knock @ wot no matter how lean/rich

[yotabeater]

i have a 91 tsi w/ b16g, fmic, 550's, 255 pump, afc, logger, etc.

no matter what i have the high settings at on the afc, i still get WOT knock. anywhere from 7 to 25. i tried richening it up to -10 across on the high, and still knock. this seems very rich to me. originally the high settings were at about -24 across.

i am to the point where i cant do a wot pull without knock.
i would richen it up or lean it out, and the high trim would stay between 112% and 120%, never lower. i am ready to pay a shop to tune it, as i am much too frustrated. any help is greatly appreciated. thank you.

 

[lowridin2g]

any exhaust leaks near the head? they can be registered as engine noise/vibration triggering the knock sensor. also how old is the knock sensor? how many miles on your motor? if theres internal engine noise, it obviously would trigger the knock senosr but probably all the time.

 

[Talonman]

stock 1G maf? youre on 550s which are around 20% larger but flowing way more air, set your highs above 3000rpm from -8 to -6 and watch knock, 02V, and timing advance.

The high trims at 120 means your too lean and the ecu is trying to compensate, trims below 100 mean your rich and the ecu doesnt need 100% of the fuel your giving it.

 

[1LE]

Too much boost for the octane you're using?

 

[yotabeater]

the previous owner built a new motor for it. it only has about 15k on it. i don't know if he replaced the knock sensor.

i don't have a stock 1g maf, i am running a 3" gm (blow-through and vented) with a translator.

boost is set at about 19 psi. i only use 92 octane, sometimes a couple gallons of 110 topped off with 94 when i can afford it.

the guy i bought the car from tuned it. then i bought it, hadn't got the pocketlogger from him yet, and my friend thought he would play around with the settings. i don't remember exactly what they originally were, but i want to say 1k-3k were @ -24 and 4k-7k were @
-22. i did not have the pocketlogger when the original settings were in place, so i don't know if they were way off or not.

thank you to all replies. keep the ideas flowing.

 

[psychlow]

When was the last time you checked your base timing setting?

 

[ACKERSON]

I think you need to post some logs so everybody can get an idea of what's going on with your engine.

 

[5150DSM]

Your car is too lean. With a B16G, FMIC and 3" MAF you are flowing a shitload more air than stock, far more than the difference between 450's and 550's. Start from scratch... reset your ECU, set all of your AFC corrections to 0% and do the same for the MAF-T. Take a drive to set the fuel trims and then go do a 3rd gear pull or two. Log rpm, knock, timing advance and 02's and then post the logs. Try to observe the car's behavior from 3K up to about 6.5K, does it bog, does it sputter, etc, etc...
Aloha

 

[yotabeater]

i already reset my ecu last night. base timing was checked a few weeks ago and is set at 5 degrees, even though the logger oscillates between 6 deg and 12 deg at idle. did a 3rd gear pull. car doesn't bog or sputter whatsoever at WOT, just knocks. results are as follows:

rpm knock o2 timing tps
3750 0 .39 30 deg 37%
4000 1 .52 27 deg 83%
4468 10 .83 17 deg 99%
4718 15 .85 14 deg 99%
5125 15 .85 14 deg 99%
5312 16 .85 15 deg 99%
5718 15 .85 16 deg 99%
5906 14 .85 17 deg 92%
6125 14 .85 19 deg 99%
6156 13 .85 18 deg 43%

high trim reads 107%
high settings are
1k -14
2k -14
3k -12
4k-7k -10
that's all i got for now. i'm gonna go do a few more pulls, then i'll post. thanks.

 

[yotabeater]

edited previous post with updated log. thanks for all the replies.

 

[Talonman]

try -9 or -8 on the safc from 4000 to 7000 rpms. .85 02 voltage seems lean, Ive heard .92 to .88 is good for a 1G at WOT. (02 voltage not being an accurate tuning tool), Mine likes to read .92V around 3500rpm (full boost) dropping off to .88 or .90V by redline, 4 knock or less.

 

[CanadianTSi]

I would try around -5, your pretty lean so you will probably need to add more then 1-2%

 

[yotabeater]

i will try richening it up tomorrow. it's weird though: before when i had the settings at -22, the o2 would read about .89 at WOT and it wouldn't really knock. i'll post some new logs tonight.

i've never noticed my o2 volts going above .89, but i haven't had it as rich as -6 yet. my low settings on the afc are 1k/+5, 2k-7k/-10. previous owner's settings, i haven't touched them since i bought the car. i heard he knew how to tune pretty well, so i tried not to mess with it.

i also noticed that i am missing a nut where my exhaust manifold bolts up to the block. could that be causing me to knock at WOT and part throttle phantom knock? how about a worn/leaky flex section? i removed my pcv valve altogether because i thought it was making a ticking noise, but it persisted. thanks for the replies.

 

[diambo4life]

Lower your boost! You are running too much boost for the octane fuel you have. Lower it to 14psi. Tune to 0 knock. Increase it to 15psi tune to 0 knock. Continue doing that to the point where your knock count is at an acceptable level. Normally, you don't really want it to go above 7 counts (as your timing will start getting pulled) but since you seem new to this, I would keep yours at 3 counts or less.

If you had an AFPR, it would help alot by bumping your base a little to 43psi if your car is a 1G.

 

[yotabeater]

i do have an afpr. i think the base setting is at 39 or 40psi. i'll have to double check.

i didn't think 19 psi was too much for pump gas. i've heard of guys running 25 psi on pump gas.

 

[diambo4life]

I'll tell you this. You have to tune your own car to where it runs best. We can only suggest what to do. It's only YOU who will eventually decide what's best. Just because someone can run 22psi or 25psi on their car doesn't mean that you can do the same. For one, they may have better mangement, may be better tuners and/or get better pump gas than you do. Start small. Turn the boost down and start from there. If you want to run close to 19-20psi without seeing alot of knock you may have to turn down your base ignition timing from stock. There are alot of setups that you can do but a car well tuned at 15psi will run better than one running at 19-20psi with knock all over the place. Furthermore, you do not want to trash your motor tuning foolishly.

 

[yotabeater]

it's funny you should mention my base timing, cuz my friend thought maybe we should try different base timing settings and seeing how the car reacts. it's at 5 degrees now. i was also looking at getting an intercooler sprayer (co2). would this be a wise decision to help battle knock and get more power?

 

[AL92]

First I think there is too much paranoia on here that any knock retard means the engine will blow up.It won't .You can get 43 counts and the engine can survive.Also have read that anything above 15 timing wot is fine.You are over that.Car likely pulls great at your current boost and if you have a good fmic you for sure should be able to run 18 to 20psi.

Now you can still go richer..like some said your o2 for whats it worth look lean still.So go richer..and if you hit rich stuttering then likely you will have to back down a bit.Now you should get less knock if you go richer.And if you still think you have too much although I woudn't be worried at all from you timing then you have other choices..lower base and something else to consider.If you car has 100,000 miles or so then likely your balancer is falling apart.Mine fell completely apart a few weeks ago but before that the timing marks were slipping.So you might think you have 5 degrees btdc but it might not even be close.You can check but setting engine to tdc and checking balancer mark.If it dont' line up perfectly at tdc then its fubar.Check it..!!! Replace it..!!!

Anyway couple other ideas..you might need bigger intercooler but personally just buy a water injection system.I got mine for www.coolingmist.com That should wipe any remaining knock away and a bit higher octane if you can get it might be worth trying like if you have 94 but even its gasohol.I noticed some knock help in my car by going to 92 gasohol from 91 normal gasoline.Maybe our winter gas is crap not sure but the gashol is working better.
Also your knock sensor if old could easily be fubar too..Change it if its old..say 100,000 miles for sure.

 

[yotabeater]

i started w/ the afc settings at 0 all the way across. did a wot pull, and it bogged down @ about 4300, and knock was like 20. i called pina motorsports, and nick said to try and set base timing at like 2 degrees and see what the car does. i will also bump up my base fuel pressure from 38 psi to 40 psi, and try to lean it out a bit on the afc.

even when i put the afc @ 0, the o2's never broke .89. i leaned it out to -16, and it still said .89. high trim at -6 still read 108%. ??? anyone who is in the king/pierce county area that would like to take a look at it is more than welcome, i am at my wits end with tuning. thanks to all that have replied. much appreciation. -Josh

 

[Cirus_93TSI]

i don't have a stock 1g maf, i am running a 3" gm (blow-through and vented) with a translator.

if this is the case, you have left out some very important information. what are your translator setings?
the maf translator can be used by itself to lean your fuel out, it may seem to you like the afc settings are too low, but if the translator is already leaning out the fuel the afc settings would be very different from what they would be on a 1g/2g mas set up.

 

[yotabeater]

i do not know what the translator settings are at. it came already installed on the car when i bought it. how do i check/change the translator settings?

 

[unclesam099]

Unscrew and remove the cover of the MAF-T box. There are a series of knobs in there.

 

[Rob Rohr]

i have a 91 tsi w/ b16g, fmic, 550's, 255 pump, afc, logger, etc.
.

Did you check your injector P/W @ WOT? My car with similar mods is maxing out (100%+) the 550 injectors at 19psi on pump gas! Personally I would never trust the stock O2 readings for tuning.

 

[diambo4life]

First I think there is too much paranoia on here that any knock retard means the engine will blow up.It won't .You can get 43 counts and the engine can survive.Also have read that anything above 15 timing wot is fine.You are over that.Car likely pulls great at your current boost and if you have a good fmic you for sure should be able to run 18 to 20psi.

Now you can still go richer..like some said your o2 for whats it worth look lean still.So go richer..and if you hit rich stuttering then likely you will have to back down a bit.Now you should get less knock if you go richer.And if you still think you have too much although I woudn't be worried at all from you timing then you have other choices..lower base and something else to consider.If you car has 100,000 miles or so then likely your balancer is falling apart.Mine fell completely apart a few weeks ago but before that the timing marks were slipping.So you might think you have 5 degrees btdc but it might not even be close.You can check but setting engine to tdc and checking balancer mark.If it dont' line up perfectly at tdc then its fubar.Check it..!!! Replace it..!!!

Anyway couple other ideas..you might need bigger intercooler but personally just buy a water injection system.I got mine for www.coolingmist.com That should wipe any remaining knock away and a bit higher octane if you can get it might be worth trying like if you have 94 but even its gasohol.I noticed some knock help in my car by going to 92 gasohol from 91 normal gasoline.Maybe our winter gas is crap not sure but the gashol is working better.
Also your knock sensor if old could easily be fubar too..Change it if its old..say 100,000 miles for sure.

Too much paranoia about knock? Have you made a pull (IN YOUR CAR) in 3rd or 4th gear with your knock pegged at 43 counts? I didn't think so. Of course you can get 43 counts, realize it and let off and everything will be ok. No one said that your car will blow up as soon as you get 43 counts for a few seconds. You can not use the stock O2 sensor values for tuning (determining whether you are rich or not.) That's just crap honestly. If I tune my car to an 11.5:1 AFR (with a W/B) and it shows .86 across on the stock O2 sensor, leave everything as it is and swap in a new one and it shows 0.92V across does it mean I am now running richer? NO! That's what happens though. People get different O2 sensor values by just switching them. That's why you cannot use/trust factory O2 sensor numbers from a buddy or anyone else to tune your car.


As I said earlier, lower your boost and try again from scratch. People are always quick to start blaming other reasons for the cause of their knock other than their tuning. If you don't believe me, add race gas. If the knock disappears, it's real and not some "phantom knock" that every other person likes to jump on first these days.

Again, just because someone with a similar setup as you can run 20 or 22psi doesn't mean you will too. Tune your own car to where it's happy and not to some benchmark set by someone else.

 

[4g64GST]

have you checked to see if the knock sensor is tight. mine vibrated loose. seen that afew times. only takes about 2 mins. . dont thing that is your problem but.