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Posted

I wouldn't mess with it if I were you... you aren't going to notice a thing. When I had my BMW 325 I ran a racing chip in it (a true Dinan ECU chip), a CAI on the front end and high flow exhaust on the back end. What I got from it was just a smidgeon of extra oomph... essentially not a whole lot of anything for the money I put into it. I may have gotten 10-15 extra hp out of it, but who knows what that translated to back at the rear wheels.

Also, I was in a race crew for a couple years (drag racing of a rail) and have had a few hot-rod muscle cars. I can surely state that once you actually ride/drive in a car with some serious horsepower and can feel the rush of it's effect, trying to modify any daily-driver grocery getter is a waste of time and energy. If you want something fast, fun, and powerful... then you should get something fast, fun, and powerful. If you want a well-rounded daily driver, then you're going to want to keep it that way, which means stock.

......although, being one who wants to modify everything I get, if you really want a full throttle boost to your ride, you should plumb in a Sneaky Pete. Have it activate only upon full throttle and there ya go... there's your extra oomph.


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Posted

Does anyone know where this resistor is supposed to go?? The kit i previously bought had wrapped cables preventing me from seeing which wire it was in series with.

And which ohm value should i use? Would 600ohm be better than 400ohm? And is it 400ohm or 400k ohm? I did a little googl'ing and am finding many values people have been using. Some 4.7k ohm, some 50 ohm. I'm not sure which is best.

Posted
Does anyone know where this resistor is supposed to go?? The kit i previously bought had wrapped cables preventing me from seeing which wire it was in series with.

And which ohm value should i use? Would 600ohm be better than 400ohm? And is it 400ohm or 400k ohm? I did a little googl'ing and am finding many values people have been using. Some 4.7k ohm, some 50 ohm. I'm not sure which is best.

I would suggest using a digital voltmeter to measure the voltage drop across the IAT at ambient and add enough resistance to increase the overall, IAT plus resistor, voltage drop by 10%....20% at the most.

Posted
Does anyone know where this resistor is supposed to go?? The kit i previously bought had wrapped cables preventing me from seeing which wire it was in series with.

And which ohm value should i use? Would 600ohm be better than 400ohm? And is it 400ohm or 400k ohm? I did a little googl'ing and am finding many values people have been using. Some 4.7k ohm, some 50 ohm. I'm not sure which is best.

I would suggest using a digital voltmeter to measure the voltage drop across the IAT at ambient and add enough resistance to increase the overall, IAT plus resistor, voltage drop by 10%....20% at the most.

Do you know how i would do this, which wires? Is the way i had the resistor placed in the diagrams correct? I don't know why of the 5 wires i need to do this on.

Posted
The only way you'll be able to tell is on a dyno, with and without the mod.

I agree that "measuring" the change can be performed on a dyno, however, "feeling" the change can be very real. For example, there are a number of "changes" that an experienced race driver can tell his crew chief about throttle response that a Superflow SF-902 or an SF-600 Flowbench CANNOT.

"..experienced race driver..."

I agree...

But how many of those do we have amongst the overall RX ownership populace.

5...??

Posted
The only way you'll be able to tell is on a dyno, with and without the mod.

I agree that "measuring" the change can be performed on a dyno, however, "feeling" the change can be very real. For example, there are a number of "changes" that an experienced race driver can tell his crew chief about throttle response that a Superflow SF-902 or an SF-600 Flowbench CANNOT.

"..experienced race driver..."

I agree...

But how many of those do we have amongst the overall RX ownership populace.

5...??

Sorry, perhaps I used an inappropriate example. My point is that "changes" in throttle response can be "felt" very often by an average driver. There are literally hundreds of posts right here on this site that describes "seat-of-the-pants" (butt dyno) experiences. :D

"..literally hundreds of posts...."

Yes, and I'm willing to bet good money that the clear majority of those "seat-of-the-pants" judgments of improvements were significant biased due to the fact that the "judge" had already spent a not insignificant amount on the modification.

I'd bet that in the majority of those "posts" you could have told the owner that the modification had been done when actually it was not and the owner judgment would have remained the same, POSITIVE.

CAI, Cold Air Intake, K&N, simple 10 cent 1/4 watt resistor in the IAT circuit, etc.

Posted

Wwest i thought you stated you've tested your rx with this resistor mod? How could you have done it if you don't know where the resistor needs to be in the circuit?

Posted
Wwest i thought you stated you've tested your rx with this resistor mod? How could you have done it if you don't know where the resistor needs to be in the circuit?

Hey, I'm 67, 68 in July, you can't expect me to remember every lttle detail, can you..??

Posted

You'll get more performance and 'throttle response' by refining your air intake (i.e., a cold air intake, or CAI) and exhaust flow (meaning a cat-back system)... and you won't be muckin' up the ECU controls either. But for the most part nobody makes any of that performance stuff for the RX, because it's a big cruiser. It is what it is.

Posted
You'll get more performance and 'throttle response' by refining your air intake (i.e., a cold air intake, or CAI) and exhaust flow (meaning a cat-back system)... and you won't be muckin' up the ECU controls either. But for the most part nobody makes any of that performance stuff for the RX, because it's a big cruiser. It is what it is.

Were you to bother to monitor the IAT (Intake Air Temperature) signal with and without the CAI, ANY CAI, you would discover NO difference. And modifying exhaust flow can have a long term adverse effect on the catalytic converter life.

Unless there is a CAI kit out in the marketplace that actively cools the intake air, say using A/C refrigerant with a secondary evaporator.

Posted
The only way you'll be able to tell is on a dyno, with and without the mod.

I agree that "measuring" the change can be performed on a dyno, however, "feeling" the change can be very real. For example, there are a number of "changes" that an experienced race driver can tell his crew chief about throttle response that a Superflow SF-902 or an SF-600 Flowbench CANNOT.

"..experienced race driver..."

I agree...

But how many of those do we have amongst the overall RX ownership populace.

5...??

Sorry, perhaps I used an inappropriate example. My point is that "changes" in throttle response can be "felt" very often by an average driver. There are literally hundreds of posts right here on this site that describes "seat-of-the-pants" (butt dyno) experiences. :D

"..literally hundreds of posts...."

Yes, and I'm willing to bet good money that the clear majority of those "seat-of-the-pants" judgments of improvements were significant biased due to the fact that the "judge" had already spent a not insignificant amount on the modification.

I'd bet that in the majority of those "posts" you could have told the owner that the modification had been done when actually it was not and the owner judgment would have remained the same, POSITIVE.

CAI, Cold Air Intake, K&N, simple 10 cent 1/4 watt resistor in the IAT circuit, etc.

wwest,

Granted, we all want our goodies to perform after spending our money.

You said "The only way you'll be able to tell is on a dyno, with and without the mod."

I said, no, that's NOT the only way.

How many of the modifications that you are proposing have YOU had dyno tested?

NONE. But the intention of my mods have NEVER been to increase HP/torque but to increase FE, and I can check THAT with a pencil and pad.

On how many modifications have you seen any certified dyno test results? Have you ever experienced a change with one of your modificatons WITHOUT a dyno test?

Yes, see above..

Again, my point is simple, I've made modifications to enhance engine performance on a variety of engines,

both race and street,

"both race and street.."

Aha, so you acknowledge that your "butt" meter has been sensitized (calibrated..??) via racing mods....

and was able to "notice" improved (sometimes worse) throttle response and I didn't need a dyno test to experience the change.

During flight training, private pilot, the instructor kept on me to pay more attention to keeping the airplane's center of gravity "correct" in a turn, I simply didn't get "it". Then I started taking my wife along on trips. I soon figured out that my "butt" meter need to be calibrated, sensitized, to the center of gravity NOT being "vertical" for my, her, body.

As far as... "you could have told the owner that the modification had been done when actually it was not and the owner judgment would have remained the same, POSITIVE."

I agree, but a "placebo" has been known to cure a disease. :P

Hmmm...

Are you implying that a "placebo" engine modification might actually result in a performance improvement...?

"I hereby withdraw the question.."

You also said "So your idea should work but the HP gain may be only 10-15% and therefore might not be really noticeable."

In my experience, a 10 to 15% gain in HP would be VERY noticeable.

I agree, but each of us differs in the level of butt sensor sensitivity, and some have even been "trained" to increase that sensitivity.

In fact, I've heard some very experienced engine builders state that experiencing (via your butt dyno) a change as little as a two or three numbers in torque in not unusual. On my Toyota truck at 110 HP, a 10% gain would be 121 HP with a similar gain in torque number. This gain would mean the difference between driving down the freeway at 65 MPH in 4th gear max, or being able to cruise down the freeway at 80 in 5th gear

If you got that level of gain with a 110HP (MAX HP) toyota engine then the WORLD needs to know.

"cruise (as in CRUISE..!!) down the freeway at 80 in 5th gear."

For most of us, " 65 MPH in 4th gear max" would imply WOT, actually using the full 110HP, whereas "CRUISE" would imply partial, or even "light" throttle. If you got that level of gain at light/partial throttle, starting out with a 110 max HP engine, then the world needs to know how you did it. Or was something wrong, VERY wrong, with the engine to begin with..??

Ask me how I know.

I'm asking, but BOTH questions, how do you know and how in hell did you do THAT..??

If the native 110 HP only got you up to a maximum speed of 65 MPH then you had to be producing upwards of 150HP, at only partial throttle yet (Cruise, remember..??), to get to 80 in 5th gear. Assuming even 1/2 way open for CRUISE, partial throttle, then the maximum HP after your mod might have been upwards of 250HP.

That's over a 200% gain, not 10-15%.

At the end of the day, 5 pulls on a dyno is WAY more interesting than anything my "butt dyno" can deliver.

I take back my thought that you have racing experience, 3 spins around Daytona in a GT3 to calibrate/check my butt dyno is WAY more interesting than standing by and watching a dyno run.

A $100 chassis dyno test provides some really interesting data to consider. A $1,000 engine dyno test sheet is even better to review and stare at, especially the numbers!

How did you get from a "$100 chassis dyno" to a $1000 engine dyno test sheet.

Oh, engine vs chassis.

I hereby withdraw the question.

Posted
You'll get more performance and 'throttle response' by refining your air intake (i.e., a cold air intake, or CAI) and exhaust flow (meaning a cat-back system)... and you won't be muckin' up the ECU controls either. But for the most part nobody makes any of that performance stuff for the RX, because it's a big cruiser. It is what it is.

Were you to bother to monitor the IAT (Intake Air Temperature) signal with and without the CAI, ANY CAI, you would discover NO difference. And modifying exhaust flow can have a long term adverse effect on the catalytic converter life.

Unless there is a CAI kit out in the marketplace that actively cools the intake air, say using A/C refrigerant with a secondary evaporator.

:huh: Uh, I think you're taking that a little too literally... I'm not suggesting a person actually chills their intake air with refrigerant (although they make cool-cans for racing)... the idea of using a performance CAI is not only to take the "cooler" air from outside the engine compartment, but more importantly to take in more of it... less restrictive flow. I know the factory airbox has a little bit of ductwork to take in some ambient air, but it's very restrictive. A performance CAI would open up the air flow and reduce restriction, after all, these are naturally aspirated engines and have to 'suck' the air into them for operation. The easier you make that air intake flow, the better it can 'breathe', and the more performance you get out... more than you'll get from a resistor mod.

In regards to exhaust modification, that would be a cat-back application, and wouldn't affect converter life at all... it would just allow the exhaust to flow out a little better.

But all this discussion is moot, for there are no CAI's for the RX3*0 application, and there are not cat-backs... in fact, there isn't even a K&N filter that fits in the factory location. Why? Because these are grocery-getters... glorified Camry's... and seriously, who wants to modify a vehicle for a power gain when the vehicle has a transmission of questionable strength (speaking of the earlier years). :rolleyes:


Posted
You'll get more performance and 'throttle response' by refining your air intake (i.e., a cold air intake, or CAI) and exhaust flow (meaning a cat-back system)... and you won't be muckin' up the ECU controls either. But for the most part nobody makes any of that performance stuff for the RX, because it's a big cruiser. It is what it is.

Were you to bother to monitor the IAT (Intake Air Temperature) signal with and without the CAI, ANY CAI, you would discover NO difference. And modifying exhaust flow can have a long term adverse effect on the catalytic converter life.

Unless there is a CAI kit out in the marketplace that actively cools the intake air, say using A/C refrigerant with a secondary evaporator.

:huh: Uh, I think you're taking that a little too literally... I'm not suggesting a person actually chills their intake air with refrigerant (although they make cool-cans for racing)... the idea of using a performance CAI is not only to take the "cooler" air from outside the engine compartment, but more importantly to take in more of it... less restrictive flow.

Less restrictive when, during the times, RARE times, the throttle is wide open and therefore NOT the MAJOR restriction to intake airflow...???

I know the factory airbox has a little bit of ductwork to take in some ambient air, but it's very restrictive. A performance CAI would open up the air flow and reduce restriction, after all, these are naturally aspirated engines and have to 'suck' the air into them for operation.

The easier you make that air intake flow, the better it can 'breathe', and the more performance you get out... more than you'll get from a resistor mod.

Were the IAT resistor modification designed to actually work, it would/could enrich the mixture even with partial throttle, not just with/at WOT.

In regards to exhaust modification, that would be a cat-back application, and wouldn't affect converter life at all... it would just allow the exhaust to flow out a little better.

Normal exhaust restrictions downstream of the converter would aid in pre-heating the catalyst to operational temperature and keeping it there. Removing exhaust restrictions might even result in a catalyst mal-function fault code.

But all this discussion is moot, for there are no CAI's for the RX3*0 application, and there are not cat-backs... in fact, there isn't even a K&N filter that fits in the factory location. Why? Because these are grocery-getters... glorified Camry's... and seriously, who wants to modify a vehicle for a power gain when the vehicle has a transmission of questionable strength (speaking of the earlier years). :rolleyes:

Google for:

rdx cai cpe wwest

For the "who wants to modify.."

Apparently lots of 'boy-racers" are attracted to the "turbo" in RDX.

Idiots all.

Posted
(heavy sigh)... really, it's pretty much a moot point when it comes to this vehicle.

I don't know, I modified an 03' Ford Explorer with a full internal rework and a Kenny Bell Supercharger. Cranked out 600+ HP and dropped 1/4 miles in the 13's. I had alot of fun in that thing! Do you know how many Mustangs, Evo's, and such I shocked? It's a blast. The way I see it, if you line up an Evo and an Explorer and the Evo wins, everyone says yeah, the Evo is fast. But if the Explorer wins, that's to talk about for weeks!! No one saw that coming!

I paid 5 bucks to line up to an LS2 GTO once.

click me to see

and me

Posted
(heavy sigh)... really, it's pretty much a moot point when it comes to this vehicle.

I don't know, I modified an 03' Ford Explorer with a full internal rework and a Kenny Bell Supercharger. Cranked out 600+ HP and dropped 1/4 miles in the 13's. I had alot of fun in that thing! Do you know how many Mustangs, Evo's, and such I shocked? It's a blast. The way I see it, if you line up an Evo and an Explorer and the Evo wins, everyone says yeah, the Evo is fast. But if the Explorer wins, that's to talk about for weeks!! No one saw that coming!

I paid 5 bucks to line up to an LS2 GTO once.

click me to see

Nice vid smooth :cheers: I love the nights at the strip B)

Posted

LOL... that's cool... really cool to see a full size Explorer walk a GTO... leaves people tilting their head saying, 'what just happened there?'. Although, this is kind of apples to oranges with the previous discussion, for that revolved around soldering some resistor into the control system to give a 'power gain'. What you've got is a full rework (a very, very nice rework, by the way) with the addition of a supercharger. Hey, anything can be modified, the question is what's the cost:benefit ratio. Back when I was racing at Renegade Raceway there was a guy out there with a FULLY modified late '70's Ford F250 4x4 on big mudders... the thing would actually smoke all four wheels off the line and pull low 12's... the sickest thing you ever saw (he was running a blown big-block). Another guy ran an alcohol burning Meyers Manx bug conversion... he was actually getting the thing to leap-frog into the air by dropping the clutch (he only did that about 3 times before something snapped in the drivetrain and he rolled it away). People make some bizarre and impressive mods.

The point is, you can modify anything and get real power out of it, but if you're starting with a non-performance vehicle, then you've got to do it right, like you did: a full rework with addition of a supercharger. It takes a lot to turn a pig into a pony. When people talk about little single-change mods and want to get noticable power out of it, then that's only going to happen when you modify something that starts with a little more performance DNA... and that ain't the naturally aspriated, relatively fuel efficient, built for smooth/quiet operation 1MZ-FE. One could do the basics of opening up the intake and exhaust to get it to breathe a little better, but that results in marginal benefits at most.

One last thing to note is that drivetrains are matched (for the most part). If you did a serious engine mod to a non-performance vehicle, you'll lose the tranny (since it's not built for the additional power). If you modify the engine and tranny, then you'll probably find your driveline is the weak spot... modify the driveline and you may find out the suspension tie in points now can't handle the power (like the suspension mount tear-out issues people have with modified 3-series BMW's (non-M)). One can see the trend here. All I'm saying is the RX is a vehicle that is better off just driven and properly maintenanced rather than modified.

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