bov....how do i eliminat bov recirculation?

jdmmilhouse · 11-03-2009, 09:26 PM

i tried to vent my stock bov to the atmosphere but car shuts off after i rev or give it gas......i plugged the hole on turbo pipe , and hooked up bov to 3000 pipe.....it sounds great but shuts off!

cre · 11-04-2009, 01:47 AM

You'll need to install and tune a fuel controller which is able to account for the fact that air that was measured isn't actually making it into the engine. On a stock system... you just have to deal with it... some people get lucky and the car remains somewhat drivable in town. Oh, and then there's the back firing... what fun!

The thing is that the ECU gets information from the airflow meter about how much air has been taken into the system. The stock BPV removes excess boost pressure by rerouting the air to further upstream where it isn't compressed but is still after the meter. When you vent to atmosphere the ECU still thinks there is a TON more air in the system than there is and keeps providing a lot more fuel than needed during those couple seconds... thus: backfire and stall problems.

jdmmilhouse · 11-04-2009, 03:36 AM

kool,thanx...........will the apexi safc work?

cre · 11-04-2009, 07:29 AM

I don't know that the SAFC would really be up to the task. I know that people have used the SAFC II and the Neo to tune around the problem.

I can't personally speak as to the effectiveness of either in this case though I run a MAFT Pro for my tuning (and AFM deletion) needs.

EDIT: A quick glance at the SACF II manual confirms that there are tip-in and tip-out controls. http://www.apexi-usa.com/content/pdf6118.pdf

jdmmilhouse · 11-05-2009, 03:44 AM

could u explain how your setup works and the cost? thanx.......also what is tip in control?

cre · 11-05-2009, 04:57 AM

Here's a really old post in which I talk a bit about the MAFT Pro:
http://www.toyota-supra.info/forums/...-oil-flow.html

To put it simply, the MAFT Pro is an air flow meter translator which will allow you to use pretty much ANY air flow meter on your vehicle. It also allows you to completely eliminate any restriction posed by an air flow meter by running what is known as a speed/density setup where the MAFT Pro *calculates* the amount of air through the readings of a small GM temp sensor in the intake piping and a reading from a vacuum line. That's right you can run straight pipe from the air filter all the way to the throttle body.

The MAFT Pro is also a fuel controller (like the SAFC II), a boost controller AND a timing controller... it's a one-stop-shop.

Add a wideband O2 controller and sensor such as the LC-1 by Innovate motorsports and you've not only got mobile and DIY tuning capabilities but you can also set up the MAFT Pro to adjust for and maintain your desired AFRs at: cruise, lean cruise, WOT and idle.

Over the past few years support has grown immensely (for the 7M-GTE... for the 7M-GE, I'm it.

). The firmware is upgradable and free and you can use a couple different programs for data logging (the program TunerPro is the most popular choice; it's shareware and a copy of the installer comes on CD with the Pro).

The Pro is a VERY versatile piece of hardware and IMO it fits right in between all other piggybacks and standalone EMSs... it bridges what used to be a chasm of a gap.

It is NOT an easy system for most to learn and get tweaked just right quickly (at least not with S/D setups) as every engine is different and there is so much control available.

In order to make use of the boost control capabilities you have to be running a S/D setup. To make use of the timing monitor feature (not related to the timing control feature) you must not be using the MAF signal input wiring.

Tip in and tip out refer to how much and how fast the fuel map is enriched and how quickly that enrichment is stopped as you lean into the throttle and as you let off the throttle. Enrichment refers to fuel added in addition to what the tuned map calls for; this is used in cases where there is a surge as the throttle is initially opened and an unexpected drop in air flow such as in the case of a BOV discharging. S/D setups require a lot of tweaking in the real of tip in controls, no adjustment is needed for tip out though as the Pro reads the amount of air after the throttle body. With an S/D setup you could run with a giant, gaping hole in the intercooler and still drive the car home... on a stock system, you're stranded.

S/D setups can be tricky to setup as the computer is calculating the airflow and not quite measuring it as is the case with any other type of meter. Installing a large GM MAF (for example) is a simple enough affair as the Pro simply translates the reading the MAF sends it... no real need to hassle with tip in adjustments unless you're tuning for perfection. Unfortunately, when running in "Translation Mode" the MAFT Pro cannot be used as a boost controller and if used with a MAF it cannot be used to monitor ignition timing advance.

This is not a cheap system, has a steep enough learning curve to scare away some people, has a decent support base, offers most of the functionality previously only available with a standalone. The other nice thing is having all of your piggybacks in one box and reading in the same data logging application.

There's also been talk of adding launch control and knock monitoring, but I don't know where that's at right now... might happen, might not.

jdmmilhouse · 11-05-2009, 06:13 AM

all this info is great! u guys are so helpful , im new to supras,ive owned hondas and know all about building and modifying them, now i have to make the transition over to supras, thankfuly my guy here in chicago knows his 2jz's and 7m's he owns a ae86 with a 2jzgte....he did all the work from mounts to wiring in his home garage ! unlike......hondatech u guys are very supporting & helpful ! thanx again

11-03-2009, 09:26 PM	#1
jdmmilhouse Stock Join Date: Nov 2009 Location: chicago Posts: 28	bov....how do i eliminat bov recirculation? i tried to vent my stock bov to the atmosphere but car shuts off after i rev or give it gas......i plugged the hole on turbo pipe , and hooked up bov to 3000 pipe.....it sounds great but shuts off!

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11-04-2009, 01:47 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	You'll need to install and tune a fuel controller which is able to account for the fact that air that was measured isn't actually making it into the engine. On a stock system... you just have to deal with it... some people get lucky and the car remains somewhat drivable in town. Oh, and then there's the back firing... what fun! The thing is that the ECU gets information from the airflow meter about how much air has been taken into the system. The stock BPV removes excess boost pressure by rerouting the air to further upstream where it isn't compressed but is still after the meter. When you vent to atmosphere the ECU still thinks there is a TON more air in the system than there is and keeps providing a lot more fuel than needed during those couple seconds... thus: backfire and stall problems.

11-04-2009, 03:36 AM	#3
jdmmilhouse Stock Join Date: Nov 2009 Location: chicago Posts: 28	kool,thanx...........will the apexi safc work?

11-04-2009, 07:29 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I don't know that the SAFC would really be up to the task. I know that people have used the SAFC II and the Neo to tune around the problem. I can't personally speak as to the effectiveness of either in this case though I run a MAFT Pro for my tuning (and AFM deletion) needs. EDIT: A quick glance at the SACF II manual confirms that there are tip-in and tip-out controls. http://www.apexi-usa.com/content/pdf6118.pdf

11-05-2009, 03:44 AM	#5
jdmmilhouse Stock Join Date: Nov 2009 Location: chicago Posts: 28	could u explain how your setup works and the cost? thanx.......also what is tip in control?

11-05-2009, 04:57 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Here's a really old post in which I talk a bit about the MAFT Pro: http://www.toyota-supra.info/forums/...-oil-flow.html To put it simply, the MAFT Pro is an air flow meter translator which will allow you to use pretty much ANY air flow meter on your vehicle. It also allows you to completely eliminate any restriction posed by an air flow meter by running what is known as a speed/density setup where the MAFT Pro calculates the amount of air through the readings of a small GM temp sensor in the intake piping and a reading from a vacuum line. That's right you can run straight pipe from the air filter all the way to the throttle body. The MAFT Pro is also a fuel controller (like the SAFC II), a boost controller AND a timing controller... it's a one-stop-shop. Add a wideband O2 controller and sensor such as the LC-1 by Innovate motorsports and you've not only got mobile and DIY tuning capabilities but you can also set up the MAFT Pro to adjust for and maintain your desired AFRs at: cruise, lean cruise, WOT and idle. Over the past few years support has grown immensely (for the 7M-GTE... for the 7M-GE, I'm it. ). The firmware is upgradable and free and you can use a couple different programs for data logging (the program TunerPro is the most popular choice; it's shareware and a copy of the installer comes on CD with the Pro). The Pro is a VERY versatile piece of hardware and IMO it fits right in between all other piggybacks and standalone EMSs... it bridges what used to be a chasm of a gap. It is NOT an easy system for most to learn and get tweaked just right quickly (at least not with S/D setups) as every engine is different and there is so much control available. In order to make use of the boost control capabilities you have to be running a S/D setup. To make use of the timing monitor feature (not related to the timing control feature) you must not be using the MAF signal input wiring. Tip in and tip out refer to how much and how fast the fuel map is enriched and how quickly that enrichment is stopped as you lean into the throttle and as you let off the throttle. Enrichment refers to fuel added in addition to what the tuned map calls for; this is used in cases where there is a surge as the throttle is initially opened and an unexpected drop in air flow such as in the case of a BOV discharging. S/D setups require a lot of tweaking in the real of tip in controls, no adjustment is needed for tip out though as the Pro reads the amount of air after the throttle body. With an S/D setup you could run with a giant, gaping hole in the intercooler and still drive the car home... on a stock system, you're stranded. S/D setups can be tricky to setup as the computer is calculating the airflow and not quite measuring it as is the case with any other type of meter. Installing a large GM MAF (for example) is a simple enough affair as the Pro simply translates the reading the MAF sends it... no real need to hassle with tip in adjustments unless you're tuning for perfection. Unfortunately, when running in "Translation Mode" the MAFT Pro cannot be used as a boost controller and if used with a MAF it cannot be used to monitor ignition timing advance. This is not a cheap system, has a steep enough learning curve to scare away some people, has a decent support base, offers most of the functionality previously only available with a standalone. The other nice thing is having all of your piggybacks in one box and reading in the same data logging application. There's also been talk of adding launch control and knock monitoring, but I don't know where that's at right now... might happen, might not.

11-05-2009, 06:13 AM	#7
jdmmilhouse Stock Join Date: Nov 2009 Location: chicago Posts: 28	all this info is great! u guys are so helpful , im new to supras,ive owned hondas and know all about building and modifying them, now i have to make the transition over to supras, thankfuly my guy here in chicago knows his 2jz's and 7m's he owns a ae86 with a 2jzgte....he did all the work from mounts to wiring in his home garage ! unlike......hondatech u guys are very supporting & helpful ! thanx again