MTNTK Performance New Product Release

[Vi-PEC Powersports]

You cannot have two absolute pressures in the same box. Two absolute pressures in the same box will seek their own level much like high pressure transfers to low pressure in the form of wind......you would end up with (60kpa + 101.3kpa)/2 = 80.65kpa(11.7psi) absolute or (60kpa + 70kpa)/2 = 65kpa(9.4psi). Now if your talking boost pressure + barometric pressure then you would have 60kpa(8.7psi) boost + 101.3kpa(14.7psi) baro = 161.3kpa(23.4psi) absolute or 60kpa(8.7psi) boost + 70kpa(10.2) baro = 130kpa(18.8psi) absolute.....you must add all pressures together. You are correct 161.3 kpa is different than 130 kpa and as such requires different injector duty cycle, tps input is different, rpm could be different, most importantly HORSEPOWER IS DIFFERENT. There in lies the altitude compensation. I have said too much already, your making too many assumptions about how the Polaris ECU software works. The sun still rose in the east and set in the west even before Galileo proposed that the earth rotated around the sun even though no one understood why.........for everyone else out there the Bullydog ECU tuning works awesome!

So what is the answer to my question ? How are you taking care of the altitude compensation if using the factory Tmap (re-scaled) as an input for boost pressure (absolute) ? When tweaking the facrory map in reference with the re-scaled sensor (tmap), the original map is overlaped and the changes in the x and y axis doesn t allow for compensation no more, it is now a Map Sensor.
We are using a lot of reflash solutions everyday (pro cobb, diablo, bullydog, hp tuner etc.) And we have tons of experience using reflash devices altering a lot more than just fuel, ignition, MAP, and i still don't get what' s going on....if anything is going on ......in regards to altitude compensation. I have no doubt you achieved great results with this solution compared to the piggy you were using before and i am sure you made your homework before bolding out about your kit....this being said, i am sure i am not the only one interested in a CLEAR answer on altitude compensation, not too many people on here understand how an ECU works and it is our job to inform the masses and ask picky questions.
Thanks again for your patience and hope you will light us up on this matter.


vi-pec powersports

 

[mountainhorse]

Precision EFI... Probably best to break this discussion out into it's own tech thread here in the turbo threads and not turn this into a "contest of mfgs" in a product release thread.

Thanks,
MH.


.

 

[mike_s]

Precision EFI, perhaps if someone puts it into some other terms you will better see what is going on here. bear in mind, I have no experience with the ECM being used in the polaris engine platform, but I have worked with several GM platforms as well as a few Bosch platforms, and at the end of the day, systems without mass airflow sensors are essentially nothing more than a speed density system, and all have the same basic algorithms.

first, boost (PSIG), and barometric pressure (PSIA) combine to make absolute pressure, this has been established.

A speed density system at its very most basic uses one constant, engine displacement, and three variables, throttle position, RPM, and manifold absolute pressure to arrive at a projected volumetric efficiency. at the end of each calculation cycle VE is really all the ECM is concerned about, as this is the only variable needed to calculate injector duty cycle. there are various other algorithms in more advanced systems with feedback loops, but to my knowledge the system in the polaris has no feedback loops.

you mention that at varying barometric pressures and boost pressures, TPS voltage will be different for similar situations, which you believe will cause discrepancies in accurate fueling of the engine, this is however inaccurate, as assuming the maps in the ECM are set correctly, it will still arrive at the correct VE, and hence the correct amount of fuel will still be injected. in short, a higher TP at a lower MAP will read to the ECM as a low VE, and less fuel will be injected. Alternatively, a low TP, and high MAP will be read as a higher VE, and more fuel will be injected.

The whole concept is actually rather simple, and has been proven for many many years (used on the Chevy Cyclone since the early to mid 80's). The real trick is getting the VE tables right.

 

[brycter]

Precision EFI, perhaps if someone puts it into some other terms you will better see what is going on here. bear in mind, I have no experience with the ECM being used in the polaris engine platform, but I have worked with several GM platforms as well as a few Bosch platforms, and at the end of the day, systems without mass airflow sensors are essentially nothing more than a speed density system, and all have the same basic algorithms.

first, boost (PSIG), and barometric pressure (PSIA) combine to make absolute pressure, this has been established.

A speed density system at its very most basic uses one constant, engine displacement, and three variables, throttle position, RPM, and manifold absolute pressure to arrive at a projected volumetric efficiency. at the end of each calculation cycle VE is really all the ECM is concerned about, as this is the only variable needed to calculate injector duty cycle. there are various other algorithms in more advanced systems with feedback loops, but to my knowledge the system in the polaris has no feedback loops.

you mention that at varying barometric pressures and boost pressures, TPS voltage will be different for similar situations, which you believe will cause discrepancies in accurate fueling of the engine, this is however inaccurate, as assuming the maps in the ECM are set correctly, it will still arrive at the correct VE, and hence the correct amount of fuel will still be injected. in short, a higher TP at a lower MAP will read to the ECM as a low VE, and less fuel will be injected. Alternatively, a low TP, and high MAP will be read as a higher VE, and more fuel will be injected.

The whole concept is actually rather simple, and has been proven for many many years (used on the Chevy Cyclone since the early to mid 80's). The real trick is getting the VE tables right.

yes you are correct on how the bully dogg is getting the work done. yes it has worked on cars.

Yes i also know that these are good aguing points. something to remember is car does not run on and off throttle under load 20 times in 30 seconds. seeing -32 degrees -40 degrees swings and climbing 6000" of elevation in 2 miles.

gino is on another page of the book. he is asking how the altitude compesation works along with a turbo. with the vipec or any other stand alone. there is a 4d and 5d timing and fuel table. Plus a air intake temp sensor that is in the mix.

true alt compensation would have a baro sensor reading elevation baro and a 3 bar sensor in the charge tube . so that your base map is configured with the baro first. then adding fuel and taking away timing as the boost comes up.

so at 0 feet of elevation you might be adding 4% of fuel to your base fuel map and taking away 1 degree of timing even before boost is coming on. that is true altitude compensation. there is just some other tables in the mix that put the sled in a better shape as you climb from 1500- 4000' in one climb. because in a big long pull you cant be worring about what the boost and fueling are doing. Or temp of the air in the motor.

like i say two differnt animals. pick your poison. one is black the other is white.

 

[Vi-PEC Powersports]

Precision EFI, perhaps if someone puts it into some other terms you will better see what is going on here. bear in mind, I have no experience with the ECM being used in the polaris engine platform, but I have worked with several GM platforms as well as a few Bosch platforms, and at the end of the day, systems without mass airflow sensors are essentially nothing more than a speed density system, and all have the same basic algorithms.

first, boost (PSIG), and barometric pressure (PSIA) combine to make absolute pressure, this has been established.

A speed density system at its very most basic uses one constant, engine displacement, and three variables, throttle position, RPM, and manifold absolute pressure to arrive at a projected volumetric efficiency. at the end of each calculation cycle VE is really all the ECM is concerned about, as this is the only variable needed to calculate injector duty cycle. there are various other algorithms in more advanced systems with feedback loops, but to my knowledge the system in the polaris has no feedback loops.

you mention that at varying barometric pressures and boost pressures, TPS voltage will be different for similar situations, which you believe will cause discrepancies in accurate fueling of the engine, this is however inaccurate, as assuming the maps in the ECM are set correctly, it will still arrive at the correct VE, and hence the correct amount of fuel will still be injected. in short, a higher TP at a lower MAP will read to the ECM as a low VE, and less fuel will be injected. Alternatively, a low TP, and high MAP will be read as a higher VE, and more fuel will be injected.

The whole concept is actually rather simple, and has been proven for many many years (used on the Chevy Cyclone since the early to mid 80's). The real trick is getting the VE tables right.

Thanks mike_s , your wikipedia/textbook description of a speed density system is accurate and well put togheter. However the polaris system, as any speed density system needs an accurate reading off of a TMap(under hood open air) or any MAP at idle as a landmark in order to start calculating and set it self in the correct cell in the fuel map and so on. Now with the tmap in the intake manifold reading absolute pressure on boost...fine, but vaccum or very little pressure at idle and vaccum at WOT and/or when driving 6000' variarion in couple minutes amd on and off throttle all the time in those variation, needs a reference somehow somewhere to compensate and "reposition itself" in the fuel table and other tables affecting fueling. I understand a slight variation in altitude, say 1000'to1500' feet wont make a big of a change but past those variation its another story....been there, done that.
I am not saying it is impossible but certainly "unkown" to us and a lot of manufacturer and certainly Polaris. How about cold start at elevation vs sea level....where does it get its baro reading? If a particular kit is tuned for a certain elevation , slight variation wont affect much but 2000' and up in variation will affect big time unless you guys found a new way to reflash/re-scale.
vi-pec powersports

 

[mike_s]

The ecm does not need a barometric pressure sensor to opperate an engine. It really doesnt care what the barometric pressure is. Only how full of air the cylinder is going to be. VE will tell it that. To determine VE, all you need (assuming the VE table stored in the ECM is correct) is manifold pressure and RPM. I have not seen the decompiled calibrations from this particular ECM, so i cannot comment on how many other functions it contains (differential TPS enrichment, temperature correction, ect.) but at its most basic, this is all that is needed. Picture your turbo is set to gate at 5 PSIG. So at any point it will produce 5 PSI above barrometric pressure. Given that, now lets say you run up a chute that changes the barrometric pressure from 14 PSI to 13.5 PSI. Your MAP sensor will read 19 PSIA at the start of the run and 18.5 at the end. There is the altitude compensation right there. To the ecm, coming from no boost to high boost is only seen as something like falling out of the sky at a high rate of speed, but it doesnt care about that. I cannot say if there is the ability to pull timing based on boost as i stated i have not seen the decompiled callibration. But i can tell you that there are thousands of turbocharged vehicles on the road running in just the trim i described, including a few that see radical altitude changes and rapid/repeated throttle changes (GM cyclone, SAAB turbo ect racing Pikes Peak).

I only wish the ECMs i work with were as simple as these. Im used to dealing with up to 30 seperate tables just for fuel and timing...LOL!

 

[Hairy Mark]

The ecm does not need a barometric pressure sensor to opperate an engine. It really doesnt care what the barometric pressure is. Only how full of air the cylinder is going to be. VE will tell it that. To determine VE, all you need (assuming the VE table stored in the ECM is correct) is manifold pressure and RPM. I have not seen the decompiled calibrations from this particular ECM, so i cannot comment on how many other functions it contains (differential TPS enrichment, temperature correction, ect.) but at its most basic, this is all that is needed. Picture your turbo is set to gate at 5 PSIG. So at any point it will produce 5 PSI above barrometric pressure. Given that, now lets say you run up a chute that changes the barrometric pressure from 14 PSI to 13.5 PSI. Your MAP sensor will read 19 PSIA at the start of the run and 18.5 at the end. There is the altitude compensation right there. To the ecm, coming from no boost to high boost is only seen as something like falling out of the sky at a high rate of speed, but it doesnt care about that. I cannot say if there is the ability to pull timing based on boost as i stated i have not seen the decompiled callibration. But i can tell you that there are thousands of turbocharged vehicles on the road running in just the trim i described, including a few that see radical altitude changes and rapid/repeated throttle changes (GM cyclone, SAAB turbo ect racing Pikes Peak).

I only wish the ECMs i work with were as simple as these. Im used to dealing with up to 30 seperate tables just for fuel and timing...LOL!

mike not to be a jerk, but my one question would be on your post is this. i have a custom turbo setup, with an identical kit being run in utah. we can not run the same fuel map since i need more fuel due to the what i think are several conditions, i.e. elevation and barometric pressure. all the fuel maps that he runs work great for me there. but when i load up my sled to come up here i have to have him load another fuel map with all the fueling numbers richer then his. if it is so simple why do the numbers change for the location. i think that alot of the change is two stroke to four stroke. but as usual i am probably wrong. lol.

 

[mike_s]

What kind of controller are you using? If it is a Piggy back combined with stock ecu then it is not compensating for barometric pressure changes properly, as the ability to do so correctly is no longer there.

 

[Vi-PEC Powersports]

The ecm does not need a barometric pressure sensor to opperate an engine. It really doesnt care what the barometric pressure is. Only how full of air the cylinder is going to be. VE will tell it that. To determine VE, all you need (assuming the VE table stored in the ECM is correct) is manifold pressure and RPM. I have not seen the decompiled calibrations from this particular ECM, so i cannot comment on how many other functions it contains (differential TPS enrichment, temperature correction, ect.) but at its most basic, this is all that is needed. Picture your turbo is set to gate at 5 PSIG. So at any point it will produce 5 PSI above barrometric pressure. Given that, now lets say you run up a chute that changes the barrometric pressure from 14 PSI to 13.5 PSI. Your MAP sensor will read 19 PSIA at the start of the run and 18.5 at the end. There is the altitude compensation right there. To the ecm, coming from no boost to high boost is only seen as something like falling out of the sky at a high rate of speed, but it doesnt care about that. I cannot say if there is the ability to pull timing based on boost as i stated i have not seen the decompiled callibration. But i can tell you that there are thousands of turbocharged vehicles on the road running in just the trim i described, including a few that see radical altitude changes and rapid/repeated throttle changes (GM cyclone, SAAB turbo ect racing Pikes Peak).

I only wish the ECMs i work with were as simple as these. Im used to dealing with up to 30 seperate tables just for fuel and timing...LOL!

Thanks mike_s for your reply but you are wrong. The problem you will encounter is not on boost it is off boost and in vaccum what so little it is. The OEM ecu does need a barometric reading to offset fueling/ignition. I won't go over again why but do you realy think Polaris included a barometric sensor in every sled simply to increase their cost? If their algorythm wouldn't need a baro reading it wouldn't be there....just like yamaha didn't need a cam sensor on the nytro motor so they didn't put it there. Again we are only talking altitude compensation here, the fact it won t altitude compensate is not catastrophic for the majority but you simply can t clean the idle up to about 30% going downhill after a 2000' feet climb as per example....i guess time will tell as we are both absolutely sure of our comments!! But congratulation on your new kit and i wish you and your team the best in this venture.

Thanks


vi-pec powersports

 

[mike_s]

We can agree to disagree efi, but I do have one correction : I don't work for or with mtntk. I'm a farmer. Lol! I just do EFI Live tuning on GM vehicles as a hobby, and did so with custom built eprom emulators before that. Funny that the only GM systems that have a baro sensor are MAF systems. Wonder why theirs work...

 

[mike_s]

Oh, and to answer your question, Polaris put a baro sensor in the stock system becaus They did not include a map sensor. The stock system doesn't even measure manifold pressure, it calculates it. That is what is being changed.

 

[Vi-PEC Powersports]

We can agree to disagree efi, but I do have one correction : I don't work for or with mtntk. I'm a farmer. Lol! I just do EFI Live tuning on GM vehicles as a hobby, and did so with custom built eprom emulators before that. Funny that the only GM systems that have a baro sensor are MAF systems. Wonder why theirs work...

Tuning/hacking your satellite dish and playing around with 2-3 tables over 180 tables in an ECU doesn't mean you understand how ECUs operates....if reading books would make anybody a good tuner/engineer, then turbo sled forums would disapear...unfortunately, trial and error, thousands of tuning hours, and years of software/firmware development make you realize how complex those computers handle the physic laws.

.

vi-pec powersports

 

[Vi-PEC Powersports]

Oh, and to answer your question, Polaris put a baro sensor in the stock system becaus They did not include a map sensor.

Never ask yourself why we call the the baro sensor in the polaris sled a TMap? Temperature and MAP in one sensor!!!


vi-pec powersports

 

[mike_s]

Tuning/hacking your satellite dish and playing around with 2-3 tables over 180 tables in an ECU doesn't mean you understand how ECUs operates....if reading books would make anybody a good tuner/engineer, then turbo sled forums would disapear...unfortunately, trial and error, thousands of tuning hours, and years of software/firmware development make you realize how complex those computers handle the physic laws.

.

vi-pec powersports

I dont do anything with my dish reciever, except change channels and bitch about comercials. And playing with 2-3 tables? LOL! I dream of the day it was that simple. Try more like 25 tables just for injection timing, a few more transient tables and correction factors. Several hundred DTC enablers, and a few hundred more diagnostic test enablers. Yeah, i just fiddle with 2 or 3 little tables. LOL! Complex computer? Not really, its still not much more than an 8 bit E-Prom controlled hex programmed box. The Nintendo NES from the late '90s had more computing power. Now, am i sensing a little hostility here? Or is it that you dont belive a humble farmer could fathom tuning electronic fuel injection?

 

[mike_s]

Never ask yourself why we call the the baro sensor in the polaris sled a TMap? Temperature and MAP in one sensor!!!


vi-pec powersports

Where is the sensor located? Is it actually in the manifold? Or is it the airbox? If i recall, its in the airbox, hence it is NOT reading manifold pressure. Generally, that is reffered to as a barro sensor. The 800 CFI engine is not equipped with a MAP sensor.

 

[Vi-PEC Powersports]

I dont do anything with my dish reciever, except change channels and bitch about comercials. And playing with 2-3 tables? LOL! I dream of the day it was that simple. Try more like 25 tables just for injection timing, a few more transient tables and correction factors. Several hundred DTC enablers, and a few hundred more diagnostic test enablers. Yeah, i just fiddle with 2 or 3 little tables. LOL! Complex computer? Not really, its still not much more than an 8 bit E-Prom controlled hex programmed box. The Nintendo NES from the late '90s had more computing power. Now, am i sensing a little hostility here? Or is it that you dont belive a humble farmer could fathom tuning electronic fuel injection?

Absolutely 0 hostility. I believe the humble farmer has read a lot of books and is a great intellectual. It is not about chips power, it is about physic laws you have to adress and a very complex interaction between sensors/program/hostile environment.
I think we should exchange by Pm from now on you and me if you don't mind....as i am waiting from MTNTK to answer the altitude compensating question themselves.


vi-pec powersports

 

[Vi-PEC Powersports]

Where is the sensor located? Is it actually in the manifold? Or is it the airbox? If i recall, its in the airbox, hence it is NOT reading manifold pressure. Generally, that is reffered to as a barro sensor. The 800 CFI engine is not equipped with a MAP sensor.

it is in the airbox and it is called a TMAP/baro or Map, it is simply about the size and scaling of the particular sensor...so MAP, TMAP, BARO....same fonction, different scaling.

vi-pec powersports

 

[Moosehumper]

I got to get on this program! Thanks for taking the time to explain things at the edmonton show. Clean kit.

MCX kits work off of absolute pressure as well if I'm not mistaken...14psi is 14psi, who cares how much is from atmosphere & how much is boost as long as adds up to 14 (or whatever number you fancy). They just adjust it through a different means. This one looked way simpler with no solenoid to freeze, stick or crap out and cause over pressuring.

 

[PMSPOLARIS]

Wow what a day on a turbo from MTNTK Performance!

Wow the MTNTK Turbo was so incredible to ride today. We went out for a 50 mile run and had a blast, I was expecting to stop and watch MTNTK tune these turbo's. Nothing farther from the truth we did not even stop to tune or take videos. We just rode I really have never road 50 miles boosted without trying to tune once. We just rode and rode . Happy happy happy