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UEL Catted header for my... Odd(?) build.
So, for starters. I'm modifying on a bit of a budget. My build ethos is essentially OEM+, or how-it-should-have-come-from-the-factory. I've swapped pilot super sports onto all four corners (and I'm planning on getting RPF-1's in the near future). I have swapped in camber crash bolts and had the car aligned (with me in the driver seat for weight distribution) to achieve the most front end negative camber that I could. Soon I'll be putting RCE Yellow springs on the stock struts as well. Front and rear sway bars are both adjustable and slightly stiffer than stock on the current settings. I have a drop-in K&N filter (who doesn't have a drop-in these days). I want to take a bit of a big next step though. Okay, background info done.
The Question: First off: I have no intention of tuning right now, period, no exceptions. I have every intention of doing it in the future but at the moment I need my warranty intact on my engine since I have a recurring crank case (timing cover) oil leak that is not uncommon for our engine. So for no: no tuning!!! Probably will heavily consider it when my warranty is up. In the meantime I want to change out my header for a CATTED UEL HEADER. I am going catted so I can (hopefully/probably) pass inspection in NC, but mostly so that I can run it without a tune with a low chance for a CEL to pop up. I'm running the OEM exhaust in its entirety behind the header, however I have spaced my muffler out from the midpipe: effectively a muffler delete without the aerodynamic loss from removing the muffler. WHICH HEADER SHOULD I GET? Let you opinions, without talk of tuning, run wild... There really aren't many options in the Catted UEL category though haha. I'm looking at the FT86-Speedfactory header the most right now but I've also seen a catted UEL header offered by JDL and I'm willing to pay the extra buck if it's really that much better. A thermal coating would also be really nice: an option I THINK only JDL offers, feel free to correct me if I'm wrong. I want a Catted UEL to remove the torque dip without requiring a tune that could possibly void my warranty. CONCLUSION: looking for a CATTED UEL HEADER to remove the torque dip without a tune. The additional maturity of the sound is just an added bonus. Performance>sound Opinions??? I don't think I missed any points but I've been studying all day, for days, for the most difficult Calculus in the engineering program at the University I attend: so I'm a little all-over-the-place. Will clarify anything I need to. |
The majority of the performance guys would objectively favor an EL over a UEL if going for performance. Food for thought.
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Yeah, I did a fair amount of research into it. EL headers provide more peak horsepower at the top end, while UEL typically boost the low end and do a better job removing the torque dip. My source is every single dyno I've seen for both EL and UEL's, and also the bolt-on guide sticky at the top of the engine thread haha. I autocross the car, a lot. (I help host an autocross once-to-twice a month in my region) and I definitely need the low end improved more than I need a peak horspepower boost. Thanks for the brain food though!
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Catless header with a tune will pass an OBD reader test and usually an emissions sniffer test as long as you keep the stock front pipe and cat, but neither will pass a visual inspection. It's illegal to remove or modify any of the stock cats on the car. If you're gonna replace the header anyway you might as well do it in the way that gets you the best gains.
Food for thought. |
I wonder if really EL is about top rpm hp and UEL about middle rpm torque, as Ace's header shown otherwise. Imho it's as simple as runner length is shorter on average UEL and other way around in EL, hence it's more of a question to which rpm range/which exhaust gas speed particular header's runner length are better fit for. Hence imho if you manage to design in unusually long/short for common EL/UEL designs exhaust tubes, you'll get needed optimisation for specific rpm range despite what type of header it is.
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Since OP is adamant on not getting a tune, I would recommend FT86speedfactory catted UELs
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Just get the UEL header, they still provide some top end power but usually not as much as an EL header.
Also you said you're modifying on a budget, so UELs are the way to go. Look into Gruppe-S or JDL if they still have that sale. |
For those saying EL and tune, that's my long term plan. Eventually I intend to run a nameless full 3" exhaust from their high flow catted EL header all the way back to the bumper. I also plan to run the delicious tuning E85 flex fuel sensor with an ecutek tune when I go full 3" piping. But right NOW I'm just trying to get some more usable power and torque dip negation while absolutely retaining my warranty, with a 0% chance of losing it. That means no tuning, for now.
Does anyone know anything about how the JDL Catted UEL fairs on an untuned motor, versus the FT86 Speedfactory one? FT86 claims on their site that it's off the shelf, no tune, but I don't think JDL makes any such claims. |
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No. You don't "need" tune to run it even if it flows/scavenges better .. just that:
1) you won't get full gains without tune 2) any, even catted, aftermarket headers eventually may throw out CEL. It's better to disable that check or clear code in tune. |
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ie the dealer will see header as soon as they open bonnet, no heat shields changed positions of 02 sensors ect. yes you can clear P0420 cat efficiency cel with obd scanner or battery cable removal. this is sort of gains you will see with header (this was catless tomei and full exhaust) and NO tune ie not much, but good reduction of torque dip with UEL header http://counterspacegarage.com/media/...r/frs_gluf.jpg |
has there ever been a case of someone being denied warranty work while using OFT and flashing back to stock before the work was done? I know OP said he does not want a tune at this time but I can't recall ever reading a denial based on that. Then again, there's 9 billion threads so I could have missed one.
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And yeah that's one of the best comparison dyno'd that I've seen! And yeah I'm really not going for some unicorn power figure without tuning: I just want the best header to run without any CEL codes or tuning that will remove the torque dip. So far the best option seems to be the FT86 Speedfactory Catted UEL but they don't have any ceramic coating options which is a must in my scenario since if the oil leak returns it will be depositing a very slow and mild drop of OW-20, possibly onto the header itself, which has been shown to be a fire hazard on an unprotected header at full temp. |
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