Building the perfect LGT

[HAMMER DOWN]

Are you running a catted DP ? I'm catless.

 

Yes, Invidia 3" DP bell mouth, high flow Cat. It's over 120db at the tailpipes @ 6000rpm:wub:.

[Max Capacity]

Yes, Invidia 3" DP bell mouth, high flow Cat. It's over 120db at the tailpipes @ 6000rpm:wub:.

 

I guess I'm getting to old than...

 

Thanks for reminding me...LOL

[MilesA]

Less maintenance. It puts the oil back into the pan instead of in a can.

So, it recycles the two tablespoons of oil you might collect over a 3,500 mile OCI. Whoa, that's a time saver.

[Max Capacity]

The AOS I have, saves some of the oil vapor that dilutes the air/fuel ratio. I got it on a group buy on NASIOC years back, Its made by SG Motorsports.

 

https://www.google.com/search?q=sg+motorsports+aos&oq=SG+motopsports&aqs=chrome.2.69i57j0l5.10855j0j8&sourceid=chrome&ie=UTF-8

[Merc6]

I guess I'm getting to old than...

 

Thanks for reminding me...LOL

 

I'm getting there as well. That and being 3rd shift I try to not be super loud when I leave. LGT has no mufflers so I'll cross that bridge when I get there.

[Sparkey]

I need some guidance with making sure my ducks are in a row before getting tuned. I've done as much reading as I can but sometimes end up over my head or sidetracked by related topics

 

I'm getting over boost (2+ PSI over target) and my LV's dont look good. No codes, supposedly 100% oem. When Heuberger did my timing belt, they replaced some vacuum lines that were bad, and I tried a ghetto smoke test but I feel it was inconclusive. It looks like Cryo does smoke tests for $65 so I will do that before my tune for verification of no leaks, but what else do I need to investigate before that? I do believe my IC is starting to leak, but everything I read says that would cause leak and boost loss right? It will be getting the JB treatment soon. A lot of my reading wants to point to the tune and a lot of people arent fond of the OEM tune so I'm hoping thats the culprit. Then I'll throw my UP/DP and a panel filter in for my tune.

 

Also when I was looking at and playing with some of the vacuum lines I noticed a lot were molded. Does it suck if they are replaced with non molded lines or are there some lines that its best to have oem/molded and the rest can just be standard vac line? Thanks.

[Sparkey]

Heres pics of my LVs

[solidxsnake]

Looks like you've got a vacuum leak (high AF correction), and also looks like it's knocking quite a bit. In addition to leak checks, I'd make sure to clean/replace the MAF sensor as well as replace the front O2 sensor. The O2 sensor is known to degrade over time and throw off fueling, but not necessarily throw a CEL.

[Sparkey]

Looks like you've got a vacuum leak (high AF correction), and also looks like it's knocking quite a bit. In addition to leak checks, I'd make sure to clean/replace the MAF sensor as well as replace the front O2 sensor. The O2 sensor is known to degrade over time and throw off fueling, but not necessarily throw a CEL.

 

What tells you that its knocking from what I posted? It does get several knock events, but from what I was reading they wernt bad ones. I can post a knock event if that helps any.

 

I will get a new front O2 today. MAF was cleaned when I did plugs a few weeks ago, but I can clean it again just to be sure.

[solidxsnake]

What tells you that its knocking from what I posted? It does get several knock events, but from what I was reading they wernt bad ones. I can post a knock event if that helps any.

 

I will get a new front O2 today. MAF was cleaned when I did plugs a few weeks ago, but I can clean it again just to be sure.

 

The timing correction across the FLKC table. The "knock event" snapshots in BtSsm are pretty much useless, IMO. It doesn't give you enough data to make any reasonable conclusions.

 

For your second LV (where the IAM is 1.0), I can tell you that after FLKC was enabled -- meaning there was some knocking already at all of the cells I'm about to talk about -- there were at least 2 knock events between 1650-2600RPM under 0.85g/rev load and between 1.1-1.35g/rev load, 2 events between 4000-4800RPM and 1.1-1.35g/rev, and 1 event between 2600-3200RPM and 1.1-1.35g/rev and 1.35-1.6g/rev.

 

Once the ECU's in "fine-learning" mode, every time it hears a single knock, it'll pull 2° of timing from the current load/RPM cell. If it doesn't hear any knock for a certain amount of time (cell-dependent), it will start adding timing back. Which is exactly what you're seeing.

 

If you log your FLKC in real-time while driving, then get into one of those cells where there's timing being pulled and stay in it (which may be difficult due to road conditions, speed limits, etc.), you should start seeing timing being added back unless the car starts knocking. If it does knock, you'll see it pull even more timing.

[Sparkey]

Is the O2/Vac leak probably causing the knock or is that a whole other issue that I need to start watching for?

 

As soon as I can I'll get my new O2 sensor in and try again to find any obvious leaks while I schedule a smoke test with Cryo.

[solidxsnake]

Is the O2/Vac leak probably causing the knock or is that a whole other issue that I need to start watching for?

 

As soon as I can I'll get my new O2 sensor in and try again to find any obvious leaks while I schedule a smoke test with Cryo.

 

Any mechanical issue can cause knock, as it hinders the ECUs ability to correctly control timing/fueling. If the car is mechanically sound and running good fuel, then the only thing left to cause knock is a bad tune. Keep in mind, I'm including a clean/tidied engine bay with my description of "mechanically sound." I mention this because you could also see knock events occur due to thing like loose and rattling heatshields, which aren't dangerous to the motor but can impact performance by making the ECU think there's actual detonation occurring.

[Sparkey]

Any mechanical issue can cause knock, as it hinders the ECUs ability to correctly control timing/fueling. If the car is mechanically sound and running good fuel, then the only thing left to cause knock is a bad tune. Keep in mind, I'm including a clean/tidied engine bay with my description of "mechanically sound." I mention this because you could also see knock events occur due to thing like loose and rattling heatshields, which aren't dangerous to the motor but can impact performance by making the ECU think there's actual detonation occurring.

 

Gotcha. Would bad endlinks and LCA bushing be enough to casue the knock or are those far enough away?

 

I'll also do a once over in the engine bay and make sure everything is tight and no loose heat shields or anything silly like that.

 

Thank you.

[solidxsnake]

Gotcha. Would bad endlinks and LCA bushing be enough to casue the knock or are those far enough away?

 

I'll also do a once over in the engine bay and make sure everything is tight and no loose heat shields or anything silly like that.

 

Thank you.

 

I think I've read of people clearing phantom knock from replacing bad endlinks before. I think that's generally pretty unlikely, though.

[Sparkey]

Why did I wait so long to get BtSsm?! I got the O2 sensor put in as well as cleaned the MAF. I still have 13.9 learn% at 0.00 MAF g/s and 2.4% at 10.0 and .6% at 40.0 but my timing correction table is 0.00 for everything!!

 

Huge thanks solidxsnake! I also tried tracking down the vacuum leak and was unsuccessful again at finding anything. Used carb cleaner to try and spray some suspect areas but didnt get anything. I will schedule a smoke test with Cryo and go from there.

 

Tomorrow I'm going to get a downpipe ordered, probably new radiator hoses, shifter bushings and what ever else I need to get over $500 to use a coupon I have. Then hopefully get my IC JB welded or bulletproofed or JBulletproofwelded so it doesnt come apart until I am able to get an upgrade.

 

I did just notice however that my IAM was at .5

[1-3-2-4]

the knock control on this car is very aggressive.. I remember those days you could floor the car and it had hardly any power at all until if I remember it got over 2k or so the power came back

[solidxsnake]

Why did I wait so long to get BtSsm?! I got the O2 sensor put in as well as cleaned the MAF. I still have 13.9 learn% at 0.00 MAF g/s and 2.4% at 10.0 and .6% at 40.0 but my timing correction table is 0.00 for everything!!

 

Huge thanks solidxsnake! I also tried tracking down the vacuum leak and was unsuccessful again at finding anything. Used carb cleaner to try and spray some suspect areas but didnt get anything. I will schedule a smoke test with Cryo and go from there.

 

Tomorrow I'm going to get a downpipe ordered, probably new radiator hoses, shifter bushings and what ever else I need to get over $500 to use a coupon I have. Then hopefully get my IC JB welded or bulletproofed or JBulletproofwelded so it doesnt come apart until I am able to get an upgrade.

 

I did just notice however that my IAM was at .5

 

Any time your IAM changes at all (goes up or down), the entire fine-learn table will reset to zero. That your IAM changes at all is a sign that your car is seeing a lot of knock, so you may want to drive it softly and figure out what problems you're having.

[Sparkey]

Any time your IAM changes at all (goes up or down), the entire fine-learn table will reset to zero. That your IAM changes at all is a sign that your car is seeing a lot of knock, so you may want to drive it softly and figure out what problems you're having.

 

I couldnt sleep last night so I went driving around for awhile after I posted. Got the IAM back to 1 and didnt see it drop and the tables stayed 0.00.

 

Is it true that with the ECU reset (to clear codes) resets the IAM as well until its driven enough to "learn" back to 1? I had started the car without the maf plugged in and coded. Then I assume the drive around the block wasnt enough to reset it.

[rhino6303]

I couldnt sleep last night so I went driving around for awhile after I posted. Got the IAM back to 1 and didnt see it drop and the tables stayed 0.00.

 

Is it true that with the ECU reset (to clear codes) resets the IAM as well until its driven enough to "learn" back to 1? I had started the car without the maf plugged in and coded. Then I assume the drive around the block wasnt enough to reset it.

The IAM is reset to whatever the ecu table calls for. I see most tuners set it to 1 or slightly below. I can't remember the value for a stock, untuned/unchanged ecu table though but it is much lower than 1.

[solidxsnake]

I couldnt sleep last night so I went driving around for awhile after I posted. Got the IAM back to 1 and didnt see it drop and the tables stayed 0.00.

 

Is it true that with the ECU reset (to clear codes) resets the IAM as well until its driven enough to "learn" back to 1? I had started the car without the maf plugged in and coded. Then I assume the drive around the block wasnt enough to reset it.

 

Yes, an ECU reset will reset the IAM to the start value that's set in the tune. For the stock tune, that means it will start at 0.5 and a couple WOT pulls should bring it up to 1.0 assuming everything's good with the car.

[JazzAvi8r]

I had the opportunity to help Sparkey this weekend in running a compression check. 98-102 on all four. seems like the car was pulling some significant timing -- possibly due to detected knock?

 

Heck of a guy, though! we had a good time. Also, does this car run a waste-spark ignition set up?

[solidxsnake]

I had the opportunity to help Sparkey this weekend in running a compression check. 98-102 on all four. seems like the car was pulling some significant timing -- possibly due to detected knock?

Heck of a guy, though! we had a good time. Also, does this car run a waste-spark ignition set up?

 

Very likely, if you look at the above. Looks like a significant amount of timing is being pulled, both via coarse and fine knock correction.

 

Was that compression check done hot or cold? Looks pretty low, but the consistency is at least a good sign.

 

I'm fairly certain that these engines don't run waste-spark ignition.

[JazzAvi8r]

the test was done warm. I took a stethoscope to it afterwards and detected a leaky valve on number2, but it wasn't so significant that it caused a drop in compression. When we put the car back together and fired it up the first time, we had the #1 and #3 coil packs reversed which caused a string of misfires. but the car still ran, so that's why I was thinking it was waste spark setup. we switched them back and she runs just fine. sounds pretty strong, so I doubt there's any issues other than the lean mixture causing knock resulting in the pulled timing. spark plugs also verified a lean mixture.

[Sparkey]

I had the opportunity to help Sparkey this weekend in running a compression check. 98-102 on all four. seems like the car was pulling some significant timing -- possibly due to detected knock?

 

Heck of a guy, though! we had a good time. Also, does this car run a waste-spark ignition set up?

 

Huge thanks again!

 

I found this thread (http://legacygt.com/forums/showthread.php/low-compression-test-do-go-herei-215218.html) and mweiner2 says that altitude can have an affect on it too - he seemed to indicate that 100psi at 5000' is good.

 

I also kept finding everyone seemed to be more focused on the difference between numbers more then the actual number it shows.

 

Curious if I should drop to a colder plug too - OEM Tune + OEM Plug = to lean of mixture with to hot of plug creating knock? I cant seem to find anything loose that would cause the phantom knock.

[JazzAvi8r]

I couldn't imagine that compression would be that low solely due to altitude. My numbers were 128 across the board and I thought that was low for my car -- granted, I'm on a slightly more aggressive tune. I agree that the bigger issue is any 10% drop between 2 cylinders though. your car seemed just fine, it's just pulling timing. colder plugs might help just a little; maybe change the gap up a little as well.