KR Spikes at WOT then normalizes.

Troubleshooting a friends car that has been acting up for a few months. He recently had his VVT done, head replaced, new spark plugs and new injector seals put in. Cylinder 4 spark plug used to not seat correctly due to the previous owner tearing the threads afiak. After all of that has been replaced I had him take some logs for me at WOT to check for any issues. For log 19 KR would spike to 6 for around 4k then normalize back to zero over the rest of the pull. For log 21 KR was steady in 3rd until the car was shifted to 4th at which point there was no KR at all. Any idea what would cause this type of behavior after all things mentioned have been fixed.

 

6 KR is really high. Is it on a stock tune or a OTS tune? I know when I was on a cobb ots stage 3 tune my KR would go all the way up to 8, comeback down slowly to 6 then go backup to 8. It freaked me out but the car felt normal and I never actually heard any knock. Turns out after I got a tune from Justin (freektune) my KR would never go above 0.70 at WOT. Turns out it has something to do with the filtering on the sensor, and with a stock tune, the filtering on the sensor allows it to pick up normal engine vibrations as knock. Since I had a balance shaft delete I could understand why the sensor was sending 8 KR. If any of this sounds familiar to you then its just ghost KR. If you are running a personalized tune and are getting knock that high I'd be scared.

 

the car is on a stage 0 tune. He will be replacing the RMM over the weekend to see if that fixes and movement that may be causing KR I was thinking an e-tune would be the next move anyways. I will update after the install.

 

Cobb maps are garbage go back to stock map, if you're looking at "stage 0" tunes then an ots map from freektune is a good option and will increase driveability form stock.

Since plugs are already done, give that maf sensor a clean. Most importantly ditch the Cobb tune. Nothing wrong with doing a compression test as well.

 

I thought stage 0 was the stock tune. Well wait a sec... You might be onto something here.
Comp test will be done when RMM is installed and we'll throw some cleaner on the maf.

 

Stage 0 is Cobb's map for a completely stock car, which you'd think would be fine but it could not be.

 

Also, false knock with motor mount upgrades is common. It's like a little blurp and then gone.

 

The logs are from before any MM upgrades were put on. New logs were taken yesterday after RMM install. I will ask him to send em to me then post here.

Freektune was just ordered. Will flash it when HPFP gets here.

 

Awesome, did he go back to stock tune in the interim? i take it no compression test yet?

 

no compression test yet. He doesnt trust autozones tester i guess. The only way we could find how to go back to stock is uninstalling the AP. Is that the correct way to go about it for now?

 

yup uninstalling the AP will load the stock tune back on if he saved it. you can still monitor things and datalog with it uninstalled i believe

 

Installed the HPFP in the garage tonight as well as loaded the new tune from Freek. The first few pulls have been good so far. KR spiked to 1.8 on one but other than that the car is running wayyyy better. Could be biased at this point so ill get the logs pulled up on my pc next time hes over.

 

I had Cobb's on for a day maybe? And yes it's a huge improvement going to freeks.
KR down to 1.8 is certainly comforting on only one pull (I assume KR was being reset on the AP between pulls or it could have come up close and you wouldn't know).

 

afaik he was resetting the AP in between pulls. It helps when I can look at his logs cause he isn't great at live monitoring. I will post them up whenever he comes over again like I said.

 

Live monitoring is not easy...sounds like a plan

 

Logs are up. His latest wot pull boost was limited at 9psi with 100 WGDC. He didn't have time but we gonna reroute the boost controller this weekend and see if that fixes the issue. Other than that unrelated problem log 27 doesn't show any KR like there was before. Log 26 did have a spike in the middle of the power band which is still lower than before but we will have to check it out once the WGDC issue is fixed.

EDIT: I forgot about your mention earlier to clean the MAF. I will make sure that is done next time he comes over as well.

 

UPDATE: Boost issue was a problem with the 3 port. The wiring had come out of the connector so we fixed that. We went through the bay tonight and tightened up some things that could possibly be smacking against stuff. We bolted in the dipstick which for whatever reason wasn't secured in the brackets from when it was at the shop. Also found some leaking around the crows feet on the injectors. It turns out the shop that replaced them installed used injector seals so we are exploring that as a potential issue.

Bigger part.. Compression test was done and numbers came back as 170 165 165 165 at 4200 ft. Pretty fantastic results tbh, we then used a borescope on the cylinders and found a few hot spots but nothing super concerning. We decided to check plug gap while we were in there and discovered they were all .30 so we regapped them. KR is still appearing at WOT on the freek basemap without any real progress. I suspect the injector seals are the culprit at this point but only way to know is to replace them which I guess we will get done someday shortly.

 

I’m the same situation with kr And have done all of the above with good comp as well. have a protune 20psi and only way to not get at most 3 kr consistently on wot pulls was to add a gallon of e85 To each tank. Now I’m starting to think I’m masking the real issue. Still get 1-2 every once in awhile

 

are you running 91/93 tune and then having to mix in a gal of e85 to try and comp for the knock ? I’m on my 3rd revision from Justin and see at most a quick spike of 3.5 and then will drop to 1.7-2.5 kn trying to see if this is normal or if this is something else I should be putting more attention to, running same boost targets 20psi on s4

 

So e25 helped a lot but I still would just spike to 5.95 and hold until I let off most pulls. On regular 91 it was every single pull. What my tuner did was turned off the knock sensor under 2k rpm and that made it only spike and hold to 3.85 on 91 and it happened way less often like 1 in 10 pulls. Then he turned it off under 4K and I never get knock now even in 91. However what you’re explaining sounds different the. What was happening to me.