VVT Tuning Noise - ADDED: Comparison Video

[donoman]

Originally Posted by OkieSnuffBox

You do understand the difference between VTEC and VVT, right?

no, but if I did, would it explain why this tune sounds so horrible?

Didn't think so.

[OkieSnuffBox]

facepalm.png
















Guess you can't educate those who don't wish to be educated.

[Shady195]

Originally Posted by donoman

no, but if I did, would it explain why this tune sounds so horrible?

Didn't think so.

Not an expert..

However while VTEC/VVT/VVT-i/VANOS and other variants all achieve basically the same outcome, they all do so differently.

All VVT systems are not designed nor do they operate in exactly the same fashion regardless of their function more or less being the same. So yes it could very well explain why it "sounds horrible" to you..

I for one don't think it sounds bad, it sounds like a slight metallic rasp. Sounds kinda angry IMO

While I was quite concerned the first time I noticed it, I'll listen to the guys on here who tune for a living, because there is not a single one who I've heard who said this was not normal and just a by product of aggressive timing and resonance.

[DJCarbine]

Originally Posted by donoman

no, but if I did, would it explain why this tune sounds so horrible?

Didn't think so.

Well, it sort of would.....

If you are talking about the the standard vtak which is just the oil controlled locking pins in the rocker arms giving more valve lift, it is quite different than i-vtec, vanos, vvt or what have you

Cam phasing can make pleasant noises, and it can also make poor noises. Cam phasing to the point of piston/valve contact makes expensive noises.

Valve lift does not make the same change in sound as advancing/retarding a cam.

[OkieSnuffBox]

Originally Posted by Shady195

Not an expert..

However while VTEC/VVT/VVT-i/VANOS and other variants all achieve basically the same outcome, they all do so differently.

All VVT systems are not designed nor do they operate in exactly the same fashion regardless of their function more or less being the same. So yes it could very well explain why it "sounds horrible" to you..

I for one don't think it sounds bad, it sounds like a slight metallic rasp. Sounds kinda angry IMO

While I was quite concerned the first time I noticed it, I'll listen to the guys on here who tune for a living, because there is not a single one who I've heard who said this was not normal and just a by product of aggressive timing and resonance.

Again guys, don't post up bad info/misinformation when you don't know what you're talking about.


Variable Valve Timing != VTEC


VTEC the cam shaft actually has two different profiles, as mentioned above, oil pressure causes pins to lock the rockers and follow the more aggressive profile giving a HP bump up top, without sacrificing torque down low.


VVT merely changes the cam timing in regards to the crankshaft position.

[Shady195]

Originally Posted by OkieSnuffBox

Again guys, don't post up bad info/misinformation when you don't know what you're talking about.


Variable Valve Timing != VTEC


VTEC the cam shaft actually has two different profiles, as mentioned above, oil pressure causes pins to lock the rockers and follow the more aggressive profile giving a HP bump up top, without sacrificing torque down low.


VVT merely changes the cam timing in regards to the crankshaft position.

I never argued that vtec was VVT..

again not an expert but while VTEC uses a secondary cam profile that is switched, and VVT simply changes the cam timing.. do they not both operate to achieve the same function though done differently? regardless of which one is more efficient or produces the best result?

[DJCarbine]

Originally Posted by Shady195

I never argued that vtec was VVT..

again not an expert but while VTEC uses a secondary cam profile that is switched, and VVT simply changes the cam timing.. do they not both operate to achieve the same function though done differently? regardless of which one is more efficient or produces the best result?

Cam phasing and changing the cam profile (ramp/duration/lift) are very different things. True cam phasing will allow you to run let's say 50 degrees of total cam adjustment using any number of degrees retarded/advanced between -25 and +25 (just an example), whereas a traditional vtec system is more of an on/off switch.

This is why the newer i-vtec incorporates phasing into their standard low/high cam profile.

Camshaft phasing gives you a lot more flexibility in extracting as much torque as you can at any given rpm, while a low/high cam profile has a single switchover point of on/off and you would get your torque characteristics from the cam grind mainly.

The best result would be from infinitely variable valve lift/timing, or an engine that only runs at a certain rpm. Also, best result is loaded... best fuel economy? Performance?

I am tying this on a phone as I poop, so I can't be as eloquent as I want to be

[Ultramaroon]

Originally Posted by DJCarbine

I am tying this on a phone as I poop, so I can't be as eloquent as I want to be

Whoa, careful with that boost pressure.

[donoman]

VVT or VTEC, who cares?

What really matters is, what is causing that horrible sound?

Resonance can mean many things.
1) Gas pressure resonance - not so bad
2) Mechanical resonance - can be bad ... think bridges collapsing and wings breaking off airplanes.

[DJCarbine]

Originally Posted by Ultramaroon

Whoa, careful with that boost pressure.

My wastegate has it under control

[OkieSnuffBox]

Originally Posted by donoman

VVT or VTEC, who cares?

What really matters is, what is causing that horrible sound?

Resonance can mean many things.
1) Gas pressure resonance - not so bad
2) Mechanical resonance - can be bad ... think bridges collapsing and wings breaking off airplanes.

You are excellent at speculation and conjecture.

[donoman]

Originally Posted by OkieSnuffBox

You are excellent at speculation and conjecture.

Actually, you asked me if I knew that VVT and VTEC were different. Doing so implies that you do know the difference. And it also implies that you believe the difference can explain the nasty sound in the VVT scenario.

So, I'd appreciate a little less dancing and a little more enlightening Thanks in advance because I would love to know what you were thinking.

[73TORANA!]

Hi all, has this post died or was there a definite answer that i haven't found. A bit late getting on board but recently purchased the OFT and have this noise at 4k and was wondering what if any finding there are. cheers

[tomm.brz]

just an acoustic resonance, don t worry