Overboost, 854 T-5R 1995
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MadeInJapan
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- Year and Model: '98 S70 T5 '07S40T5
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I think he's saying he gets boost but not the extended 30 second boost that's characteristic of the T-5R.
'98 S70 T5 Emrld Grn Met/Beige Tons of Upgrades Mobil-1
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo
When does this 30 seconds of boost happen? Every time you press on the throttle or at full throttle. I understand the T-5R has more horsepower than the T-5, but is it only for the 30 seconds. What hpppens after the 30 seconds has expired?
I found this info about turbo charger control in my Vadis software for a 850 turbo. I hope it will help.
Turbo charger (TC) control
Overview
The function of the TC control system is to optimise boost pressure and, as a result, engine output under the most variable conditions. Since boost pressure is controlled electronically, the TC delivers full output at a speed as low as 2000 rpm. This, in turn, means that high torque is available throughout the entire speed range.
TC boost pressure is controlled by the ECM.
Turbocharger (TC)
The function of the turbocharging system is to increase engine output. This is achieved by compressing the intake air in the turbocompressor. The engine management system detects that the cylinder is being charged with a greater quantity of air and responds by injecting more fuel. In other words, the cylinder is charged with a greater quantity of air/fuel mixture than would be induced normally. The pressure developed in the system is known as boost pressure.
Exhaust gases enter the turbine through the inlet chamber (1) and are discharged to the exhaust pipe (2). Fresh air is drawn through the intake pipe (3) and, following compression, flows to the engine intake manifold through the outlet chamber (4) and charge air cooler (CAC).
Wastegate valve
The boost pressure may become excessive if the turbine speed is too high. This is prevented by the wastegate valve (5), which bypasses a proportion of the exhaust gases flowing to the turbine.
TC control valve
The wastegate valve is controlled by the boost pressure by means of the TC control valve (6). An output on the ECM (7) supplies the valve with a pulsating signal, the duty cycle of which can be varied to control the pressure delivered to the wastegate valve servo. When the ECM determines that a higher boost pressure is permissible, the duty cycle of the signal delivered to the TC control valve is increased and a proportion of the pressure delivered to the servo is relieved to the air intake. The control pressure and wastegate valve opening are thereby reduced, increasing the flow of exhaust gases through the turbine and increasing boost pressure.
Control of TC boost pressure
The TC control valve duty cycle (pulsating signal) is controlled by a desired value computed by the ECM.
The ECM uses signals from the following sensors for this purpose:
*TP sensor (8)
*MAF sensor (9)
*RPM sensor (10)
In other words, the system is not equipped with a pressure sensor. The ECM uses the MAF sensor signal (a measure of the flow through the ACL) to compute boost pressure.
Boost pressure reduction
When the car is driven in 1st or reverse, wheel spin may easily occur if normal turbo control is in operation. To prevent this, the boost pressure is reduced below 3000 rpm when these gears are engaged.
On manuals, the boost pressure reduction function is controlled by the ECM. On automatics, the TCM transmits a signal to the ECM requesting a reduction in the pressure and the request is implemented by the ECM if a reduction is needed.
On automatics, boost pressure reduction also takes place when the
Turbo charger (TC) control
Overview
The function of the TC control system is to optimise boost pressure and, as a result, engine output under the most variable conditions. Since boost pressure is controlled electronically, the TC delivers full output at a speed as low as 2000 rpm. This, in turn, means that high torque is available throughout the entire speed range.
TC boost pressure is controlled by the ECM.
Turbocharger (TC)
The function of the turbocharging system is to increase engine output. This is achieved by compressing the intake air in the turbocompressor. The engine management system detects that the cylinder is being charged with a greater quantity of air and responds by injecting more fuel. In other words, the cylinder is charged with a greater quantity of air/fuel mixture than would be induced normally. The pressure developed in the system is known as boost pressure.
Exhaust gases enter the turbine through the inlet chamber (1) and are discharged to the exhaust pipe (2). Fresh air is drawn through the intake pipe (3) and, following compression, flows to the engine intake manifold through the outlet chamber (4) and charge air cooler (CAC).
Wastegate valve
The boost pressure may become excessive if the turbine speed is too high. This is prevented by the wastegate valve (5), which bypasses a proportion of the exhaust gases flowing to the turbine.
TC control valve
The wastegate valve is controlled by the boost pressure by means of the TC control valve (6). An output on the ECM (7) supplies the valve with a pulsating signal, the duty cycle of which can be varied to control the pressure delivered to the wastegate valve servo. When the ECM determines that a higher boost pressure is permissible, the duty cycle of the signal delivered to the TC control valve is increased and a proportion of the pressure delivered to the servo is relieved to the air intake. The control pressure and wastegate valve opening are thereby reduced, increasing the flow of exhaust gases through the turbine and increasing boost pressure.
Control of TC boost pressure
The TC control valve duty cycle (pulsating signal) is controlled by a desired value computed by the ECM.
The ECM uses signals from the following sensors for this purpose:
*TP sensor (8)
*MAF sensor (9)
*RPM sensor (10)
In other words, the system is not equipped with a pressure sensor. The ECM uses the MAF sensor signal (a measure of the flow through the ACL) to compute boost pressure.
Boost pressure reduction
When the car is driven in 1st or reverse, wheel spin may easily occur if normal turbo control is in operation. To prevent this, the boost pressure is reduced below 3000 rpm when these gears are engaged.
On manuals, the boost pressure reduction function is controlled by the ECM. On automatics, the TCM transmits a signal to the ECM requesting a reduction in the pressure and the request is implemented by the ECM if a reduction is needed.
On automatics, boost pressure reduction also takes place when the
I also found this info in my software but in a different place.
A pressure regulator (3) which controls the waste gate valve via a link (4). The pressure in the regulator is controlled by an electronically controlled turbo valve. If the turbo valve fails the pressure regulator ensures that boost pressure is limited to approximately 135 kPa (absolute pressure). Maximum boost pressure : 166
A pressure regulator (3) which controls the waste gate valve via a link (4). The pressure in the regulator is controlled by an electronically controlled turbo valve. If the turbo valve fails the pressure regulator ensures that boost pressure is limited to approximately 135 kPa (absolute pressure). Maximum boost pressure : 166
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