N54 Helix 3X / 19T Timing Corrections w/ KR turned off

[sman217]

Short and sweet... I'm at a loss for words. Installed Turbo Parts Canada Stage 2 19T chargers for this season, and also installed a new dual LPFP setup for additional fueling down the line. I currently have been using a helix 3X, and last year had a 3X on pure600's on 27-24 psi, but this year we cannot, and i repeat CANNOT get rid of timing corrections over 5K to redline. I have used JSR, and i even paid an additional tuner to help remedy the issue, but every time the car gets over 5K rpm, we start getting serious corrections.

At this point, I am curious if the helix is the culprit, or a lackthereof, fuel flowage. JSR and I turned KR off from 5K-7K rpm, and i still had insane corrections. (datazap below) FYI, cars on E50, low timing of 9* peak, and every single maintenance item has been done. Index 12, New coils, plugs, good gap, brand new FCP euro HPFP, Walnut blast... no hard part is old. Run race grade ethanol as well, not octane related. Didn't have these issues on pure600's.

My question at this point is... Are there other factors that create timing corrections other than knock feedback? and if so, what could they be? Please, keep the scope of the conversation away from "get port injection" or "octane" or "bad fuel" or "traction control" I have covered all these bases, we are on revision 15 and have tried Vanos, tried different target AFR's, tried 5* timing up to 12*, nothing fixes and nothing changes the corrections. They are inconsistent, sometimes huge, sometimes only one two cylinders, but theyre large.

The only other thing i can mention is that on some of the revisions that I have had, the car will go into Fuel mode 15. (open loop) but only at around 6000-6500.

The other tuner i started working with for trouble shooting thinks that the rail pressure of my setup should be remaining static, but i personally dont understand how the rail pressure would remain constant, or straight lined, when im running close to the limit of fuel capacity the helix can support. (we are running about 27-26 psi on E50 w/ large A/R 19t's, it should be close to 650 whp)

Brief description of the car...

-2007 N54 335i
-Auto, XHP stage 3, torque reduction on upshift selected, and line pressure bump
-TPC 9 blade 19T chargers
-Helix 3X/PR Stage 3.5 LPFP (bucketed)
-PR Relo. Inlets/VRSF Outlets
-Index 12
-97506 gapped .018 EXACTLY
-Eldor Coils
-ATM Race exhaust
-MHD tune only

 

[sman217]

Here is a log of the car with KR disabled from 5K-7K.

datazap.me | Sman217 | jsr 5.1.2 Knock turned off 5K-7K

datazap.me

 

[wheela]

I didn't look at the log, but mention of the helix - don't those tend to vibrate pretty badly? Perhaps the helix is getting worn and vibrating more, to the point of regestering as knock though the knock sensors? Not really sure how you can test that out short of removing/replacing it.

 

[Dumaurier7]

I didn't look at the log, but mention of the helix - don't those tend to vibrate pretty badly? Perhaps the helix is getting worn and vibrating more, to the point of regestering as knock though the knock sensors? Not really sure how you can test that out short of removing/replacing it.

Does your Helix kit have the support bracket and billet flange? also are you sure your NEW LPFP is good?

 

[carabuser]

It's knock related. The table the tuner is using to disable it is probably not the right one.

The cause of the knock reduction is the tricky issue. Those helix overdrive units always seem to cause issues but it's strange that it didn't happen on the previous tune.

My guess would be that you have something contacting the engine or exhaust that's passing noise into the block.

 

[BloodyZ4]

Log looks fine to me except the low MAF readings.
Seems to be a mechanical issue.
If it was the Overdrive I would expect the Corrections to be closer to the front cylinders.
Maybe your motor mounts are shot and transfer vibrations to the engine block or something is touching it.

Some other ideas:
Might be ovaled injector bores. Did you change the decouplers when installing the new Index 12's ?
Our engines also can suffer from micro cracks in the spark plug holes.
Oil vapors entering the combustion chamber also do lower your octane rating and can contribute to detonation.
Also I would strongly advice from turning off or dampening any knock sensor related tables, best way to blow your engine up!

 

[sman217]

oh yeah, all that stuff was done long ago. i had the helix last year and didnt have this issue.

 

[sman217]

It's knock related. The table the tuner is using to disable it is probably not the right one.

The cause of the knock reduction is the tricky issue. Those helix overdrive units always seem to cause issues but it's strange that it didn't happen on the previous tune.

My guess would be that you have something contacting the engine or exhaust that's passing noise into the block.

may be on to something here. let me talk to my tuner more about this. what knock tables should be modified to adjust the sensitivity of the KR? Im not trying to install trim pots, honestly

 

[carabuser]

may be on to something here. let me talk to my tuner more about this. what knock tables should be modified to adjust the sensitivity of the KR? Im not trying to install trim pots, honestly

The knock tables have been talked about on here previously. https://www.spoolstreet.com/threads...uning-even-for-built-closed-deck-motors.8363/

If you say they disabled knock above a certain RPM then that sounds more likely to be the misfire detection. Misfire and knock and two different things completely, maybe your tuner doesn't understand that.

It's better to find the cause of the false knock. Built motors are often noisy so need these changes. If you have stock pistons and block then I wouldn't touch the knock tables.

 

[sman217]

The knock tables have been talked about on here previously. https://www.spoolstreet.com/threads...uning-even-for-built-closed-deck-motors.8363/

If you say they disabled knock above a certain RPM then that sounds more likely to be the misfire detection. Misfire and knock and two different things completely, maybe your tuner doesn't understand that.

It's better to find the cause of the false knock. Built motors are often noisy so need these changes. If you have stock pistons and block then I wouldn't touch the knock tables.

i will mention this to tuners; im using JSR and shoup at this point, but shoup hasnt modified anything with knock feedback, hes more concerned with the fact that the helix isnt generating lots of rail pressure.

how does the dme pickup misfire? how is misfire detection established? I think that's actually the issue, i actually didnt know about that, and the reason i think that's the problem is because whenever my car goes into fuel mode 15, it'll throw a CEL for multiple cylinder misfires; I have never had a knock code in my car, ever.

 

[Torgus]

You could try targeting lower boost and see if it keeps happening, my guess is it will.

Why don't you remove the helix and see if the problem goes away? If it does then go PI.

 

[sman217]

You could try targeting lower boost and see if it keeps happening, my guess is it will.

Why don't you remove the helix and see if the problem goes away? If it does then go PI.

happens on 17 psi, and 27. lol! I just ordered reflex plus and Phoenix raceworks manifold. we are removing the helix and going full E... I just wish i could know whats wrong.

 

[ShocknAwe]

Money's on the helix.

DI is great but once exceeded it's shotgun or nothing for me. I like the idea of PI since you get some induction and fuel cooling as well as valve wash effect. All good for longevity and none attained by forcing the DI system to do the work.

 

[sman217]

@Jake@MHD are there any ways i can monitor knock sensor activity in MHD, noise, knock sensor voltage, something? I've been working with JSR and shoup on trying to eliminate the timing corrections and all signs keep pointing back to helix and false knock/noise/misfire

If i run the car on 17 psi, it doesnt change anything; itll still pull timing. on 24 psi and 7 degrees of timing (requested.. never hits it because the corrections are so serious) thats why we think its noise. It's every cylinder

The strange thing that I keep mentioning that i want people to elaborate on, is if i stay in the car, WOT, until 150-160, by the time the car gets to 5th gear and like 6,000 rpm, the timing corrections stop, and they dont come back.... its like they smooth out. only then, will things be okay.

 

[BloodyZ4]

You could have a local tuner do a dyno run with det cans or a plex monitor and see if it`s real knock or not.
Would certainly ease your mind.
The thread that @carabuser linked has the custom user channels to log the things you want.

 

[sman217]

You could have a local tuner do a dyno run with det cans or a plex monitor and see if it`s real knock or not.
Would certainly ease your mind.
The thread that @carabuser linked has the custom user channels to log the things you want.

I just saw that in the thread. I downloaded the Zip for the user channels, i forget, how do i add these to my Android tablet to have those parameters included in my datalogs?

 

[BloodyZ4]

You just unzip it into your MHD root folder and then select them as normal.

 

[carabuser]

i will mention this to tuners; im using JSR and shoup at this point, but shoup hasnt modified anything with knock feedback, hes more concerned with the fact that the helix isnt generating lots of rail pressure.

how does the dme pickup misfire? how is misfire detection established? I think that's actually the issue, i actually didnt know about that, and the reason i think that's the problem is because whenever my car goes into fuel mode 15, it'll throw a CEL for multiple cylinder misfires; I have never had a knock code in my car, ever.

I think fuel mode 15 shuts down injection, it's to protect emissions components like the cat. It's caused by either excess knock, misfire, rail pressure, VCV faults, intake valve timing and fuel tank being empty.

You are either seeing it because of the excessive knock or misfire. Misfire is detected by crankshaft rotation and knock is picked up by the knock sensors.

I wouldn't be so fast to blame the helix. Check everything else out first before spending money on PI.

 

[carabuser]

I just saw that in the thread. I downloaded the Zip for the user channels, i forget, how do i add these to my Android tablet to have those parameters included in my datalogs?

Those parameters aren't going to tell you anything other than that you have knock. They are really useful for tuning out false knock but you don't want to tune the knock out unless you have a built engine, you need to actually find the cause.

 

[jzx_andy]

Please keep us updated once you switch to PI.

If it fixes the problem, I'd say its the differing load on the timing assembly and different vibrations going through it and the block (as opposed to an untouched hpfp assembly) that are being detected as false knock at high rpm.

Inline 6 motors are more susceptible to vibration/harmonic issues to my understanding. I'd hazard a guess at the slightly heavier timing assembly in the S55 playing a part in why that motor has more reported spun crank hubs relative to other N5x's achieving similar output/rpm's.