OFT quirk
 

I just got my OFT and immediately flashed their newest stage 1 tune. Aside from small things in my signature, I haven't done any mods.

This weird quirk happens at 4k. There is a hiss from the engine, sounds similar to a blow off valve letting out a small amount of pressure. I can make it happen consistently when over ~50% throttle. Does anyone else have this issue or can explain it?

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its the exhaust timing. very aggressive right at 4k.

So perfectly safe?

Yes of course.

okay, thanks for the fast response!

You wouldn't mind explaining why such aggressive timing at 4k? is it for the dip?

Yes I believe it is to reduce torque dip. If you change to UEL headers it does not have to be as aggressive so noise is eliminated.

As far as valve timing goes, it's hard to differentiate between "aggressive" or not. It's not like ignition timing in that respect. In the case is the OTS maps, valve timing goes through a rather large swing to minimize the torque dip. With the stock VVT mapping, the change is more gradual making it harder to perceive.

Read this/watch this.

http://www.ft86club.com/forums/showthread.php?t=59475

Is there any way to tune it out? Honestly I'd rather deal with the dip more than have my car sound like it's going to blow.

The first time I heard the sound I was alarmed --- maybe my intake covers it up just enough but I feel like I'm the only one who likes it.

Here are two of my videos of this noise. Totally normal and safe.

[ame="https://www.youtube.com/watch?v=nKCK_zViHks"]4000k RPM Note Change on e85 - YouTube[/ame]

[ame="https://www.youtube.com/watch?v=BwKDJyYLggo"]4000rpm Note Change - YouTube[/ame]

I have yet to hear of an engine make that sounds before blowing up :)

Count me in as a fan as well! The first time my wife heard it she was very curious as to what it was. Of course I had to tell her it was AVCS kicking in, yo! :D

In reference to the tip-in knock thread posted prior, this noise has NOTHING to do with knock. Knock sounds completely different, and for anyone who spent significant time around K-series, 2zz or other motors that are high comp and as sensitive to fuel grade as ours are, you'd know the difference. I am astounded sometimes by the amount of mechanical hypochondriacs here. Just drive it and enjoy it :)

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mechanical hypochondracs :lol:

There is a degree of truth to that. I can hear a knock from 40 feet away. But my ears completely ignore the intake noise at 4000rpm because I've heard it before in so many cars, that it falls into the list of acceptable and safe noises :)