Hey guys...
I have been trying to find out if there is an "acceptable" amount of knock under boosted load...
Noob question but I have. Been searching with no avail.

 

any kind of knock detonation is not acceptable.

yet there is a difference if your actually getting knock or your sensors are too sensitive depending on your ECU set-up

judging by your username. if your running 15lbs of boost.

adv timing is good around 13-15 degs depends on weather conditions and gas quality

afr is always good to keep it around 11.3

 

It's pretty normal to get a little knock during shifts but you shouldn't be logging any knocks during pulls.

 

+1 with 93 octane I would never run my car over 16 degrees of timing, and I keep it fat. if running methanol i go 18ish degrees, but too much methanol will cause knock as well. If your not hearing knock or experiencing it, it could be a bad knock sensor, but can be ruled out with an OHM check.

 

Ohm check?
It's only running about 5 deg. Of timing according to the map... logged once today and it is only registering 1 knock counts. I'm thinkin its just the sensor..

I am having a few confusing things happen..

Would anyone else agree it is Polly just the sensor if its only counting 1 knock at a time? I am not hearing anything out of the norm, but it is a new car also...

 

I don't mean to hijack this thread OP, but this may be related to your knock issue...

On my recent tune with Osiris, my tuner noticed the ECU was taking off timing because of false knock readings....we didn't hear any knock or notice any smoke on the tune and the AFR's were below 12's, and he verified the ECU knock readings were false because when we turned on the meth the ECU took off even MORE timing...so besides my super safe base tune with the knock sensor on we also have a tune w/ the knock sensor disabled, since we can't calibrate the knock sensor sensitivity with Osiris...

Is this possibly a bad knock sensor or just my noisy built engine fooling my ECU with false knock readings...?

And to add, I have a noisy-as-hell Vortech too...

 

i am wondering as well..
plus still really confused about the boost control not working..
i have noticed a significant drop in boost ramp up after turning down the boost levels in the utec..

 

update...

I talked to the guy who originally built and tuned the car today. He said that the tune was still loaded in the utec. The reason for the knock reading was due to the tune being done on 92 octane and here fargo the best we have is 91. He told me to keep the boost and everything where it is at and use a fuel additive. Will 1 octane make that much of a difference?

also asked about the boost control... I explained how i had turned it down and it really didnt do anything about the level of boost... he acknowledged and bypassed the question... lol

so today after work (i re-entered the original #'s on the boostmap) we went for some runs.. The first two runs i was getting a misfire or cutout at 5500revs at full throttle.. bumped up the fuel map my a smidge.. solved.. still was seeing intermitant knock counts.. lowered the boost map #'s from 275 to 250.. same thing with the knock.. and the same boost levels.. felt slower..
adjusted the map to 200... still knock..17 counts this time for a high.. Felt way slower (wife agreed) but still were hitting about 15.5+ psi.. ..

Then remembered how the computer adjusts for knock with timing adjustments..

pull over - reset the utec and ecu.. go for another run.. and still were gettin knock counts.. i will try a fuel additive tomorrow..

my main frustration is why would the utec not be turning down the boost?
Lowering the boost map from 275 to 200 and only getting a .5psi response?
but again the car felt noticably slower..

Thanks for the help... and sorry for the novel but wanted to share everything..

cliffnotes: 91 octane gas reason for misc. knock counts??? Really?
bumped up fuel map at 5250-5500-5750 revs to get rid of misfire or cut-out
utec not lowering boost levels??? why?
when lowering boost levels on map- get same psi but car feels slower..

 

it felt slower bc the UTEC was pulling timing when it detected knock. you need to back you timing off 3-4*. that will fix your knock problem.

Do you even know what wastegate springs you have. They may be 1 bar, so of course your boost controller wont do anything. Have you tried setting the boost gain to 0 and see what your boost is?

sounds like you really need to stop messing with this yourself and take it to a shop.

 

If I back off timing on the timing map, it will be at 0.
it is only pulling 4* according to the map.

Wastegate springs are 5lbs.

Have not tried setting the boost gain to 0.

even after re-setting the utec it still was not as fast as prior runs...
I Appreciate your advice

 

boost map turned to 0.
It was oscillating between 5 to 8 pounds under full throttle.
is that normal to bounce that much?
no knock was detected as expected.

 

boost shouldn't bounce.

going from 92 to 91 octane shouldn't have that profound of an effect unless it was tuned on the ragged edge. fuel additive is junk, it raises fuel octane like .1 octane. It's been proven ineffective so don't waste money on it.

I would check all your vac lines and make sure everything is ok. It sounds like there is something causing boost to bounce like that.

Also, if it's only pulling 4* that means 4* off stock timing. Stock timing at WOT is like 24-26 degrees so your timing would be very high if it's only pulling 4*.

I would take it to a tuner and have it safely tuned for your octane on a dyno. Blowing and engine is expensive.

 

UTEC doesn't 'pull' any timing from stock...it has full control. So if the map states 4' of timing, you're running with 4'. That being the case, you need to get a tune because 4' is a ridiculously low value.

 

What's your set up? I can tell you my values in utec for a better base line, because 4* is stupid low. Under full load after 5500/6500 I believe I'm at 14*. It's been a good while since I've looked.

 

Ok, so i realized while taking a shower (all my best thoughts come to me then..)
that i actually set the utec to 1.. not 0 in my boost map.. when i entered 0 it defaulted to ecu which i now believe would have been the right thing to do...
thus the reason for the bouncing boost.. the boost solinoid was working correct? so changing it to 0 and having it read "ecu" is the correct way to shut off the boost solinoid and run straight off spring presure??

I believe I have also decided im just going to close my business the needed 2 days and take it to mpls to get it tuned.. any recomendations on shops?
rs motorsports
maperformance

 

if its on just the spring, it will fluctuate some.

take a screen shot of your timing screen.

 

Map0 essentially disables the UTEC and hands over full control to the stock ECU. So you were boosting with no tune at all... for the love of god, get your car to a competent UTEC tuner ASAP before your rods are ejected.

I take it you still haven't read the manual start to finish like I told you to in the other thread.

~Randy

 

I didn't drive the car today.. its at home.. i will get one up asap..

 

Hey Randy... Have read the manual..
yes. the car was tuned at 15psi... i just believe its not that good of a tune..
(due to the knock at wot)
lol.. i'm not gettin you worked up am I?
Eric
btw- i did just call the tuner and set up an appt for a couple weeks from now..

 

ah, it sounded like it pulled timing by the way he was talking.

so yes, 4* timing is really low. Too low of timing can cause excessive combustion temps which could cause preignition and a lot of bad things just as much as running too much timing.

It seems to be that low teens would be safe based on what everyone claims to run here and from what i ran on my stock block and on my built block. That should be safe and not too low (like 4*).

definitely take the time to have a shop do it so they can log knock on the dyno and get it done properly.