Has anyone thought about, or maybe even tried, "hard-wiring" the turbo wastegates fully open to see what FE would be like without BOOST..??

I've only driven, test driven, the RDX once but it seemed to me that the turboes came online too quickly. Probably not quick enough for some but insofar as FE is concerned it seems to me as if it might be better if BOOST was only provided if I truly needed (requested??) HP/Torque, LOTS of HP/Torque.

To me, for me, it seems like it might be better to only have BOOST if I RAPIDLY depress the gas pedal or depress it beyond, say, 2/3's.

 

assuming the rdx is "fly by wire" you aren't necessarily even fully in control. if you want to feel what the rdx is like without boost, pull a vacuum hose. you will learn real quick what a stock FI car is like with no boost. i believe i saw the CR was 8.8:1 ... if thats true ... the rdx is will pretty much be just a large slug.

 

Not suggesting the RDX be without boost, just asking, wondering, how much the FE would improve if the boost could be under some level of control by the driver. The experiment would ascertain just how much the modification might return on the investment.

The idea was/is to delay the onset of boost unless/until there is some sort of definitive action by the driver that HARD acceleration is deired vs slow/easy/ligh acceleration that could likely be accomplished by the ICE acting alone.

So driving an RDX absent all boost for a period of time would give us a good starting number for FE improvement and that would tell us if it's worth going forward at all.

 

Don't blame it on the SH-AWD system..!!

The problem is an 8.5:1 compression ratio in order to "accomodate" the turbo boost once the turboes actually spool up. The problem is that until those turboes spool up, FULLY spool up, you are running, accelerating, with an EXTREMELY inefficient, low (poor) compression I4 engine.

The RDX needs a form of VVT-i, Variable Valve Timing w/intelligence on the intake cam side. Modify the intake cam timing on the fly, dynamically, so it moves in and out of Atkinson cycle mode under control of actual boost pressure. Only move, gradually, into Atkinson cycle mode as the boost level rises higher and higher.

Atkinson cycle would allow a portion of the A/F mixture in the cylinder to be forced back out into the intake manifold thereby resulting in lowering the "effective" compression ratio as boost level increases.

See:

https://acurazine.com/forums/showthread.php?t=2264More...

 

as anyone tried to drive an rdx WITHOUT BOOOST? WHAT?

 

give it a shot. pull a vacuum hose. won't hurt anything.

 

now why in the world would i wana do that

how bout this, u give it a shot lol

 

you could get a boost controller.

 

alright, will do. still won't be easy to describe through. u gotta try it out for yourself.

 

and again, lol i have absolutely no desire and/or reason to wana do this. if i wanted to feel a slow moving truck id go drive a dump truck.

 

If you are looking for decent fuel economy, a mini-suv, or a full suv shouldn't even be under consideration. I mean seriously people. If FE is something you're worried about, go buy a mid-sized sedan or smaller...better yet, go get a hybrid.

 

I really dont care about FE as long as the car is fun too drive. Hybrid cars are FE but are they fun to drive???

 

Sorry, I cannot resist a Hybrid slam, here. People need to do the math on hybrids. Calculate the break even time between the added cost of the drivetrain against the lower fuel bills. The best break even at 4 years, most Toyotas are in the 10-12 year range. Stupid.

If you really care about fuel economy, wait till the fall and buy a new-tech diesel from any number of manufacturers. Do the math on your trade-in/depreciation vs. fuel cost. A couple of thousand bucks buys a lot of gas.

Do the math on the fuel economy issue in general, people. Unless you are in the 20k miles/year club the numbers do not justify much of any expense to do anything about it (like trade in your car for a better fuel economy, etc). Drive it like you stole it and have a grin on your face.

 

Get a Tornado Fuel-Saver: Tornado Fuel-Saver

SAVE FUEL!!! INCREASE POWER!!!

HELP, I CAN'T STOP SHOUTING!!!

 

Buy and install 2, double your savings! With 3 in-line, you'll have to stop and siphon off all the fuel going back into your tank!!!

 

FE isn't the only reason for buying a TRUE hybrid, one designed for FE, NOT HP. I'd like my grandkids, and their kids to come, to be able to breath....

 

If you include the environmental impact of the manufacture and disposal of the battery systems, they are not as green as a Suburban. Don't be fooled by the hype.

 

The RDX is NEVER in boost as long as you're cruising within highway speeds. Your point is moot unless you're heavy on the pedal. I agree with you that the boost is provided too quickly or at least too much, but that short boost window wouldn't make noticeable impact on average per-tank fuel efficiency (although, I know you're extremely picky with your details; yes, FE is lost due to the use of gas leading to the increase in torque).

Remember, the K23 is pulling a 2 ton vehicle that isn't very aerodynamic and rides on a 5-speed auto. A 6 speed tuned properly would probably bump the MPG a couple notches while increasing acceleration and smoothing out shifts. Besides, the motor runs a bit rich...a proper tune would also bump the MPG a couple notches in itself (being it's Honda/Acura's first production automobile turbo I find it easy to understand why they tuned it so conservatively).