Quote:
Originally Posted by Tainen
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.
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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.