Timing advance and boost - DM vs. plugs

E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

I filled the intercooler last night and tried it again. The DM screenshot is below. Note that it's the second run. I messed up the recording on the first one, so re-ran. IAT temp started at 120 and climbed to 140 by end of run (ambient was about 75). Is that acceptable? I checked to see if the pump was running and there was a little movement and some bubbles in the upper IC, so I assume it's working.
Also, the boost control still looks terrible to my (inexperienced) eye, even though it's significantly improved. No KR, still, but not great acceleration.Where should I focus my attention?

 
sytyguy

sytyguy

Moderated User
Re: Timing advance and boost - DM vs. plugs

MAT temps are much better.

SW Missouri.....probably 75-80 degrees when you ran?
90% or so humidity?

On a second pull, that's very acceptable (esp. if you still have EGR on the truck). Your timing is still very low for those conditions. Start by verifying base timing (0 deg BTDC with timing connector unplugged), then you may want to bump up the timing in F80 from 3200 and up. See if it starts to "come around".
 
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Eric Sy GN

Donating Member
Re: Timing advance and boost - DM vs. plugs

I received your log file.

For the boost, notice that the wastegate duty cycle has to get to 100% just to get to 15psi or so. Then on the shift, when the dc is programmed to drop, you get a huge boost drop.
I think you would benefit from increasing the preload on the wastegate actuator (shorten the rod). Maybe try one full turn at a time. This should bring the max WG DC down, and help the boost drop on the shifts.

On the timing, if you want to add some, the chip has adjustable parameters for that. Be careful where you add it, as the chip has more timing in the lower gears (16-18*) compared to the higher gears (12-14*). Watch for knock.

capture90.jpg
 
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intheclouds1977

New member
Re: Timing advance and boost - DM vs. plugs

That's looking better. Looks like you can probably mess with the WG DC in the VeloSyTy a little to smooth the boost out, but you're getting closer. Try to make the 2-3 shift a little more domed rather than spiked on the boost and try to get the upper end of 3rd gear nice and level on boost. The spikes you see are causing a major droppoff of boost to save the motor...and a major loss of power as boost slowly builds back up.

The VeloSyTy chip lets you advance timing in 1-2 gear and 3-4 gear. Recommend advancing each until you get about 1-3° of KR...that'll be the sweet spot.
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

Thanks for the great info. I'll try both the wg actuator (first) then a bit of advance. I just ran out and looked at the wg actuator. What's the best way to adjust it? It looks like a wrench wouldn't have room, but I think I see a e-clip underneath. Is it easier to pop the clip off and pull the rod out to adjust it or leave it on and fight the rusty nut?
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Timing advance and boost - DM vs. plugs

Pull the inner fender, loosen the nut, pull the pin/washer and then you should be about turn the rod end.

I disagree with wanting 1-3 KR. Personally, I would increase timing until you get a knock event and then reduce the timing so it has '0' KR. If the data log showed knock at 15.6 degrees I would probably back it off to 14.8 (instead of 15.2 degrees), so you aren't so close to the edge. Reading plugs with conductor removed is even better than reading scan tool.
 
T

TurboSBC

New member
Re: Timing advance and boost - DM vs. plugs

E.Murray said:
Lots of great stuff. Thanks. I'll order the Walbro pump and an AFPR today. Can I stick with stock injectors (for the moment to save some cash)? I don't have big plans for it, other than driving to work on nice days.
As far as the IC goes, I pulled the cap and the level was low (could see just a little in the bottom). I topped it up. I can pull the cap off the upper IC with the truck running and not just make a mess?
As far as the chip goes, I'll get the number tonight when I get home. I'm not driving it until I get everything sorted. Thanks again for all the help.
Eric
Click to expand...

Make sure you buy your Walbro from a reputable source.

Www.ApeUSA.com seems to be highly recommended on here.
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

Thanks for the plug reading link.
So I shortened the wastegate actuator rod a turn or so and re-ran. Here's the data.

Huh? Why is the wg showing 100% dc when I was sitting waiting to turn around? And it looks like it's still maxing out. Shorten it more or is there something else at work?
 
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Eric Sy GN

Donating Member
Re: Timing advance and boost - DM vs. plugs

It's normal for it to stay at 100% while not in boost.
It's still climbing up to 100% when in boost, so I think I would shorten it more and see what that does.

Eric
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

I shortened the actuator one and a half turns for this run. Seems better to me. Temp outside is 93. While I was at it, I checked plug gaps and gathered compression data on cylinders (140-152 psi). Does this data look OK? I still get that boost oscillation.

To get the speed, I need to adjust timing. As soon as somebody replies to my DM monitoring thread, I'll try that, too. Thanks for all the help. We will get there...
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

Final tweak on this thread. I advanced the timing from -1.8 in the top two gears to +.7 (I think? 2 steps up on the chip) and another .5 lb boost. I have a couple questions. First, the wgdc is back to 100%, but it's giving me all the boost I want, so is that OK? Second, what about the odd blip in boost at each shift? Is that the initial boost setting? Thanks for any direction you can provide. This run was the first time it truly felt faster seat-of-the-pants.
 
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Eric Sy GN

Donating Member
Re: Timing advance and boost - DM vs. plugs

Boost control is still funky. The little spikes on the shift are typical (for the stock turbine/wastegate setup), and that's why the wastegate duty cycle is programmed to drop on a shift.
If you can get the boost most consistent, and also maybe bring the boost up faster by increasing the initial boost duty cycle parameter, you should notice a difference.
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

The initial boost duty cycle was set at 95 when I got the truck. I bumped it to 97 for this run. If it's safe to crank up some more, I will. My concern was that it would make that blip worse. You say I should focus on getting the boost more consistent. What should I look at for that?
The only time the KR budged off of 0.0 was shifting into 4th, when it went briefly to .7 degrees.
On a separate, but related, note, I've been very tempted by both a WBO2 and boost controller (looking at AEM). Would the boost controller do the job?
Thanks much for the patience and willingness to work with me.
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Timing advance and boost - DM vs. plugs

I think your boost control looks pretty good for a stock turbo. I dont know if you can access the values needed in the program through the turbto make the boost control better.
 
E.Murray

E.Murray

Donating Member
Re: Timing advance and boost - DM vs. plugs

I did a couple runs last night and my big boost oscillation is back. It's calling for 15 psi and I'm getting it to bounce between 15.5 and 17.2. You can hear it and feel it, too. 2 questions:
1. Could it be due to the fact that a PO (not intheclouds1977) removed the cat and put an aftermarket muffler on it (i.e. not enough backpressure)?
2. Does the VeloSyTy chip have a good boost control routine or would I be better off with either an electronic boost controller or external wastegate? If so, which would get me stable boost?
Unfortunately, DataMaster has been really wonky. Last night, it would only do monitor mode. I tried saving it (should dump the last bit of data), but it only got chunks of the run. Any help is appreciated.
 
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intheclouds1977

New member
Re: Timing advance and boost - DM vs. plugs

Are you still running that extra .5 pounds of boost that you added? If so that could make for some very choppy boost...every time it overboost it'll drop, overboost, drop, etc.

DataMaster - did you buy a license? I think you only get 10 free unlicensed runs.
 
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Eric Sy GN

Donating Member
Re: Timing advance and boost - DM vs. plugs

I can make some adjustments in the chip program to help, but it won't help the wastegate duty cycle going to 100%. The stock turbo can be difficult to stabilize, especially with no cat.
Eric
 
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