New Tune update...

[AN7]

It's not the exact same car. Different intake setups, hood open, etc. was what I was referring to.

It's not hitting the clutch that makes the noise, it shifting then opening the throttle right after. Creating huge vacuum then no vacuum air is rushing past the throttle body making noise.

Now you are kidding me.
What does the intake setup and the opened or closed hood have to do with that noise. I posted a vid before with my car making the same sound, do I have the same mods with andres?
No, even if you hitting the rev limiter with neutral the clattering is there. You should know that if you have personal experience from the problem.

Valve float WILL show up in logs as a rich A/F mixture, huge immediate drop of power, and MAF readings would probably show something weird if intake valves are floating as the air reverses and pushes back into the intake. MAF value would drop despite turning more RPMs. Might hear popping and backfiring in extreme cases.

It is not neccessary that with valve float(or valve spring float or whatever is going on in there) you will have missfires, or backfires etc.
Mine, from the rpms that was starting doing the noise, it was loosing power on the diagram

Nope..it's how I wrote it. 7,000 reads on the tach, 72xx - 7300 shows up as max RPM in the logs.

I 've logged 6 different Mazda 2s(1.3 + 1.5), 6/6 the tachos were showing more rpm.

 

[flatlander937]

Now you are kidding me.
What does the intake setup and the opened or closed hood have to do with that noise. I posted a vid before with my car making the same sound, do I have the same mods with andres?
No, even if you hitting the rev limiter with neutral the clattering is there. You should know that if you have personal experience from the problem.


I hear no clattering from Andres video. What I hear is an air rushing pssshh sound. Having different intake setups or hood open will have EVERYTHING to do with what is heard. Especially by a camera.




It is not neccessary that with valve float(or valve spring float or whatever is going on in there) you will have missfires, or backfires etc.
Mine, from the rpms that was starting doing the noise, it was loosing power on the diagram

I never said it was necessary to misfire, I said in extreme cases. It will show up in MAF readings though as the intake valve will be closing later than typical(essentially like adding duration to the cam, but uncontrollably and not tuned for it).

It WILL show in logs.

I 've logged 6 different Mazda 2s(1.3 + 1.5), 6/6 the tachos were showing more rpm.

I'll be tuning my own car pretty soon. I'll have the limiter set to 7450 and hit it and see for myself.

Either way the point is that valve float cannot be diagnosed via YouTube video.

 

[AN7]

I'll be tuning my own car pretty soon. I'll have the limiter set to 7450 and hit it and see for myself.
Either way the point is that valve float cannot be diagnosed via YouTube video.

Exactly.
So why are you so strong all this time against valve float?

I never said it was necessary to misfire, I said in extreme cases. It will show up in MAF readings though as the intake valve will be closing later than typical(essentially like adding duration to the cam, but uncontrollably and not tuned for it).

It WILL show in logs.

Lets talk about it after you gain some experience after you tune your car.
There are MANY MANY MANY things that can go wrong and in datalogs everything seems fine. Believe me.

 

[flatlander937]

Exactly.
So why are you so strong all this time against valve float?



Lets talk about it after you gain some experience after you tune your car.
There are MANY MANY MANY things that can go wrong and in datalogs everything seems fine. Believe me.

...because you are literally the only person who believes this. Every B-spec cars revs to 7300. Many who autocross do more than that. Dynotronics has done tons of testing with these and no problems with stock cams floating valves.

Maybe Joe can provide a dyno graph of 7500+RPM?

I'm a 10yr master tech. I use scan tools daily that cost more than my car. I'm not pulling this idea out of my ass. I'm not some dipshit tuner who modifies stuff and bolts on this or that without knowing how anything works.

I don't have experience with Mazda2 float... I've been putting off my tune until my suspension was squared away.

But in other applications(GM V8 primarily) I've encountered it. No noises associated with it... Found on the dyno only then confirmed with MAF rate decreasing as RPM increases.

We can agree to disagree, that's fine. I know you have more direct experience modding these, I've followed your turbo build... I'll eat crow if it turns out you're correct but I'm confident enough its not valve float.

 

[OVT]

The valves are not floating at 7300 RPM or anywhere near that.

The valves don't even float on stock cam / stock spring on the MZR engine at 7800 RPM....

 

[AN7]

Ok.
Lets say that indeed its nothing about the valves.

What is that sound that comes from the engine(with stethoscope I was hearing it under the vavle cover) and the engine starts making it over the stock revlimiter?

Mine, even at 7000rpms i could hear that noise.
A friend with 7050, was ok.
Another friend at 7000 was ok.

So, whats it that ?




flatlander937
Do we have any incar of a b-spec car?

 

[Andres3165]

So, whats it that ?

I know....



my grand father told me a while ago.....



...... your ear piece batteries are running low




Merry Christmas and Happy New Year !!!


Andres

 

[flatlander937]

Ok.
Lets say that indeed its nothing about the valves.

What is that sound that comes from the engine(with stethoscope I was hearing it under the vavle cover) and the engine starts making it over the stock revlimiter?

Mine, even at 7000rpms i could hear that noise.
A friend with 7050, was ok.
Another friend at 7000 was ok.

So, whats it that ?




flatlander937
Do we have any incar of a b-spec car?

I don't know what you're hearing. You exclaimed that the whoosh/pssshh noise in the video was valve float. You hear this same noise with a stethoscope on the valve cover? Or is it tapping/ticking? Holding steady RPM? Not shifting right? On a dyno under load? Or free revving in neutral?


Is your valve lash in spec?


And also because I'm not sure... This is a stock 1.5 with no more than exhaust/intake/tune right? Not your turbo car correct?

You'd have to ask Corksport or Dynotronics or another B-spec team to confirm if their cars make noise or not.

 

[AN7]

I don't know what you're hearing. You exclaimed that the whoosh/pssshh noise in the video was valve float. You hear this same noise with a stethoscope on the valve cover? Or is it tapping/ticking? Holding steady RPM? Not shifting right? On a dyno under load? Or free revving in neutral?


Is your valve lash in spec?


And also because I'm not sure... This is a stock 1.5 with no more than exhaust/intake/tune right? Not your turbo car correct?

You'd have to ask Corksport or Dynotronics or another B-spec team to confirm if their cars make noise or not.

The video that I posted before, was from my car revving up to 7300, when it was N/A with intake,cat back exhaust and ecu remap(obviously).
When you hit the rev limiter(over 7000) in neutral, on dyno or on the road the car made this noise, "whoosh/psshh" as you call it.
With an inspection stethoscope, on neutral and on dyno(with load is bit louder the sound) the sound looked like it was coming under the valve cover.
Before I tune the ecu, I did a full inspection of the engine, valve lash, compression etc. And everything was fine.
4 months or so, after the car revved up to 7300 and 7k miles, the valve lash was in spec but at the maximum limits.(before was in the midle - to lower limits)




Because you made me doubt myself, I set the rev limiter today on my car, turboed, much more sensitive if there is something with the valve train like float.
Test on wastegate pressure (0.8bar 215 whp)
After 6950 the car misfires, not form the plugs or anything.
6600 ok
6700 ok
6800 ok
6900 ok
6950-7000 missfires until 7100 that I set the limiter.

At this time I don't have on my hands the Mazda IDS to log what the vvt is doing.

 

[jasyatz]

Interesting that you said misfire. You said not the plugs but did you scope each spark signal? Maybe the spark signal isn't strong enough or not enough fuel? Recent logs have shown very lean condition at or near 7,000 RPM. I figured it was a soft fuel cut preparing for the rev limiter. Maybe the fuel system just cant keep up with the revs? Or maybe the spark signal can't keep up with 7,000 rpm(116-117 revs per second)?

And revving the car to redline in neutral is never, ever a good idea. Even for diagnostic purposes.

 

[AN7]

Interesting that you said misfire. You said not the plugs but did you scope each spark signal? Maybe the spark signal isn't strong enough or not enough fuel? Recent logs have shown very lean condition at or near 7,000 RPM. I figured it was a soft fuel cut preparing for the rev limiter. Maybe the fuel system just cant keep up with the revs? Or maybe the spark signal can't keep up with 7,000 rpm(116-117 revs per second)?

And revving the car to redline in neutral is never, ever a good idea. Even for diagnostic purposes.

No, its not the fuel nor the spark.
If it was the spark or the fuel that causes the missfires over 6900rpms on my wastegate pressure (0.8bar), at 1.7bar that is my high boost it wouldn't be able to pass 4000rpms.

 

[Dynotronics1]

No, its not the fuel nor the spark.
If it was the spark or the fuel that causes the missfires over 6900rpms on my wastegate pressure (0.8bar), at 1.7bar that is my high boost I couldn't pass 4000rpms.

ok,you do realize that the higher you turn up the manifold pressure, the lower the actual seat pressure is, right? So, while you might be fine at atmospheric pressure, you are losing 10-20 lbs of seat pressure with the high boost you are running. So it is 101% possible you are floating the valves in this case.

I'm sorry I did not snap to it earlier, but I simply forgot you were running high boost

 

[AN7]

ok,you do realize that the higher you turn up the manifold pressure, the lower the actual seat pressure is, right? So, while you might be fine at atmospheric pressure, you are losing 10-20 lbs of seat pressure with the high boost you are running. So it is 101% possible you are floating the valves in this case.

I'm sorry I did not snap to it earlier, but I simply forgot you were running high boost

As i Said, because its turbo its more clear what happens.
But what are the odds, that at 7000rpm and higher when I was N/A I had that noise and the logs showed nothing and now with the turbo after 6950-7000 I have misfires.


Just to clarify because my previous post may be misleading, I have no problem at my high boost to pass 4000, runs up to 6800 that I've set the rev limiter the past 2 years no problems.

 

[vdsracing]

Ok.
Lets say that indeed its nothing about the valves.

What is that sound that comes from the engine(with stethoscope I was hearing it under the vavle cover) and the engine starts making it over the stock revlimiter?

Mine, even at 7000rpms i could hear that noise.
A friend with 7050, was ok.
Another friend at 7000 was ok.

So, whats it that ?




flatlander937
Do we have any incar of a b-spec car?

I have my engine ecu tuned and i hear the same noise at 7000rpm (7400 on tacho). It is very easy to reproduce especially when I hit the rev limiter several times and then back off the throtlle a little bit.
Half way also uses stiffer valve spring for tuning the rev limit at 8000rpm. http://www.halfway.co.jp/parts_demio_engine.html