TD_D mod journey. From stock to the 'bastardmobile'

[Td_d]

I've always had low levels of knock there abouts, for as long as I can remember - it seems to be that that area is particularly sensitive to any changes in fueling or timing. I've tweaked the VE table to match the final fueling better, and dropped timing a little - I'm not getting no more than -1.4, so it looks like timing might need to be dropped after all.

 

[Vermont]

This just seems very odd that when you added fuel that you still get it. Although the fact that you have always had it makes me think it might be the built block. I have heard of forged pistons, and the slap that comes with them, on cold start up causing the knock sensor to go hay wire. But this is with a warmed up block so unless your clearances are all out of wack then your knock sensor should not be able to pick anything up. I would chalk this more up to something in the tune rather than mechanical at this point.

 

[HolyCrapItsFast]

I looked at your rom and you can guess what I'm going to say.

What I would prescribe is to continue to richen it up between 2800-3600 rpm and load 1.10 and 1.4 to the low 12's and remove a few degrees of timing from load 1.10 to 2.10 as well. The primary timing tables are very conservative so I would not be removing any timing from them. Use the Knock Correction Advance tables for that. It looks to me that this is where most of your knock is coming from.

All in all a combination of fuel and timing will solve your issue.

 

[HolyCrapItsFast]

Oh didn't read your previous post...

I was going to say that your timing is VERY conservative across the board and you really shouldn't be getting any knock. Though in the original log you posted, most of the areas that see knock you are actually targeting fuel between 13.73 and 12.46 and between load 1.1 and 1.59. There is also knock in higher loads and those loads are rich IMO.

 

[HolyCrapItsFast]

Do me a favor... To rule out knock we can perform a very simple test...

Zero out your Knock Correction Tables and then log again...

That should cover the entire range and eliminate any knock... If it does not go away then it is false knock and you can then reactivate the advance tables and then either find the culprit or adjust your knock control accordingly

 

[Td_d]

Thanks Holy - that's basically what I've done - I figured the base timing tables were quite conservative, my tuning approach has generally been higher boost and conservative timing.

What I will also try and do is relook the AVCS tables. In originally trying to deal with knock, I reduced intake AVCS markedly in the 0.8 to 1.4 load region (as others have done, I had it ramping up rapidly to peak advance by 1.4 - 30*). Reduced I had 10* advance right up until 1.4 - which I believe may be part of the problem as well (in terms of how the car feels spooling up).

 

[Td_d]

Do me a favor... To rule out knock we can perform a very simple test...

Zero out your Knock Correction Tables and then log again...

That should cover the entire range and eliminate any knock... If it does not go away then it is false knock and you can then reactivate the advance tables and then either find the culprit or adjust your knock control accordingly

Touch?. That's why one needs to step back from tuning every once in a while :tard:

Will do, and will see the results.

 

[Td_d]

Well, the good news is that reducing the timing has brought knock right down - -1.4 at the most, so with a little more massaging, I should be able to remove it. With intake AVCS advanced earlier as well, it's spooling up like a mofo again - and interestingly did very little to change fueling. I'm a little surprised at the low tolerance for timing at the low end, but it's not really affecting driveability (in actual fact, it's quite nice not to have it hesitate occasionally).

On the down side, I can officially verify that 29psi (2bar) is not a good idea on my set up With the weather having cooled down markedly in the past couple of days, the 'offset' on my EBCS (basically boost error correction) was set too high, and with target boost set at 1.9 (which is the ragged edge of what my TMIC can handle, even with meth) it climbed up to 2bar going full tilt in 4th gear. AFR resistance went down to 19... with current still being pulled. Yikes, 850* celsius plus. Pulled 3* of timing, not great, but not extreme (she's outlasted worse treatment). Doesn't feel like there's an issue, however - if I had fried the rings, I think I would know about it quite quickly. CEL flash to the rescue - pulled off throttle immediately. So useful...

I think I need to be reasonable at keep it at 1.8bar at the most.

 

[HolyCrapItsFast]

Yeah I'm kinda wondering why your engine requires such conservative timing, but what ever works is what you go with. :tup:

I doubt you could have done anything bad to the pistons or rings. If they were stock then maybe but even then you would need an event less than -5 at mid range to do anything. Typically ring lands go at high rpm and load and a knock event less than -10 and even then it has to happen more than once. Or at least that has been my experience.

 

[Vermont]

Yeah I'm kinda wondering why your engine requires such conservative timing, but what ever works is what you go with. :tup:

I doubt you could have done anything bad to the pistons or rings. If they were stock then maybe but even then you would need an event less than -5 at mid range to do anything. Typically ring lands go at high rpm and load and a knock event less than -10 and even then it has to happen more than once. Or at least that has been my experience.

-10? Holy mother of god..... In what type of situation would you ever see anything lower than that? Hell I remember when I messed up on installing my EWG and it boosted right up to 26 psi, with the stock injectors... I saw -4 then and that's the most I have ever seen (I also almost shit my self when it happened).

 

[Td_d]

-10? Holy mother of god..... In what type of situation would you ever see anything lower than that? Hell I remember when I messed up on installing my EWG and it boosted right up to 26 psi, with the stock injectors... I saw -4 then and that's the most I have ever seen (I also almost shit my self when it happened).

Screwed up MAF scaling, or meth kit failure. Boom...

Yeah, I figure I'm good. It's really time to go rotated and front mount - and 35R I think. 27psi is as much as I can push on the Dom3xtr. Gotta say, the thing is tearing around like crazy, and the fat tires are putting it down nicely... Guess I'm just greedy, aren't we all

 

[Vermont]

Yuck Dom 3.... Honestly I love my Dom 1.5 but I would never pick up their Dom 3. To much lag for how low the flow rate is in my my opinion. Maybe upgrade to a Borg Warner EFR, if you are going to go rotated might as well go with the best...

 

[Td_d]

^ yeah, I have to admit, it's laggy for a 52lb/min turbo - but it's served me well, and pretty decent top end given my set up. But I'm at that giant hairdryer point, and the block can take much more abuse. I just have to find the patience to have her in again...

 

[Td_d]

HTA3582 is my vote.

Yeah, I'm leaning towards an FP again - I was supposed to get a Green initially, but they stopped making them at the time.

A Borg Warner EFR would be great, but pricey...

 

[HolyCrapItsFast]

29 psi... that would be the reason for conservative timing. Also remember the guy is on a TMIC.

Yep I got that... The thing is he probably doesn't reach that till something like 4000 rpm or more... Timing should be normal up to that point and then drop off sharply.

Sent from my Desire HD using Tapatalk

 

[Td_d]

^ yup, that. And yet my setup is not very tolerant of high timing in the low to mid non-cruise areas as well. Go figure. Eh... Still goes like a shitkicker :tup:

 

[HolyCrapItsFast]

Post up something I can actually read log wise and I'll look at it...

And George, sharp changes in timing are a NO-GO

Who says.. bumps in data are a no go...

Sent from my Desire HD using Tapatalk

 

[HolyCrapItsFast]

I should clarify... I don't mean going from 30* to 8* in one load cell. I mean sharpening the overall slope :tup:

 

[Td_d]

Interesting - as I lower the KCA timing in the lower areas of knock, I'm getting higher loads at lower RPMs, which are pushing the knock up the load scale. At least the strategy is working, and I'm still getting decent performance down low - in fact, the lack of knock now seems to be increasing torque (also a function of the intake AVCS advance coming on earlier) - I'm getting load of 2 under 2850 RPMs.

Started messing around with the MAF IAT compensation tables today to deal with the fluctuating trims due to heat soak - speed density with the IAT sensor still in the intake is quite susceptible to it, and it can cause swings from what I've seen of up to 20%~25% AFRs. Thankfully, I already have quite a wide range of SD data, at very different IATs - the hottest being 144F and the lowest in the 60's. Looking at the logs after the compensation, it's made a marked improvement - giving the O2 sensor a much more reasonable range to work with (as opposed to 25% with very hot IATs, and up to -18% with low IATs).

Have dialed the boost back to 1.8bar - looking at the EGTs - well within the right range now, with probably a little room to manoevre. Looks like 1.85 bar is the most I can push on the Dom3xtr and my TMIC (with meth) before it becomes a furnace in there.

 

[Td_d]

Ah.... took my car out for some fresh air, and opened her up thoroughly. Nice to actually thrash it once in a while, and not tune :tard:

Had a silly Audi S3 try to buzz me. I forget how fast this car is sometimes, from a roll in 1st gear, I left this poor bastard behind by busloads. He gave up after the second attempt :lol: Bah. DSG. I got me FFS!

Me being me, had a look at the logs afterwards :tard: - how does engine load of 4, and 23psi of boost.... in 1st gear, sound?

Chuckle...