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PB -PC Challenger 2009 - 2014 Covering 2.5 HP diesel

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  #21  
Old 1 Week Ago
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After a bit more thinking and a bit of research I believe what “Challenged” has observed is highly likely to occur in the function of the automatic transmission of both the Challenger with the Jatco 5 speed and the Pajero Sport with the Aisin 8 speed autos.
Mitsubishi have been using PWM (Pulse Width Modulation) on their Auto trans computer controls for many years, basically it varies the percentage of torque convertor lockup from 70% to 99.6%, the AT ECU checks that this is happening at a certain time frequency, if it does not detect TC variance then it throws a fault code.
So the engine drive is never 100% connected to the gearbox, there is always some slip in the torque convertor.
This is why even with a “locked” torque convertor an automatic will never have the same fuel economy and engine braking that a manual transmission has.

OJ.
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2011 PB Base White Auto, Smartbar, Cooper STMaxx LT235/85R-16,TPMS, HR TB, 3 x Bushskinz, front +40mm Dobinson , rear +50mm EHDVR Lovells, Dobinson MT struts and shockers, Peddars 5899 cone springs, Windcheater rack, GME UHF, Custom alloy drawer system inc. 30lt Engel & 2 x 30 AH LiFePo batteries + elec controls, Tailgate hi-lift/long struts, Nightbreaker +130LB & Phillips +100 HB, Lightforce 20" single row driving beam LED lightbar, Scanguage II.
MM4x4 Auto Mate, Serial No 1 .
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  #22  
Old 1 Week Ago
ron.dunn ron.dunn is offline
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That would be a 12% difference, Jack ... 200 rpm difference at 1700rpm.

That's simply not possible on a Pajero Sport.

I've got the Munji, on and off makes no difference to RPM. We're not talking about 20-30rpm that might make a sound difference, we're talking about four clearly identifiable tick marks on the tacho.
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Last edited by ron.dunn; 1 Week Ago at 11:15 AM.
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  #23  
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Quote:
Originally Posted by ron.dunn View Post
That would be a 12% difference, Jack ... 200 rpm difference at 1700rpm.

That's simply not possible on a Pajero Sport.

I've got the Munji, on and off makes no difference to RPM. We're not talking about 20-30rpm that might make a sound difference, we're talking about two clearly identifiable tick marks on the tacho.
I have always been able to detect an engine pulse, rpm change when cruising at highway speed in my Challenger, I cannot detect an indicated rpm change on the dash display or on my Scanguage II but I can see a slight change in boost pressure on my Scangauge II. It could be the refresh rate used in the cars computers is slow/dampened so as not to display the rpm fluctuations, the only way to be sure would be to directly monitor the rpm sensor output voltage.
For several years I had a digital volt meter with an accuracy of 0.001 vdc connected to the Torque Convertor Lockup Solenoid. I could not only see when the Torque Convertor locked up but I could also see the Pulse Width Modulation voltage control of the TC Lockup Solenoid.

In the Workshop Manual for the Pajero Sport there are diagrams for the Torque Convertor Lockup Dampner Control Solenoid, these clearly show periods of partial TC lockup (slip area).
Here are the diagrams for 4th, 5th, 6th, 7th and 8th gears.
http://mmc-manuals.ru/manuals/pajero...388AB00ENG.pdf
http://mmc-manuals.ru/manuals/pajero...389AB00ENG.pdf
http://mmc-manuals.ru/manuals/pajero...390AB00ENG.pdf
http://mmc-manuals.ru/manuals/pajero...391AB00ENG.pdf
http://mmc-manuals.ru/manuals/pajero...392AB00ENG.pdf


OJ.
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2011 PB Base White Auto, Smartbar, Cooper STMaxx LT235/85R-16,TPMS, HR TB, 3 x Bushskinz, front +40mm Dobinson , rear +50mm EHDVR Lovells, Dobinson MT struts and shockers, Peddars 5899 cone springs, Windcheater rack, GME UHF, Custom alloy drawer system inc. 30lt Engel & 2 x 30 AH LiFePo batteries + elec controls, Tailgate hi-lift/long struts, Nightbreaker +130LB & Phillips +100 HB, Lightforce 20" single row driving beam LED lightbar, Scanguage II.
MM4x4 Auto Mate, Serial No 1 .

Last edited by old Jack; 1 Week Ago at 11:36 AM.
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  #24  
Old 1 Week Ago
Challenged1 Challenged1 is offline
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Quote:
Originally Posted by ron.dunn View Post
I have a Munji cable. In fact, for reasons not related to this topic, I've just removed it.

I understand that you might believe what you are saying, but it is impossible.

Your engine is connected to your gearbox. Your gearbox has a fixed ratio of gears. The only way to change the speed of your vehicle at a given RPM is to physically change the gears. Put it another way, the only way to lower your RPM at a given speed is also to change the gears.

Let's just suppose that the cable made your engine run 200rpm slower. Unless you've pulled apart your gearbox and replaced its internals - which I strongly doubt you have done - it is simply not possible that your car can run its engine slower and deliver a higher speed.

There are two possibilities that might be misleading you. (1) The RPM is not reported directly from the engine, and is calculated in some way that is influenced by the cable. Unlikely. (2) The speed is not reported directly from the gearbox, and is calculated in some way that is influenced by the cable. Also unlikely.

You could eliminate both of these possibilities by using an accurate GPS to measure the speed. An OBDI reader might give a different view of RPM, but may still be influenced by [unlikely] calculations.
Well, it appears we have achieved the "impossible with 2 cars! We have used the Pajero Sports GLX in built GPS and my Garmin to measure the speed of both cars. Both GPS's read the same speed.

I have been around many things mechanical since I built my first billy cart with my Grandfather way back when. I have built my own motorcycles and cars and their engines. I do my own repairs and maintenance. I have a very good hands on understanding of many things mechanical and for you to tell me that what I am OBSERVING with my own eyes and that of my other half is wrong is just plain offensive. I fully understand how gearing works, but thanks for the lesson anyway. I am not trying to sell any particular product (are you?) but rather just telling my observation of a certain modification that has benefited our cars. If I thought it was a waste of time and money, why would we do the same mod to the new car?

I can tell you from seat of the pants experience that just about every engine on the planet (I don't know of 1 but you probably do) runs much better with cooler air. Isn't this what intercoolers and direct injection is all about? Problem is, the EGR valving is AFTER the intercooler and so negates the benefit of having it. They've even tried putting a cooler at the EGR valve. Wonder why Mitsubishi did that......

I drove a HR truck with trailer up and down the east coast for many years and I can tell you for fact that the engine always performed better in colder conditions. I could hear the change in the engines behavior (and loved the sound of the turbo whistling happily) and would usually be a gear better going up known hills. It would use much less fuel. It was my truck, I knew it very well (900,000 + k's together) and I always wanted cooler conditions for my trips. It was easier on my wallet and easier on the truck.

It's a well known fact that the EGR systems in modern diesel engines are an engine killing device that induces heat and contaminates oil and fuel. It also decreases performance by heating up the air going into the cylinders. Hot air means decreased performance and that means the engine has to work harder to achieve a desired speed. Conversely. a good performing engine does any desired speed much easier which equates to less weight on the right foot needed to do the same speed, particularly in an auto.

I also have a gut feeling that the autos clutch is engaging earlier and firmer with the ECU thinking it's cooler. Surely a clutch that isn't slipping would benefit the RPM's needed to do a given speed. I think you are choosing to ignore the fact that there is a centrifugal type clutch in our autos and not just a torque converter.

Just to reiterate, no where have I ever mentioned a brand of anything. I'm just passing on something that I know has benefited our cars. If you choose to not believe me, that's fine by me. It's your car and your money.
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  #25  
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Challenged1 Challenged1 is offline
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Quote:
Originally Posted by ron.dunn View Post
That would be a 12% difference, Jack ... 200 rpm difference at 1700rpm.

That's simply not possible on a Pajero Sport.

I've got the Munji, on and off makes no difference to RPM. We're not talking about 20-30rpm that might make a sound difference, we're talking about four clearly identifiable tick marks on the tacho.
No body but you has mentioned a 200 rpm decrease. And where you get 1700 RPM from is beyond me. I think you better read my post again. I clearly stated 150 RPM down from just below 2200 RPM to just above 2000 RPM at 100kmh. And by the way, It's TWO clearly identifiable tick marks on the PB....
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  #26  
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ron.dunn ron.dunn is offline
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Quote:
Originally Posted by Challenged1 View Post
No body but you has mentioned a 200 rpm decrease.
That's odd, I could have sworn your post says, "At 100kmh both cars have gone from just under 2200rpm to just over 2000rpm", which suggests an approximate 200rpm decrease.

Still, that number doesn't add up. If you have a Pajero Sport, the RPM at 100km/h should be somewhere in the order of 1700-1750 in 8th gear. And I can't take a picture to prove it because I'm several thousand kms from my car at the moment, but the Pajero Sport tacho has 20 tick marks per 1000 rpm, so 200rpm would take 4 tick marks.
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  #27  
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Challenged1 Challenged1 is offline
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I'm not going to argue semantics with you. If you read 200RPM decrease when I clearly typed 150RPM decrease, then who am I to argue.....

I may be wrong about the RPM's in the PS. I have to check with the Mrs. I have never driven it since the EGR cheat and I can't personally recall the engine speed when I did drive it. I was just impressed with how much smoother and quieter the motor is compared to the PB's motor.

When the other half tells me it has dropped around 150RPM and is using way less fuel from wherever it was standard, I believe what she tells me. She's the one who drives it everyday.

I will let you know what engine speed the PS is at 100kmh.
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  #28  
Old 6 Days Ago
Challenged1 Challenged1 is offline
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Ok, so know I now where ron.dunn got 1700 RPM from. The PS runs at a lower engine speed than the PB Challenger. My apologies for any confusion.

After a quick drive in the Pajero Sport I can tell you that with the EGR cheat we have in the car, it sits at just below 1700rpm (guess 1650 - 1670) on the tacho at GPS 100KMH which is about 104KMH on the speedo. Cruise control was on and driving on a fairly flat stretch of road. There was a bit of side wind.

I don't have a scan gauge or any such device so I can only rely on the cars instruments and my eyes.
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