Noob M30B35 Build

[tig]

So far so good. I tweaked it this morning to remove a bit of timing at 1800rpm and think it's now nailed. Here's how this tweaked map compares to the map that works on Tim's car.



Area with bold numbers is where my map now differs.

It's nice being able to chug around in this low RPM range and not be petrified of knock. Previously I was constantly having to stir the gears to avoid that region. I actually didn't realize how used to doing it I had gotten!

[trevmmeister]

Incase you ever sell Vlad, I call dibs.

[Kyle in NO]

Incase you ever sell Vlad, I call dibs.

I doubt that.

[turbodan]

Those are ignition advance angles right? In degrees? No offset? 50+ degrees in the mid load range is a hell of a lot.

[tig]

Those are ignition advance angles right? In degrees? No offset? 50+ degrees in the mid load range is a hell of a lot.

From the WAR manual:

Ignition is displayed in the GUI as actual timing in degrees. If it says 14, you are running
14 degrees of timing BTDC (advance).
If it says -14, you are running 14 degrees of timing ATDC (extremely retarded timing)

[Kyle in NO]

Do you have any previous tuning experience? Sounds like this may be another Duke experience. Kaboom!

[tig]

Do you have any previous tuning experience? Sounds like this may be another Duke experience. Kaboom!

What part of "Noob" don't you understand?

[Kyle in NO]

Where on earth did you get those huge timing advance values from? I've never heard of 50 Deg BTCD either. I would think 36-40 would be absolute max.

[tig]

Where on earth did you get those huge timing advance values from? I've never heard of 50 Deg BTCD either. I would think 36-40 would be absolute max.

This is a tune provided by Brody to another customer with an identical engine to mine (B35, 10.5:1 compression, PB N21 cam, 24lbs injectors, headers).

Below is the "179 AFM" map from the Miller tune library. Unmodified. Brody tells me this is identical to the stock ECU map.




The "179 AFM 87 Oct" map has P/T timing values IDENTICAL to "Tim's" tune (as well as my previous starting point) so I assume that's where Brody started.

There *are* tunes in the library for the 179 ECU that have far less advanced timing (e.g. max 39-40).

Like I said:

[turbodan]

55 degrees of advance is insane on a 10.5:1 motor, even at part throttle. The only thing we don't have is any indication of scale since the horizontal axis is labeled in meaningless numerical values. I'm guessing thats a range from low load at 1.15 to high load at 6.55 but I don't have any idea how that would relate to manifold pressure. Assuming its a linear relationship, 55 degrees at mid load would probably be 50-60 kpa MAP which would be wildly excessive. My 8.5:1 M20 was running 36 degrees in that same load range.

There are portions of the map that look okay. The full load column is reasonable. It just doesn't make any sense to have over 20 degrees of vacuum advance. If thats the stock map from a -179 DME it'd be the most radical ignition advance map I'd ever seen, especially for a high compression motor.

[tig]

55 degrees of advance is insane on a 10.5:1 motor, even at part throttle. The only thing we don't have is any indication of scale since the horizontal axis is labeled in meaningless numerical values. I'm guessing thats a range from low load at 1.15 to high load at 6.55 but I don't have any idea how that would relate to manifold pressure. Assuming its a linear relationship, 55 degrees at mid load would probably be 50-60 kpa MAP which would be wildly excessive. My 8.5:1 M20 was running 36 degrees in that same load range.

There are portions of the map that look okay. The full load column is reasonable. It just doesn't make any sense to have over 20 degrees of vacuum advance. If thats the stock map from a -179 DME it'd be the most radical ignition advance map I'd ever seen, especially for a high compression motor.

Thanks Dan. Note that it is my understanding that the stock 179 DME map above is NOT for a high-comp motor. Are you implying that high compression engines should have LESS advanced timing than lower compression engines, in general?

Brody says you can break the load into thirds: "Light Throttle & Cruisng", "Medium Part Throttle Accelerating", "Heavy part throttle accelerating". My pinging has been happening in the middle 1/3.

I appreciate you tuning in as I know you have a lot of experience & knowledge.

[Kyle in NO]

What scares me is all of the detonation you aren't hearing due to engine and other background noise, because believe me, you are getting some. With no knock sensors, its actually pretty dangerous. I can envision your piston ring lands taking a huge beating every time you drive. I'd look at a stock 179 ignition timing map and incrementally increase it from there, but then again I also suck at tuning.

[tig]

What scares me is all of the detonation you aren't hearing due to engine and other background noise, because believe me, you are getting some. With no knock sensors, its actually pretty dangerous. I can envision your piston ring lands taking a huge beating every time you drive. I'd look at a stock 179 ignition timing map and incrementally increase it from there, but then again I also suck at tuning.

I dunno, Kyle. If advance angles like this were truly that odd, then all of these other engines would have espolded by now and it would've been on CNN Headline News by now...

FWIW, the stock 179 map is posted above and has these same high values.

The tune you use if you have a Gen 3 MAF on a B35 using Miller's cam:


A similar engine build, unknown cam;


The tune for an Alpina B10 3.5, which is a 10:1 compression motor:


Another tune with unknown cam and 10:1; this one shows a wildly different type of map:


For shits-and-giggles, here's the stock 059 timing map:


When we had the car on the dyno, we wore ear muffs so as to hear the knocking better and only heard pinging in the 1800-3000 rpm range and at WOT; we adjusted for both. I've become quite tuned into the sound of pinging and done a lot of testing with the windows open, driving next to concrete walls. I *think* I know when it's doing it when it's not.

That said, I'm backing off anyway. If a tune like the Alpina one didn't require such aggressive timing, then I certainly don't.

[BENAllison]

Thanks Dan. Note that it is my understanding that the stock 179 DME map above is NOT for a high-comp motor. Are you implying that high compression engines should have LESS advanced timing than lower compression engines, in general?

Yes. Higher compression engines should have LESS advance. This is the same principle that the turbo cars need. As cylinder pressures increase due to either boost or higher compression all other things equal (fuel quality, quench, head material, etc) ignition timing needs to be retarded (i.e less advanced) to prevent preignition "pinging".

I will agree with the others and state that the map you are using looks way wrong, especially for a 10.5:1 pump gas motor. Assuming that what you show in the table is really the advance the engine is seeing. The only way to know for sure is to go old school and mark the balancer and put a timing light on it to verify timing both at idle and through the advance curve. It would be very rare to see over 40-45 deg advance for a 10:5:1 pump gas engine. Also it looks like the pinging you are experiencing (moderate load 1800-3000) is right where the map gets weird. Try dialing back to more like 40 deg and work from there. You can sniff around the forced injection forums for some example timing curves for the 0-100KPA range to see what other peeps are using. Noting of course that most of those are 8:5-9.0:1 motors, but it should give you a starting point.

* Caveat I do not claim to be an expert in timing, but have experience in tuning a MSII turbo car from basically scratch for advance curves, and timing curve experience from my Muscle car days of distributors and points

[Bav3.5]

When I ("Tim" with the exact same set-up) got the base tune from Brody, it was supposedly based on a few other set-ups they have done specifically using the N21 and Paul Burke's 10:5-1 pistons versus other cams, etc. I had even specified that I'm limited to CA's 91 octane. I'm now worried and will second guess this again, but I don't think i'm experiencing any audible pinging or detonation with the timing curves cek showed on the tune i'm using. When originally inquiring prior to purchase about the high-compression and the possibility of detonation, I was told the cam has an effect....the pinging people experience from stock M90/dirty m30's are due to the "primitive camshaft compared to the N-21, which accounts for its less than optimal cylinder filling and the possibility of detonation on pump gas." How much truth there is to this...I don't know.

[12valves]

The table for the stock B35 (which has domed pistons) has a lot more advance at low loads compared to the table for the stock B34 (which has dished pistons). This actually mirrors my experience with a high(ish) compression M10. Despite the higher CR, it wanted plenty of "vacuum advance" just like a stock M10B18 (which again has domed pistons). I ran as much as 52deg. My M30B32 (flat top pistons) however does not benefit from so much advance at light loads.

Also a stock M50 map tops out at 43deg, and that's with a much smaller bore, central spark plug, and dished piston. After seeing that as well as stock Eta maps I could believe that the 179 table really has 54 in it.

Of course it doesn't hurt to error on the safe side, especially at the higher loads. And on these maps that are indexed to MAF voltage or whatever it's hard to know exactly how much load the value represents unless you have a way of logging the actual voltage while driving.

[tig]

The table for the stock B35 (which has domed pistons) has a lot more advance at low loads compared to the table for the stock B34 (which has dished pistons). This actually mirrors my experience with a high(ish) compression M10. Despite the higher CR, it wanted plenty of "vacuum advance" just like a stock M10B18 (which again has domed pistons). I ran as much as 52deg. My M30B32 (flat top pistons) however does not benefit from so much advance at light loads.

Also a stock M50 map tops out at 43deg, and that's with a much smaller bore, central spark plug, and dished piston. After seeing that as well as stock Eta maps I could believe that the 179 table really has 54 in it.

Of course it doesn't hurt to error on the safe side, especially at the higher loads. And on these maps that are indexed to MAF voltage or whatever it's hard to know exactly how much load the value represents unless you have a way of logging the actual voltage while driving.

Thanks. Good intel. Question: What does a motor "wants more vacuum advance" mean? For more performance? To generate more vacuum pressure?

[tig]

FWIW, my tune as of this morning. I tried REALLY hard on my relatively short and hill free commute in to get it to ping and couldn't. More as I try moar.



I also have a call into Paul Burke as I think it's time I bugged him about this and other things.

[12valves]

What does a motor "wants more vacuum advance" mean?

Vacuum advance refers to the timing at part throttle, which is generally more advanced than at WOT. At part throttle there is a certain amount of vacuum in the intake, while at WOT there is essentially none. Cars that didn't get computer-controlled ignition timing often had a vacuum hose running to the distributor, so the vacuum would actuate a lever in the distributor resulting in more spark advance.

So for example, on this map they didn't bother to tune for part-throttle conditions at all. The downside to this would be subpar fuel mileage and throttle response.

[tig]

What does a motor "wants more vacuum advance" mean?

Vacuum advance refers to the timing at part throttle, which is generally more advanced than at WOT. At part throttle there is a certain amount of vacuum in the intake, while at WOT there is essentially none. Cars that didn't get computer-controlled ignition timing often had a vacuum hose running to the distributor, so the vacuum would actuate a lever in the distributor resulting in more spark advance.

So for example, on this map they didn't bother to tune for part-throttle conditions at all. The downside to this would be subpar fuel mileage and throttle response.

Super helpful!

On our cars WOT is determined by the TPS, right? I mean you are either at WOT with the throttle or not, right?

FWIW, my throttle response has always felt fine (and still does with this latest tune) across the range.

However my fuel mileage has suckaged. I'm getting about 16mpg... I expected better with this motor.

[12valves]

Yeah, that's a good question. I'm not sure about Motronic 1.3. Some versions of Motronic have a potentiometer TPS, others a switch, and some have a completely separate set of maps for WOT.

But I was speaking about it generally. Since the X axis of the map is the amount of air going in, WOT would be over towards the right somewhere, whereas cruising at part-throttle would be towards the left.

[tig]

1.3/179 ecu has a separate maps for fuel and timing for WOT. I was wondering what caused it to switch to it; just tps or something else. Fwiw, I'm not touching my WOT maps because we spent a lot of time with them on the dyno.

I backed off my P/T timing more and really got confident the knocking is gone. The map ended up looking pretty homogeneous but not too dis-similar to the Alpina B10 3.5 tune. I like the fact that it appears someone put some time into it, so that's what I've been using last few days. No pings.

So now vlad has Alpina wheels AND an Alpina tune. I think ill put an Alpina badge on it now.

[kzolee]

Dont't forget the 'I was in Romania, and did'nt bought the first E28 I saw' sticker.

It looks like, the guys in Bovensiepen knew something about high compression engines, in the eighties. l

I am a fan of this topic, btw.

[tig]

Today, at 3400 miles since the engine was installed, I did an oil and filter change. Oil came out looking exactly as you'd expect oil at 3400 miles to look. I will be sending the oil to Blackstone for analysis; just because I think it's fun, not because I think I'll learn anything, but who knows.

While the oil was out I also pulled the plugs and put my endoscope into the motor to see what I could see.

First, the plugs look fine (I had checked them once at about 500 miles):


I scoped inside the head from the oil fill. It was hard to get the camera oriented, but I was able to capture this still of one of the cam lobes. Looks fine to me, but what do I know?


Then I put the scope in each cylinder through the spark plug hole. All 6 looked very similar (I did not rotate the engine, so only 1 & 6 had the pistons down enough to really see the cylinder walls). There is slight scoring in 1 & 6 that looks like this:


This Youtube video shows much more detail. You can also see carbon build up on the piston face. http://youtu.be/vsBkdFA_dck

In #5 I was able to see the top side of an exhaust valve. There's some carbon build up there that this short video does an ok job of showing (watch to the end).
http://youtu.be/ZIu3hoGgUrQ

In #6 more scoring is visible; similar to #1. This video: http://youtu.be/035Dl0uTsyk

I don't know enough to know if that scoring is concerning at 3400 miles or not. There's not much I can do about it, so even if it is concerning I'm going to just live my life in denial. But I'd love 'experts' thoughts if you have any. Thanks.

[athayer187]

Looks pretty good to me. Borescopes have a way of distorting things and making them seem out of proportion.