Tuning question (knock I cant get rid of)

[tips000]

Ok, I have a 1g 1990 talon with stock 6 bolt, 650cc injectors, maft, safc2, wally 190, FMIC, intake, full 3 inch exhaust, and a big 16g

My problem is I have my car tuned pretty well but at anything above 14-15 psi causes knock in the 4600-5300 rpm range. I have added fuel so my wideband reads lower than 10.5, taken away fuel until it reads 11.3, and it still knocks the exact same amount at the exact same rpms. Its only 3 counts of knock at 4600 then it tapers off to 1 count by 5400 and then no knock from there up.

I have read that the 1gs have a timing curve that is too agressive, which somewhat explains this.

I want to run 18-20 psi which I have had no problem running on my 2g with the same mods.

I have read some places that its ok to have knock up to 10 counts, and other places saying that anything over 0 counts of knock is unnaceptable.

This car is just a daily driver so I would like to say pretty safe on my tune but with my fuel mods I should have no problem running 20+ psi.

Do you guys think its Timing related?
If so should I take out 1-2 degrees of base timing?

Im averaging 22-24 mpg, logging in 3rd gear. I have logged in the day time with temps at about 60* outside and at night when the temp. was only 40* with the same results.

`````log``````

rpm knock timing
2700 0 29
3000 0 25
3500 0 18
3650 0 17
3750 0 17
3390 0 20
4000 0 20
4250 0 21
4350 0 19
4500 0 19
4600 3 19
4700 3 17
4800 2 19
5000 2 20
5100 2 20
5250 1 21
5400 1 21
5500 0 21
5750 0 23
6000 0 25
6200 0 24

 

[Spoolin92GSX]

Adjusting air fuel ratios affect EGT more than anything else. Knock is directly related to timing (and cylinder pressures) and yes, 1Gs do have a very odd timing "bump" around 4500rpms. Using an SAFC to adjust for larger injectors makes this worse also, since it tricks the ECU into running lower load cells in the fuel and timing tables. Pull a degree or two of timing from the first cell that knocks, run a log, and keep adjusting the timing until you get zero knock. As far as how much knock is bad, any amount of knock can kill an engine. If it's possible always tune for zero knock. Hypothetically, if you build an engine to withstand 35+psi of boost and only run 20psi, you have some margin to get a few counts of knock without a catastrophic failure - take that same motor and run the full 35psi, and even one count of knock can ruin your day.
EDIT: Just noticed you also have a MAF-T, same rule applies as with the SAFC in fooling the ECU.

 

[MathixPerforman]

Also you are about at the limit with the safc for injector size. One probrlem with a maf-t and safc is they can't adjust for timing. Though plenty of people run the same-ish setup you will find that a lot of them run into this problem. I would almost try turning the boost down to around 15 psi and work your way up from there.

 

[hotrodssnova]

I had the same problem with maft. I switched to speed density and jackal just so I could have complete control. Knock(pun intended) down your boost...free, or step up and get a tuning solution....$$.

 

[Spoolin92GSX]

I had the same problem with maft. I switched to speed density and jackal just so I could have complete control. Knock(pun intended) down your boost...free, or step up and get a tuning solution....$$.

TunerPro is also a great option for a slightly tighter budget. I run it on my 1G and love it, full control of everything and plenty of room to grow.

 

[tips000]

Do you think if i took out 1-2* of base timing it would help me out?

 

[My1GLaser]

Have you checked your base timing with a timing gun? You can try retarding your base timing some, but 1* should be enough and probably not necessary. What plugs are you running? I would definitely run BPR7ES at 18-20psi. Maybe even try the non-projected ones if it knocks worse when you up the boost.

3 counts of knock is 1* of timing retard IIRC. I see 1.4* here and there all the time. Its not very consistent and I normally ignore anything below 2* of retard. If it happens at the same rpm every time I drive, then I might tune it out.

The timing "bump" is actually from 5k to 6500 rpms and your knock is decaying by then. I attached the stock 1G timing map.

 

[MadDashImports]

check you knock sensor?