Porkskins

Just noticed some decent vibration when under boost anywhere from part to full throttle. I logged a couple quick runs on the AP and they show the ecu pulling timing down to 4 degrees under boost. There is little to no knock logged, but with half a second between data recordings there could be more.

This was with my custom tune from Cobb, but I flashed back to stock and also tried the SF stage 1 map from Cobbs website. The car felt the same and logs showed the same timing drops when boost came up. IAT's were in the 60-80s...sorry but no AFRs to show.

I did a quick check of everything intake related and didnt find anything loose, but dont have time tonight to do a good inspection or a hard run and check plugs.
Any ideas?

Besides the SF intake, cobb inlet and tune the engine is stock. Here is an example of what the logs are showing:



Thanks for any input

goofygrin

iTrader: (5)

You're getting knock. Bad gas?

Porkskins

Went through 2 tanks from 2 different stations across town, went to stock tune and back to stock intake.

I also put the multimeter to the fuel pump relay and saw what i think are the correct values: posts 1 & 2 were 142 ohms unenergized and 3 & 4 were .4 ohms when 1 & 2 were energized. Also tried swapping with the high beam relay for grins and they stayed on(non hid gsr).

Is there something I should add to the logs for a clue? Here is one from today, and its obviously still pulling timing.

goofygrin

iTrader: (5)

36# of boost?! Your WG is 100%, so it's trying to build full boost.

Are you running the new maps from Cobb that disable the DTCs? You could be spiking boost WAY too high (like 36#!) and the ECU is doing whatever it can to keep the rod from exiting the block.

How about a full log? This isn't going to 4krpm.

You can just swap the horn's green relay with the fuel pump if you think that's it...

goofygrin

iTrader: (5)

also, without a wideband it's super hard to diagnose stuff.

Whitewind

iTrader: (3)

This can't be stock turbo right 36psi? Well you got two timing maps and when 7 Counts of knock (I don't know how AP logs knock this is with Evoscan) it will switch timing maps.

But it showing on your second pull no knock at all. But like you said there about half second that's not logged because its slow. Evoscan will log .2 ever 1.0 of a second. How is boost controlled? MBC EBC or ECU???

Also you make sure there is nothing loose around your engine, if knock sensor hears anything it will count as knock so remember that.

Whitewind

iTrader: (3)

Also do me favor log with car off and see where boost is at (if you can with an AP) or guess at idle make sure that's right. Cause 36psi is way F'ing high man on stock turbo lol! (BOOM!!!)

lodifreefly

iTrader: (1)

that's absolute pressure not relative pressure (boost).

Porkskins

Subtract 14 from abs pressure those numbers and you will have to correct psi. My mechanical boost gauge was only showing 22psi, but Im not sure why the "boost pressure" on the AP log shows the same as absolute pressure. It sure doesnt feel like it has that much boost.
And that last log is the factory tune.

I can do a full log tonight or tomorrow. Wideband is coming at months end

lodifreefly

iTrader: (1)

Might need to update your software? I know the AP used to either not have relative pressure or report it incorrectly. This was fixed in a software update AFAIK.

goofygrin

iTrader: (5)

^ ya, like a year ago this was updated IIRC.

Whitewind

iTrader: (3)

Okay got ya on psi now. Knew it could not be that high.

Porkskins

Here is closer to a full log. Third gear, about 78f outside. Felt much smoother in todays warm weather than it has been, but you can see its still pulling timing down low and there is some knock recorded. Going to pull the plugs right after a few pulls this weekend and see how they look.

Also, can you normally hear a whine around the fuel rail when the key is set to on but the car isnt running? I noticed when i had the lights on and the relays swapped a whine that was oscillating up and down. The fuel pump is obviously running, but I havent noticed the noise before in the engine bay.

goofygrin

iTrader: (5)

What does your timing map look like?

At 5700 RPM (where you get your initial knock) , my log (on E85) looks like this:
At 6535 RPM:
The ECU pulled 1* of timing for my knock there... and I'm 2* less than you. I'm in a different load range than you though (slightly higher load).

I think you might simply have too much timing in your map.

For whatever reason, the resolution of your log sucks. You're missing a TON of data. It's hard to tune only getting a log every 400rpm. You might see what Cobb says about that, but IIRC that's really low. It looks like you're running at like 1.2ish Hz.

UT_EvoX

Your timing advance is way too high for those load levels. Drop it by 2 degrees up top, the knock will go away.