How to introduce a Rev Counter to car without one.

[Mr Vlad]

As much as I love my RX450h one thing, which I've mentioned elsewhere, which bugged me is its lack of Rev Counter. I'm sure I've read elsewhere on this forum if it's possible to introduce a Rev Counter and although there were many replies I didn't come across a possitive answer.

Very recently I Googled  said question and came across an American Lexus forum. Someone found that you can introduce a surface mount OBD reader which has a Rev counter within its plethora of other readings. I thought what a good find and proceeded to amazon and purchased an OBD reader which pleased my eye and was small. Needless to say I'm a  happy bunny now and I'm gobsmacked how low my car revs in various situation's and just how fast it gets to 6200 revs. Wow it revs quick and for a big V6 that's impressive. 

Below are a couple of photos of where I have mine mounted and a pic of which I have. 

Yes OK some wire shows but it's not a bother. 

A wider angle pic to show how small but very effective it looks.

This is the reader I chose.

I hope this will interest those, who like me, would love a Rev Counter in their car.

Dead easy to fit and it also reads all other info and can read faults if they occur.

[Gliderpilot]

Why on earth do you want one, you can't control the engine with the throttle. I use Hybrid Assistant via an OBD dongle it gives you far more info than just a rev counter. Try it out it's a free android app.

[Mr Vlad]

Because Peter I prefer and always have done to have a rev counter.

If I can't control the engine with the throttle then how the hell do I make it go?????

My OBD reader can do much much more than do just revs but it's revs what I wanted.

OK an android app. I understand what you mean but to look at a phone whilst driving isn't on. Not even if it's mounted on the dash somewhere which to me is totally unsightly and makes the dash ugly.

There are lots of folk like me who'd like a rev counter. I have posted a solution. 

Thanks for your reply btw. 

[ColinBarber]

4 hours ago, Mr Vlad said:

Wow it revs quick and for a big V6 that's impressive. 

Not really. The CVT allows the engine to rev up essentially without load. The same as having it in neutral and revving the engine.

I'm with Peter really, in a hybrid the engine is mainly running below 2000 rpm or giving up maximum power above 5000 rpm. The throttle pedal doesn't have a direct relationship  with the engine throttle as the electric motors, and Battery charging, affect what the engine is doing. Might be interesting for a few weeks to understand what the engine does in different conditions but long term I don't really see the benefit.

Good that you found a solution to your problem though 🙂

[rayaans]

Don't really see the point because from the one on the 4RX it just does what it wants to. Revs keep moving up and down unless flooring it or coasting.

[Mr Vlad]

Wow what a couple of extra inputs. 

Firstly Colin what a load of tosh you stated " the CVT allows the engine to rev up essentially without load". Utter crap and from someone I've respected comments from.

How the hell can any type of transmission allow an engine to rev up without a load?

OK Rayaans I know where you're coming from kind of. Maybe the electronic's in the 4RX are different. In my previous is300h's I had the rev counter on always and it responded directly to my boot pressure. The rev counter did Not however do what it wanted to. The OBD reader I have also does NOT do what it wants to.

What I've seen is true engine revs and been pleasantly suprised at what revs I've been at at certain conditions. Even more so than in the is300h's probably coz of the V6.

Crikey I'm really suprised at these replies.

To anyone else who is interested in my thread please ignore the above 2 posts.

[BROUWERS]

A lot of people don't see the use of a rev counter in a hybrid, me included. You do. You are happy with it. You showed us where to get one should one want one. Job done.

[ColinBarber]

9 hours ago, Mr Vlad said:

Firstly Colin what a load of tosh you stated " the CVT allows the engine to rev up essentially without load". Utter crap and from someone I've respected comments from.

How the hell can any type of transmission allow an engine to rev up without a load?

Taking this thread a bit too far off-topic but as you are clearly ignorant to how the transmission works in your vehicle you could read the following site:

http://prius.ecrostech.com/original/PriusFrames.htm

http://prius.ecrostech.com/original/Understanding/ContinuouslyVariableTransmission.htm

For any given road speed, the computer figures out how fast the ring gear is spinning.  From the power demand, it decides how fast it would like the ICE to spin. Then it just solves a simple equation to figure out how fast MG1 must spin. Then, it adjusts the power drawn off by MG1 to speed up or slow down the ICE until the desired condition is achieved.

 

[mrfunex]

Interesting as a toy to play with, but as others have said, a rev counter is pointless - as long as the drivetrain provides the power you demand of it, who cares if the engine is on or not!

Does this simply plug straight into the OBD port? What else can it do? What’s the update frequency? 

[Mr Vlad]

Thanks for your post Brouwers. Job done.

I suppose Colin I was/am 'ignorant ' how the trans works in my car. I miss read what you posted re as if revving in neutral. But thanks for the links. 2nd one a good read.

All I know is I drive a superb car and love it and also am gobsmacked at how the engine revs in different conditions. Yes the revs fluctuate and that's coz of the trans and that's what I love. Throttle at one position yet revs fluctuate between flats hills and downhills. No engine revs dragging as in a standard manual trans. Comfy quick/fast and economic. 

Think I should have posted this thread in general so more folk could read it. I know there are lots of folk who'd like a rev counter. 

Yes mrfunex it plugs straight into the OBD port and it's just like a reader but all I want it for is a rev counter. Job done.

[NemesisUK]

My RC has the rev counter as a separate customisable function, fascinating to watch and really quite useful when the transmission is in 'manual' mode 

[ColinBarber]

14 minutes ago, NemesisUK said:

My RC has the rev counter as a separate customisable function, fascinating to watch and really quite useful when the transmission is in 'manual' mode 

I believe all the current models can display a rev counter, either only when in sport mode or as a customisation. Slightly strange that the series III RX didn't have that option as it does have the simulated manual mode. The previous 400h didn't have any manual mode so there really was no reason for a rev counter.

[Jaystar77]

I wasn't even aware they had omitted the tacho from the third gen, TBH it would annoy me too.

I know it's not in keeping with the general feel of the cabin but I'm no stranger to aftermarket gauges peppered over the dashboard in my other cars so that gauge looks quite sedate all things considered.  Never seen an OBD2 version of these, I'd imagine it can read a lot more than just RPM Vladimir?

[Mr Vlad]

Yes jaystar. Oil n water temp. Throttle position. Engine load which is interesting. And much more. Takes too long to go thru all the menu lol

 

[Gliderpilot]

I've found that if I leave the OBD dongle plugged into the socket overnight, when I start the car I get all sorts of messages up and light on the dash that have to be reset with my scanner, It has even stopped the cruise control from working. I have several dongles and it does it with all of them.

[Jaystar77]

16 minutes ago, Mr Vlad said:

Yes jaystar. Oil n water temp. Throttle position. Engine load which is interesting. And much more. Takes too long to go thru all the menu lol

 

 That's pretty handy, I've only added gauges to pre-OBD2 vehicles so I'd still be looking for the RPM wire to splice into and where to get a vacuum feed through the bulkhead! 

Isn't technology wonderful 😎

[Mr Vlad]

Maybe Peter that you get messages etc is because yours is a dongle. Mine however is an actual reader. I don't get any messages. 

From what I remember from my Ford days in the forums lots had OBD dongles bluetoothed to their phones but none left them in over night. They are a good piece of kit and very useful.