possibly boost leak.....

[Silver Ecstasy]

Thanks! thats a little bit more reassuring!

My wastegate is open too much I think. under WOT, my WG duty cycle goes up to 100% Why could it be doing this?

It's supposed to. It does that to build boost first, then slowly, the percentage closes as it leaks excess boost.

 

[stealthyspeeder]

It's supposed to. It does that to build boost first, then slowly, the percentage closes as it leaks excess boost.

Is WG duty cycle not mean % of time the WG is open during cycle ?

so

0 = WG open 0% of time during cycle = WG shut = no exhaust gases being diverted around the turbo = more compression = more boost

100 = WG open 100% of time during cycle = WG fully open = maximum ammount of exhaust gases being diverted around the turbo = less compression = less boost

Is that logic chain incorrect?

If its right, what would cause my WG to open so prematurely and before boost threshold has been reached?

 

[Darth Vader]

A number of things could cause this:

A leaky/sticking wastegate, abnormally high load values (datalog this), leaky WG control solenoid, High KR values...

Just off the top of my head....

 

[Bravnik]

Thanks! thats a little bit more reassuring!

My wastegate is open too much I think. under WOT, my WG duty cycle goes up to 100% Why could it be doing this?

If your WGDC is at 100% than it has closed the Wastegate in the turbo to allow maximum boost. In other words, 100% WGDC = Closed WG = MORE boost. 0% WGDC = Open WG = No Boost. Your WGDC should hit 100% upon mashing the pedal (most DH's will not see this as it is quick) and then tapper off to maintain your boost targets. The higher the WGDC the harder it's trying to meet your targets and the lower the number it does not have to work hard to maintain.

So in your case (or anyones) where the WGDC is 100% then you have a leak somewhere as the WG is staying closed because you are not meeting your boost target.

In the OP's case, the WGDC is perfect and he has no issue as far as I can see. Yes he is losing boost but it is past where the WG can control it (which is weird as I believe the WGDC is based off Mani Pressure). His WGDC is like 38% which implies he is bleeding boost to meet his target PSI which is fine as it implies he is making more boost than needed and has to bleed boost to maintain his target PSI. Maybe a bad map on the AP? Have you tried another MAP? Usually there is a higher WGDC Map associated with the map you're running. If not, then try another MAP and see if it improves. I honestly don't see any issue with your logs. Your boost targets in the map you are running might simply be too low. I would seriously try another MAP and see if that helps. Also I thought the AP had issues with the CPE SRI?

Here is a copy of my most recent log. You can see that the WGDC goes high then tappers off and maintains. This is along the lines of what you should see.

http://spreadsheets.google.com/pub?key=t6-dtnBwAL7gFdCfGvGZorQ&output=html

 

[stealthyspeeder]

If your WGDC is at 100% than it has closed the Wastegate in the turbo to allow maximum boost. In other words, 100% WGDC = Closed WG = MORE boost. 0% WGDC = Open WG = No Boost. Your WGDC should hit 100% upon mashing the pedal (most DH's will not see this as it is quick) and then tapper off to maintain your boost targets. The higher the WGDC the harder it's trying to meet your targets and the lower the number it does not have to work hard to maintain.

So in your case (or anyones) where the WGDC is 100% then you have a leak somewhere as the WG is staying closed because you are not meeting your boost target.

In the OP's case, the WGDC is perfect and he has no issue as far as I can see. Yes he is losing boost but it is past where the WG can control it (which is weird as I believe the WGDC is based off Mani Pressure). His WGDC is like 38% which implies he is bleeding boost to meet his target PSI which is fine as it implies he is making more boost than needed and has to bleed boost to maintain his target PSI. Maybe a bad map on the AP? Have you tried another MAP? Usually there is a higher WGDC Map associated with the map you're running. If not, then try another MAP and see if it improves. I honestly don't see any issue with your logs. Your boost targets in the map you are running might simply be too low. I would seriously try another MAP and see if that helps. Also I thought the AP had issues with the CPE SRI?

Here is a copy of my most recent log. You can see that the WGDC goes high then tappers off and maintains. This is along the lines of what you should see.

http://spreadsheets.google.com/pub?key=t6-dtnBwAL7gFdCfGvGZorQ&output=html

Are you sure this is correct about the WGDC? When my car is at idle or even up until 2000 rpm, the WGDC is 0. From what your saying, this would mean that the Wastegate was full open at that rev range? that does not make sense to me. When I accelerate hard, it jumps from 0 to 100%. It would appear to me that this would be the transition fom full shut to fully open. This would also explain why I have a constant inability to generate boost.

I had a proffesional boost leak test done and I am not loosing any boost from the intake side, compressed or uncompressed. This means that I am losing boost due to the Wastegate being open.

The dask hawk readings show WGDC @ 0 on idle and up to 2000, then 100% after (when i should be starting to generate boost)
The actuator was checked and it is physically working, however it has crossed my mind that when it closes in theory according to the ECU, it is not actually fully closed (this would be the only possible explanation fo boost loss if bravniks WGDC % meanings are correct)

However, I think the WGDC is the other way round, this would point to a faulty MAP (manifold absolute pressure) senser? Does the mazdaspeed3 engine have one of these or does it just generate a value using the MAF (Mass airflow sensor)??

What is the voltage of the MAP normally (ignition on but engine off), the diagnostics guy found it to be 2 volts which he thought was a little strange as anything he has seen was at 5 volts.

 

[fuzzybmx]

good morning everyone! its been a while since i have been on here. Well i got the turbo inlet pipe. and my problem seems to be better other than that fact i cant get the t-bolt clamp tight on the TIP. I would tighten it down then my car would see good boost. then I would check it and it would seem lose again. so i am going to go buy another lock-nut for it and maybe some lock tight stuff. but im pretty sure its the TIP causing my problem. I should be able to work on it tonight and i will post tomorrow.

 

[Bravnik]

Are you sure this is correct about the WGDC? When my car is at idle or even up until 2000 rpm, the WGDC is 0. From what your saying, this would mean that the Wastegate was full open at that rev range? that does not make sense to me. When I accelerate hard, it jumps from 0 to 100%. It would appear to me that this would be the transition fom full shut to fully open. This would also explain why I have a constant inability to generate boost.

I had a proffesional boost leak test done and I am not loosing any boost from the intake side, compressed or uncompressed. This means that I am losing boost due to the Wastegate being open.

The dask hawk readings show WGDC @ 0 on idle and up to 2000, then 100% after (when i should be starting to generate boost)
The actuator was checked and it is physically working, however it has crossed my mind that when it closes in theory according to the ECU, it is not actually fully closed (this would be the only possible explanation fo boost loss if bravniks WGDC % meanings are correct)

However, I think the WGDC is the other way round, this would point to a faulty MAP (manifold absolute pressure) senser? Does the mazdaspeed3 engine have one of these or does it just generate a value using the MAF (Mass airflow sensor)??

What is the voltage of the MAP normally (ignition on but engine off), the diagnostics guy found it to be 2 volts which he thought was a little strange as anything he has seen was at 5 volts.

Think about what you are saying, you don't want your WG closed at idle as that means your car is building boost. When you are idle the WGDC should be at 0% as it is letting your WG stay open as you are not trying to build boost. The reason it does not close to 2k is because the ECU does not have a boost target set below 2k. You would blow your motor if you hit max boost at 500PRM. When you go WOT your WGDC jumps to 100% because it slams shut the WG in the turbo so you can build boost. Then it slowly bleeds off boost (by opening the WG slowly) in order to maintain your boost targets that are set in your ECU. I know it's easy to get it confused and I use too as well until a use here explained it to me. Then it all made sense.

As far as the MAP goes 5 Volts is what you should get I believe and what it should be I think (but not positive). However, I don't think a bad MAP would do anything bad. Take the example of using a MAP clamp. The point of using one is to Clamp your MAP at a certain Volt max which in turn would fool your ECU into seeing a MAX number of Boost and not the actual boost. This will allow you to run more boost than you normally would without getting boost cut from the ECU.

I know when I use to run a MAP clamp I clamped mine at like 3.5v as that was about 15PSI (Well I set it to 15PSI on the DH which equaled about 3.5v for the MAP). The higher the V the higher the Boost the MAP will report to the ECU and anything above 17.8PSI you will get cut. So in your case, 2v would only allow your ECU to see about 8PSI if that. So the danger here is overboosting which would pop your motor. Ether way if you only see 2v and the norm is 5v I would replace the MAP just to ensure you don't overboost and blow your motor. However, it might be that the MAP Volts go up and down based on your boost levels that it sees. So maybe 2v at idle is normal for no boost and as you start to build that Volt number increases, but again I very well could be wrong as I'm just thinking out loud on this.