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Datsports' car was not suffering from detonation. The noise was pieces of broken material inside the converter. Same as Cambo's car.
I understand that technically the sound may not be detination/pinging
but trust me I have had plenty of vehichals in the past that have pinged , and it is the closest explanation as to the sound you here from the jag suffering blocked cats !
Mine was nota small rattle like you pointed out , it was a clear as day pinging that could be heard through the floor with the windows up ,
and also even louder with the windows down with the wind noise of 180+kph . The sound was intrusive , I had no loose bits inside my old cats I shook them both , they seemed to be in tact just blocked..
I understand that technically the sound may not be detination/pinging
but trust me I have had plenty of vehichals in the past that have pinged , and it is the closest explanation as to the sound you here from the jag suffering blocked cats !
Mine was nota small rattle like you pointed out , it was a clear as day pinging that could be heard through the floor with the windows up ,
and also even louder with the windows down with the wind noise of 180+kph . The sound was intrusive , I had no loose bits inside my old cats I shook them both , they seemed to be in tact just blocked..
What I hear is not that loud or intrusive. I have to really listen carefully with the A/C off to hear it, so may be cats not blocked? or starting to block?
In any case, I read on the forum that changing to "race" cats improves the sound. Is that true? I have the doubt of wether the magnaflow CAT "converter" is a real CAT or just a pipe?. May be I change to those just in case (and for the sound) even though I'm only 33k miles.
What I hear is not that loud or intrusive. I have to really listen carefully with the A/C off to hear it, so may be cats not blocked? or starting to block?
In any case, I read on the forum that changing to "race" cats improves the sound. Is that true? I have the doubt of wether the magnaflow CAT "converter" is a real CAT or just a pipe?. May be I change to those just in case (and for the sound) even though I'm only 33k miles.
yes the magnaflows are real cats and come in many different options .
yes the sound is improved if you call ''increased'' an improvement.
but really the most astounding part of the sports cat conversion, is the replenished power delivery. well worth the money right there.
this is one of my magnaflow 200cell cats before installation
to clarify further my car pinged when i purchased it .
and the sound was subtle or fairly quiet, until i fitted the 1.5psi powerhouse top S/C pulley , then it was just nasty it pinged its a@# off.
only at WOT and only above 4500ish rpm . it seemed as if it could breath up until this point . and was very unhappy after this point . it also had the odd small pinging fit just after flooring it but just before it kicked down a gear . that one was always just a few quiet knocks/pings then down shift at under 3k rpm .
not one single ping from it since the cats were done .
after reading that jorge911's str was nancyed around , to the point it shot a pile of crap out the exhausts when someone finally treated it right .
my money is on compromised cats and plugs . but really this needs to be confirmed with checking the fuel trims . but in saying that my fuel trims were also compromised by the bad cats . so no amount of throwing gaskets and o-rings at my car would ever get the trims back on track. vicious circle !!
Datsports' car was not suffering from detonation. The noise was pieces of broken material inside the converter. Same as Cambo's car.
LOL what????
Sorry mate, no, for sure it was detonation, there were no noises from my cats at all, nothing loose, the bricks were intact, just choked up to the point they could not flow enough for high-rpms.
I shook the crap out of them once they were off the car, not a sound.
Exhaust gases not getting completely out of the combustion chambers, higher temperatures in the chambers, causing detonation.
For trims says only "bank 1"! what program should I use to read both banks?
I had this reading about trims because I knew nothing about it: https://www.obd-codes.com/faq/fuel-trims.php
You need readings from bank 1 and 2 ,
You need to take readings at idle and at about 2500rpm.
Obd car doctor does both , as would most obd apps.
I'm sure if you search around on that app a bit you may find it as well as longterm trims .
@idle
AFR = Air to Fuel Ratio
STFTn = Short Term Fuel Trim bank n
LTFTn = Long Term Fuel Trim bank n
Some times there are fluctuations on 02 sensor and STFT, engine is at operating temperature, is it normal?
Then @2500 rpm
It stays stable there, not like at @idle
This is what happens when I release the accelerator
And this when I press it again to 2500rpm
By the way, the dashboard rpms where almost 400rpm higher than reported by the ODB. I guess we should trust the ODB rpms, right? And is quite a hot day, intake temperature around 42 şC (107 şF).
Sorry mate, no, for sure it was detonation, there were no noises from my cats at all, nothing loose, the bricks were intact, just choked up to the point they could not flow enough for high-rpms.
I shook the crap out of them once they were off the car, not a sound.
Exhaust gases not getting completely out of the combustion chambers, higher temperatures in the chambers, causing detonation.
I already correct my statement about loose bits, I had that confused with another event.
My experience is that clogged exhaust results in a misfire, not detonation. I've stated since day one that your event did not sound like detonation.
There is a problem here . My guess is brake booster vacume o-ring . As so many seem to fail . Also wouldn't hurt to get a can of maf cleaner wile your at it !
I think your next investment should be buy can of eather (starting fluid) and spray it around the throttle body and pcv connections . Wilst watching your trims at the same time .
If the numbers spike then you will locate your problem.
There is a problem here . My guess is brake booster vacume o-ring . As so many seem to fail . Also wouldn't hurt to get a can of maf cleaner wile your at it !
I think your next investment should be buy can of eather (starting fluid) and spray it around the throttle body and pcv connections . Wilst watching your trims at the same time .
If the numbers spike then you will locate your problem.
Somo more data from tonight road run. Going downhill STFT1/2 =0 LTF1=0.8 LTFT2 = 1.6
uphill (load) everything 0. idle SFTF1/2=0. LTFT1=9.8 LTFT2=10.2
I woder if it is a small leak and for that reason it affects more to idle than to load.
Also I don't understand why LTFTs vary so much. Shouldn't they move slowly as they averages?
when I get back home I'll try to record a sesion with Torque (learning how it works)
I also saw a video in youtube about pushing smoke, with the engine off, on the admisión to see where it gets out to detect the leak...
Ok, I have here the results of yesterdays recording with Torque.
I got very strange values from Torque which I guess are not possible and might be a bug on the ODBII or the Torque App. The issue is that sudenly the value of some sensors jump to what I think are imposible values. For example at 55s FTLT is 0 and at 56s is 9375! That must be a wrong reading, the FTLT cannot change like that, isn't it? Also the rpms are recorded some times at -64.25! That I'm certain that is not possible
So what I did is a graph with those peaks "corrected" to 25 so the scale is such that we can see everything, but remember, when there is a peak of 25 it really means a much higher value.
JagV8: Yes, I'll look for the leaks, but it could be many other things also, from what I have read, right? O2 sensors, CATs, coils, sparkplugs, oil vapours valve stuck open (don't remember its name) and may be others... I read or viewed a video where they tried to find the reason for the bad FT looking at the conditions under which it was happening (load, revs, etc).