2JZ-GE VVti cam question???
01-06-11, 07:44 AM
#16
I think its a sensor not what's opening it.
https://www.clublexus.com/forums/per...lp-needed.html
https://www.clublexus.com/forums/per...lp-needed.html
Last edited by Ali SC3; 01-06-11 at 07:52 AM.
01-24-11, 08:03 PM
#17
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The DBW throttle setup is a little confusing on certain Lexus models. IS300, SC300 and GS300's in particular.
The throttle cable goes from the pedal to a sensor on the throttle body assembly that tells the ECU the desired throttle position.
On most (if not all) new cars, there's no cable, and this sensor is built right into the pedal assembly. (more on why these cars have cables, read on)
There is then a motor connected to the throttle blade (through an ECU controlled electric clutch) that the ECU then commands commands the position of, using a second sensor to determine the actual throttle blade position as feedback.
Now, in the case that something in the DBW messes up, the ECU disengages the electric clutch and the cable will still be able to physically open the throttle blade about 15-20% or so. (to get you to a service shop)
Since DBW throttle was a relatively new technology back then, the engineers wanted a failsafe system that wouldn't leave you stranded on the side of the road and that's why the cable is still there.
Since DBW has proven its reliability in the past years, most cars don't have a cable any more. On those cars, in case of DBW failure, the throttle will sit at about 15% position and the pedal will actually adjust ignition timing to "simulate" throttle opening so you can get off the road for service.
The throttle cable goes from the pedal to a sensor on the throttle body assembly that tells the ECU the desired throttle position.
On most (if not all) new cars, there's no cable, and this sensor is built right into the pedal assembly. (more on why these cars have cables, read on)
There is then a motor connected to the throttle blade (through an ECU controlled electric clutch) that the ECU then commands commands the position of, using a second sensor to determine the actual throttle blade position as feedback.
Now, in the case that something in the DBW messes up, the ECU disengages the electric clutch and the cable will still be able to physically open the throttle blade about 15-20% or so. (to get you to a service shop)
Since DBW throttle was a relatively new technology back then, the engineers wanted a failsafe system that wouldn't leave you stranded on the side of the road and that's why the cable is still there.
Since DBW has proven its reliability in the past years, most cars don't have a cable any more. On those cars, in case of DBW failure, the throttle will sit at about 15% position and the pedal will actually adjust ignition timing to "simulate" throttle opening so you can get off the road for service.
01-24-11, 08:13 PM
#18
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Also, I would highly recommend keeping the VVTi and stock intake manifold with the flip/flap valve in it. Those two combined are worth a 30-40% increase in torque on the low end.
The VVTi allows for better cylinder air filling at low RPM's and the flip/flap valve changes the harmonics of the intake manifold to also increase cylinder filling. If you go to a FFIM, you'll lose all that.
On Turbo applications, depending on your turbo size, this can help the turbo spool time decrease by 500-700RPM compared without having it, plus almost DOUBLE your torque in those ranges vs. no VVTi and flip/flap valve.
The VVTi allows for better cylinder air filling at low RPM's and the flip/flap valve changes the harmonics of the intake manifold to also increase cylinder filling. If you go to a FFIM, you'll lose all that.
On Turbo applications, depending on your turbo size, this can help the turbo spool time decrease by 500-700RPM compared without having it, plus almost DOUBLE your torque in those ranges vs. no VVTi and flip/flap valve.
01-24-11, 08:18 PM
#19
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http://www.youtube.com/watch?v=86uVecdKugM
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
01-24-11, 08:44 PM
#20
http://www.youtube.com/watch?v=86uVecdKugM
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
01-24-11, 08:59 PM
#21
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It depends on who built your AEM EMS harness kit for your car. I am not sure if the Dezod or other kits control it through the EMS of leave it to the stock ECU.
On all the IS300 harnesses kits I've built, I control it through the AEM EMS along with the VVTi. (Usually LS1 output for flip/flap control valve) I do this because with cams and other engine mods, they can be optimized fully for the particular setup. Leaving it to the stock ECU usually leave a little power left on the table.
Usually, the way it should be controlled is to be switched over at an RPM point, usually somewhere in the 3000-5000RPM range. In the car in the video, the output for the flip/flap control valve was turned "on" below 4800RPM and "off" above 4800RPM to give best power/torque.
You should be able to see it move with changes in engine RPM. (May need to be on a dyno under load if stock ECU still controlling it)
Also, the flip/flap is called "ACIS", couldn't remember that earlier, it stands for Acoustic Control Induction System.
On all the IS300 harnesses kits I've built, I control it through the AEM EMS along with the VVTi. (Usually LS1 output for flip/flap control valve) I do this because with cams and other engine mods, they can be optimized fully for the particular setup. Leaving it to the stock ECU usually leave a little power left on the table.
Usually, the way it should be controlled is to be switched over at an RPM point, usually somewhere in the 3000-5000RPM range. In the car in the video, the output for the flip/flap control valve was turned "on" below 4800RPM and "off" above 4800RPM to give best power/torque.
You should be able to see it move with changes in engine RPM. (May need to be on a dyno under load if stock ECU still controlling it)
Also, the flip/flap is called "ACIS", couldn't remember that earlier, it stands for Acoustic Control Induction System.
01-25-11, 09:05 AM
#22
I knew it was Acis, I just thought Aem was capable of turning it on for us.
I found out that the 1100/1101 controls the acis through LS5 output.
default is set to always on, which means the flap is always closed (I hate aem engineers).
Its not supossed to be on all the time, and can limit top end power (where you want short runners.. like an FFIM).
As you said I just changed it to only be on over 30% throttle and under 4500 rpms.
What a difference!!! I have my top end back again now that the valve opens up above 4500 it feels great. Another AEM EMS cal file error. just go to options > configure outputs and change ls5 as I wrote above. wow, thanks alot man.
I found the info for the output and setting courtesy of Kurt from supraforums here
http://www.supraforums.com/forum/sho...ntake-Manifold
He even has the dyno numbers to show the difference. I will never knock the stock intake manifold again, It does have a purpose!!
I wouldn't trust it over 20 psi though, just in case its true that it can shatter at higher boost levels.
I found out that the 1100/1101 controls the acis through LS5 output.
default is set to always on, which means the flap is always closed (I hate aem engineers).
Its not supossed to be on all the time, and can limit top end power (where you want short runners.. like an FFIM).
As you said I just changed it to only be on over 30% throttle and under 4500 rpms.
What a difference!!! I have my top end back again now that the valve opens up above 4500 it feels great. Another AEM EMS cal file error. just go to options > configure outputs and change ls5 as I wrote above. wow, thanks alot man.
I found the info for the output and setting courtesy of Kurt from supraforums here
http://www.supraforums.com/forum/sho...ntake-Manifold
He even has the dyno numbers to show the difference. I will never knock the stock intake manifold again, It does have a purpose!!
I wouldn't trust it over 20 psi though, just in case its true that it can shatter at higher boost levels.
Last edited by Ali SC3; 01-25-11 at 09:09 AM.
01-25-11, 11:31 AM
#23
http://www.youtube.com/watch?v=86uVecdKugM
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
IS300 on dyno.(me tuning and AEM EMS piggybacked). If you stop it at time 6:42, you can see a comparison of the torque/power of no VVTi & flip/flap vs. VVTi & flip/flap on and tuned properly.
It will not help out max HP (as you can see by the curves) but makes for a very lively bottom end that pulls like a freight train below ~4000RPM depending on the turbo sizing.
The only draw back is that it makes your piping a bit to be desired with both pipes going to the passenger side.
Thank You
01-25-11, 07:44 PM
#24
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Glad to hear you got your ACIS working and it got you some more power! It does make a big difference.
The AEM startup calibrations are only as good as the person that generated it and did the initial tuning. Being a former AEM employee (I did EMS stuff and taught the EMS training class) I know who did that cal and he was not very good at nailing down the small details. The NA startup calibration for the 30-1100/1101 is not one of the best, but the one for the new 30-6101 box is leaps and bounds better.
The AEM startup calibrations are only as good as the person that generated it and did the initial tuning. Being a former AEM employee (I did EMS stuff and taught the EMS training class) I know who did that cal and he was not very good at nailing down the small details. The NA startup calibration for the 30-1100/1101 is not one of the best, but the one for the new 30-6101 box is leaps and bounds better.
01-25-11, 07:54 PM
#25
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The OBDII is still functional, but give codes with an AEM EMS piggybacked.
One of the reasons we went with an AEM EMS for that IS300 is that the stock ECU is very picky when it comes to the fuel trims through the stock O2 sensor feedback and MAF so an FIC, because of the way it works, can be very troublesome to make the engine run correctly all the time with the stock ECU still in the loop. Additionally, the EMS allows for full control over the VVTi, ACIS, much more precise fuel and timing control, boost control, anti-lag, and (best of all to some) allows complete removal of the MAF.
One of the reasons we went with an AEM EMS for that IS300 is that the stock ECU is very picky when it comes to the fuel trims through the stock O2 sensor feedback and MAF so an FIC, because of the way it works, can be very troublesome to make the engine run correctly all the time with the stock ECU still in the loop. Additionally, the EMS allows for full control over the VVTi, ACIS, much more precise fuel and timing control, boost control, anti-lag, and (best of all to some) allows complete removal of the MAF.
01-26-11, 09:25 PM
#26
Since the port will still throw codes, whats the benefit of using the EMS as a piggyback instead of using it as a stand alone? Thank you for shedding so much light on this topic so far, Im just trying to get educated before I start purchasing products.
01-27-11, 08:43 AM
#27
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On the VVTi engine, an AEM EMS must be run piggyback if you want to retain the factory DBW throttle and want all of your factory gauges to work. These are the two major things the AEM EMS cannot do by itself so you need to leave the stock ECU in place to take care of these. The AEM EMS handles all the other engine control functions.
If you wanted to run only the AEM EMS with no stock ECU, you could mod your throttle body so it is fully cable controlled - I have had some IS300 customers do this. And of course, adding in some gauges, like coolant temp, is not that hard to do.
If you wanted to run only the AEM EMS with no stock ECU, you could mod your throttle body so it is fully cable controlled - I have had some IS300 customers do this. And of course, adding in some gauges, like coolant temp, is not that hard to do.
01-27-11, 02:10 PM
#28
On the VVTi engine, an AEM EMS must be run piggyback if you want to retain the factory DBW throttle and want all of your factory gauges to work. These are the two major things the AEM EMS cannot do by itself so you need to leave the stock ECU in place to take care of these. The AEM EMS handles all the other engine control functions.
If you wanted to run only the AEM EMS with no stock ECU, you could mod your throttle body so it is fully cable controlled - I have had some IS300 customers do this. And of course, adding in some gauges, like coolant temp, is not that hard to do.
If you wanted to run only the AEM EMS with no stock ECU, you could mod your throttle body so it is fully cable controlled - I have had some IS300 customers do this. And of course, adding in some gauges, like coolant temp, is not that hard to do.
Thanx once again
01-27-11, 03:20 PM
#29
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In my opinion, yes. Anything over just a basic bolt on turbo kit running 6-7psig, and an EMS is the way to go.
The price is a but higher (not quite $2k though, closer to $1K) but you get what you pay for. With an EMS vs. an FIC, the engine will make more power over the whole RPM range, consistently and much safer. Plus, part throttle drivablity is much better, you can remove the MAF and the EMS will handle just about whatever you throw at it engine modification wise.
I have had many IS300 customer switch from the FIC or a Greddy E-Manage to an EMS once they get a chance to drive/ride in a car equipped with one. It makes a big difference in the overall driving experience.
The price is a but higher (not quite $2k though, closer to $1K) but you get what you pay for. With an EMS vs. an FIC, the engine will make more power over the whole RPM range, consistently and much safer. Plus, part throttle drivablity is much better, you can remove the MAF and the EMS will handle just about whatever you throw at it engine modification wise.
I have had many IS300 customer switch from the FIC or a Greddy E-Manage to an EMS once they get a chance to drive/ride in a car equipped with one. It makes a big difference in the overall driving experience.
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