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07-23-2010, 07:22 PM | #1 |
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Electronic cutouts questions
I'm interested in electronic exhaust cutouts, e.x. http://www.m3post.com/forums/showthread.php?t=196007
A couple questions:
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07-24-2010, 08:49 AM | #2 | |
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I *edit* "perceive" a difference at high RPM, but since I don't have a baseline, I am not sure if it's because the the flow rate is reduced with the valves closed relative to stock, or if it's the increase with them open. >It's possible that with ECU tuning I could get more power out of more exhaust flow rate. The same statement can be said for any exhaust change. I am not motivate to. The car drives fine and it's not worth the warranty headache. >Yes, you will need to hack up the tubing between the muffler and midpipe connection. Since the OEM tubing is hydro formed (with an irregular cross section), you are probably best off cutting out a large length between two round cross-sections and replacing with standard round SS tubing. Warranty-wise, sure the muffler is now likely no longer under warranty. Rest of the car is fine. If you ECU tune, and they can detect it, your motor is voided. >I've had cutouts since Feb 2009. Aside from the shitty mechanical design of the Raceready units, I like them a lot. The jekyll/hyde tunability adds a ton of character to the car without changing the livability. W/r to drone, yes, there is low-mid range drone with the valves completely open, and as the car gets older and the interior loosens up, that turns into buzzes and rattles that sing to you at different times as the car sweeps through 2K - 4K rpm. The simple design of the cut-outs also lets you control how far they are open, so you can crack them open a bit to change the character of the exhaust without introducing any major drone issues. No regrets except the raceready units. I would try another brand next time around, something with a better coupling between the "servo" (if you can call a motor on a transmission without position control a servo) and the valve. I've seen/heard a few different systems at the track, and the unanimous feedback I get is that my car sounds the best from the stands/infield - though this is redneck country down here. Last edited by jml; 07-24-2010 at 05:01 PM.. |
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07-24-2010, 01:45 PM | #3 |
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Thanks for the detailed response.
Regarding the ECU question, I didn't mean I wanted to tune the ECU, rather someone mentioned that it will automatically adjust to changes in the exhaust system, however switching back and forth using cutouts might not give the ECU time to adjust, thus you'll always be running more inefficiently than with fixed exhaust systems (at least in one of the two positions). I don't know if that's true though. |
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07-24-2010, 02:41 PM | #4 | |
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I've heard that there is no really solidly designed and durable valve on the market for this applicaiton. You could probably buy a nice aerospace certified valve buy maybe not in quantities of 2 and the price would probably be astronomical. Do let us know about any leads on a truly solid brand. Also, are you saying you can feed the power effects from this valve? I kind of doubt that. I'd guess you can get 5hp max from this which is only about 1%. If you can feel 1% hats off .
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07-24-2010, 05:00 PM | #5 |
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07-24-2010, 05:18 PM | #6 |
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To be honest in fine with having to replace the valves every couple years. The valves aren't welded directly to the pipes, right? They're bolted onto the flanges, so they should be easy to replace on your own?
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07-24-2010, 08:43 PM | #7 |
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