Lyris - Email Marketing Software
Current forum: sconz |
You are: not logged in
messages search conference my_account my_forums all_forums about help
Create New Message
BCC Question   2004-02-13 10:40:00 <Dave>
I have a 1993 Jspec TT,

I have tried raising the boost it will climb to 15-16 psi then just drop back to the stock 11, Is this the fuel cut coming in or what? I am not getting any engine lights or anything coming on its like the ecu regulates the boost somehow..
any help would be awesome
Dave
Reply

Re: BCC Question   2004-02-13 10:43:00 <Cully Paterson>
Hi Dave,

> I have a 1993 Jspec TT,
>
> I have tried raising the boost it will climb to 15-16 psi then just drop
back to the stock 11, Is this the fuel cut coming in or what? I am not
getting any engine lights or anything coming on its like the ecu regulates
the boost somehow..
> any help would be awesome

What method are you using to up the boost? I'm pretty sure that I can
answer the question straight off, but want to confirm how you're controlling
the boost first.

Cully


Reply

Re: BCC Question   2004-02-13 10:43:00 <Dave>
I am using a go fast bits Manual controller
Reply

Re: BCC Question   2004-02-13 10:46:00 <Dave>
Hi Cully,

I am removing the same hose for the bleeder T mod and replacing it with the manual controller (under bonnet controller) just one of those allan key types
Reply

Re: Re:BCC Question   2004-02-13 10:53:00 <Cully Paterson>

> I am using a go fast bits Manual controller

OK, I assume you're talking about one of these:
http://www.gofastbits.com.au/boost.htm

The answer in which case is: get a boost control that's not a piece of crap.
By their description it's simply a wastegate bleed, which is never
particularly good for controlling boost. The weirdo sequential setup on the
Mk-IVs probably doesn't help matters much either.

I'd also suggest taking careful note of their claims on the web page:
"Why use a GFB boost controller? The most obvious reason is that YOU control
the boost! You can wind it up for those go fast times, or you can even lower
it below the factory setting to save fuel on long trips. Don't want someone
else to thrash your car? Simply wind the adjusting screw in before handing
over the keys!"

It's absolutely impossible to lower boost below the standard wastegate
setting using a bleed system - Im-Poss-I-Ble.

Do it right - get a decent electronic controller. They're relatively easy
to find second hand in good condition. I got my EVC-IV for quite low money,
and it kicks butt.

Cheers
Cully

Reply

Re: Re:BCC Question   2004-02-13 10:59:00 <Dave>
Cully,
Thanks heaps that really helps me out, but does this mean my fuel cut is disabled already or I just haven't boosted high enough for long enough yet?
Dave
Reply

Re: Re:Re:BCC Question   2004-02-13 11:01:00 <Cully Paterson>

> Thanks heaps that really helps me out, but does this mean my fuel cut is
disabled already or
>I just haven't boosted high enough for long enough yet?

The latter. Fuel cut means exactly that - the fuel gets chopped completely
for a fraction of a second. It's like hitting a brick wall.

Cully


Reply

Re: BCC Question   2004-02-13 11:03:00 <David Gillard>
Cully,
Thanks for your help too
the hose I replace is the one which goes from the Actuator to the VSV under the hood on drivers side, near the alternator.  I remove the hose and install 2 hoses attached with the GFB controller.
regards,
Dave

Cully Paterson wrote:
Hi Dave,

  
I have a 1993 Jspec TT,

I have tried raising the boost it will climb to 15-16 psi then just drop
    
back to the stock 11, Is this the fuel cut coming in or what?  I am not
getting any engine lights or anything coming on its like the ecu regulates
the boost somehow..
  
any help would be awesome
    

What method are you using to up the boost?  I'm pretty sure that I can
answer the question straight off, but want to confirm how you're controlling
the boost first.

Cully



---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: BCC Question   2004-02-13 11:03:00 <David Gillard>
Cully,
 Thanks heaps that really helps me out, but does this mean my fuel cut is disabled already or I just haven't boosted high enough for long enough yet?
Dave

Cully Paterson wrote:
I am using a go fast bits Manual controller
    

OK, I assume you're talking about one of these:
http://www.gofastbits.com.au/boost.htm

The answer in which case is: get a boost control that's not a piece of crap.
By their description it's simply a wastegate bleed, which is never
particularly good for controlling boost.  The weirdo sequential setup on the
Mk-IVs probably doesn't help matters much either.

I'd also suggest taking careful note of their claims on the web page:
"Why use a GFB boost controller? The most obvious reason is that YOU control
the boost! You can wind it up for those go fast times, or you can even lower
it below the factory setting to save fuel on long trips. Don't want someone
else to thrash your car? Simply wind the adjusting screw in before handing
over the keys!"

It's absolutely impossible to lower boost below the standard wastegate
setting using a bleed system - Im-Poss-I-Ble.

Do it right - get a decent electronic controller.  They're relatively easy
to find second hand in good condition.  I got my EVC-IV for quite low money,
and it kicks butt.

Cheers
Cully


---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: BCC Question   2004-02-13 11:06:00 <Cully Paterson>

>the hose I replace is the one which goes from the Actuator to the VSV under
the
>hood on drivers side, near the alternator. I remove the hose and install 2
hoses
>attached with the GFB controller.

Dave, you sure you've connected to the correct hose? You do understand how
the sequential set-up works on the Mk-IV, yeah? You realise there is only
one wastegate for the two turbos, and the other actuator is for the
seqential valve?

Cully

Reply

Re: Re:Re:BCC Question   2004-02-13 11:08:00 <Dave>
Cully,

Ok I am not getting the feeling of hitting a brick wall or anything the car just won't hold the boost
Dave
Reply

Re: BCC Question   2004-02-13 11:14:00 <Dave>
I hope I am doing it on the right hose I will atach a pic of the hose I am removing.
I am basically doing the mod attached but with the controller instead of the "T Piece"
Wastegate Bleeder T mod
below is the steps for the mod

Purpose: To create more boost than stock (11psi). With this mod on a stock Supra, expect about 15-17 psi of boost, which is about 60-70 HP!
Note: do the BCC before doing this mod to prevent fuel cut!
Parts Required: two 1/4"x1/4"x1/4" vacuum Ts (available at auto parts stores), knife, 2" long 1/4" diameter hose (optional).
Time Required: 5 minutes.
How it Works: By bleeding off air from the actuator, the wastegate stays closed longer, which builds more boost than stock.
Disclaimer: This modification puts additional stress on the turbos, clutch, transmission, etc. These components may wear out prematurely. Obviously this modification will void your warranty (however, it is easily reversible). A boost gauge is essential to monitor boost levels. The general consensus is that you should not run more than around 18 psi on a regular basis.
Steps:

1. Locate the black, 6" hose that goes from the vsv to the brass actuator. Figure 1 shows the general location: front, left side of the engine bay, just above the alternator.

2. Figure 3 shows a close up. Cut hose 2 in half. Insert a vacuum T (fig. 2) into the two hose ends that were just created by cutting.
Note: there are two ways to insert the vacuum T:
As in fig. 4 (this is the classic method, creates approx. 15psi on a stock motor).

As in fig. 5 (this creates additional 1-2 psi of boost because most of the airflow coming out of the actuator goes straight thru the open end of the T). I recommend using a a Manual Boost Controller to limit boost if this method is used.


Note: An alternate/better way is to disconnect hose 2 from the actuator. Connect a 2" long, 1/4" diameter hose to the actuator. Connect hose 2 to this new 2" hose via the vacuum T. This method doesn't require cutting the factory hose, making it easier to put the car back to stock condition.

3. If desired, attach a 12' long 1/4" diameter hose to the open end of the T (as shown if fig. 3) and run hose into the cockpit (if desired). A simple valve can be attached to this hose that can be used as a Manual Boost Controller.

4. To gain approx. one more psi of boost, cut hose 1 in half and insert a T (fig. 6). Note that you can't use this in conjunction with the Manual Boost Controller unless you run another hose and valve off this T as well. On my car, I just keep the T on hose 1 capped unless I go to the drag strip.
Note: some people have found that 1/4" vacuum Ts aren't tight enough. If a hose blows off the T then use a 5/16" T instead, and/or consider using hose clamps.

To create the maximum amount of boost (for the drag strip, etc.), simply disconnect hoses 1 and 2.

Reply

Re: Re:BCC Question   2004-02-13 11:21:00 <Cully Paterson>
Yuuuuuuuck. Refer to previous - get a competant boost controller, do it
right, live happily ever after.


----- Original Message -----
From: "Dave" <david.gillard@buseco.monash.edu.au>
To: "Supra Club of NZ Mailing List" <sconz@list.supras.org.nz>
Sent: Friday, February 13, 2004 11:08 AM
Subject: Re:[sconz] BCC Question


> I hope I am doing it on the right hose I will atach a pic of the hose I am
removing.
> I am basically doing the mod attached but with the controller instead of
the "T Piece"
> Wastegate Bleeder T mod
> below is the steps for the mod
>
> Purpose: To create more boost than stock (11psi). With this mod on a stock
Supra, expect about 15-17 psi of boost, which is about 60-70 HP!
> Note: do the BCC before doing this mod to prevent fuel cut!
> Parts Required: two 1/4"x1/4"x1/4" vacuum Ts (available at auto parts
stores), knife, 2" long 1/4" diameter hose (optional).
> Time Required: 5 minutes.
> How it Works: By bleeding off air from the actuator, the wastegate stays
closed longer, which builds more boost than stock.
> Disclaimer: This modification puts additional stress on the turbos,
clutch, transmission, etc. These components may wear out prematurely.
Obviously this modification will void your warranty (however, it is easily
reversible). A boost gauge is essential to monitor boost levels. The general
consensus is that you should not run more than around 18 psi on a regular
basis.
> Steps:
>
> 1. Locate the black, 6" hose that goes from the vsv to the brass actuator.
Figure 1 shows the general location: front, left side of the engine bay,
just above the alternator.
>
> 2. Figure 3 shows a close up. Cut hose 2 in half. Insert a vacuum T (fig.
2) into the two hose ends that were just created by cutting.
> Note: there are two ways to insert the vacuum T:
> As in fig. 4 (this is the classic method, creates approx. 15psi on a stock
motor).
>
> As in fig. 5 (this creates additional 1-2 psi of boost because most of the
airflow coming out of the actuator goes straight thru the open end of the
T). I recommend using a a Manual Boost Controller to limit boost if this
method is used.
>
>
> Note: An alternate/better way is to disconnect hose 2 from the actuator.
Connect a 2" long, 1/4" diameter hose to the actuator. Connect hose 2 to
this new 2" hose via the vacuum T. This method doesn't require cutting the
factory hose, making it easier to put the car back to stock condition.
>
> 3. If desired, attach a 12' long 1/4" diameter hose to the open end of the
T (as shown if fig. 3) and run hose into the cockpit (if desired). A simple
valve can be attached to this hose that can be used as a Manual Boost
Controller.
>
> 4. To gain approx. one more psi of boost, cut hose 1 in half and insert a
T (fig. 6). Note that you can't use this in conjunction with the Manual
Boost Controller unless you run another hose and valve off this T as well.
On my car, I just keep the T on hose 1 capped unless I go to the drag strip.
> Note: some people have found that 1/4" vacuum Ts aren't tight enough. If a
hose blows off the T then use a 5/16" T instead, and/or consider using hose
clamps.
>
> To create the maximum amount of boost (for the drag strip, etc.), simply
disconnect hoses 1 and 2.
>


----------------------------------------------------------------------------
----


> ---
> Supra Club of New Zealand
> http://www.supras.org.nz/
>

Reply

Re: Re:BCC Question   2004-02-13 11:30:00 <Dave>
LOL thanks for that I will buy a Profec Bspec II I can pick it up tonight.
So If I boost it up when will I hit fuel cut?
Dave
Reply

Re: Re:Re:BCC Question   2004-02-13 11:41:00 <Cully Paterson>

> LOL thanks for that I will buy a Profec Bspec II I can pick it up tonight.
> So If I boost it up when will I hit fuel cut?

I think about 19psi on a standard set-up, give or take. You really don't
want to push those turbos too hard though - they're a bit too delicate to
take much abuse.

Cully

Reply

Re: Re:BCC Question   2004-02-13 12:04:00 <David Gillard>
no worries thank you very much I will put the bcc I ordered on hold and see how it all goes.
you have been a great help thanks
Dave

Cully Paterson wrote:
LOL thanks for that I will buy a Profec Bspec II I can pick it up tonight.
So If I boost it up when will I hit fuel cut?
    

I think about 19psi on a standard set-up, give or take.  You really don't
want to push those turbos too hard though - they're a bit too delicate to
take much abuse.

Cully


---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:BCC Question   2004-02-13 13:16:00 <Dave>
do you think I need to buy a BCC or has it been deleted from the ecu or something, cause I can get the car over 180km pretty easy too, is there any way I can tell if someone has performed a bcc
Reply

Re: Re:Re:BCC Question   2004-02-13 13:19:00 <Cully Paterson>

> do you think I need to buy a BCC or has it been deleted from the ecu or
>something, cause I can get the car over 180km pretty easy too, is there
>any way I can tell if someone has performed a bcc

I assume you're referring to Boost Cut Controller? Otherwise known as Fuel
Cut Defencer, also known as spawn of satan's bottom...

That hint enough?

Cully

Reply

Re: Re:Re:BCC Question   2004-02-13 13:22:00 <Dave>
you mean they are no good?
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 13:23:00 <Cully Paterson>
Hint well taken.

----- Original Message -----
From: "Dave" <david.gillard@buseco.monash.edu.au>
To: "Supra Club of NZ Mailing List" <sconz@list.supras.org.nz>
Sent: Friday, February 13, 2004 1:21 PM
Subject: Re:[sconz] Re:Re:BCC Question


> you mean they are no good?
> ---
> Supra Club of New Zealand
> http://www.supras.org.nz/
>
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 13:28:00 <Dave>
how come? what can you run your boost at without one?
Reply

Re: Re:Re:Re:Re:BCC Question   2004-02-13 14:11:00 <Cully Paterson>

> how come? what can you run your boost at without one?

Ok, given this topic comes up time and time again, I may as well make a full
article out of it and post it in the tech section of the web site...

<title>
Using Fuel Cut Defencers, AKA blowing up your engine.
</title>


Fuel Cut:
Fuel Cut is a deliberate mechanism put into ECUs by car manufacturers as a
safety feature. It exists in order to prevent turbos being over-boosted and
the consequent effects on the engine from the increased intake heat,
mechanical load, and other such factors. In Toyota's case when fuel cut is
triggered the ECU hard chops fuel delivery to the engine for a fraction of a
second. This is enough to kill the boost and bring the engine back to
within normal operating parameters. Fuel cut is particularly important on
some vehicles, as raising the boost above stock level will almost invariably
cause the turbine shaft to snap due to the extra load: certain Subaru and
Mazda set-ups are particularly prone to this.

Fuel cut is triggered in various different ways. In general the trigger is
tied to the volume of air that is being injested by the engine, not boost
level. This explains why it is easier to hit fuel cut on cold nights than
it is on hot days - the denser cold air means a larger mass of air is
entering the engine for any given boost level.

The following general methods are used to trigger fuel cut:
- Flap air flow meters (1GGTE, 5MGE, early 3SGTE, etc): Either AFM reading
reaching a certain value and/or microswitch trigger when the flap is opened
a certain distance.
- Karman Vortex AFMs (7MGTE, 1UZFE): Threshold built into the ECU that
triggers when a certain flow is reached through the AFM
- MAP (1JZGTE, 2JZGTE, late 3SGTE, etc): Threshold built into the ECU that
triggers when a certain pressure is reached by the MAP sensor.

What Fuel Cut Defencers do:
FCDs monitor the signal from the AFM/MAP sensor, and when the output reaches
the level that will trigger fuel cut they begin to modify the output,
telling the ECU that no more air is entering the engine, regardless of how
much more air is actually being stuffed in there. This is *EXTREMELY*
dangerous on turbo engines, as it causes the air/fuel mixture to run lean.
A lean mixture under boost promotes detonation, which in turn causes a
variety of ailments ranging from blown head gaskets up to electrical faults
(caused by pistons and rods exiting the block and knocking off the
alternator on the way past).

Arguments people use to try to justify the use of FCDs:
"The engine runs rich anyway, there's plenty of fuel there, it doesn't
matter if it runs leaner".
Answer: Turbo engines must run rich by design. Compressing the air causes
the intake charge to heat up significantly, which is a prime cause of
detonation. The ECU runs the engine rich so that the excess fuel will cool
the intake charge and assist bringing it back down to a level that will
prevent detonation from occuring. An FCD will effectively remove this
safety buffer. Typically turbo engines will run richer than they absolutely
need to in order to ensure the safety margin is maintained, in which case
the FCD will 'get away' with leaning out the engine for a few extra pounds
boost. However that does not allow for any variation in fuel quality,
ambient temperature, etc, all of which contribute to eroding the safety
margin before the FCD even enters the picture.

"The ECU learns! Surely it'll use feedback to work out that it's running
lean and adjust to suit"
Nope. ECU learning is based on Exhaust Gas Oxygen sensor feedback. The
oxygen sensor gives the ECU a rough guide as to whether the engine is
running rich or lean, and the ECU will compensate to try to achieve the
correct mixture. However, this only applies when the engine is idling or
under light cruise - as soon as you put your foot down the O2 sensor
feedback goes right out the window and the ECU resorts to pre-programmed
fuel maps that are made to cope with normal conditions up to the point where
fuel cut occurs, and not beyond. Once that point is reach and passed the
ECU is in 'wildly inaccurate mode'.

"But plenty of people buy these things, they MUST work without harming my
engine!"
Really? OK, in that case I've got some penis enlargement pills here you
might be interested in too, and a really good investment scheme in Nigeria
that will make you $500,000 (FIVE HUNDRED THOUSAND US DOLLARS).

Getting around fuel cut:
There are various ways to do it, some good, some not. The essential problem
is to make sure that the correct amount of additional fuel reaches the
cylinders once the engine goes beyond where fuel cut normally happens. Some
examples of methods to do achieve this:
- Additional injector controllers: Used to run a 7th injector to add fuel.
FCD also required to enable the engine to go beyond fuel cut. Not
particularly nice method due to fuel distribution and atomisation problems.
- Rising rate fuel pressure regulator: Cheap hack. Used to ramp up the fuel
pressure to the injectors as boost increases, thereby deliberately
overfueling the engine. FCD also required to make this work. Very
inaccurate method, and fuel injectors have limitations as to how much extra
pressure can be usefully delivered to them.
- Remapping daughter boards: The only equivilent to 'chipping' for Toyota
ECUs. Additional board that is added to the ECU to monitor and alter the
signals going to/from the ECU. Has the advantage over FCDs that it can also
be used to alter the fuel delivery and ignition timing. If done properly
then this is the next best thing to the last option...
- Complete replacement ECU: Link, Autronic, Motec, Haltec, etc etc.


Criticisms welcome.

Cheers
Cully



Reply

Re: Re:Re:Re:BCC Question   2004-02-13 14:38:00 <David Gillard>
thanks for all that info very useful. 
So how much boost can you run on your car? without boost cut?

Cully Paterson wrote:
how come?   what can you run your boost at without one?
    

Ok, given this topic comes up time and time again, I may as well make a full
article out of it and post it in the tech section of the web site...

<title>
Using Fuel Cut Defencers, AKA blowing up your engine.
</title>


Fuel Cut:
Fuel Cut is a deliberate mechanism put into ECUs by car manufacturers as a
safety feature.  It exists in order to prevent turbos being over-boosted and
the consequent effects on the engine from the increased intake heat,
mechanical load, and other such factors.  In Toyota's case when fuel cut is
triggered the ECU hard chops fuel delivery to the engine for a fraction of a
second.  This is enough to kill the boost and bring the engine back to
within normal operating parameters.  Fuel cut is particularly important on
some vehicles, as raising the boost above stock level will almost invariably
cause the turbine shaft to snap due to the extra load: certain Subaru and
Mazda set-ups are particularly prone to this.

Fuel cut is triggered in various different ways.  In general the trigger is
tied to the volume of air that is being injested by the engine, not boost
level.  This explains why it is easier to hit fuel cut on cold nights than
it is on hot days - the denser cold air means a larger mass of air is
entering the engine for any given boost level.

The following general methods are used to trigger fuel cut:
- Flap air flow meters (1GGTE, 5MGE, early 3SGTE, etc): Either AFM reading
reaching a certain value and/or microswitch trigger when the flap is opened
a certain distance.
- Karman Vortex AFMs (7MGTE, 1UZFE): Threshold built into the ECU that
triggers when a certain flow is reached through the AFM
- MAP (1JZGTE, 2JZGTE, late 3SGTE, etc): Threshold built into the ECU that
triggers when a certain pressure is reached by the MAP sensor.

What Fuel Cut Defencers do:
FCDs monitor the signal from the AFM/MAP sensor, and when the output reaches
the level that will trigger fuel cut they begin to modify the output,
telling the ECU that no more air is entering the engine, regardless of how
much more air is actually being stuffed in there.  This is *EXTREMELY*
dangerous on turbo engines, as it causes the air/fuel mixture to run lean.
A lean mixture under boost promotes detonation, which in turn causes a
variety of ailments ranging from blown head gaskets up to electrical faults
(caused by pistons and rods exiting the block and knocking off the
alternator on the way past).

Arguments people use to try to justify the use of FCDs:
"The engine runs rich anyway, there's plenty of fuel there, it doesn't
matter if it runs leaner".
Answer: Turbo engines must run rich by design.  Compressing the air causes
the intake charge to heat up significantly, which is a prime cause of
detonation.  The ECU runs the engine rich so that the excess fuel will cool
the intake charge and assist bringing it back down to a level that will
prevent detonation from occuring.  An FCD will effectively remove this
safety buffer.  Typically turbo engines will run richer than they absolutely
need to in order to ensure the safety margin is maintained, in which case
the FCD will 'get away' with leaning out the engine for a few extra pounds
boost.  However that does not allow for any variation in fuel quality,
ambient temperature, etc, all of which contribute to eroding the safety
margin before the FCD even enters the picture.

"The ECU learns!  Surely it'll use feedback to work out that it's running
lean and adjust to suit"
Nope.  ECU learning is based on Exhaust Gas Oxygen sensor feedback.  The
oxygen sensor gives the ECU a rough guide as to whether the engine is
running rich or lean, and the ECU will compensate to try to achieve the
correct mixture.  However, this only applies when the engine is idling or
under light cruise - as soon as you put your foot down the O2 sensor
feedback goes right out the window and the ECU resorts to pre-programmed
fuel maps that are made to cope with normal conditions up to the point where
fuel cut occurs, and not beyond.  Once that point is reach and passed the
ECU is in 'wildly inaccurate mode'.

"But plenty of people buy these things, they MUST work without harming my
engine!"
Really?  OK, in that case I've got some penis enlargement pills here you
might be interested in too, and a really good investment scheme in Nigeria
that will make you $500,000 (FIVE HUNDRED THOUSAND US DOLLARS).

Getting around fuel cut:
There are various ways to do it, some good, some not.  The essential problem
is to make sure that the correct amount of additional fuel reaches the
cylinders once the engine goes beyond where fuel cut normally happens.  Some
examples of methods to do achieve this:
- Additional injector controllers: Used to run a 7th injector to add fuel.
FCD also required to enable the engine to go beyond fuel cut.  Not
particularly nice method due to fuel distribution and atomisation problems.
- Rising rate fuel pressure regulator: Cheap hack.  Used to ramp up the fuel
pressure to the injectors as boost increases, thereby deliberately
overfueling the engine.  FCD also required to make this work.  Very
inaccurate method, and fuel injectors have limitations as to how much extra
pressure can be usefully delivered to them.
- Remapping daughter boards: The only equivilent to 'chipping' for Toyota
ECUs.  Additional board that is added to the ECU to monitor and alter the
signals going to/from the ECU.  Has the advantage over FCDs that it can also
be used to alter the fuel delivery and ignition timing.  If done properly
then this is the next best thing to the last option...
- Complete replacement ECU: Link, Autronic, Motec, Haltec, etc etc.


Criticisms welcome.

Cheers
Cully




---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 14:50:00 <Cully Paterson>

>thanks for all that info very useful.
>So how much boost can you run on your car? without boost cut?

Well, given I've got a different engine the comparison is moot. However
with the Lexus AFM and 550 injectors I can run to about 18/19psi before it
cuts.

Cully


Reply

Re: Re:Re:Re:BCC Question   2004-02-13 15:46:00 <David Gillard>
cool as thanks

Cully Paterson wrote:
thanks for all that info very useful.
So how much boost can you run on your car? without boost cut?
    

Well, given I've got a different engine the comparison is moot.  However
with the Lexus AFM and 550 injectors I can run to about 18/19psi before it
cuts.

Cully



---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 16:20:00 <David Gillard>
which model Lexus AFM do you have?

Cully Paterson wrote:
thanks for all that info very useful.
So how much boost can you run on your car? without boost cut?
    

Well, given I've got a different engine the comparison is moot.  However
with the Lexus AFM and 550 injectors I can run to about 18/19psi before it
cuts.

Cully



---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 16:23:00 <Cully Paterson>
I guess you're not familiar with that mod then. The 1UZ V8 AFM straps straight onto the 7M. Add 550cc injectors equals about 7psi extra max boost.

----- Original Message -----
From: David Gillard
To: Supra Club of NZ Mailing List
Sent: Friday, February 13, 2004 3:36 PM
Subject: Re: [sconz] Re:Re:Re:BCC Question


which model Lexus AFM do you have?

Cully Paterson wrote:

thanks for all that info very useful.
So how much boost can you run on your car? without boost cut?

Well, given I've got a different engine the comparison is moot. However
with the Lexus AFM and 550 injectors I can run to about 18/19psi before it
cuts.

Cully



---
Supra Club of New Zealand
http://www.supras.org.nz/
---
Supra Club of New Zealand
http://www.supras.org.nz/

(html version)
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 16:27:00 <Dave>
My engine is the 2jz-gte Twin Turbo does this still work?
what engine have you got?
Reply

Re: Re:Re:Re:Re:BCC Question   2004-02-13 16:28:00 <Cully Paterson>


> My engine is the 2jz-gte Twin Turbo does this still work?

No, you don't have an air flow meter to start with! Putting one on ain't
going to do much for you...


> what engine have you got?

Again, 7MGTE.

Cully

Reply

Re: Re:Re:Re:BCC Question   2004-02-13 16:30:00 <Stuart>
On Fri, 13 Feb 2004 16:25, Dave wrote:
> My engine is the 2jz-gte Twin Turbo does this still work?
> what engine have you got?

Nope, it's a 7M-GTE mod.

You have a MAP system, it's much harder to mod, but already good for quite a
bit of power. just for god sake don't allow a fuel-cut-defender on it!

If you wind up your boost you will start to discover that your wastegate is
not large enough, and the boost will skike, or creep up, and soon kill your
turbos, especially with a larger exhaust - I would recomend staying below
about 16PSI if you want them to last.

Stuart W.
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 16:50:00 <David Gillard>
so if I haven't done anything apart from exhaust and Filter on the 2JZ with a proper controller I should be able to obtain 16psi and hold it?

Cully Paterson wrote:
  
My engine is the 2jz-gte Twin Turbo does this still work?
    

No, you don't have an air flow meter to start with!  Putting one on ain't
going to do much for you...


  
what engine have you got?
    

Again, 7MGTE.

Cully


---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 17:06:00 <Stuart>
On Fri, 13 Feb 2004 16:30, David Gillard wrote:
> so if I haven't done anything apart from exhaust and Filter on the 2JZ
> with a proper controller I should be able to obtain 16psi and hold it?

That sounds reasonably safe, but you should install a good fast analogue boost
guage and watch it for boost creep.

And change oil regularly and good stuff, and cool down turbos after driving,
etc, etc...

Regards,
Stuart W.
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 17:58:00 <David Gillard>
no worries thanks alot for that I will give it a bash tonight, see if I can hold some decent PSI

Stuart wrote:
On Fri, 13 Feb 2004 16:30, David Gillard wrote:
  
 so if I haven't done anything apart from exhaust and Filter on the 2JZ
with a proper controller I should be able to obtain 16psi and hold it?
    

That sounds reasonably safe, but you should install a good fast analogue boost 
guage and watch it for boost creep.

And change oil regularly and good stuff, and cool down turbos after driving, 
etc, etc...

Regards,
Stuart W.

---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 18:02:00 <Andy S>
Hey Dave

We here at SCONZ mostly own Mk2 and Mk3 supras (yours
is a Mk4). There is another email list that caters
specifically to your model which can be found through
http://www.mkiv.co.nz

Feel free to ask your questions here, but few of us
have experience with the 2JZGTE engine you are asking
about, though your questions so far have been fairly
general :-)

Cheers
Andy S

=====
Visit my website http://andy.supras.org.nz

Home of the 5MGE-->7MGTE conversion!

__________________________________
Do you Yahoo!?
Yahoo! Finance: Get your refund fast by filing online.
http://taxes.yahoo.com/filing.html
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 18:46:00 <David Gillard>
Hi Stuart,
Thanks for that mate helps me quite a bit.
Can you tell me why the boost goes up to about 15-16psi around 4300 rpm  then it  regulates to 11 psi from about 4700rpm.  Cully said it would be my manual boost controller, do you agree?
Stuart wrote:
On Fri, 13 Feb 2004 16:25, Dave wrote:
  
My engine is the 2jz-gte Twin Turbo does this still work?
what engine have you got?
    

Nope, it's a 7M-GTE mod.

You have a MAP system, it's much harder to mod, but already good for quite a 
bit of power. just for god sake don't allow a fuel-cut-defender on it!

If you wind up your boost you will start to discover that your wastegate is 
not large enough, and the boost will skike, or creep up, and soon kill your 
turbos, especially with a larger exhaust - I would recomend staying below 
about 16PSI if you want them to last.

Stuart W.

---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 18:46:00 <David Gillard>
Sorry I am getting confused how can I boost up my Supra

David Gillard wrote:
so if I haven't done anything apart from exhaust and Filter on the 2JZ with a proper controller I should be able to obtain 16psi and hold it?

Cully Paterson wrote:
  
My engine is the 2jz-gte Twin Turbo does this still work?
    

No, you don't have an air flow meter to start with!  Putting one on ain't
going to do much for you...


  
what engine have you got?
    

Again, 7MGTE.

Cully


---
Supra Club of New Zealand
http://www.supras.org.nz/
  
---
Supra Club of New Zealand
http://www.supras.org.nz/
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 22:36:00 <Stuart>
On Fri, 13 Feb 2004 16:37, David Gillard wrote:
> Hi Stuart,
> Thanks for that mate helps me quite a bit.
> Can you tell me why the boost goes up to about 15-16psi around 4300 rpm 
> then it  regulates to 11 psi from about 4700rpm.  Cully said it would be my
> manual boost controller, do you agree? Stuart wrote:

Yep, I agree 100%. it sounds like you have it installed wrong so that it is
changing the boost level before the two turbos go to the twin setup, but not
the main boost regulation. Remember the setup on the sequention turbos on the
Mk.4 (what you have) is quite complex, and especially with a manual boost
controller it must be installed just right to work correctly.

You may well end up stressing the primary turbo excessively workin them this
way.

Regards,
Stuart.
Reply

Re: Re:Re:Re:BCC Question   2004-02-13 22:43:00 <Stuart>
On Fri, 13 Feb 2004 16:52, David Gillard wrote:
> Sorry I am getting confused how can I boost up my Supra

The air flow meter is a device on the front of the intake system of SOME supra
models that allows the computer to read how much air is entering the engine,
and therefore how much fuel it needs to add (it's a lot more complex than
that, but you get the idea..), and notably on the 7M-GTE engine you can make
changes to this that, along with larger fuel injectors, allow you to move for
boost limit up from 12PSI to around 18PSI.

However, you engine (2JZ-GTE) does NOT use an air flow meter, it uses a sensor
that tells it the air pressure in the plenium (the intake area between the
throttle and the runners leading to the valves), and it then uses a
mathematical description of how this particular engine works to work out how
much air will actually go in, and therefore how to add the fuel. This system
is not so easily modified.

However again, neither of these have anything to do with your boost level,
that is decided by the turbos waste gates (a complex enough situation on the
sequential turbo 2JZ). The computer just decides the limit to how much boost
you can run.
On a stock 7M-GTE this is around 12PSI (where stock is 7PSI), on a stock 2JZ
this is around 17PSI (from memory, where stock is 12PSI). the change of AFM
which Cully refers to is a modification to the 7M-GTE which allows you to run
around 17-18PSI on it before you reach the limit.

There are very bad devices for both engines called FCD's, of fuel cut
defenders, which trick the computer into allowing more boost, but they are a
VERY BAD tHING, because they force the engine to run lean at higher boost,
and this will soon kill the engine, and at a minimum means you get no more
power anyway. These are unrelated to a SCD (speed cut defender), which allows
you top run over 180Km/H.

Engine for one sitting?

Regards,
Stuart W.
Reply

Re: Re:Re:Re:BCC Question   2004-02-14 01:18:00 <David Gillard>
Thanks man thats very helpful
If I setup the boost controller so it bypasses the vsv would it work
properly?
Dave

----- Original Message -----
From: Stuart <stuartw@kcbbs.gen.nz>
Date: Friday, February 13, 2004 8:45 pm
Subject: Re: [sconz] Re:Re:Re:BCC Question

> On Fri, 13 Feb 2004 16:52, David Gillard wrote:
> > Sorry I am getting confused how can I boost up my Supra
>
> The air flow meter is a device on the front of the intake system
> of SOME supra
> models that allows the computer to read how much air is entering
> the engine,
> and therefore how much fuel it needs to add (it's a lot more
> complex than
> that, but you get the idea..), and notably on the 7M-GTE engine
> you can make
> changes to this that, along with larger fuel injectors, allow you
> to move for
> boost limit up from 12PSI to around 18PSI.
>
> However, you engine (2JZ-GTE) does NOT use an air flow meter, it
> uses a sensor
> that tells it the air pressure in the plenium (the intake area
> between the
> throttle and the runners leading to the valves), and it then uses
> a
> mathematical description of how this particular engine works to
> work out how
> much air will actually go in, and therefore how to add the fuel.
> This system
> is not so easily modified.
>
> However again, neither of these have anything to do with your
> boost level,
> that is decided by the turbos waste gates (a complex enough
> situation on the
> sequential turbo 2JZ). The computer just decides the limit to how
> much boost
> you can run.
> On a stock 7M-GTE this is around 12PSI (where stock is 7PSI), on a
> stock 2JZ
> this is around 17PSI (from memory, where stock is 12PSI). the
> change of AFM
> which Cully refers to is a modification to the 7M-GTE which allows
> you to run
> around 17-18PSI on it before you reach the limit.
>
> There are very bad devices for both engines called FCD's, of fuel
> cut
> defenders, which trick the computer into allowing more boost, but
> they are a
> VERY BAD tHING, because they force the engine to run lean at
> higher boost,
> and this will soon kill the engine, and at a minimum means you get
> no more
> power anyway. These are unrelated to a SCD (speed cut defender),
> which allows
> you top run over 180Km/H.
>
> Engine for one sitting?
>
> Regards,
> Stuart W.
>
> ---
> Supra Club of New Zealand
> http://www.supras.org.nz/
>

Reply

Re: Re:Re:Re:BCC Question   2004-02-14 23:52:00 <Stuart>
On Fri, 13 Feb 2004 22:52, David Gillard wrote:
> Thanks man thats very helpful
> If I setup the boost controller so it bypasses the vsv would it work
> properly?
> Dave
couldnt tell you from the top of my head.. I'm sure the Mk.4 people have a web
site describing it somewhere, have you tried them?

Regards,
Stuart W.
Reply

Re: Re:Re:Re:BCC Question   2004-02-16 11:25:00 <David Gillard>
I bypassed the vsv and it worked a treat I can now hold anything up to 18 PSI

Cully Paterson wrote:
thanks for all that info very useful.
So how much boost can you run on your car? without boost cut?
    

Well, given I've got a different engine the comparison is moot.  However
with the Lexus AFM and 550 injectors I can run to about 18/19psi before it
cuts.

Cully



---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-16 11:30:00 <David Gillard>
you were right on the money mate, I have bypassed the VSV I can now hold anything up to 18 PSI
regards,
Dave

Stuart wrote:
On Fri, 13 Feb 2004 22:52, David Gillard wrote:
  
Thanks man thats very helpful
If I setup the boost controller so it bypasses the vsv would it work
properly?
Dave
    
couldnt tell you from the top of my head.. I'm sure the Mk.4 people have a web 
site describing it somewhere, have you tried them?

Regards,
Stuart W.

---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply

Re: Re:Re:Re:BCC Question   2004-02-16 12:05:00 <Stuart>
On Mon, 16 Feb 2004 11:20, David Gillard wrote:
> I bypassed the vsv and it worked a treat I can now hold anything up to 18
> PSI

It is quite probably not running as a simple twin-turbo setup, not the
sequential turbo system that it would notmally be - are you noticing less
low-rpm boost and a bit more lag? if so this could be why.

I'm no expert on the Mk.4 sequential setup (it's been a long time since I've
had to look at one).

Regards,
stuart W.
Reply

Re: Re:Re:Re:BCC Question   2004-02-16 17:41:00 <David Gillard>
Steve,

The car is running in the correct sequential way.  It was I had the MBC hooked up on the wrong tubing.  no problems now.
thanks for your help too.
Dave

Stuart wrote:
On Mon, 16 Feb 2004 11:20, David Gillard wrote:
  
 I bypassed the vsv and it worked a treat I can now hold anything up to 18
PSI
    

It is quite probably not running as a simple twin-turbo setup, not the 
sequential turbo system that it would notmally be - are you noticing less 
low-rpm boost and a bit more lag? if so this could be why.

I'm no expert on the Mk.4 sequential setup (it's been a long time since I've 
had to look at one).

Regards,
stuart W.

---
Supra Club of New Zealand
http://www.supras.org.nz/
  
Reply























































Lyris - Email Marketing Software