VVT Tuning Noise - ADDED: Comparison Video

[Malt]

Originally Posted by Dezoris

Here is the comparison video of the before and after tuning. One with aggressive cam angle and one with stock angle. I am keeping the tune with the stock angle, much more refined. Dyno scheduled for 2 weeks.

Did you have any vibration during the rpm range that the aggressive change occurs? I've developed an odd vibration that occurs around 3k rpm and I'm trying to narrow it down.

[krulux]

Just my opinion, I don't think the sound is mechanical in nature... that is could be the sound of metal on metal leading to a failure sound.

It is harmonic noise IMO... that's it.

Since I've been following this thread, good information by the way, I've read a good deal on the topic of tuning intakes, fluted intakes, VVT harmonics and all sorts of information that is relative to the topic at hand.

To me, running the aggressive tune to compensate for the dip is simply introducing increased exhaust gases through that range that cause the effect of pressure pulses/waves bouncing off one another back and forth - which generates the raspy sound. It is the same concept behind tuned intake runners for optimal power. Hell Ferrari even tunes their flutes to give a distinctive pleasant sound - the sound we all associate with a screaming wot/v12.


To reiterate - I've not heard the noise, that is the rasp, that was otherwise noticeable post header installation. I'm running a stage2 tune that is aggressive. The engine breaths better. The engine runs/feels better. Definitely sounds better.

I don't feel the least bit worried about running the aggressive tune. My engine runs so well now that my previous urgency to Force Induct the lil FA20 has all but subsided. For less than $1500 in mods I'm kickin 200whp all in the ass on 93oct...

[regal]

Originally Posted by krulux

I don't feel the least bit worried about running the aggressive tune. My engine runs so well now that my previous urgency to Force Induct the lil FA20 has all but subsided. For less than $1500 in mods I'm kickin 200whp all in the ass on 93oct...

Maybe splitting hairs but an OFT+OFH only sets you back a grand. Care to share your $1500 200 whp mods?

[krulux]

Originally Posted by regal

Maybe splitting hairs but an OFT+OFH only sets you back a grand. Care to share your $1500 200 whp mods?

OFH/OFT, 2.5" Magnaflow Cat-back and a K&N drop in filter... best bang for buck on all of those purchases!

[wparsons]

Originally Posted by Dezoris

Here is the comparison video of the before and after tuning. One with aggressive cam angle and one with stock angle. I am keeping the tune with the stock angle, much more refined. Dyno scheduled for 2 weeks.

I'm not going to say you shouldn't run the stock VVT mapping, but the noise is 100% there with both tunes in that video.

It's more pronounced on the aggressive tune, but it's most definitely there on the stock VVT mapping.

If the noise you were getting was from the rapid rate of change in cam angles it would be more pronounced in 1st and 2nd where the revs are climbing faster so the cam would be changing angles even faster. Instead, it's most pronounced in 4th where there's more load on the engine and the revs climb slower.

I bet if you pull a log of VVT angle change on the stock mapping in 2nd it's changing angles faster than the most aggressive tune you have does in 4th gear.

At the end of the day it's your car, and you have to be happy with it, but IMO there's nothing wrong with the noises it made on the more aggressive VVT mapped tune.

[DJCarbine]

Ended up wrapping my header and the tick/rasp is greatly reduced to the point where it doesn't bother me anymore

I think most of it was just the exhaust pulses resonating in the header/collector

[regal]

Originally Posted by wparsons

I'm not going to say you shouldn't run the stock VVT mapping, but the noise is 100% there with both tunes in that video.

It's more pronounced on the aggressive tune, but it's most definitely there on the stock VVT mapping.

If the noise you were getting was from the rapid rate of change in cam angles it would be more pronounced in 1st and 2nd where the revs are climbing faster so the cam would be changing angles even faster. Instead, it's most pronounced in 4th where there's more load on the engine and the revs climb slower.

I bet if you pull a log of VVT angle change on the stock mapping in 2nd it's changing angles faster than the most aggressive tune you have does in 4th gear.

At the end of the day it's your car, and you have to be happy with it, but IMO there's nothing wrong with the noises it made on the more aggressive VVT mapped tune.

My car doesn't have a tune, it only makes this noise in 3rd going up a steep hill. 1st and 2nd don't have the noise. 4th is too fast for public roads which is how the got out of the di issue,

[s2d4]

Originally Posted by regal

My car doesn't have a tune, it only makes this noise in3rd going up a steep hill. 1st and 2nd don' have the noise.

Why don't you get logging to confirm what you think is going on with your car?

[Sirsimon]

Purely anecdotal evidence here, but I noticed this a bit when stock. I just eclipsed the 1000mi mark and drove aggressively a few times and wondered if it was VVT or my TRD exhaust resonating in a crazy way.

Went OFT stage 1 this afternoon, and I can say it is definitely more pronounced, but that could be because I seem to hit that RPM range more often and it passes more quickly. Either way, I'm not worried - I think it is just a characteristic of this engine.

[regal]

Anyone remember savine for one of these?


http://www.ebay.com/itm/EFI-Associat...ffa5d3&vxp=mtr




I don't think we're quite as far with D4-S as we were with the Bosche stuff back then.


Thank God for pioneers like @Dezoris. Now that Delicious allows self tuning (unlocked factory ROMS) with EcuTek with your passion could lead to a book deal.


Hang in that and don't trade in for a Porsche please!




DI set tuning back 15 years at least a think?

[Dezoris]

I am not convinced its a problem either but will gladly run the VVT in oem mode.
Can't be much I am losing in performance.

[Victor Draken]

Originally Posted by regal

Anyone remember savine for one of these?


http://www.ebay.com/itm/EFI-Associat...ffa5d3&vxp=mtr




I don't think we're quite as far with D4-S as we were with the Bosche stuff back then.


Thank God for pioneers like @Dezoris. Now that Delicious allows self tuning (unlocked factory ROMS) with EcuTek with your passion could lead to a book deal.


Hang in that and don't trade in for a Porsche please!




DI set tuning back 15 years at least a think?

Delicious allow self tuning? didn't understand what you meant... lol

[regal]

Originally Posted by s2d4

Why don't you get logging to confirm what you think is going on with your car?

Sorry I thought you were an ecutek spammer till a saw your post count. To answer you question I ordered a tratrix 2.0 last week. Hopefully we will get good enough datalogging for poor folk out of that.


I also bought the parts to log oil pressure probably the most important gauge with a boxer?


Do you log EGT that's another neglected but important one. Got a wideband heeoked up?


Useful datalogging is expensive and Ecutek is missing some important ones.


Correct me if I'm wrong.


good luck

[wparsons]

Originally Posted by Dezoris

I am not convinced its a problem either but will gladly run the VVT in oem mode.
Can't be much I am losing in performance.

The difference on an N/A engine is very noticeable, but with your supercharger adding power in that range already I doubt it's nearly as noticeable for you.