get prototyped one way or the other. This is the first production header we will be offering and we'd like to gain as much development knowledge as possible from the process.

Lets chat!

Jason Griffith
Engineering Director
Nameless Performance

Placeholder for more photos.

Update: Up 46ft lb and 36whp in the dip:

http://i1260.photobucket.com/albums/...psd3872ef9.png

Dyno results of prototype 1.625 primary 4-2-1 Catted Header with full exhaust:

Combined Data (note that lower peak modded run made 29hp vs. the lower peak power baseline, albeit at the very top of the range). Needless to say, once the tuning solutions start popping up, this header will support some serious top end capacity...and the catless versions should do even better based on their ability to run more appropriate, longer, secondaries:

http://i1260.photobucket.com/albums/...TopEnd29hp.jpg

Horsepower Alone:

http://i1260.photobucket.com/albums/...HPCompiled.jpg

Torque Alone:

http://i1260.photobucket.com/albums/...ueCompiled.jpg

Gains in HP/TQ and % Increases:

http://i1260.photobucket.com/albums/...Comparison.jpg

(note, these graphs above are still for prototype parts, we're pretty confident there is more power to be had with other configurations that we will be testing very soon)

Weight Specifications:

Factory Header w/o Heat Shields: 15.0lbs
Nameless Performance Stepped 1.625-1.750 Catted Header w/o heat shields: 11.6lbs
Nameless Performance Stepped 1.500-1.625 Catted Header w/o heat shields: 10.9lbs

Wow FWIW that header looks nice. Since this will be a DD more than anything for me I'd prefer to keep the cat. Who makes the high flow you use btw?

I'd like to see results for this baby before I suggest your next move. (no cat/longer secondaries)

It's a Magnaflow. We use them in our Jaguar XKR downpipes, Jaguar S-TypeR, Jaguar XJR, Subaru WRX & STi Downpipes, Kia Optima/Hyundai Sonata Turbo Midpipe and have had zero field failures in 2.5 years. And Supercharged Jaguars eat factory catalytic converters for lunch.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

I'd be real wary of a non-catted header system right now I think. I say that because we don't have any tuning solutions, so the stock o2 sensors are expecting a cat of some sort. I'm no tuner so I don't know what that would do, but without the ability to properly adjust the ECU to account for cat-less, I'd stay with the cat. Maybe target a catless system for 4 months out or so, when ECU tuning is more prevalent.

For now, my biggest concern is the heat soak. It's right next to that coolant line, and surrounds the oil pan. Doing some sort of a coating or wrap would probably help, but I'd love to see temperature data on the difference to know that a coating or wrap would be good enough to keep coolant/oil temps in check (and to keep that line from melting).

Where does the 02 bung go?
Will I melt my coolant line without coating this thing, or cause bad coolant temps?
For a torque bias design with smaller diameter pipes, what would you think it would do, higher torque down low but less overall power? percentages or thoughts?

excited to see dyno graphs.

Cool :thumbup: I've never used a magnaflow one. Lots have had great experiences with renault high flows like HiTech uses. I've had horrible experience with junk like carsound high flow cats.

Disclaimer: I have no subaru experience.

However, headers on Hondas can be <1" from the oil pan and very close to AC lines and some coolant lines and it's never caused an issue there.

Although I'm sure they can offer a model with a heatshield.. IMO it's just one more thing to break. Coating wouldn't be a bad idea. I don't like wraps myself..

Concerns on Catless: I'm not as worried about this as it seems you are. The primary O2 sensor is the critical sensor to provide closed loop feedback to the ECU for proper functionality of the fuel maps. That being said, there is a bit of a challenge in getting a good metering of all four runners should we choose a tri-y catless design. The secondary O2 sensor is, on almost all cars, only used for monitory catalyst efficiency and warm-up times. So really the challenge for us is to develop an secondary O2 sensor bung that will limit what that sensor sees so that the ECU doesn't throw a code for primary catalyst below efficiency or primary catalyst warmup. I've run catless on many turbocharged and naturally aspirated engines with no check engine lights if the secondary O2 sensor challenges are met.

Heat concerns: This is a naturally aspirated car with very little backpressure in the primary catalytic converter. If it were a turbo car, I'd expect to see manifolds glowing white hot, but in this application I am not a bit concerned about proximity to the coolant line or the oil pan if some method of shielding is provided. As for melting the coolant hose, you'd have to work REAL hard to accomplish that. Even a small air gap in that are is going to provide enough thermal barrier to prevent that heat from reaching damaging levels. The good news is, we do have the ability to build faceted heat shields to selectively reduce the thermal transfer between critical components. We also have laser temp guns to monitor temperatures on the dyno. And we will be doing so. The other thing to note is that a two dimensional photo doesn't do justice to the distances that exist between these components. We did our best to keep the equal length while optimizing clearance for future development of heat shields as well as keeping this as clear as possible from the engine.

Additionally, if you're worried about track oil temps, we have plans for a thermostatically controlled oil cooler as well - but I think your track driving behavior is going to be the oil temp modifier far more than the headers proximity to the oil pan. Again, all things we plan on monitoring and gathering data from in order to add components that are necessary for optimal design on the street and the track.

As for the O2 sensor bungs, they are in the factory locations up top.

Torque biasing header I think you would indeed sacrifice top end power, but it's really a testing question - if you gain 8 additional ft-lb of torque and lose 2hp at the top end, that's an easy selection to make. We could also do a triple stepped design, but again, that requires all of the real estate occupied by the header.

More questions/thoughts!! Keep em comin'!

Jason Griffith
Engineering Director
Nameless Performance, Inc.

sweet header!!!!

I also think a torque increasing header is a great idea....the high flow exhaust and intake will increase top end power.....the ideal powerband for racing (track) is 4500-7000 or so....unless you need 2nd gear, then it would be 7400 (redline)...

It looks like I will use 3-4-5 (maybe) at my home track, Thunderhill in Willows CA...I think 2nd is a bit too low, since the slowest corners are 40-45mph, and followed by turns...so you would have to short shift, or redline shift at the apex (not a good idea)

My current race car performs quite well, due to its high low end torque.....it provides a significant advantage getting off the corners....

I agree with all of this. The header wraps work fine on T304, but they will accelerate degradation of the material. Remember, just because you alloy stainless with a pile of nickel and chromium doesn't mean you get rid of the iron and carbon.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

We've worked with the US Built Vibrant units (one of the only parts they have made in the USA) which are nice but extremely spendy, Magnaflow, Eastern Catalytic as well as the old Carsound brand. We have sold > 200 of these in 2.5 years with zero failures. And we back the products we incorporate into our systems. If you got a failure, we'd replace it. And it would probably drive us to investigate a change in manufacturer, but up till now we're very pleased with these spun metallic units.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

I vote for:

1) Keeping a primary cat
2) A metal heatshield for a more "OEM " look (so upon a brief inspection it doesn't look "modified")

As far as flow designs - I would test the current design vs. the torque biasing.

Intuitively I think that a good design (ie equal length and routing) would offset the possible small losses in a smaller stepped design. So far it is the direction I'm leaning. Either a 1.5-1.625 or a triple step 1.5-1.625-1.375. Biasing peak HP at 6000rpm our software said 1.375-1.500-1.625!!! 7500 it indicated 1.500-1.625. But we're doing a few major assumptions on camshaft profile as well as lift, which no-one has at this point. I got the valve sizes, I talked to the guys at Brian Crower to discuss what their thoughts were given their experience with naturally aspirated Subarus and we made the best guess for the information we had on hand. I've searched every FSM and had our contacts at 2-3 major dealerships help in that search and found nothing.

We also used the other data available: What the factory used. While I doubt a lot of the factory's reasoning for a lot of their design concepts, header diameter doesn't have any 'reason' to change the bias for economy or engine behavior for the most part. Now, why they ran an unequal length design (32% variance between Y lengths) from the factory when they could have accomplished exactly what we did is beyond me...but then again, Subaru sends the US insanely unequal length headers for the STi and the JDM model gets EL header w/ Twin Scroll turbo.

Jason Griffith
Engineering Director
Nameless Performance, Inc.
360.263.5001

Spoken like a true comrade of the Democratic Peoples Republic of California. :-D I grew up there so I feel your pain. And I completely agree that an option for this is of primary concern for California residents. #AlsoTheReasonIMovedToWA

Going to do some look-see from the top and bottom to see how crazy we'd have to go on this to accomplish what you're describing.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

Maybe two versions.

Some of us may end up making more top end through tuning and maybe cams.

It would be sweet if the torque curve held on for another 500 rpm.

You got it! :lol:

I also don't mind swapping parts every couple years, so I don't need too much in the way of "design compromise."

Hell, I have a 3.5L 2GRFE in my MR2 Spyder

We'll make as many configurations as function for different applications. I did the math again last night and our 2011-2012 STi Sedan TurboBack Exhaust has 20,412 possible configurations. If there's reason to sell multiple designs with varied configurations, we'll do our best to facilitate that. Especially when it comes to preferential items like heat shields vs. ceramic coating. I don't want to jack the price of the base header up just to add provisions for heat shields if someone isn't going to use them. We do have a great stockpile of ceramic wool (one level higher density than the factory heat shield packing - the only place I've ever seen that material on a production car) to work with for bolt on heat shielding options because we pack our mufflers with it. I can put a single 1" thick pad of it on the palm of my hand and blast it with a MAP gas torch without any heat on the other side. We threw a chunk of it, soaked in oil, into a bonfire and it survived intact.

Jason Griffith
Engineering Director
Nameless Performance, Inc.
Follow us on Facebook to see our day to day progress.
360.263.5001

Good to know.

In many ways I'd prefer catless (o2sim or mounting the so2s a bit out of the flow to fix the cel issue) but I really don't want to deal with cleaning the back of another catless car :)

OK so if we just throw the 2nd o2 sensor post downpipe cat that'd work then, for people that have a catted downpipe? I know some in the STI world do that.

OK, you sold me. I'll take a header system with some sort of coating or shielding. Delivered by... say... thursday night, to my front door.

and pick me up some o2 sensors for my daily driver while you're at it- and then you've earned a customer for life. :lol:

There's always the secondary catalyst in the downpipe. Also, we have contemplated what our options are for making the secondary catalyst the monitored catalyst. Really not much room to get the sensor that far back, but we could always engineer a solution to make that work.

j

would having a single high flow cat scrub the air enough? would it smell funny at all?

Either in the header, or the downpipe, so that way people can drop down to 1 cat for performance and weight reasons, and retain relatively smell free exhaust

<< kinda forgot about the 2nd cat. Not used to that crap :)

Single cat certainly de-stinks just fine. We run single on all of our other designs. And I had one pass on my EJ22 powered VW Vanagon Syncro on the sniffer recently as well. And it was only about 24" from the tailpipe, with UEL header.

J

Any chance on doing a legit 4-1 ELH similar to the Killer B WRX STI one? I just love that thing :)

edit: lmao i didn't realize i was posting in a thread for one.

double edit: oh nevermind this is 4-2-1, but still interested :/

Oh so as long as I can keep one cat.. I'd be good with the catless header and a downpipe with a cat. Depends on which makes more power but I'd guess the catless header over the catless downpipe.

yeah... hmm. I'd vote for a real nice catless header setup too, then. Hopefully that becomes more clear when tuning and o2 sensor solutions start popping up.

We know the catted downpipe makes power, from the other nameless threads- catted downpipe and axleback netted 11whp. So I think you're right. catted downpipe, catless header.

I'll third that.

Nice looking header, I'm excited to see dyno results.

I'd be surprised if the 1.75 lost anything over the 1.65. My experience isn't with subarus either, but this isn't a Subaru valve train. Testing will be the only way to know for sure, but I think you're on the right track as well.

I would 4th that, but the heat shield would help. :thanks:

subscribed.

I think I saw in a Toyota service post that the cams were 255° (so 200-210ish at .050"?). Can you share valve size, my estimate is 34.5mm. So I'm putting my lift estimate at ~9mm.

???

Are you guys keeping the stock primary lengths so we don't have to chase returns with the AVICS? I get the impression that a positive return from the primaries is what is killing the top end. So you could size the lengths of the secondaries (catless version) to cancel the bad top end return?

Looks very nice.

I was looking at 2013 DI Impreza data and I got was ~35mm intake ~32mm exhaust. with 205 duration at .050. My lift estimates were 9mm. :-D I'm guessing for designing this system in a 'shoot close, re-aim' method like we are doing, our numbers are as my dad used to say "Close enough for telephone work." (he worked for the phone company). I put the exhaust port centerline length at 3.25" as these damn Subaru heads have that stupid dogleg port on one valve for a ~3.65" port centerline length and ~3.00" port centerline length. You have no idea how badly we want to design billet heads for the EJ and FA engines. I hate those port designs.

If I plug your valve size estimate in with smaller valve sizes than I estimated I'm still having to round up or down very slightly on the recommended primary/secondary diameter, and the only other item that changes is the overall recommended primary and secondary lengths drop slightly. The problem is, there's only so much you can increase the length and almost none that you can decrease the length. Recommended is 11.4-13 inch if I bump the port centerline length slightly to accommodate the dogleg in second valve section of the port (for those of you who haven't seen inside a Suby head, the 2 exhaust valves have different 'sub-port' lengths, one being substantially longer than the other), but goes up to 13.4 if I cut it back down to 3" for the shorter of the two port centerlines.

To switch the subject entirely (i'm good at that), if we go to a three stepped 4-1 header, and switch to a triple stepped header (rounding runner diameters to primary = 1.5, secondary = 1.625 and tertiary = 1.750), this design seems very do-able in terms of the lengths recommended. This also lends some credence to the idea that a larger exhaust may work well. Otherwise the numbers point to a smaller ~2.5" exhaust.

That's all I've got for now. I'm tired and it's time for dinner. I'll be back tomorrow to weigh in on this more. Unless I can't sleep tonight (probable).

J

This is great that you are involving the community. Great info and posts. Cat-less is great, I would love that option, but for me it isn't very practical. Inspection and emissions testing in Pennsylvania wouldn't have that, no longer a daily.

More torque at the bottom end seems to be the way to go with this application.

Looking forward to the final decisions.

Badass!
 

OK. Now your just show'n off:popcorn:

That looks great, but I'd bet it is going to sound even better. I love the underhood sounds that a nice large tube/thin wall header adds to the driving experience.

weight specs?

Stock: 15.0lbs.
1.625 Primary / 1.750 Secondary Catted Header: 11.6lbs
1.500 Primary / 1.625 Secondary Catted Header: 10.9lbs

J

Is 200-210ish at 0.050" the typical figure for "255" cams? I wonder because the Prius is equipped with "270*" cams which seem to blow about 1/4-1/3 of the mix back out, maybe a bit less. So it should have 225 degrees "effective" duration minimum, and I guess 210+15 (or 270-45) =225, but intake acoustics mean you'd expect a little more than that. Additionally, the 2GR has ~250 degree cams which is oddly close to 255 considering that the FA20 makes peak torque at a 25% higher engine speed or so.

Excuse my rambling, we can get back to headers now.

I need to keep a eye on this thread! that header looks sexy.