kreionic

iTrader: (14)

I thought it was (IPW*RPM)/1200?

nj1266

iTrader: (6)

I used to have one of these gauges and it was off by 1-1.5 psi when I logged the boost. So your spike to 26 is probably ~ 24.5 psi.

codgi

iTrader: (22)

Geez Brad where you been hiding . You need to get a wideband ASAP to really see where you are.

urBan_dK

iTrader: (6)

Hehe Dwayne. It's lonely up here in the north end.

Like I said earlier in the thread, that Zeitronix unit looks tempting.

Wow I suspected the gauge was reading a bit high, that sort of fuels my suspicion.

Will do. Thanks for the advice, all.

cpoevo

iTrader: (1)

the formula you listed is wrong it is (IPW*RPM)/1200
you added an extra 0 on both of your formulas.

coolnick

iTrader: (9)

No I didn't, I pulled that right out of the excel file. It is as I wrote it and that will report back the true DC. You then set the column format to percentage and it makes it a nice non-decimal number. If you leave off the two zeros you don't have to set the column to percent. I am an engineer so I do it the accurate way.


You can have DCs higher than 100% because the ECU is only reporting how long the injector is open. It can stay open way longer than 100% if forced to, but you won't be using that fuel, maybe it could make neat puddles on the back of the intake valve or something. The ECU does not shut off the injector after compression, it lets it do it's thing. It is up to you to monitor your fuel consumption and upgrade injectors when necessary. Maybe they give us a margin of safety, maybe they don't. I ordered injectors.

Titanium

As a NON-EXPERT tuner...

1. Log 2byteload. Loadcalc is undependable and inaccurate, and 2byteload is easy to do.

2. Get a wideband. LC-1 is a cheap, much cheaper than head/valves/pistons/rings/etc.

3. If you get a REALLY odd spike...like 319...this happens. It's just an log error.

4. There are probably 100000000 ways to tune your boost. You can check out tuningbubble and my's blog on it here: https://www.evolutionm.net/forums/sh...d.php?t=266208. That's just one way, it works nicely for me.

5. If I had to guess...seeing your mods are similar to mine...I would shoot that you are running leaner than you think. This happened to me, I figured I was running fairly rich like 10.8 or so, found out I was running 12.6 and higher under boost. If works did anything but richen your fuel map, you are probably running on the lean side.

20psiMR

iTrader: (6)

Not true. The stock maps run very rich. Works tunes do not lean out much either, I know I had one. About all they do is lean out about 1/2 a point from 3500 up.

Also, as far as their boost control. Their BDEL is set that way because they use WGDC to tune boost. Look at your WGDC #2 map, and at the boost spike area, lower those numbers. Also they leave load offset at 80, which is fine. Its a combination of those 3 factors to determine load. Then if load is off, it uses the error correction map. They dont 0 that out at all. I think it works pretty well actually. You can try setting your load offset to 100, but to be honest I didnt have much luck with that. When I raised mine to 100, my boost didnt move. And Im logging with a zeitronix map sensor.

RazorLab

iTrader: (8)

WGDC is always the thing that will set the boost level. Tuning the BDEL , Load offset and error correction tables correctly is what makes sure the boost is always close to what you set it at no matter the load, gear, etc. That is what makes it a closed-loop system.

I've seen alot of cars with the BDEL maxed out at 159 all the way down and every single one has weird boost issues going through the gears and/or varied loads on the street and dyno. If the BDEL and offset is set correctly, no issues.

Everyone has their own 'strategy' to tune boost but I have found the above to be the most consistant and repeatible to me, on alot of evos. This is how the stock tables do it as well.

mrfred

iTrader: (50)

Hey razorlab, I've seen you mention a number of times about the 159.4 in the BDEL table and weird boost response (which I seem to be getting). I had always assumed that the target load (BDEL + load offset) is all that mattered. Are you saying that, for instance, a target load of 159.4 + 80 will give a different boost response than a target load of 149.4 + 90? I was going to PM you on this but thought it might be better to discuss here so other people could benefit.

RazorLab

iTrader: (8)

If the BDEL + Offset = target load at that RPM, the more consistant the boost will be. Whatever it takes to get close to that target load with BDEL + Offset will work.

Evo's with less mods can use the 159 + 80 at 3500/4000 depending on boost level because they will most likely be around the 240 load. Evo's with more boost / more mods or open filters, can easily hit 280-300 and 159 + 80 will be 40 - 60 load shy, the boost will over shoot it wildly, the error correction will kick in much more aggressively and pull it down even lower than 240, then error correction will kick back in to raise it back up to 240, and on and on and on. You can tune that out a little by bringing down the error correction % but then your higher gears might have some problems.

I usually use offset of 100 or so and set BDEL lower to allow some more flexibility. So lets say a evo that hits 250 load at 3500/4000, I will usually use BDEL 150 + offset 100.

Setting the BDEL + offset correctly becomes even more important in higher rpm / longer gears. If you have BDEL maxed out, it might be ok in lower gears with less load in higher rpm because the turbo won't have time or enough load to hold boost more in the higher rpm, but in 4th and 5th, which are longer and hold more load, you could hold higher boost with much more load for longer periods of time. Lets say you are running 20 psi at 6000 rpm in 3rd, but in 4th or 5th at 6000 rpm, you might be holding 22-23 psi at the same rpm. If you BDEL + offset is set correctly for each RPM point, the ecu will be able keep the boost consistant in every gear because it's looking for the right target load, so 20psi at 6k in 3rd, will most likely be 20psi at 6k in 4th/5th as well. You might be hitting 240 load at 6k in 4th, but if you have the BDEL + offset set to target 220 load, then the boost will be brought down to try and hit 220 load in all gears at that RPM. This works in lower gears with less load as well, taking out the MBC effect of less boost in lower gears a bit.

This is all a fine balancing act. Tuning boost for one gear is fairly easy, tuning for all gears, a little more complex. If you live on a dyno in one gear, it's easy. If you tune boost for the real world, more complex, as loads change in gears, on declines, inclines, wind, weather, etc.

If you don't believe closed-loop boost is important, Set your boost purely by the WGDC table in 3rd, max out the BDEL table and set error correction at 0 through the whole table. You can get your boost curve in 3rd tuned perfect. Now go do some 4th and 5th WOT runs and watch your boost go higher and higher without any correction.

These are my findings and experience, YMMV.

Titanium

FEI (for everyone's info)

I use WGDC only with a maxed out BDEL table and my boost is the same in each gear. My boost curve is fairly flat as I like it, and as of yet has had no "funky spikes", in any gear/load/environment.

This doesn't mean the same method works for everyone, but mine is consistant and reliable.

Jeff_Jeske

iTrader: (66)

So much easier to get an EBC and call it a day.

20psiMR

iTrader: (6)

Bryan, mine has seemed pretty consistent gear to gear from naked eye peeks over at the gauge. To be honest though, I havent logged the boost with the zeitrnoix much though, I need to get off my **** and do it. Im going to give messing with the BDEL a try, because I do get that spike to 20, drop to 18, then comes back up to 20 and holds. So it looks like its hitting the error correction table. I just havent had time to tune the car lately

urBan_dK

iTrader: (6)

UPDATE:

Well, I had the chance to do some logging again tonight. I put the intake cover back on and I am now logging 2 byte load.

I didn't get a great run in worth posting but I did a quick 2-3-4 on an onramp which showed peak of ~280 in each of the three gears, which correlates with the spike of 25ish I saw in each gear. This seems like too much load to me.

I turned off boost correction in the positive direction to make sure it wasn't spiking because of this, so it can't be that. Intake cover is back on, so it can't be that.

My BDEL is 160 + 80 offset for a target of 240 load across the board. Frankly, it is doing a good job of stabilizing to that value after the initial spike, but it takes about 1000 RPM to do this.

My theory: WGDC is simply too high in several places, maybe everywhere. Boost error correction must be taking it down to where it needs to be, but it takes a bit of time.

Possible solution: Turn off all boost correction and see what boost levels I get. If they are higher than I am seeing now, then lower the WGDC in applicable areas.

Boost limit fuel cut and my eyes on the gauge should prevent me from overboosting too terribly, but I'm guessing I will see overboost.

Could this be something to try?