wwest

I find that I like the RDX and the CX-7 pretty much equally so both are at the moment on my possible next purchase list. Both begin with what is potentially a highly fuel efficient I4 engine. I find that more attractive than even one of the basically more safe R/AWD vehicles with a GAS HOG V6 (HH or RX400h included) or V8.

My analysis indicates that the RDX's SH-AWD system is most likely the best of the BEST insofar as beginning the design with a sideways mounted engine and transaxle. On the flip side I sincerely dislike the RDX's dash/instrument panel CLUTTER.

On the other hand the AWD option and the DFI aspects of the CX-7 engine makes that vehicle equally, or moreso, attractive to me.

Were I to end up purchasing the CX-7 I would immediately pull the cylinder head and have it milled for a 12:1 compression ratio while at the same time "wiring" the turbo bypass fully open in order to achieve significantly improved FE. I would also look into the possibility of removing one front drive halfshaft and "locking" the rear drive into full coupling, fulltime coupling.

At my age I have little interest in owning an SUV that can be touted for 0-60 "times". My '01 911/996 C4 satisfies that "craving" quite well.

There also is a third party device for using a FWD as a 4-down TOAD that would allow the front halfshaft to be manually engaged and/or disengaged "at will".

Third on my list, not as "upscale" IMMHO, is the MMH, Mercury Mariner Hybrid, where I could also disconnect "at will" the front drive and electrically lock-in the rear drive.

My ideal, of course, would be an RDX with the MMH hybrid drive system due to the RDX's SH-AWD system. Of for matter even a CX-7 with the MMH hybrid drive.

Any educated guesses as to the resulting MPG improvement and/or HP loss with the CX-7 technique..??

Other modifications...

A: Disable ABS until/unless the stability system activates indicating the vehicle is not following the desired "track".

B: Use the ABS/Trac solenoid valves to disable front braking altogether until/unless ABS "attempts" (see "A" above) to activate for alleviating rear braking capability or in the alternative if brake fluid pressure exceeds a specific, moderately HIGH, level.

C: Improve FE and SAFETY via disabling the A/C compressor entirely except for actual cooling or initial cool-down.

D: Improve FE via revising the factory HVAC system such that the reheat/remix "mode" involves remixing with cabin atmosphere rather than actual reheating of a portion, or all, of the previously cooled airflow.

E: Improve A/C efficiency via installing a valve to BLOCK the flow of engine coolant, HOT engine coolant, to the heater core when the A/C compressor operation is enabled.

F: provide a means to continuously HEAT the interior surface of the windshield via HVAC system HEATED airflow during cool or cold weather operation.

G: Modify the defrost/defog/demist function such that upon ANY activation of this mode the system provides fully high blower speed and FULLY HEATED airflow. The driver would subsequently de allowed to moderate the heating level and/or blower speed even though remaining in defrost/defog/demist mode.

But ANYTIME the 3D mode is initially activated the system would immediately go to full heat and blower speed.

H: Convert the headlighting system to HID and all of the street/parking/turn/marker/tail/stop lights to LED bulbs.

I: install or modify the DRL system to power/illuminate all of the LED bulbs and use a 3 watt luxeon LED for forward, high beam "like" DRLs.

J: Replace the high mount brake light with a LED multi-color light bar that will indicate to the rear following driver my current "mode" of driving, constant speed, accelerating, RAPIDLY accelerating, coasting down, braking, HARD braking, braking with ABS activation, turn direction.

wwest

A: Disable ABS until/unless the stability system activates indicating the vehicle is not following the desired "track". For off roading, maybe. But really, why disable?

There are proven instances wherein ABS activation, un-necessary activation, can result in an accident, say from elongated stopping distances caused by ABS.

The sole purpose, function, of ABS is to prevent complete lock-up of the wheels, especially the front/stearing wheels, thereby allowing you to maintain directional control of the vehicle in conditions wherein lock-up might otherwise occur. If you have VSC, PSM, etc, and it isn't active, then the vehicle is following the desired path.

B: Use the ABS/Trac solenoid valves to disable front braking altogether until/unless ABS "attempts" (see "A" above) to activate for alleviating rear braking capability or in the alternative if brake fluid pressure exceeds a specific, moderately HIGH, level.
Most braking power is via the front, not sure why you want to disable it. 4000 lbs is a lot to ask to stop, even mildly.

I'm suggesting that only "mild" braking be allocated exclusively to the rear.

If you have ever towed a trailer with the ability to apply the trailer brakes independent of the towing vehicle brakes on a questionable roadbed surface you will understand immediately. For myself I have often used slight and/or judious use of the rear implemented E-brake to hold the "line" driving down a slippery incline.

If only the rear brakes are enabled and ABS attempts to active then you're clearly asking more of the rear brakes than road conditions permit.

C: Improve FE and SAFETY via disabling the A/C compressor entirely except for actual cooling or initial cool-down. There is still a load because the belt, not sure how many mpg can be saved by keeping it diabled. I am sure if you mess with the circuitry, you can disable it somehow.

Many newer vehicles are now useing a variable displacement A/C compressor to accomplish the FE improvement. And my '01 RX300 has a C-best option which I had the dealer set. I added a switch in series with the A/C compressor clutch on my '01 911 C4.

D: Improve FE via revising the factory HVAC system such that the reheat/remix "mode" involves remixing with cabin atmosphere rather than actual reheating of a portion, or all, of the previously cooled airflow.Personally, I so not know how that will help

This would allow the A/C compressor to operate a much lower percentage of the time. It is a HUGE waste of energy to first cool the system airflow to as close to 32F as is possible and then reheat it to very near your temperature setpoint only for purposes of dehumidifcation.

E: Improve A/C efficiency via installing a valve to BLOCK the flow of engine coolant, HOT engine coolant, to the heater core when the A/C compressor operation is enabled. It is a good idea in theory, but is the heater core that close to the air vents to change their temperature? If so, perhaps better insulation would help. A electronically controlled box with a thermostat type device would also need to fit in there somewhere, too.

Before the beancounters prevailed most vehicles included a vacuum or electrically operated valve to do this. The (190F) heater core is located, typically, inside the A/C/heater plenum and therefore cannot be easily insulated from the system airflow and certainly not from the radiant effects. In the case of systems remaining with the reheat/remix functionality enabled (see "D" above) this would improve the system's cooling capability dramatically while also improving FE not insignificantly.

F: provide a means to continuously HEAT the interior surface of the windshield via HVAC system HEATED airflow during cool or cold weather operation. Messing with the defroster circuit and disabling the A/C part is an option. Was found on Protege's.

Good.

G: Modify the defrost/defog/demist function such that upon ANY activation of this mode the system provides fully high blower speed and FULLY HEATED airflow. The driver would subsequently de allowed to moderate the heating level and/or blower speed even though remaining in defrost/defog/demist mode. I think the above is the same.


No, the above, "F", involves keeping the interior windshield surface warmed continously, regardless of HVAC system mode, cooling (face, upper body system airflow, "outflow"), heating (footwell, mixed system airflow, "outflow"). Even with the system otherwise "off", if the OAT is below ~47F.

But ANYTIME the 3D mode is initially activated the system would immediately go to full heat and blower speed.

H: Convert the headlighting system to HID and all of the street/parking/turn/marker/tail/stop lights to LED bulbs.Yay, I got HIDs already! LED's are not as bright, consider HIDs for the fogs, too, I think. Apexcone.com is a good start.

Inexpensive, brighter, longer life (in the extreme), and QUICKER, LED bulbs for street/parking/turn/marker/tail/stop light bulbs are available in the marketplace today...V-LEDs on Ebay.

In most states fog lights are legal for use... alone... only during daylight hours, 1/2 hour before sunrise until 1/2 hour after sunset. Headlights MUST be on for all other times. Fog lights should NEVER be used in conjunction with headlights as these are a safety hazard in that mode, shortening your night distance vision.

HID fog lights...Sheer idiocy.. I think...!!

I: install or modify the DRL system to power/illuminate all of the LED bulbs and use a 3 watt luxeon LED for forward, high beam "like" DRLs. A little drilling and wiring, that is possible.

J: Replace the high mount brake light with a LED multi-color light bar that will indicate to the rear following driver my current "mode" of driving, constant speed, accelerating, RAPIDLY accelerating, coasting down, braking, HARD braking, braking with ABS activation, turn direction. Like in motorcycles, eh? I love that idea. Not sure where to get it from. Possibly buy and LED kit on ebay and retrofit?[/QUOTE]


I currently have an engineer working on this latter project.

MMike1981

dude.