Ok, I just got my tune today but the car knocks. At 20 psi, I made 350whp and 330wtrq on a Mustang dyno but the ECU pulls timing for 1-4 knock counts. I stopped at 20psi. I was on Tonoco 100 unleaded race fuel. These are what my timing and AFR maps are like.

We tried to up the boost and knock counts went crazy (12-40) knock counts. I'm thinking phantom knock or very super sensitive knock sensor. Tell me if there is anything wrong with these timing and AFR maps. My tuner and I just couldn't figure it out. We even tried unplugging the knock sensor but the ECU still counts 9 knocks under boost and pulls timing.

When I got home, I turned up the boost to about 25 psi and logged with EvoScan. I got 2-3 knocks from 1 first to 3rd gear. I then logged again with a 3rd gear only pull. I got 12-19 knocks. But when on the dyno I get 12-40 knocks on lower boost? Something is seriously wrong. I need some input and advice. I'm on 1000cc Precision injectors scaled to 812.
At the 300-320 load and 3500-4500rpm, I should be able to run 1-3 for timing but I can't. It just keeps pulling timing and I end up with anywhere from -8 to -12 degrees. HELP ME. Haha.



Mods
Green turbo
GSC S2
1mm oversize valves
Wiseco 0.020" oversize pistons
Eagle rods and crank
Open element air filter
Buschur intercooler piping with ETS 3" intercooler
Buschur TBE

 

i had a slight problem as well getting 8-10 counts of knock. It turned out to be my dp was resting on the oil pan. Make sure you dp isnt touching the oil pan.

 

First, do a compression/leakdown/boost leak test.

~What are your AFRs?
~What are your LTFT's?
~Is this on a VIII or IX? Judging by 20psi and timing figures I'll guess an VIII?
~What is your peak tq load cell?
~What load cell does the car reach at the top of the RPM map?
~Might want to try to smoothen the 1750-4k from 260-320 load cells, looks real choppy -could reason the onset of knock. Remember the car interpolates between cells/rpms. If it cannot find a "good" variable it will knock.

 

Possible bad gas? Was it in a sealed metal container?

 

Your knock counts dont seem right the highest the ECU goes to 36 I believe, and the ECU will only pull timing to -10*. What clutch are you running? I saw a car that knocked like crazy and was totally inconsistent, it had a twin plate carbon/carbon clutch for street driving.

 

he has a act 6-puck spring clutch

 

something is not right! you hit 300-320 load cells with 20 psi at 3500-4500 rpms. With 24 psi peak, I barely hit 250 load cells.

 

Your timing maps looks quite, umm, terrible. What the heck is going on at 2500 rpm?

My advice, take that timing map, and throw it in the garbage, and start over with a rescaled stock timing map.

There are some sections of your timing map that in 500 rpm can swing from 4 to -4 degrees, a difference of 8*. In another 500 rpm it will go back positive.. No wonder you are having so many problems..

More advice for you:

Take your timing map and fuel map, and graph them out in excel. Take a stock fuel and timing map, and throw them into excel. Look at the pretty picture's of your maps, and a stock maps. Notice the stock map looks like a nice *gentle* hill slope, and your map right in the middle has a grand canyon. The idea, in a very small nutshell, is to make your map look like the stock map, only with the numbers your car needs to run good.

 

Well, thanks. I myself don't know tuning that much. My tuner did my tune. I would try myself but it's too scary and there are so many factors involved.

 

If you get more knock with more boost that tells me its REAL knock. Just because you don't like it doesen't mean it isn't true.

 

Yeah but only a lot of knocks from a WOT 3rd gear pull. If I do it all the way through from 1st-2nd-3rd-even 4th, I only get 2-3 knock counts within a certain area. Same boost level. If you can explain to me why that is, maybe I'd understand more.

 

Most likely because when you are doing your 3rd gear only pull, you are getting into those screwy scalings and timing changes at lower RPMs.


Eric

 

exactly - if hes just doing a drag run, hes only hanging out at the top of the rev range in each gear. nowhere near the screwy timing in the lower rpms.

the timing should be smooth, large transitions easily cause knock.


edit: post some logs - so we can see where in the map you're having issues, and what your timing is doing when it knocks.

 

No offense but both of those tables are a mess. Consider finding a new tuner if you have no intentions of fixing it yourself.

That rescale is terrible, why would your tuner keep 10,20,30,40 (10) in areas that are tuned very similar and and then jump (40) 120-160-200-240 in areas that need precise control.

 

Well, I don't know. That's a surprise.
Mitsulogger only shows a max of 159.X load. I don't know if that is correct or not. If not then I don't really have a clue what my car is actually hitting for load. I don't know what to correct when doing it myself.

But anyways, you guys are saying that the whacked up timing in the middle is causing the knock? Big transitions, right? May I ask what load cells and what RPM cells?