Just installed 550's-still knocking

[iamtall77]

I installed a 2G MAS a couple weeks ago and had alot of trouble trying to tune on the stock 450 injectors. So I went and got some 550's and a new fuel filter while I was at it. I let the engine "learn" for awhile and left my S-AFCII settings at 0. Then I adjusted everything rich a little to keep it safe, no more than 10% accross the board. With the 2G MAS and the 550's, my car should run pretty stock. However, i'm still getting a good amount of knock. (about 12 counts, 15-20deg of timing<good>) I only ran it to about 4500 rpms, staying safe, and it definately is not making power. What type of MAS airflow should i be seing? I'm only running 14lbs of boost and my mods should be listed in my profile (don't wan to wast space) Should i turn down the boost and try starting there? Should I just further richen things up? The car always seemed to run a little lean. Let me know. I've got a date with the ¼ mile in a week and half. Probably my last chance this season. Any suggestions welcome. Let me know if you need more info.

 

[kyle h.]

definatly having some problems.

i have a 2g mas on my 1g with the stock 450s, it runs real good, the way i have it set.

i get max 24 counts of knock on the hot days.

im running 14b at 10psi, creeps fast to 19psi.

i dont think you would need to turn the 550s up that much either.

is the mas gutted?


but ya know, everything is different, keep turning the fuel up till you see better timing. what your gas mileage also, you shouldn't get terrible gas mileage.

watch your air temps as well. if they are excesivly hot that might be an indication of another problem. possibly heat soaking the intercooler real early... i dunno, it could be anything. start checking it out tho.

 

[iamtall77]

24 counts of knock is huge for a 1G! You should have set it up for no knock. With the lower static compression of our motors (7.8:1) knock in that quantity is big. Besides, running 19 psi on pump gas with the 14b will kill everything quick. At least in theory. Back to my car though, i'm only running 14psi with no creep and 20 counts of knock at only 4500rpms. That won't do. I'm thinking i just need to richen up the area where my boost hits, which is also about where the torque curve comes on creating high cylider pressures. I'm going to just richen that area and run about 12 lbs of boost and see what happens. I've got a date with the track this sunday, so hopefully i can get things working well enough to do some real nice WOT passes and get everhthing NICE! Thanks for the input, if anyone has more ideas, send then this way.

 

[kyle h.]

i can't even hear 24 counts of knock. so i dont think it's that HUGE of a deal, i know it's bad, so i just dont boost it on the hot days.

but i have a friend running 21 psi + dry nitrous (not sure on the shot, i would assume 50) on a 14b with the stock injectors and hacked 1g mas, also a supra intercooler side mount, 12.82 1/4 time...he says it runs fine, i would assume with minimal knock as well.

i dunno, i think the 14b and stock fuel can do a lot more than people think it can.

 

[BrokenTsi]

21 psi on 14b with nitrous? yeah he's knocking. diamondstarmotorsports ran mid 11's on 14b with 43 counts of knock passing the finish line. they ran like 26psi on it. in any case, your basetiming needs to be adjusted probably. i know they say 5 btdc, but my car will not run at 5 btdc, im actually at 2 btdc and i get no knock on 14b with 680's, safc, afpr, and fmic.

 

[markgholland]

i know they say 5 btdc, but my car will not run at 5 btdc, im actually at 2 btdc and i get no knock on 14b with 680's, safc, afpr, and fmic.

You are not knocking because you have your timing retarded, which will prevent detonation/knock...

Set your timing to 5 degrees btdc, change you plugs, and do a pull. You could change your wires too, depending on when the last time you swapped them out was. You may as well use the ngk 7's(I'm not sure of the "official" part number) while you are at it and make sure you gap them right.

All you people who say, "I only get 24 counts of knock @ XX psi" need to learn how to tune. Turn your boost down till you understand what kind of damage you can cause by running higher boost without appropriate supporting modifications. You should be striving for less than 3 counts of knock. Set an alarm on your logger to 5 counts and listen for it when you are doing a pull(assuming your logging software has the capability to set an alarm).
~Mark

 

[yo2001]

My 550 and 2G MAS was lean until I got the fuel pressure up to 43.5psi.

I'm running more boost than 14psi though

 

[iamtall77]

Just got some advice from someone that i consider a DSM guru. He told me to lean it out, and that my knock was more than likely rich knock. Haven't had a chance to do a pull, but will do so here shortly. Advice from him and his freind/Mitsu certified mechanic-"lean is mean. it takes a lot to break these engines. Crank the boost to 20psi and just watch out for heat soak." Sounds crazy to me, but i trust them, so i'll be doing some runs tonight hopefully and will post my logs here to see what you all think. wish me luck

 

[markgholland]

They are very easy to break with improper tuning! I bet they just didn't tell you to turn up the boost and not look at your logger though Have fun and let us know how it turns out.
~Mark

 

[kpt4321]

i can't even hear 24 counts of knock. so i dont think it's that HUGE of a deal, i know it's bad, so i just dont boost it on the hot days.

You'll never hear knock, even if it kills your engine. The 4G63 doesn't tend to knock loudly, and other parts on the cars are usually loud enough to drown out everything else.

but i have a friend running 21 psi + dry nitrous (not sure on the shot, i would assume 50) on a 14b with the stock injectors and hacked 1g mas, also a supra intercooler side mount, 12.82 1/4 time...he says it runs fine, i would assume with minimal knock as well.

Don't assume.

First of all, that is not a very good time for that amount of boost plus nitrous. Second of all, that's really ####ing stupid.

 

[ericlws66]

Set base timing.
I pretty had same setup, and was getting crazy knock. Then set base timing again, dont know how it came off from this janurary, and all of my knock was gone. Even my part throttle knock, what i thought was phantom knock.