Pro-drive EBCS - w or w/o pill?

[Deer Killer]

Looks like the wastegate is opening just slightly too early, and then oscillates.

 

Try feeling with your hands if the spring tension at closed position is the same as actuated. If it's weak here, that would cause this. The pill softens the initial response but it's still slightly open at 10psi causing it to ramp slower.

[LittleBlueGT]

Looks like the wastegate is opening just slightly too early, and then oscillates.

 

Try feeling with your hands if the spring tension at closed position is the same as actuated. If it's weak here, that would cause this. The pill softens the initial response but it's still slightly open at 10psi causing it to ramp slower.

 

Spring pressure seems proper.

I will log when the temps are in the 10s or 20s and I bet we will see minimal rise above 10 or so psi.

 

Right now I am getting boost creep in the real cold.

 

My VF40 would boost creep up to 16.1 psi in the cold. (WGDC 0%)

[Deer Killer]

http://i141.photobucket.com/albums/r69/mickeyd2005/bbbwgdc0.jpg

 

 

That is pretty low.

 

I didn't think I could go that low and still get good response.

 

My response is definitely different. Your seems to go right to your WG spring value and stay there, whereas mine slowly climbs there.

 

What temps?

bbb's definitely lost response there, he's a few psi behind. It would probably help to replace the actuator with a better suited one. The ratio between air pressure to bladder force vs spring pressure is key, I wouldn't really say it's adjustable. I started at 1 psi and started putting turns on the rod. Without getting it tight it's not strong enough to hold the wastegate shut against exhaust pressure. I'm up to about 13 psi now, and the last 2 turns from about 10 psi seem to have made slight gains in response. Or is that carbon coating the valve?

 

I don't have a dip either BTW.

[LittleBlueGT]

Funny, I can't really explain this, but things are good with my WG actuator now.

 

I had a chance to make sure it was all working smoothly, make sure the lines weren't pinched, and were as short as possible.

 

Took out the pill, and voila!

 

http://i248.photobucket.com/albums/gg194/littlebluegt/WGspringonlynopill.jpg

 

 

Now I am still getting creep a bit, but it real cold out right now. No dip though, and if there is no dip now in the cold there will definitely be no dip in the warmer temps.

[Deer Killer]

Still looks broken to me. Check out how much spool I got with a little more adjustment, and it's basically flat, <0.3psi hump.

[LittleBlueGT]

Still looks broken to me. Check out how much spool I got with a little more adjustment, and it's basically flat, <0.3psi hump.

 

I will have to do a log in the summer, and show you the affect that temp plays in boost creep. What CBE do you have?

 

What temp were your logs done at? Mine was done at -32C!

 

I think that the spool will be gained back with the WGDC up there with good proportional td tuning.

 

Either way I will be logging a few different settings come spring, and I will know if there is more spool to be had or not.

 

FWIW the stock spring is enough to hold the WG closed, so I would imagine my WG set to around 10 psi si enough to keep it totally closed with high WGDC values.

[Deer Killer]

I will have to do a log in the summer, and show you the affect that temp plays in boost creep. What CBE do you have?

 

What temp were your logs done at? Mine was done at -32C!

 

I think that the spool will be gained back with the WGDC up there with good proportional td tuning.

 

Either way I will be logging a few different settings come spring, and I will know if there is more spool to be had or not.

 

FWIW the stock spring is enough to hold the WG closed, so I would imagine my WG set to around 10 psi si enough to keep it totally closed with high WGDC values.

 

stock cans, cobb catted DP, perrin mid/y

 

40-50F

 

"stock spring" means nothing, it's all about preload.

 

I think at this point I will make gains with wastegate control, however I don't believe that spool could be gained back with wastegate control no matter what at 10psi or less. A different actuator is needed which has high preload but still opens at 10psi.

[LittleBlueGT]

stock cans, RESTRICTION RIGHT THERE, cobb catted DP, perrin mid/y

 

40-50F BIG DIFFERENCE vs my temps

"stock spring" means nothing, it's all about preload.

 

I think at this point I will make gains with wastegate control, however I don't believe that spool could be gained back with wastegate control no matter what at 10psi or less. A different actuator is needed which has high preload but still opens at 10psi.

 

So you think below 10 psi my wg door is partially open? If so don't forget that a high WGDC will cause a lot less then 10 psi to see the actuator.

 

I really don't think my spool will be affected at all. I think I have enough pre-load to keep the door fully closed despite exhaust pressure.

 

Either way I will adjust and log in the spring, and I will know for sure.

[rc0032]

The stock cans are not that much of a restriction if they were you would gain more than 5whp without then...

[LittleBlueGT]

The stock cans are not that much of a restriction if they were you would gain more than 5whp without then...

 

I refuse to believe that, but you guys can go on thinking what you want.

 

 

 

I actually can't imagine them being much more then a 5whp restriction, but that combined with cold weather can cause creep.

[Deer Killer]

So you think below 10 psi my wg door is partially open? If so don't forget that a high WGDC will cause a lot less then 10 psi to see the actuator.

 

I really don't think my spool will be affected at all. I think I have enough pre-load to keep the door fully closed despite exhaust pressure.

 

Either way I will adjust and log in the spring, and I will know for sure.

The wastegate valve only needs to open a very very small amount to be effective, so it needs to be shut *tight* for full spool.

[Deer Killer]

I refuse to believe that, but you guys can go on thinking what you want.

 

 

 

I actually can't imagine them being much more then a 5whp restriction, but that combined with cold weather can cause creep.

 

No, no, no.

 

 

Less restriction = more creep

More restriction = less creep

 

I had to scale down wastegate duties by more than 10% ( think I ended up at about 16%) to keep the boost down with only the addition of the perrin mid/y pipes. This was _clearly_ a huge restriction.

 

Dyno charts prove nothing, because you need to run different timing with more restriction, which might not be making power that's much different. The only fair comparison is an experienced tuner tuning both setups for MBT.

[rc0032]

I refuse to believe that, but you guys can go on thinking what you want.

 

 

 

I actually can't imagine them being much more then a 5whp restriction, but that combined with cold weather can cause creep.

Jon at TDC dynoed it...it was 5hp. Believe what you want

[LittleBlueGT]

The wastegate valve only needs to open a very very small amount to be effective, so it needs to be shut *tight* for full spool.

 

Agreed.

[LittleBlueGT]

No, no, no.

 

 

Less restriction = more creep

More restriction = less creep

 

I had to scale down wastegate duties by more than 10% ( think I ended up at about 16%) to keep the boost down with only the addition of the perrin mid/y pipes. This was _clearly_ a huge restriction.

 

Dyno charts prove nothing, because you need to run different timing with more restriction, which might not be making power that's much different. The only fair comparison is an experienced tuner tuning both setups for MBT.

 

Exactly, I have less restriction, therefore I have more creep. Yes, yes yes.

 

I wish I knew what you where saying "no" to.

 

I will not use dyno charts to show any loss of spool due to less pre-load on my WG arm. I will log (only logging a couple of items to maximize resolution) manifold pressure vs rpm, plot it, then tighten the WG arm (leaving the same td values, as I will likely be returning the pre-load to previous setting) and repeat. Same day, same road, same everything.

 

The plots should show any difference in spool. What is wrong with that methodology?

[LittleBlueGT]

Jon at TDC dynoed it...it was 5hp. Believe what you want

 

Can you get a joke?

 

I believe 5 whp.

 

Although I do think it might be more on some cars. Was it a VF40 equipped car that got the 5 whp gain, or was it a bigger turbo? If it was a bigger turbo then increasing percentage gains would be realized.

 

Either way, it is still a restriction that will most definitely make at least a small difference in boost creep.

[bugblatterbeast]

there are two sources of HP gains when you add the catback. Depending on the tune one of them may not be that noticable. hence the variable results people see. this is how I see it:

 

the first is just the decrease in pumping losses due to the drop in back pressure. this one is a little misleading as the backpressure at the engine is not always easy to estimate. first you have the back pressure post turbo. this one is easy to measure but it doesnt translate directly to what the engine sees. you need to look at the turbine map and see what pressure ratio you will be running at for the given shaft speed. this too is misleading because pressure ratio will level off as the wastegate opens to regulate boost. for most applications the turbine pressure ratio will be between 2 and 3, tapering down at low flows. once you know the backpressure at the engine, the pumping loss will be roughly the swept volume per unit time multiplied by the backpressure. This term initially increases rapidly with exhaust mass flow then levels off to a more gentle slope.

 

the second source of HP gain with decreased back pressure is the ability to tune more agressively. the engine needs to be retuned to take advantage of this. just slapping on a cat back may not net this gain if the engine was knock free to start with.

[LittleBlueGT]

there are two sources of HP gains when you add the catback. Depending on the tune one of them may not be that noticable. hence the variable results people see. this is how I see it:

 

the first is just the decrease in pumping losses due to the drop in back pressure. this one is a little misleading as the backpressure at the engine is not always easy to estimate. first you have the back pressure post turbo. this one is easy to measure but it doesnt translate directly to what the engine sees. you need to look at the turbine map and see what pressure ratio you will be running at for the given shaft speed. this too is misleading because pressure ratio will level off as the wastegate opens to regulate boost. for most applications the turbine pressure ratio will be between 2 and 3, tapering down at low flows. once you know the backpressure at the engine, the pumping loss will be roughly the swept volume per unit time multiplied by the backpressure. This term initially increases rapidly with exhaust mass flow then levels off to a more gentle slope.

 

the second source of HP gain with decreased back pressure is the ability to tune more agressively. the engine needs to be retuned to take advantage of this. just slapping on a cat back may not net this gain if the engine was knock free to start with.

 

So in other words, the decrease in back-pressure means that, all things being equal, the WG is open just a little more to obtain the same amount of boost, thus decreasing ever so slightly the backpressure on the turbo.

 

That means that one can tune slightly higher boost with a freer exhaust and thus gain more power, even though that number may be very small.

[Deer Killer]

Depends on your definition of outside efficiency range:

 

http://i248.photobucket.com/albums/gg194/littlebluegt/AVO380compmap.jpg

 

 

 

I will say that I was close, but not outside. The above chart was made with an overly large assumption of 2 psi loss at the TMIC. (likely more like 1 psi). FWIW I bet if we had comp charts of a VF40 and VF39 we would see that our typical stage2 looks very close to what I was pushing out of the AVO380. Trust me, I am not advocating it.

 

To keep things on track. Being close to edge of the comp chart had nothing to do with my boost bump. It still happened at less then 15 psi which is well within the efficiency range.

 

Hmm help me with something, maybe my math is all messed up, but I assume it's just easier to track air through the system by mass since we meter by mass. I get 45lbs/min = 340g/s. This seems like a sane number.

 

45lbs/min is the choke point at pressure ratio of 2.25/17.1psi on the unadulterated avo380 compressor map. If this is achievable with VE being what it is, it would be the optimum point. What am I looking at above? This seems far of the mark?? It indicates that the avo380 is a very large turbo since 8000rpm goes through the meat of it? Who's math is wrong? In one case I taper to 17 psi, in another case I hold out a "shitload" of boost to redline.

[Deer Killer]

Ok I'm pretty convinced the compressor map xls that chart is from is very wrong. There's a much easier way to plot where you are in the compressor map, and you can't do what that xls says at all!!!

[LittleBlueGT]

Ok I'm pretty convinced the compressor map xls that chart is from is very wrong. There's a much easier way to plot where you are in the compressor map, and you can't do what that xls says at all!!!

 

That is just the comp map from Garret. We don't know how the AVO cover affects it, and we do know that the 380 hotside is gonna restrict things a fair bit.

 

I plotted mine out on the high side. I used a 1.5 to 2 psi TMIC pressure drop, I think it is less then that.

 

I have also since found that my scaling on the aftermarket MAP (that I had installed) don't agree with the scalings on the OEM MAP. Let me explain. I built a container that could be pressurized. I then but the new MAP's line into the container and measured the voltage (using the ECU). I built my scalers from there. (the ones Zeitronic supplied seemed wrong). I used two separate gauges to verify that the 20 psi was 20 psi. I will summarized the rest:

 

All said and done my MAP scaling agreed with 2 other gauges, but now that I compare it with the OEM MAP I see some differences. Either the OEM reads low or the MAP I installed and scaled read high, or a combination there-of.

 

All said and done the chart that I mapped out may not have been that high of a PR. 1.5 psi lower for the margin of error on the MAP scaling and a bit more for the assumed pressure drop across the IC.

 

 

I would be interested to see you plot out what you think is an accurate chart showing PR on the AVO380.

[Deer Killer]

That is just the comp map from Garret. We don't know how the AVO cover affects it, and we do know that the 380 hotside is gonna restrict things a fair bit.

 

I plotted mine out on the high side. I used a 1.5 to 2 psi TMIC pressure drop, I think it is less then that.

 

I have also since found that my scaling on the aftermarket MAP (that I had installed) don't agree with the scalings on the OEM MAP. Let me explain. I built a container that could be pressurized. I then but the new MAP's line into the container and measured the voltage (using the ECU). I built my scalers from there. (the ones Zeitronic supplied seemed wrong). I used two separate gauges to verify that the 20 psi was 20 psi. I will summarized the rest:

 

All said and done my MAP scaling agreed with 2 other gauges, but now that I compare it with the OEM MAP I see some differences. Either the OEM reads low or the MAP I installed and scaled read high, or a combination there-of.

 

All said and done the chart that I mapped out may not have been that high of a PR. 1.5 psi lower for the margin of error on the MAP scaling and a bit more for the assumed pressure drop across the IC.

 

 

I would be interested to see you plot out what you think is an accurate chart showing PR on the AVO380.

 

I haven't even thought about your/my MAP yet, I'm just saying, the compressor map on that worksheet is scaled incorrectly!!

 

Here's some plots I just did today, ~19.5->17 psi up to about 6700rpm, got to about 300g/s. Probably hard to correlate with the other worksheet, but it's very different, and I'm sure more correct. Your compressor map shows 8000 rpm basically going through nearly the most efficient region, and the turbo really being oversized for this application. It is not.

 

Basically divide grams/sec by 7.55987283 for lbs/min, and then work out your pressure ratio based on estimated loss in the IC, and plot.

[LittleBlueGT]

I have no idea how accurate my chart was, it was the best I could find. I make no claims on it being very accurate.

 

I like your chart, looks fairly close. What pressure drop across the IC are you using?

 

Also what MAF voltage is 300 g/s on your scale?

 

FWIW I hit 300 g/s the other day at 15.5 psi. Yup, 4.77 volts..............of course it was -30!

[Deer Killer]

I have no idea how accurate my chart was, it was the best I could find. I make no claims on it being very accurate.

 

I like your chart, looks fairly close. What pressure drop across the IC are you using?

 

Also what MAF voltage is 300 g/s on your scale?

 

FWIW I hit 300 g/s the other day at 15.5 psi. Yup, 4.77 volts..............of course it was -30!

It changes entirely the meaning of what you are showing. If you're basing boost of this, it's just wrong.

 

4.69->4.73 volts.

 

That chart is with 1 psi fixed a loss. If it's not obvious, if there's actually more loss, you must shift that curve upwards.

[LittleBlueGT]

It changes entirely the meaning of what you are showing. If you're basing boost of this, it's just wrong.

 

I didn't base boost on that. I just plotted it out as best as I could after my own findings.

 

I kept turning things up and watched acceleration times and airflow. If they went up and my power went up, I upped the boost another .5 psi. Just kept going, I was starting to find the boost limits, and was going to play with AFR a bit more when I had the alky incident.