18 months - Still Detonating

[GLen20]

Thanks fellas.
I just re-read my post, just to clarify, my max boost I'm running is 14psi (peaks to about 15.5 with the MBC) but this issue is occurring even when the load on the engine is about 50% and boost is at ~6psi.

Example is: I take off from the lights at half throttle, boost picks up at ~2500rpm and holds steady at 6psi, engine passes through exactly 4300-4000rpm and "tink tink tink". The engine then continues up to 5-6000 or so without problems when I change gears. (Its an Auto by the way).
Its not false knock as I can really hear it in the cabin ,really clear the other day when I was on the highway towing a jetski.
The detonation is proportionally worse to how much load I put on the engine but is definitely present at even ~50% load.
The weird part was it disappeared after a ECU reset but has now come back....

Kenneth yes is still the stock intercooler
Steve - Engine mounts are all replaced with 3 x solids and 1 x stock (rear roll)

BUT, I just checked my records and the external fuel filter is now 30,000kms old....

So unless you think otherwise, first step is I'll change the fuel filter..

If its still there afterwards, do you think I have the right to have my tuner investigate and repair at no cost? (Loaded question?)
Its just that I emailed him 3-4 weeks ago and haven't heard anything back. Then again he might just be really busy.

Thanks again

 

[TME_Steve]

I'd chase him up, easy to be busy and forget.

 

[Kenneth]

14 psi is too high for the stock intercooler in warm climates. I did this in NZ to an otherwise stock car and had lots of detonation too.

With an upgraded exhaust, I am not surprised that you can get that at 50% throttle.

Even a cheap bar and plate intercooler will do the trick. Not guaranteeing this will fix the issue of course, but cheap way to sort something that isn't up to what you are trying to do.

 

[GLen20]

Copy that on the IC. Its gonna help everything.
Also will chase up my tuner again and might crank the pounds down in the meantime.
Appreciate the advice

 

[TME_Steve]

But tuned at 14psi should be able to cope with stock intercooler. Just before i sold it I was running 16 on mine, tapering down to 14 by 5000rpm. Stock car plus fuel pump and 3 port and tune. No knock

Then there's all those others I've tuned with stock intercoolers. No knock

 

[GLen20]

Hmmm... Yes I do believe that a better intercooler is always going to be a worthwhile upgrade, but I don't think the stock intercooler is the problem in this issue.
Ambients are low at the moment and the region where this det is still present is 6psi, below what the factory boost is and what the original intercooler is designed for.
It's fair to say that if the cause of the detonation was due to high air temperatures caused by the increase in boost then an aftermarket cooler would rectify this, but the intake charge should be heated no more that normal at 6psi and the thing is still pinging.
I think something else is crook and am just trying to think what it could cause it at this very specific RPM band.
A wrong number (lean) entered into one of the fuel tables at 4300->4400rpm?
Timing wildly advances due to wrong value in timing table like above?
Something else?

Probably is too hard to try and diagnosed without actually having access to the actual dataset which is something only my tuner has ATM.
Either way, I think Ive worked out that this is not normal (touch up tunes are sometimes required for this type of bug after an initial tune?) and I need to go back to my dyno guy for him to sort it.

Or Steve you could visit Rads again and do another round of 3 ports for all the new owners that are cropping up! Haha All good.

 

[TME_Steve]

I'd love to come over again, just needa group of 4 or 5 to make the trip justifiable

 

[STAGTR]

Resurrecting an old post here, but just a reminder for all, if you start seeing knock creep in, and after you clean your MAF, check mounts etc., it pays to check when you last changed your fuel filter!

30,000km and mine was causing all my knocking through lean condition under load, could've sworn it was false knock. At least it motivated my to change plugs, swap front to rear colipacks, and finally helicoil that inlet manifold bolt hole!

I guess there's less headroom for crappy fuel over time in the Cooper/Ryco alternatives.

 

[GLen20]

Good advice there.
Since my last post Ive had a HDI intercooler installed, new fuel filter and had my car tuned by Steve with 3 port.

It's still pinging at 4200-4400rpm even on 40% throttle. It's not false knock cause I can hear it from the cabin and it blows black smoke when doing it.
Steve reckons the problem is unique to my car.

I've done some logging and me and Rob (@twisted32) noticed that my O2 sensor is "sticking" on a steady reading at some points, but being narrow band I'm not sure this unusual in the readings.
(The car shouldn't be in closed loop at this point anyway?).
Have unplugged the sensor to run in open-loop and thought for a minute that I'd cracked it, but it's still there.

I'm completely out of ideas and welcome anyone with any input. Maybe pm me your email and I'll send the logs to have a look?

 

[TME_Steve]

@GLen20 can you send me those logs again? i seem to have lost them steve@transformance.com.au

 

[TME_Steve]

Resurrecting an old post here, but just a reminder for all, if you start seeing knock creep in, and after you clean your MAF, check mounts etc., it pays to check when you last changed your fuel filter!

30,000km and mine was causing all my knocking through lean condition under load, could've sworn it was false knock. At least it motivated my to change plugs, swap front to rear colipacks, and finally helicoil that inlet manifold bolt hole!

I guess there's less headroom for crappy fuel over time in the Cooper/Ryco alternatives.

wow 30k is not long at all!

 

[GLen20]

Emailed through Steve. Thanks!