Boost spiking/High

[Spykexx]

No lifting because it's an automatic. I wouldn't say I'm losing 2psi through shifting either because it doesn't drop at the shift, it is just constantly bobbling between 20 - 22.5.

MASSIVE derp moment LOL! That thought didn't even cross my mind :headbonk:

That's good feedback. I'm a turbo noob and not really sure what to expect. I'm very familiar with superchargers and would expect that to be much smoother or I would be looking for belt slip, maybe a tensioner issue. With the turbo, I didn't know it should be smoother. For all I knew it might be a normal process of the ECU trying to manage the boost level and the 2.5psi was considered very good.

Your waste gate should be keeping it at the pressure demanded. It shouldn't be so choppy (At least this is my understanding of it. Mine is MUCH smoother in keeping straight boost)

I'm not sure I understand that correctly. Are you saying the spring will just help hold the boost during shifts and without the spring it will be much like the stock BPV just not leak and should be holding at a steady 22.5psi in my case? If so, then in my case, it seems the no spring option would be best since I'm not losing boost during shift.

It'll help during both, but WITH the spring it's even firmer is my understanding. But yes without the spring it should hold 22.5~ better, but since you don't have to worry about shifting nearly as much. But would make a difference when letting off the throttle and then getting back on.

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[TEXAS HEAT]

Can you guys help me with the use of the spring? I purchased the DV+ but haven't installed it. Is the use of the spring optional? What is the benefit or negative from using it? To be honest, I haven't installed it yet because I haven't seen an issue. Mine holds at about 22.5 psi pretty steady.

If you're an auto car, ditch the spring as there is no benefit to having the spring pressure reseat the valve. This may also be the culprit in the boost spikes for those having the issue with auto cars.

The spring really only benefits the manual trans cars by quickening the valve reseat time during shifts which improves post shift boost recovery.

 

[TEXAS HEAT]

Logically I'd think the opposite should happen with a binding piston spring shouldn't it? Would keep it from returning to sealed, not the other way around. Also not seeing any reason for the DV to rotate as it is a simple up/down movement. Some require free movement to spin, but I don't see why the DV+ would.

I was purely trying to deal with the DV+ to try and the get spike to calm down as it's spiking over 30 PSI.

@jbailer I believe you are probably correct on the wastegate. Mine is still stock/untouched. Could be a loose vacuum connection somewhere, or not operating correctly. What strikes me odd is that the DTC is supposed to trip at 4psi over demand.

The spring sits on top of the plunger with it's function being to reseat the plunger quickly. However, if it's bound up, it would take more pressure to crack the plunger, so the symptoms of boost spikes seems to be inline with what you found to be the culprit.

 

[Spykexx]

The spring sits on top of the plunger with it's function being to reseat the plunger quickly. However, if it's bound up, it would take more pressure to crack the plunger, so the symptoms of boost spikes seems to be inline with what you found to be the culprit.

I could see that if it was bound at full length. But if stuck depressed it'd leak like hell. But I think it's safe to say the DV+ is the cause of the spike.

I'm more worried about the car over-boosting 6 PSI consistently. I'd be willing to bet swapping springs on the DV+ will at least minimize the spikes. The over boost not so much. Seems far too high for stock.

 

[TEXAS HEAT]

I could see that if it was bound at full length. But if stuck depressed it'd leak like hell. But I think it's safe to say the DV+ is the cause of the spike.

I'm more worried about the car over-boosting 6 PSI consistently. I'd be willing to bet swapping springs on the DV+ will at least minimize the spikes. The over boost not so much. Seems far too high for stock.

Right after I installed mine, I saw boost spikes up to 27.5. I then had my tune adjusted and have not had a problem since. It holds pressure when it's supposed to, lifts and returns without incident.

 

[Spykexx]

Shhhh some of us peasants are still stock lol

 

[arghx7]

How can you compare the "smoothness of the boost" between two different engines with two different tunes, and without confirming the measurements have the exact same sample rate?

The only thing that's not smooth here is the bigass boost spike.

That's laughable at best. If this was the case there would be no aftermarket. As stated by [MENTION=25032]ForYourOwnGood[/MENTION], the intercooler is a great example. It's absolute garbage.

We don't have to go into a big intercooler debate, but there's nothing wrong with it for a stock car. It makes the advertised power under SAE engine dyno conditions.

http://standards.sae.org/cpfd2_15mustman/ and http://www.sae.org/certifiedpower/data/

It performs as advertised. It's going to heatsoak, like any other heat exchanger. But the stock tune makes the power despite the fact that charge temps heat up as rpm increases. This is a reflection of a good system design, rather than only making the power on a cold day. SAE standard conditions are 25C inlet temperature with post intercooler manifold air temperatures set according to vehicle conditions.

Why didn't they include a DV catch can?

I think you are referring to the crankcase ventilation. Crankcase ventilation is heavily regulated by the government including OBD requirements.

Why did they leave a ridiculous amount of power on the table, but will be utilizing it in 2018 refresh with overboost?

I don't know what the 2018 will be rated at, but OEMs leave power on the table all the time with boosted engines, so they have something to sell in model year updates or overboost features. That doesn't mean it's a bad product or doesn't perform as advertised. And the engine has to go through durability torture tests at extreme conditions.

Why did they use a DV that leaks like crazy even brand new?

It makes the power it says it does. It's SAE certified. I wasn't in the room when they decided the design, but if it makes peak power for hundreds of hours in a torture test it can't be that bad. I'm betting it's a feature, not a bug.

You seem to think that the DV+ replaces the entire DV. It's just an upgraded piston for the stock DV. Tear your DV apart and look at the piston. It's a joke. Flimsy little plastic piston with holes in it.

You replaced the piston and your car overboosts. Hmm.

 

[ForYourOwnGood]

It makes the power it says it does. It's SAE certified. I wasn't in the room when they decided the design, but if it makes peak power for hundreds of hours in a torture test it can't be that bad. I'm betting it's a feature, not a bug.

This is BS and you know it. The stock ecoboost doesn't make peak power for two full gears let alone hundreds of hours. The intercooler is heat soaked in the first few seconds and the timing is pulled. Thats why so many publications trashed it when it came out, they would get slower and slower the more you ran them.

 

[arghx7]

This is BS and you know it. The stock ecoboost doesn't make peak power for two full gears let alone hundreds of hours. The intercooler is heat soaked in the first few seconds and the timing is pulled. Thats why so many publications trashed it when it came out, they would get slower and slower the more you ran them.

SAE certified power has nothing to do with how much power it makes in any gear. It's how much power it makes on an engine dyno following a standardized method. The air to the airbox comes from a big air conditioning system, the air to the intercooler and the performance of the intercooler is controlled by a lab cooling system.

Manufacturers don't advertise dynojet numbers tested in Billy Bob's Performance Shop. They advertise vehicle acceleration performance and engine performance. For SAE certified power, there is a standard method and a witness who signs off on it.

The Mustang Ecoboost performs as advertised. Now maybe Ford doesn't get into the technical specifics of what SAE certified power really is, but the engine performs as advertised, or the SAE witness test has been falsified.

Remember the 3.5L Ecoboost torture tests that were all over Youtube? Those are, in part, peak power durability tests run for many many hours. They just advertised and marketed what they normally do.

 

[Spykexx]

This is BS and you know it. The stock ecoboost doesn't make peak power for two full gears let alone hundreds of hours. The intercooler is heat soaked in the first few seconds and the timing is pulled. Thats why so many publications trashed it when it came out, they would get slower and slower the more you ran them.

Com'on man. Real world doesn't count. Only lab testing. Who cares that some people are seeing double the thermal timing threshold? Or that people are pulling timing hard on low temp days. 120-130 IAT2's stock on a 65 degree day is garbage while cruising.

The intercooler may have been designed this way...but it certainly wasn't because it does a good job. I stopped reading at "it's just fine for a stock car".

 

[arghx7]

Com'on man. Real world doesn't count. Only lab testing.

It sounds absurd, but yeah. It doesn't matter for 95+% of people. If you didn't have a tool to record spark timing, you wouldn't even know. The boost goes up and the timing goes down when it's hot, due to torque and airflow model based controls. When it's cold out, the spark advances and the boost goes down. Power varies a little bit, with heat soak and ambient temperatures but not drastically.

Cooking the thing in a hot shop, running pass after pass with a fan and stagnant air on a chassis dyno isn't an accurate reflection of how it runs in the vehicle. The air temps can even go down when you boost it, as the fresh air pushes out the hot stagnant air.

When you mod the car a lot of this goes out the window, but in stock form there's nothing wrong with the intercooler or the blowoff valve. It meets the requirements of the vast majority of drivers; it performs as advertised.

The intercooler may have been designed this way...but it certainly wasn't because it does a good job. I stopped reading at "it's just fine for a stock car".

Most people don't care. They just don't. They hit the gas, it pushes them in their seat, and they know it makes x more advertised horsepower than their neighbor's 4 cylinder Camaro, which was also certified on an engine dyno with all the same constraints.

 

[Spykexx]

It sounds absurd, but yeah. It doesn't matter for 95+% of people. If you didn't have a tool to record spark timing, you wouldn't even know. The boost goes up and the timing goes down when it's hot, due to torque and airflow model based controls. When it's cold out, the spark advances and the boost goes down. Power varies a little bit, with heat soak and ambient temperatures but not drastically.

I don't see ignorance as being an acceptable answer. Does it happen? Sure. Still not right.

Cooking the thing in a hot shop, running pass after pass with a fan and stagnant air on a chassis dyno isn't an accurate reflection of how it runs in the vehicle. The air temps can even go down when you boost it, as the fresh air pushes out the hot stagnant air.

Agreed. But 50-60 degrees over ambient ON THE ROAD when it was still climbing when I finshed my log? I don't even wanna see how this thing performs on a track.

When you mod the car a lot of this goes out the window, but in stock form there's nothing wrong with the intercooler or the blowoff valve. It meets the requirements of the vast majority of drivers; it performs as advertised.

Most people don't care. They just don't. They hit the gas, it pushes them in their seat, and they know it makes x more advertised horsepower than their neighbor's 4 cylinder Camaro, which was also certified on an engine dyno with all the same constraints.

And this is where we will end in agreeing to disagree. I don't see either side swaying. No use in arguing a never ending battle.

 

[arghx7]

We'll agree to disagree, but I want to leave one last thing to consider.

This is compiled from SAE certification reports. 15-20 degrees C (59-68F) over ambient is pretty common across manufacturers. Dotted line is the supply air temperature, each line represents the manifold air temperatures. It doesn't have the 2.3 Ecoboost on there, but I suspect it is similar.

So when the engine is rated at a particular horsepower using the SAE witness test method, the manifold air temperature usually reflects this heat soak.

 

[ForYourOwnGood]

SAE certified power has nothing to do with how much power it makes in any gear. It's how much power it makes on an engine dyno following a standardized method. The air to the airbox comes from a big air conditioning system, the air to the intercooler and the performance of the intercooler is controlled by a lab cooling system.

Manufacturers don't advertise dynojet numbers tested in Billy Bob's Performance Shop. They advertise vehicle acceleration performance and engine performance. For SAE certified power, there is a standard method and a witness who signs off on it.

The Mustang Ecoboost performs as advertised. Now maybe Ford doesn't get into the technical specifics of what SAE certified power really is, but the engine performs as advertised, or the SAE witness test has been falsified.

Remember the 3.5L Ecoboost torture tests that were all over Youtube? Those are, in part, peak power durability tests run for many many hours. They just advertised and marketed what they normally do.

You've derailed this thread enough with your stuff that doesn't matter but I'll just encourage you to remember how many times Ford has been caught lying about advertised power. So of course you can trust them, they engineered it.

 

[Spykexx]

So I finally got around to returning back to stock...And who would have guessed...same exact issue. Looks almost identical, although the boost is MUCH more choppy stock. DV+ had a nice smooth line since it didn't have any issues holding boost. It's staying between 22-24 psi, but spiking up to 29 psi still. So much for how "awesome and certified" the stock BPV is. I guess the question is...Is it safe to be spiking 7 psi? I doubt an increase of 32% boost is a good thing for the life of the engine.

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