BOOST GAUGE Installed and VIDEO

[CRD]

Guys I didn't know how low was the 1st and 2nd gear boost, I NEED TO DO SOMETHING ABOUT IT.

I "SEMI" installed my Electric Boost Gauge to test the boost on the CX-7

WELL

Average 1st and 2nd gear is: 6-8 psi
Average 3rd and 4th gear is: 14-17psi (17psi are spikes)

I'm going to tested later on the highway.

on the video I took off holding the brake at 2,000rpms that's why you hear the chirp of the tires.

I WANT 15psi ALL THE TIME

CLICK HERE FOR THE VIDEO http://media.putfile.com/CX-7-Boost-gauge

[CRD]

Another Video

After hitting 3rd the boost raises to 15psi but it drops very fast to 11-12psi.

http://media.putfile.com/Mazda-CX-7-Boost-Gauge

[MAZOOM]

Is your CX-7 all stock? Cool vids, but I wonder why the boosty is limited in first and second like the MS3? Is your CX-7 FWD or AWD?

[HunterSwift]

or boost leak

[CRD]

Is your CX-7 all stock? Cool vids, but I wonder why the boosty is limited in first and second like the MS3? Is your CX-7 FWD or AWD?

My CX-7 is FWD, it doesn't have leaks and is STOCK, on the second video I opened the Air intake box to hear the turbo sound , but it drop me the psi more quickly, I guess is because the Airbox ramair wasn't working. don't know.

But every time i tested the cx-7 1st and 2nd shift was always 7-8psi, and sometimes 12psi as a spike. on third gear it jumps to 15psi and 17psi spikes.

[MAZOOM]

If you have the stock BPV, you're leaking boosty.

[CRD]

If you have the stock BPV, you're leaking boosty.
OH THAT LEAK , well yes I have that leak but still sucks. I'm hopping C-PE finish the PLUG and PLAY piggy to buy it and I will buy a intake and bov on the same day hehe.

[rexercx7]

OH THAT LEAK , well yes I have that leak but still sucks. I'm hopping C-PE finish the PLUG and PLAY piggy to buy it and I will buy a intake and bov on the same day hehe.

Do you have the latest re-flashes for the PCM and TCM in your CX-7? Those will improve the way that your vehicle accelerates across the board, from 1st gear through 6th gear, whatever...tremendous changes. As for Mazda's PCM programming, I can't make any apologies for it. It is what it is, and we've all got to live with it presently.

Their conservative thinking in terms of allowed boost in 1st and 2nd gears is apparently their way of protecting the driveline, ie the transmission, the axles, the CV joints, and eliminating torque steer to a great extent. The CX-7 is a family vehicle, an SUV, and I doubt that any manufacturer would give such a car 15 pounds of boost in 1st and 2nd gears.

By the way, "an intake and bov" and the CP-E Standback unit will be excellent additions to your CX-7, but I'd also suggest replacing the stock TMIC as it's woefully inadequate for massive amounts of air being fed through it. Also, you might think about an exhaust system on the vehicle too, at least the cat-back type, if you're going to suddenly be ramming 20 pounds of boost through the motor. It's not going to be a happy motor if it's constipated by the stock system, and your performance figures won't be what they could be if the motor had an easier way of getting exhaust out.

Welcome to the Forum, and it's good to see your resourcefulness in pinpointing the weak boost PCM programming in the lower gears on the CX-7. ..I'm sure we all appreciate knowing approximately what it actually is.

Kindest regards,
rexercx7:cool:

[CRD]

Do you have the latest re-flashes for the PCM and TCM in your CX-7? Those will improve the way that your vehicle accelerates across the board, from 1st gear through 6th gear, whatever...tremendous changes. As for Mazda's PCM programming, I can't make any apologies for it. It is what it is, and we've all got to live with it presently.

Their conservative thinking in terms of allowed boost in 1st and 2nd gears is apparently their way of protecting the driveline, ie the transmission, the axles, the CV joints, and eliminating torque steer to a great extent. The CX-7 is a family vehicle, an SUV, and I doubt that any manufacturer would give such a car 15 pounds of boost in 1st and 2nd gears.

By the way, "an intake and bov" and the CP-E Standback unit will be excellent additions to your CX-7, but I'd also suggest replacing the stock TMIC as it's woefully inadequate for massive amounts of air being fed through it. Also, you might think about an exhaust system on the vehicle too, at least the cat-back type, if you're going to suddenly be ramming 20 pounds of boost through the motor. It's not going to be a happy motor if it's constipated by the stock system, and your performance figures won't be what they could be if the motor had an easier way of getting exhaust out.

Welcome to the Forum, and it's good to see your resourcefulness in pinpointing the weak boost PCM programming in the lower gears on the CX-7. ..I'm sure we all appreciate knowing approximately what it actually is.

Kindest regards,
rexercx7:cool:


Actually I bough my CX-7 on February of this year and i haven't take it to the dealer for anything yet. I'm gonna try to take it this week for the PCM re-flash and see

[rexercx7]

Get the TCM re-flashed also(Transmission Control Module)...two distinct re-flashes that radically adjust the transmission, the drive-by-wife throttle, boost parameters, and turbo lag (hesitation below 2000 RPM). Tell your service adviser that the transmission is "shuddering" at highway speeds, and in 4th, 5th, and 6th gear lock-up modes it's weak, ie doesn't want to kick down fast, that it responds like a dog. Tell the adviser that your throttle feels dead below 2500 RPM's, that there's significant turbo lag, and you don't feel safe accelerating away from a stop many times.

That will get his attention, trust me. You can also take in the TSB for the transmission from my post on it, here:

(we've made it a Sticky in the Issues and Problems Forum)

http://www.mcx7.com/showthread.php?t=1402

Just print out that post, take it into your service dept with you, and that will insure that your PCM gets handled also.

Kindest regards,
rexercx7:cool:

[shadow1]

There is nothing wrong with your CX7, CRD. Mazda tuned the CX7 to limit boost in 1st and 2nd gear. My CX7 pulls harder in 3rd gear as well which is consistent with full boost. Mazda did it as a safety feature (no wheel spin), to improve fuel economy around town (more boost=more gas burned), and I suspect to save wear on the tranny. Aftermarket boost control will eliminate this but I would not do it without logging wideband O2 sensor readings to make sure the stock fuel system can handle the extra boost (especially in 1st and 2nd gears). I bet you cannot increase 1st and 2nd gear boost without ECU tuning. Also, the CX7 turbo by design cannot hold full boost to redline. It is a small turbo that spools fast but runs out of steam fast too. The MS3 and MS6 turbos have a larger hotside which is laggier but will hold boost to higher RPMs. Hope that clarifies things.

[SassiMac]

Under no circumstances use bleed valves or electronic boost controllers on your CX7. This is a sure fire way to have a constant CEL issues.

[shadow1]

Are you speaking from experience? If so, please share... I currently use a Hallman manual boost controller on my Evo. Holds boost very consistently. Set it and forget it. The Hallman is one of the best MBC out there and is not a bleeder type controller. Are you sure the OEM boost control in the CX7 is not a bleeder type? The OEM boost control on my Evo definitely uses a boost control solenoid that bleeds off boost back into the intake.

[rexercx7]

Sassi, you're getting into Shadow1's area of expertise here!;) He's had a lot of experience, apparently, with modifying turbo cars, to wit his evil Evo, and he hasn't blown it up yet AFAIK. It's my uninformed opinion that the CP-E Standback system, coming out soon, will in fact change boost parameters with our CX-7's, and I also assume that CP-E wouldn't put something out to market that's going to damage our motors. At least I certainly hope so!:confused: But what do I know? I'm still doing a lot of reading on turbo systems, how they work, how boost is controlled etc and my knowledge is limited.

Shadow1 makes a good point about our system's boost control, and how it works. When you start messing about with boost, you've got to have enhanced fuel delivery as well, as more boost=more fuel+ spark has got to be adequate to boot. Who knows how much fuel our stock system is capable of delivering? I certainly have no idea about it, but if it's not up to the task a leaned-out motor condition is a recipe for disaster. Especially at higher RPM's! I have experience tuning a 426-Stage III wedge motor in a Plymouth drag race car, and I know that the more power you're putting out, and the higher the RPM's go, you've got to richen up the fuel mixture with bigger jets in the carburetor, or a different carburetor setup altogether.

As far as sufficient spark in our motor goes, the Mazda DISI system uses one electronic coil per cylinder, mounted directly over the plug, so I think we're good there. But fuel delivery concerns me, and I'd like to know more about the stock system before I installed any kind of boost controller on my CX-7.

Kindest regards,
rexercx7:cool:

[SassiMac]

I never said anything about damaging motors.....

From direct experience, bleed valves and EBC's caused me hell on my previous car. The ECU was so good, it was able to understand what was occurring. Bleed valves set the limp mode which needed the ECU to be reset every day. The EBC in combination with a fuel cut defender allowed for higher boosts, but constantly set off the CEL due to O2 errors. Even interceptors ( similar to Standback ) caused permanent CEL's. This was a fact of life with the generation of car I previously owned. Interceptors had to be retuned every 6 months as the ECU was capable of learning 'over the top' of the setting. The principles of interceptors are very simple. The name gives it away really. all they do is intercept a sensor signal, alter it, and feed it back to the ECU ( or Mazda PCM ).

Now I will certainly concede that this is not always the case. I am just commenting on my experience. In fact, all people that used EBC's in the club I ran swapped them out in favour of ECU flashes.

In the long run the best option is a retune. It is only a matter of time before this becomes an option. The limitations will be the capacity of the turbo system to maintain boost, and the fuel system to deliver fuel.

FYI, my business sold ECU tunes. I spent three years experimenting with various systems including water injection, intercooling, EBC, bleed valves and custom ECU tunes I modified. My personal equipment list includes Flash tuning tools, software, ECU data loggers, accelerometer and wideband O2 monitors. I have data logs that show the effect of water injection, bigger intercoolers and more powerful ECU tunes.

[rexercx7]

No, I'm the one who mentioned it...also FYI lean fuel/air ratios are the No. 1 cause of burned valves in race cars, and that any boost hike in the Mazda power cycle would need more fuel delivery, pretty simply put. It's not known if the Mazda fuel delivery system is enough for any radical boost change, but what do I know? I'm simply stating the obvious with no actual knowledge of the flow capacity of the fuel pump and primer system, or the ability of the PCM to maintain proper A/F ratios at any boost setting. For all I know it's stout and could do whatever is necessary, or it could be the other way too...

Interesting about your business. Doing that, should Mazda detect it, voids the factory warranty here, FYI. Guaranteed. That's the one area that Mazda will not allow tampering with, or so my Service Manager told me when I asked about it long ago, back in February of this year. My intake system Mods are fine with Mazda, and my Service Department, in fact they compliment me on them when my CX-7 is in for service. We even have had conversations about the parts department carrying the CP-E CAI system, and the ETS 3" TMIC for the CX-7 and the 3.5" TMIC for the Speed 3 and Speed 6, but just conversations so far.

My home dealer is a very liberal-thinking place, and I'm very much used to the treatment I get there. I hope I never have to require service at another point, because who knows what outlooks I'd run into somewhere else.

Kindest regards,
rexercx7:cool:

[shadow1]

BTW most dealer technicians can not tell if a car's ECU has been reflashed other than the vehicle being faster.

[SassiMac]

BTW most dealer technicians can not tell if a car's ECU has been reflashed other than the vehicle being faster.

If the modified file is correctly written, that is usually true. The only way to determine if the file is different is to use software to analyze or compare the two files. This software is typically EXTREMELY expensive...

Most modern diag equipment used by factories can "snapshot" a running engine's parameters. They can snapshot boost readings, which would be a dead giveaway. The GM Tech2 is capable of doing this.

Rexercx7: Yes, highspeed leanout will destroy engines.

[Superstretch18]

MS3 & MS6 guys are getting 300+ whp on the same fuel delivery system before they start to cut out. I would think we have a lot of headroom before we run out of fuel. Not to say that a wideband is not a good idea anyway...

[mattbracing]

I have a 2000 audi S4 and in 1st and 2end 3rd you dont get full boot becuase the timing does not allow for in and iam guessing that the CX-7s and the same

[rexercx7]

I am making a simple educated guess that virtually ANY PCM/ECM/ECU system limits somewhat the available boost and fuel delivery in 1st and 2nd gears, just because it makes sense. Can you imagine an AMG Series IV motor like the 604HP/738Ft Lbs of torque twin-turbo V-12 that's in the Mercedes-Benz AMG S65 sedan putting out full boost in 1st and 2nd gears?:eek: The car would be out of control, and the traction control system would be hard-pressed/possibly overwhelmed in dealing with that much power and torque; in fact I think that scenario would be impossible, just wouldn't happen.

It's possible that our power train could handle more than the 6-7 pounds of boost that it's dealing us in 1st and 2nd gears at this time, but 15 is totally out of the question, with the Aisin 6-speed transmission being the real performance hang-up of our cars, not the motor.

Kindest regards,
rexercx7:cool:

[shadow1]

Depends on the vehicle. The Subaru STIs and Mitsu Evos get full boost in all gears. Of course, a manual tranny is better able to deal with the torque. And no traction issues with AWD.

[shadow1]

I'm going to moderate myself and Rexercx7 to stay on topic!!

[Superstretch18]

I'm going to moderate myself and Rexercx7 to stay on topic!!
LOL, you two crack me up.

Back on topic; honestly, timing is not the issue; the ecu is regulating the boost for traction control in lower gears. The MS3 guys (I refer to them alot; I know) are getting around this with a manual boost controller and fuel cut bypass. With that, they are getting up to 15 psi in first & second.

I know, I know, that's a stick, so that doesn't address the tranny issue. Still not convinced one way or another that is truly the weakest link or not. I posted in another thread this same info, but the Aisin that we are using is the same model number that is used in the heavier and more powerful Volvo SUV. That model comes stock with 311 hp and about the same torque, so we should have some head room (assuming that it uses the same gearing, torque converter and valve body). There are tons of drag cars out there running 10's with 4 speed automatics, so auto < manual is not necessarily true in every case...

[shadow1]

Agreed, it is a traction issue. 200+ lb-ft of torque coming on strong with a quick spooling turbo could easily spin the tires especially in wet weather. Mazda chose to ease the torque in gradually by limiting boost in 1st and 2nd gears. Total safety issue. But the traction control system could accomplish the safety issue without limiting fun when the roads are dry....

[Superstretch18]

Zoom-zoom... ;)