weird correlation knock and temp?!?!?

[Mike Marnik]

Ok so ive finally got my car back up and running after a short in one of the wires to the radiator fans which goes back to the ignition wire. Well ive noticed that if i sit at a light for 10 sec or so and the coolant temps drop to like 190-195 and i take off and give it some gas (not wot) the knock will go up. I wont even be hitting more than 5 psi but once the coolant temps go back up to 197+ the knock completly goes away. I also notice this when cold start the car and go drive that it will do it at only partial throttle. It seems like some kind of phantom knock to me. The only real bad thing i can see about this is when im at the track this spring/summer and sitting at idle while waiting in line and the engine being below 197. The car will bog horribly (timing being pulled) untill it get to temp then the knock dissapears and the car pulls like a raped ape. Any help would be appreciated.

TIA,
Mike

 

[kelvinb]

I was with mike helping him tune, and i was thinking it possibly heatsoaking? any input on that? The reason being, that 2nd gear we had little to no knock. And by that I mean 5 at most through the entire pull. But do a 3rd gear pull, it will look like the logs above.

MIKE-did you change your profile yet?

 

[andymoraitis]

Kelvin,

Thanks for working Mike last night on the tune. It shouldn't be considering that it's cold enough and that you're only running 14-15psi creeping to 16-17. I ran my stock SMIC on a bigger turbo and could run a fairly aggressive air/fuel ratio and timing curve at 21psi without knocking more than 3-5 in third.

It has to be the AFC settings,

Andy

 

[Mike Marnik]

wow were all on line at once. Thanks for helping out last night kelvin. You wanna help out again tonight?? After class today i will be looking at the maf and resetting the ecu. Just give me a call when you get off work.

 

[kelvinb]

Something we can use to tune also, is my wideband. Currently I have a bung welded into my downpipe. Now I can easily take it out, and hook it up in his car, but I am lacking an exhaust clamp and extended wire for it to reach back there. Maybe we can swap turbo-back exhaust systems? both are 3in turbo back, but different brands.

 

[Mike Marnik]

Is there anyway we can get the exhaust clamp and wire extension today??? If i cant get this sorted out i am probally going to do dsm link. That would require me to get a job though and that will be hard with school damn dsm.

 

[Mike Marnik]

Hey i reset the ecu and rechecked the fuel pressure (its was off about 3-5 psi) nowi am getting 12-15 psi maximum and the timing is looking pretty good the o2 is at about 82 in the upper rpms so i still need to ad a little fuel. I also figured out that im running the stock temperature range on the spark plug i thought i was one range colder. So im going to be switching out to brp7es instead of the 6s tomorrow. I may also raise the fuel pressure a few psi to richen it up a little more. also move the boost pressure up to 12-13 instead of 9.

 

[andymoraitis]

Sounds like a plan Mike. Glad you're getting closer to getting it right.

Andy

 

[spyderturbo007]

Woo hoo. Looks like we have a little work to do here.

Sorry for taking so long to get to your thread, but my wife had surgery last week and I have been babysitting her this week.

Anyway, I'd like to take this back to the beginning and see if we can get you all fixed up.

For starters, do a leak cheak and go ahead and put your plugs in....make sure they are gapped properly. I am assuming that your mod list is correct, except that the SAFC is currently.

I would like to have you set the base FP to stock levels, as I am never an advocate of changing base FP. Also, go ahead and turn the boost up to around where you will want to run it when we are finished tuning. My guess would be somewhere around 12 - 15psi. Next, set your TPS trigger points on the SAFC to 30% and 80%.

Your Ne Points look good (assuming that you have the original SAFC and not the SAFC-II). Set them to -14% across the board and make a 3rd gear pull logging timing, knock, O2, RPM and airflow only. This is a manual not an automatic, correct?

I am guessing that you are not heatsoaking the SMIC yet, as the temperatures are pretty cold out. In the summer, I am normally able to get 3 or 4 third gear pulls on my SMIC before I start heat soaking and that's on a EVO III 16g @ 20psi.

Also, do you have access to some race gas?

 

[kelvinb]

we have access to 100 octane from one pump here locally at 5 dollars a gallon

 

[andymoraitis]

Are you kidding me? 110 Leaded is $4.60 here and I think that's pretty steep. Sorry, back on topic.

Andy

 

[Mike Marnik]

right now with the fuel pressure at 39 psi (stock) i am taking out only about 2 % on the high end and getting the 12 counts

 

[Mike Marnik]

well i went and rest the fuel pressure again and turned up the boost today. Shes now running like a champ and getting at most 1-2 counts here and there. thanks for all the help every one.

 

[kelvinb]

whats fp at now? i get off at 6 tomorrow, so we can get it to 0 knock sucka

 

[spyderturbo007]

well i went and rest the fuel pressure again and turned up the boost today. Shes now running like a champ and getting at most 1-2 counts here and there. thanks for all the help every one.

Chalk another one up for me! I must be butter, cus' I'm on a roll. Sorry, I had to do that.

Now that we figured that one out, you could still post up a log, along with you SAFC corrections. You can always try and squeeze a little more HP out of her.

 

[andymoraitis]

Nathan: Great job helping the guys out and for bringing your expertise to the thread.
Kelvin and Mike: Way to stick with it and not become discouraged.

Definitely get Nathan a log and he'll score you some more power while keeping it safe.

Well done all around gentlemen,

Andy

 

[Mike Marnik]

ya ima lean it out when im able to get an exhaust bung for the wideband sensor welded in. im pretty content for now