Monitoring VVT / VVT not working

[Ade 517]

34 minutes ago, Rich said:

The O2 sensors give temp readout in torque and they are next to the primary cat, which is the critical point for EGT really if you're concerned about cat breakdown. I'm not sure if you can read both sensors, or just the front (or back) sensor.

The O2 has a heater element which can be used in reverse. I.e put the constant current though it and measure voltage and plot on a curve. The ECU does this to calculate EGT at that point. It isnt very accurate as the 02 heater resistance varies a lot so it can be out by 20% but a nice little feature. 

Im not sure which one it is either by @knightryder might be able to tell us? Hopefully its the "wide band" at the front before the cat. 

 

 

[lukester 20]

I had a quite look in DashCommand before work and logged SAE.CATTEMP11 on the way in - I guess this is one we're talking about? Can graph it later if anyone's interested...

BTW my tune was a custom Fensport job. Adrian seemed to think that maybe the issues I was having were mainly exhaust related - too much back pressure and the ECU plays safe? He did see VVT not engage a couple of times when mapping (and the manifold was new, installed with the SC) so there's something not quite right, but not as bad as it might have seemed. I've got DashCommand set up with a realtime graph of VVT and just from eyeballing it I've not seen it misbehave like in the initial post in this thread (the worst one being coming off cruise control and it seemingly just stuck). Looking forward to the new ecutek version so only have to watch for a engine warning light...

Anyway, learning a lot. Thanks!

 

[Ade 517]

2 hours ago, lukester said:

I had a quite look in DashCommand before work and logged SAE.CATTEMP11 on the way in - I guess this is one we're talking about? Can graph it later if anyone's interested...

BTW my tune was a custom Fensport job. Adrian seemed to think that maybe the issues I was having were mainly exhaust related - too much back pressure and the ECU plays safe? He did see VVT not engage a couple of times when mapping (and the manifold was new, installed with the SC) so there's something not quite right, but not as bad as it might have seemed. I've got DashCommand set up with a realtime graph of VVT and just from eyeballing it I've not seen it misbehave like in the initial post in this thread (the worst one being coming off cruise control and it seemingly just stuck). Looking forward to the new ecutek version so only have to watch for a engine warning light...

Anyway, learning a lot. Thanks!

 

Sound to me like the JDL part was defective then. 

[lukester 20]

2 minutes ago, Ade said:

Sound to me like the JDL part was defective then. 

Oh I dunno, I reckon it performed exactly as they intended - had been on 3 months at the track day ... they give a 90 day guarantee on the cat

I guess I could ping them and see what they say, but can't see them doing much. Maybe a few $ but no replacement or anything.

It is viable for an exhaust specialist (maybe H&S?) to remove the void where the cat was, weld on a new bit of pipe and flange, or not worth the hassle? Just wondering how much the additional noise is the void (vs lack of cat and now Cobra front pipe).

It looks like this:

Cheers!

 

[Ade 517]

4 minutes ago, lukester said:

Oh I dunno, I reckon it performed exactly as they intended - had been on 3 months at the track day ... they give a 90 day guarantee on the cat

I guess I could ping them and see what they say, but can't see them doing much. Maybe a few $ but no replacement or anything.

It is viable for an exhaust specialist (maybe H&S?) to remove the void where the cat was, weld on a new bit of pipe and flange, or not worth the hassle? Just wondering how much the additional noise is the void (vs lack of cat and now Cobra front pipe).

It looks like this:

Cheers!

 

H&S certainly would be able to replace it with a bit of pipe and flange, or alternatively they could weld in a new cat. They use high quality german made cats that cost about £400 though so that + welding/labour you are probably taking £600, but worth asking. Having the cat in the manifold means it lights up quicker and easier to pass MOT. the H&S item is only 100 cel but its enough when hot. You get what you pay for.  

[lukester 20]

3 minutes ago, Ade said:

H&S certainly would be able to replace it with a bit of pipe and flange, or alternatively they could weld in a new cat. They use high quality german made cats that cost about £400 though so that + welding/labour you are probably taking £600, but worth asking. Having the cat closer means it lights up quicker and easier to pass MOT. the H&S item is only 100 cel but its enough when hot. You get what you pay for.  

OK ta, I guess the JDL job being only an additional $150 for the cat wasn't the bargain it appeared...

[Ade 517]

3 minutes ago, Ade said: H&S certainly would be able to replace it with a bit of pipe and flange, or alternatively they could weld in a new cat. They use high quality german made cats that cost about £400 though so that + welding/labour you are probably taking £600, but worth asking. Having the cat closer means it lights up quicker and easier to pass MOT. the H&S item is only 100 cel but its enough when hot. You get what you pay for.  

OK ta, I guess the JDL job being only an additional $150 for the cat wasn't the bargain it appeared...

$150 for a cat. No wonder it shit itself.

 

Sent from my SM-G935F using Tapatalk

 

 

[lukester 20]

11 minutes ago, Ade said:

$150 for a cat. No wonder it shit itself.

 

Sent from my SM-G935F using Tapatalk

 

 

Wonder how the Cobra will hold up, much the same price difference between catted and not... Oh well, always got the stock one to fall back on!

[Deacon 1357]

I have the JDL one and have had no cat issues. Sam also ran one before and had no issues. Both of us were NA though. I've seen nothing on the US Facebook pages to suggest the JDL cats are crap so it may be you were just really unlucky. I think it's worth dropping them a message and see what they say. Nothing ventured and all that.

[Ade 517]

10 minutes ago, Deacon said:

I have the JDL one and have had no cat issues. Sam also ran one before and had no issues. Both of us were NA though. I've seen nothing on the US Facebook pages to suggest the JDL cats are crap so it may be you were just really unlucky. I think it's worth dropping them a message and see what they say. Nothing ventured and all that.

So you have decat FP and still passed MOT?

EGT should not kill a decent cat from being supercharged if it tuned properly. 

 

[Ade 517]

Thing is most of the US states dont have mandatory emissions testing. So all they need to do is look like a cat and pass roadside inspection. Passing an MOT in the uk is a different kettle of fish. You need a decent CAT and most of the aftermarket cheap metallic high flow cats wont pass mot on their own. 

[Deacon 1357]

1 hour ago, Ade said:

So you have decat FP and still passed MOT?

No, I never mentioned a decat fp. I have both. Sam had a decat fp and passed with the cat warm.

[lukester 20]

This was a dull commute home logging SAE.CATTEMP11 in DashCommand. Might try something a bit more spirited at the weekend...

Not sure what it means, other than it takes too long to get out of Cambridge.

 

[nerdstrike 186]

600 is ok from what I recall. 800 is hot, but I used to regularly see that on my old RX8.

[Mark@Abbey M/S 235]

I think your find the 600deg C is the controlled temperature of the element in the O2 internals. The sensor is heated for it to work quicker and more consistent.

[Ade 517]

Basically if you want an accurate EGT reading you have to measure it with a therocouple right at the cat inlet. 

 

[Mark@Abbey M/S 235]

21 hours ago, Ade said:

Basically if you want an accurate EGT reading you have to measure it with a therocouple right at the cat inlet. 

 

Yes you are correct , the Stock EGT reading will sit around 600deg C at idle which is the controlled temp for the O2 sensor element.  Once running hard you will see a delayed increased reading of EGT