Delanoso's 2.9L Build

[Delanoso]

I thought about that post when I saw the new dyno chart. Nailed it.

Yeah, it feels freed up. It clearly needs a bit more work but it's so much better.

[2mAn]

It must be significantly better too now in everyway

[ForcedFirebird]

That's more like it!

[McGyver]

Congrats on sticking with it and getting some good numbers out of it!

Too funny

[2mAn]

After MS ECU
Here's all runs from yesterday:

Id aim for a realistic number around 175-180whp and anything more is a bonus. Might need more cam, but should be a strong setup as-is when properly tuned

[Delanoso]

Got the o2 sensor sorted out and have the car running reasonably well on the wideband now. DIYautotune helped me find a TunderStudio setting to fix the tach signal. Idle is still a little quirky but it's actually better than what I had on the stock ECU - actually, everything is better than the stock ECU, even with the Megasquirt still untuned. I've run VE Analyze some but I think I've reached the end of what I can do with it. The VE table is spiky and uneven and I realize I can smooth that out by hand but I'm not certain it matters. I think the AFR targets and timing need to be adjusted by someone with real knowledge and a dyno. Put it on the same dyno as before and got what I think is promising results. Is there another 5-10% to be achieved just from tuning?

Before MS ECU:


After MS ECU:


Here's all runs from yesterday:

[Delanoso]

Plugs looked better than I expected - they were definitely black and rich but they were dry and with out any build up. Changed them out anyway.

I'm thinking I have a 5v short on the o2 sensor input to the ECU. Friday afternoon I suddenly got a reasonable AFR in TunerStudio and a very low idle. Was able to run VE Analyze long enough to get the car running and driving on Saturday morning. I think the logs show that the AFR signal just blips to max (5v) from time to time and then shakes loose. Still has idle issues but I think I found those - I have't told MS what the open and closed limits of the ICV are yet and I think the idle valve frequency is set low. I'll correct those this afternoon.

Also the strangest tach signal issue - TunerStudio shows a correct signal but the dash shows something very different. Idle shows below the scale. A light touch of the throttle send the dial upward to about 1500 or 2000 on the dash while TunerStudio shows 3500 or 4000. At that point the dial in the dash literally changes direction and goes downward at what seems a linear rate to the actual engine RPMs increasing. Obviously I've got something crossed up and sent to the dash in place of the correct RPM signal.

[ForcedFirebird]

It's batch fire, so all the injectors fire at the same time anyways.

As I mentioned in the email, when there's a lot of unburnt fuel, it can psych out the sensor and it will read lean. The logs showed dead rich, now matter what we were doing with the fueling.

How did the plugs look when you pulled them?

You can also check the injector spray patterns pretty easily with MS. With the valve cover off, you can slide the whole rail out, with the injectors attached still (if you have the long connector, you will have to remove it and plug it back in). Put some cardboard under them laying flat to see the patterns, and go in Tunerstudio: canbus/test mode>output test modes>injector channel to test: all

[Delanoso]

Still running stupid rich or at least it smells that way. TunerStudio shows off the charts lean AFRs or off the charts rich. The tach reading in TunerStudio is different form what shows in the dash. Is there a chance that the coil is firing on a different timing than MS thinks and therefor the fuel pulses and spark are out of sync? That would likely leave a bunch of raw fuel in the intake but the exhaust would read stupid lean, exaggerating the next cycle?

Edit: Never mind, a timing light on the engine has shown correct several times. Still don't understand why the stock gauge and TunerStudio don't match.

[Delanoso]

Understood about the manifold leak at WOT. But even the plots you just link show that a TPS not allowing the ECU to go inot open loon will cause a reduction in peak power - unless I'm reading those wrong. I just meant that between a TPS not making WOT and the manifold leak, the engine wouldn't have gotten near it's real peak at any RPM. Maybe part throttle above 3500? It actually felt pretty good there.

[ForcedFirebird]

Correct. If the switch wasn't being triggered, you lose that ~9° of timing at MBT, as well as the ECU stays in closed loop and uses the o2 feedback. In the race cars running stock DME's, I always delete the o2 sensor just to avoid this very situation. Look at the AFR's before/after on the first two plots: https://www.r3vlimited.com/board/for...ad#post9875136 as you can see, the ECU is oscillating along with the o2 readings. When cruising, this is fine, but when going through the RPM's very quickly in WOT, the oscillations become clear.

As far as the leak affecting power in itself, probably not since the dyno is measuring power output after you hit WOT (physically the TB is wide open), so vacuum leaks become moot since you will be hitting near atmospheric kpa in the manifold anyways.

[Delanoso]

I'm with Digger on this one. Since you are measuring WHP/dyno power at WOT, a vacuum leak won't affect overall power

Assuming it was actually going into the WOT maps, correct?

However, with the stock ECU and the suspicion that it wasn't going into the WOT maps, I would say the intake leak would affect it MORE. The NB o2 sensor would be throwing all kinds of wonky voltages, and since the ECU was staying in closed loop, it would read this feedback, and respond accordingly. The stock ECU was a marvel for it's time, but as many of us know, everything has to be tip-top for it to work correctly. Modern (and even slightly less archaic) systems have "plan B's", or fail-safes in place for when sensors are out of range, or absent all together.

If it *wasn't* going into the WOT maps, then that means two things: First, the manifold leak would kill low end power. Second, the fact that it wasn't going into open loop means it wasn't ever making peak power potential at any RPM. If both of those things are correct, then the engine would suffer at low RPMs and at high RPMs, correct? That would look like a double whammy at full throttle/low RPMs ie a drag run, right? What affect would you expect just open loop to have on a dyno plot? Another thing we found yesterday when I calibrated the TPS is that the lock nut for the throttle cable had fallen off and the cable was loose. What are the chances the WOT switch wasn't making contact because of that?

Digger, I'm still not sure it's seen a dyno other than the one time I had it on there myself. I found out recently that specific dyno may have trouble getting AFR readings, which is probably why he didn't put them on the run he did for me. It sucks not to know where the good people and equipment is around here. Atlanta is too huge not to have many of both.

Should have more info later today after we get the manifold back on and try cranking it again.

[digger]

It raises another question why the dyno operator never plotted out AFR for the OP. That should be rule number one always plot AFR. A wideband up its ass is good enough even with cat(s)

[ForcedFirebird]

I'm with Digger on this one. Since you are measuring WHP/dyno power at WOT, a vacuum leak won't affect overall power (significantly, anyways - too many details to extrapolate), but, will make idle and lower partial throttles a mess.

However, with the stock ECU and the suspicion that it wasn't going into the WOT maps, I would say the intake leak would affect it MORE. The NB o2 sensor would be throwing all kinds of wonky voltages, and since the ECU was staying in closed loop, it would read this feedback, and respond accordingly. The stock ECU was a marvel for it's time, but as many of us know, everything has to be tip-top for it to work correctly. Modern (and even slightly less archaic) systems have "plan B's", or fail-safes in place for when sensors are out of range, or absent all together.

[digger]

The leak likely won’t affect power as it is a big proportionate of the idle airflow but at wot it’s insignificant. It could affect the global trims but I’d not expect it to be a big effect. Atleast with the new ecu you will know you have the right fuel and timing and that way you’ve extracted all that cAn be had with that combo