larryt1026

Hello,

So I just traded in my TSX for a used '12 RDX. Really psyched about the turbo and the extra space! However, I have a question about the turbo meter. It seems like during regular driving around town, regular acceleration, normal driving the turbo meter never really gets past the first quarter of the meter, and sometimes the needle bounces. Is that normal?

Also, it seems like I need a really heavy foot to get the meter to the top of the +. What do you guys think? Normal or no. Thanks!

Mr Marco

Normal stuff for the RDX. The boost gauge is not specifically calibrated to reflect a true boost number. If you want a real reflection of boost you could try an OBD plug–in device that will give you other real time engine information.

mrgold35

Sound normal to me. Lower the boost guage, the better your mpgs.

You have a variable valve turbo in the RDX. This helps with the power delivery at lower RPMS (like having twin turbo engine). When the rpms and pressure increases, the valve opens for full power. That is why you see the turbo PSI guage jump up and down.

larryt1026

I see. Thank for the input guys! This is my first turbo car so I am trying to learn everything I can about it. So I am getting boost even though the needle is barely moving? I just went out a couple minutes ago to run an errand about 5 miles away locally and the needle didn't move that often (even during some accelerations) and when it did move it never went past a quarter of the way. I guess if they run the turbo too much the MPG will be terrible? Thanks guys! Excited about joining the RD community

ray1031

I'm getting used to it as well. I drove 1000 miss last week in one day and at times while doing 100 mph the neede would just sit in the middle while cruising at tha speed in Mexicos toll highways.

Mr Marco

If you get an intake, like the CP-e, you'll understand the process and won't even look at the boost gauge anymore. With an intake you can hear the BOV (blow off valve) dumping excess pressurized air back into the intake. When you hear the different degrees of hiss it speaks to you. No hiss at all under full throttle and you know you are at full boost. I love it, but my wife hates it. I've been trying to sell it so I can trade off the RDX, but I kinda don't want to give it up.

DanRDX

Talk her into letting you keep it, I did with my wife especially if you have no car payments. The car is too much fun to give up

Mr Marco

I know, it is a great ride. But I have car fever and only room for 2 cars at the house. Want Scion FR-S too. Never wanted the TL! I was going to buy an S-2000, but we got a 4GTL loaner...she drove it...and poof, suddenly we owned a TL.

larryt1026

That's odd...mine lays dormant (at the bottom) more often than not. And when it does go up it won't go up past quarter way and it usually drops right back down after gear shifts. Maybe the meter/turbo is messed up..hope not! Wary of buying used vehicles.

larryt1026

I can hear the hissing now (from the turbo?). I bet it would sound awesome with an intake!

mrgold35

It does not take much to max out the turbo boost gauge. Even when you floor the gas pedal and let the 5AT shift to 1st, 2nd & 3rd gear close to redline, the PSI gauge never goes past 1/4?

In normal driving around town, I'm usually about 1/4 to 1/2 on the turbo-O-meter depending on how I accelerate to keep up with traffic. I can even feel when the turbo variable valve opens up and power/PSI increases during straight line acceleration when I push it a little harder from a stop. I'm close or near zero during straight line cruising (5,000-5,500ft in ABQ).

I also have Hondata and it provides a few more PSI earlier and longer for more power across the rpm band (about 26hp/33TQ extra). I don’t think it is available for 2012 yet?

http://www.hondata.com/reflash_rdx.html

larryt1026

That's why I worry because it seems tough for my turbo-O-meter to hit the max. I only get there (max out the guage) if I apply a heavy foot on the gas pedal. In normal driving around town, sometimes the needle wouldn't even move on the turbo-O-meter and it usually never gets past 1/4 of the way when it does move

XIS

Get the Hondata re-flash and you will notice the boost gauge moving much much more, at lower RPMs and it also increases max boost.

jcl78

Not sure why people are telling you that behavior of the boost gauge is normal. If the boost gauge is bouncing, it could be an indication of a boost leak or boost creep.

Boost is all dependent on exhaust flow. If you floor it off the line, you have very little exhaust flow through the turbo, so the needle will reflect this as little or no boost. Let's say you plant your foot, you will see the gauge rise as exhaust flow now is spooling the turbo. This is followed by a nice woosh of power as the turbo produces max boost for that RPM. The RDX pushes 13 - 14 PSI of boost until 4500 Rpms, then tapers off to only 8 PSI at 6500. The needle should reflect 14 PSI as the top of the gauge ( + ). Then you can see it taper off to the lower top end of the gauge (8 PSI)

I would honestly get it checked out for a boost leak.

Mr Marco

OP, This guy doesn't own an RDX and probably has never even driven one^.

Trust us, your car is OK.

larryt1026

Thanks guys! Really appreciate the feedback and now feel at ease with the RDX. Plus I had it checked out by an indy mechanic today and everything checks out and he sees no exhaust leaks. I will prob do the reflash when my warranty runs out..especially since I know my dealership will get on my case.

Have all of you reflashed already? Pros and cons?

Thanks again all!

jcl78

Good deal Larry, glad you got it checked out, always the best thing to do. Just FYI, the gauge should never "flutter" if you are steady on the gas.

Enjoy!

dcmodels

My 2009 RDX does not take much (driver) effort to cause full boost. There is a 100 foot high hill from a stop light, about 1/2 mile long, up to the turn-off into my Condo complex. Unless I take care _not_ to apply more than about 1/8 throttle, the boost will be about 1/2. Any more than 1/8 throttle and the 2-3 shift will product full boost at about 30mph.

Full throttle from a stop, will only produce full boost after the RPMs hit around 2.5K rpm in first gear, after the exhaust flow is fast enough to spool up the turbo. That is the infamous turbo-lag.

On level ground, around town, when crusing about 30-35mph in 4th gear, increasing throttle to about 1/2 will cause an increase to around 3/4 boost on the gauge. My RDX will almost always pull high(er) turbo boost, before the trans will decide to downshift. That is normal, and is done to improve gas milage. An engine is always more efficient at high load at low RPMs. It is less efficient at low load (low throttle) at high RPMs.

It can be very difficult to diagnose from a post whether or not you actually have a problem. What you are calling difficult to produce high boost, I might call low effort.

Anyway, for me, unless I am very careful with the throttle, both from a stop and when accelerating at 30-40 to pass, 1/4 to 1/2 boost pressure is pretty normal (for me). And it does not take much more throttle to product full boost.

Also, at 60mph on the freeway, using 1/2 or more throttle to pass, will easily always produce full boost. I never see the boost needle 'flutter', it is always steady and somewhat 'slow' to move. I am assuming it is purposely damped.

Your car does not sound 'normal' to me, but again, I am not sure. If there is a problem, it may be with the boost gauge itself or its line connection (actual physical line or electrical sensor), rather than with the turbo.

larryt1026

This is some great info. Thanks! And like you said it's very subjective...I believe my turbo and meter might be working fine, it was certified so dealer inspected and I also had an indy mechanic inspect it. But again, we have different definitions of full throttle, and I personally believe my full throttle is less throttle then other people. I am a bit timid on the gas. As for the meter bouncing, as I am accelerating and the turbo meter hits a certain point as it is going up, sometimes it will go back down briefly and then subsequently go back up as I continue to accelerate. That is what gives it that bouncing look I was suggesting. I tired to get on the gas the other day, and although I didn't red line, I gave it some good gas at S mode. Still never really reached the top. It's close! I remember seeing a thread about this issue and the person changed the engine filter and it fixed it. I am having it changed this weekend. Thanks again for the info! Let me know what you think!

dcmodels

There is only one definition of FULL THROTTLE - smashed firmly to the floor.

My RDX boost gauge often displays full movement, with only 1/2 throttle, if the throttle is applied at low rpm, such as < 2K rpm. That always produces high engine loading, and high boost.

I would be interested if replacing the air cleaner alters your turbo boost gauge behavior. I replace my RDX air cleaner once per year, which is around 8K miles, because I live in a desert area (lots of dust) and yearly range fires (lots of smoke particles). The OM (owner's manual) does state to change the air filter at 15K miles if driving in dusty conditions.

dcmodels

Here is a test that I did several times, with my own 2009 RDX, at 4000 feet where I live. It is simple and unambiguous, for anyone who is uncertain if there is a problem with their own turbo system.

1. find a street with a posted limit of 40mph or more, but no traffic, and the street is level with no traffic-lights for at least 1/2 mile.

2. drive along at a constant 25mph in Drive (not sport mode)

3. quickly apply between 1/4 and 1/2 throttle

4. the transmission should down-shift, and within 2 seconds the turbo should show FULL BOOST and then you will be going 40mph - so let off the throttle immediately. Also, even if you do not let off the throttle, the boost will begin to drop, because you are not using full throttle. And because of the turbo-lag, you should not reach higher than about 40mph within 2 seconds. So if there is no traffic, this is pretty safe to do.

And if the above does NOT produce FULL BOOST, then there is some problem. I suppose there might be some slight difference if the above is done at sea level, but my guess is that it would only be that the car accelerates faster, because of the denser air?
---eof

pickler

Yes my turbo is also very sensitive to throttle response so much so that i can make the gauge needle dance. I never had issue with lag and i track this cuv at least 2 times a month. The only issue i used to have stock was lack of top end power which Hondata fixed it.