2007 CX-7 FWD - Need help tuning

Discussion of tuning specific to CX-7 vehicles
mituc
VersaTuner guru
Posts: 1323
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: 2007 CX-7 FWD - Need help tuning

Post by mituc »

Oh man... how much did they charge you for that tune?

The WGDC is 0 from line 24 (about 3600rpm) and up to the end of the pull (6000rpm). At lines 30-33 you have a boost oscillation which without having any point of reference for WGDC it's impossible to tell where is it coming from: VVT, leak, exhaust, or most probably fueling, or something else. Those oscillations are visible even on your dyno chart, I told you about them in a post above.

Also, by looking and the load values that's pretty low for a MS3/MS6 turbo, that ignoring the huge load in the mid range (lines 16-30 the load is above 1.9 which is not wise when not having upgraded fuel pump internals). The Fuel Rail Pressure is nowhere in your logs, at this point you're running blind, I would not go WOT if I were you until:
1. fix the current boost control issue;
2. add fuel pump internals;
3. get a proper tune.

With this tune, hardware upgrades (turbo, intake, exhaust), hardware deficiencies (fuel pump), and hardware issues (boost control) you are on a very straight and fast path to ZZB. Stop going WOT, baby the car and get all these issues addressed as soon as possible.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
marauder
Posts: 11
Joined: March 13th, 2014, 8:50 am

Re: 2007 CX-7 FWD - Need help tuning

Post by marauder »

Paid $600 for the tune because of the dyno time. Yeah, I respect what you're saying. Please understand I'm not trying to make this thing a hotrod at all. I am just trying to drive it to work. Like I said above, I added these parts to save money over OEM and maybe get a little more efficiency. I am not looking to make an suv fast by any means. I'm just trying to make the parts I put on this thing work so I can get to and from work without a major headache in my ideal rpm range.

So, I'm trying to understand my issue on this EBCS... I suspect this is why my last turbo went bad. I can feel the oscillation under higher loads and yes that's visible on the dyno as well. We spent 3 hours on this thing with about 20 pulls total - I know what it is not doing, opening the wastegate when it should be, which causes the boost spike. The question is why? How should the EBCS work on this engine? If I understand correctly it's a bleeder valve that allows air past to keep the wastegate closed or closes to force the wastegate open. This valve is controlled by the BCS DC Base table in order to meet boost targets, correct?

What kind of psi should I see coming from the turbo wastegate actuator to the EBCS? I tried capping the line from the turbo to the EBCS to see if the wastegate would open at all and nothing changes. I've also tried hooking it up to the turbo inlet pipe to bypass the solenoid. From what I can tell the solenoid appears to be working, but if I take that out of the equation entirely, nothing changes. I just don't know where else to look to diagnose. What else could be preventing pressure (or vacuum?) at the EBCS? With my limited turbo knowledge I'm having a hard time understanding this EBCS and how it should work.
mituc
VersaTuner guru
Posts: 1323
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: 2007 CX-7 FWD - Need help tuning

Post by mituc »

It's not about making your car fast, but about making it reliable and powerful enough for the parts you added. At this point your car is far from being so, it can blow any time you go WOT esoecially if you do that at low rpm (2500-3200), and I'm not exagerating at all.

I think the pressure you should see coming from the EBCS port to the wastegate should be around 1-1.1bar. At 1.1-1.2bar the wastegate should be fully open IIRC, and at about 0.6-0.7bar it should start opening already.

I've seen this behavior to one of my friends and I ended up sending him my factory EBCS. Another friend of mine had a similar problem with a stuck wastegate (stuck closed) and he ended up getting one from turbosmart. So if you re-used the wastegate you should check that as well, make sure the arm is moving freely, eventually try to open it with compressed air and see if it moves at 0.8bar and if it's fully open at like, say,1.2bar. Also check the hoses coming to and from the EBCS.

P.S.: with $600 you would have gotten 2 e-tunes and 2 weeks of top-up.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
marauder
Posts: 11
Joined: March 13th, 2014, 8:50 am

Re: 2007 CX-7 FWD - Need help tuning

Post by marauder »

I know, lessons learned, I'm gaining quite a bit of knowledge out of this though which is nice so I look at it as at least I learned something from the investment. I will likely end up having another tune done by the e-tuners once the problem is resolved if I end up keeping this thing. For now though, I'm looking to resolve the issues and sell this thing so I can buy something easier on gas. I drive 600 miles a week easy, and average 18mpg on the high end with 93 octane. Honestly I miss having a manual transmission too.

The turbo is brand new "reworked" K04 from a MS6 - nothing was reused from the stock unit as they did not use my core. I am able to move the wastegate actuator arm, I will measure exact pressure tonight when I get home. I did not have a way to test that when I was checking everything out this weekend. Everything leads me to believe the tube between the compressor and the wastegate actuator is either clogged or leaking. It is still connected so I know that it didn't pop off. I will have to keep chippin' away at it.

I know it sounds like I'm all over the place with this, but I'm learning a lot as I go to better understand and explain the issues. Every day is a school day.

Thanks again for your help! I'll keep you posted. :beertoast
mituc
VersaTuner guru
Posts: 1323
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: 2007 CX-7 FWD - Need help tuning

Post by mituc »

There are ways of getting better gas mileage from a CX7 as well. A little work on the AFRs and timing in closed loop at low load can make wonders, if you will be able to keep the car in that range and keep it off boost when it's not necessary you should be able to get 22-24mpg easy. People with Mazdaspeed6 were getting 26-29. Of wait, yours it's the FWD CX7, even if its like 200 pounds heavier you should be able to get almost as much mileage. I didn't try this myself, I only know it's possible even if it's a bit hard on the factory catalytic converters. Once you fix your issues and get it properly tuned ask your e-tuner about this.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
marauder
Posts: 11
Joined: March 13th, 2014, 8:50 am

Re: 2007 CX-7 FWD - Need help tuning

Post by marauder »

Tested the wastegate actuator last night and confirmed my suspicion with the help of a handy bicycle pump. Zero pressure building, and a nice breeze blowing out on the compressor side of the wastegate actuator at the fitting. The reason I did not feel this when checking the lines initially is due to it being on the top side of the line and impossible to see from above or underneath the car. The line was cut when the people that installed my turbo were hooking my turbo inlet pipe up, they had rotated the clamp so that the bolt cut the line running from the compressor to the actuator. Protege Garage uses a nice silicone hose and it essentially split at the end where they hit it making a flap, which was impossible to feel until pressure was applied and air passed through opening it up as if no line were connected.

So all this frustration and chasing my tail to find out the most simple thing was causing my problems. I clipped off the bad section of tube, put it back on and secured it with another ziptie. Problem solved. :facepalm

Hopefully someone else can learn from my ignorance. Now I just need to log and adjust my wgdc and check fuel pressure and see how things are going. Right now wastegate is staying open and boost is slower to build so the system is working properly now just a few adjustments and I'll be happy.

You VT guys have been so helpful. :beertoast
marauder
Posts: 11
Joined: March 13th, 2014, 8:50 am

Re: 2007 CX-7 FWD - Need help tuning

Post by marauder »

Drove around yesterday for a while with WGDC set at 95% - feels more sluggish than before. I have a lot of studying to do...

WOT Pull - 4th Gear log attached.
Attachments
Custom Log #1.csv
(11.7 KiB) Downloaded 609 times
mituc
VersaTuner guru
Posts: 1323
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: 2007 CX-7 FWD - Need help tuning

Post by mituc »

Well, I guess you're very far from hitting the load targets... Above like 4300rpm the WGDC is 0 or close to 0, meaning that you're boosting at spring rate which shows in the MAP values as well (7-8PSI of boost).
At this point I'd start with an OTS map or at least use the BCS DC tables from an OTS map. Or contact an e-tuner.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Post Reply