Lancia 16v head sequential twin turbo
Posted: February 24th, 2013, 3:52 pm
Hi Guy ,
I would like to ask some questions based on Lancias Abarth triflux ecv2 engine with the sequential twin turbo engine . I am sure that most of us are familiar with this engine !
I am thinking of a twin turbo project on the Lancia 16v turbo engine with a twin turbo sequential set up with max turbo response and high rpm power and i would like your thoughts on this very complicated idea !
My Engine current spec:
Bore 85mm
stroke: 86mm
inlet vlave diameter :35.5mm flow:173,5cfm @.55 inch lift @10"
ex valve diameter:30mm 147cfm @.55 inch lift @10"
camshaft spec:
inlet:valve lift = 11,75mm duration @ .1mm= 280 inlet:duration@ 1mm =244 lift@ tdc 2,8mm set @110degr full lift
exhaust: valve lift = 11.05mm duration @ .1mm= 262 inlet:duration@ 1mm =234 lift@ tdc 1.4mm set @115degr full lift
power : 720hp flywheel @ 9120rpm @28psi
torque: 58kgm flywheel @ 5800rpm @28psi
There are two options of doing this .
Option A.
Fabricate two exhaust manifolds 4 into 1 design with 28mm internal diameter, and each manifold will use 1 exhaust port per cylinder isolated from the other ex port ....this will require a minor welding at the end of the ex ports close to the manifold flange !
2:Each ex manifold will direct the ex flow to its small turbocharger with a max capacity of 360hp at 30psi of boost.
3:Turbocharger number one will use all the available ex gas from the engine ,to spool as quickly as possible! when the max boost of 28-30psi is reached an external waistegate valve will direct the excess of ex gas to the turbine inlet of the turbo number two.
3:Turbocharger number two will be fitted with a turbine outlet valve being shut( after the turbine housing on the ex downpipe) that will control the ex gas flow for this turbo, starting to open at around 4,500rpm and 28-30psi of boost . On the compressor side of turbo number2, a one way reed valve will direct the air flow to the intercooler inlet pipe during the 1st stage (waistgate gases of turbo1 to tubine inlet of turbo2 ) and then at higher rpm when the turbo2 has reached a higher boost 28-30psi a throttle valve will be used to direct the flow to the intercooler inlet .
Option number 2:
Fabricate one exsaust manifolt with 4 into 1 into 2 design with 40mm internal diameter and attahed both turbos with a Y joint !
All other parameters and valves on the systems will be working same as option A.
My questions are :
1:Will option A benefit a significant turbo spool (at least 500-800rpm sooner )at lower rpm due to the fact that all ex gases will have to pass from the smaller diameter exsaust valves , ports and exsaust pipes ?How much the exsaust gas velocity will affect turbo response?
And if yes will this affect the cylinder ex scavage in a positive way (at lower rpm) since only one ex valve will be used to scavage the ex gases up to 4500 rpm(bearing in mind that we are using a long duration cam wiht lots of overlap)?
2:On a high duration turbo cam ,during overlap some of the fresh air-fuel mixture will probably escape from the exast valve ...giving additional cooling to the ex valve ! Keeping the flow shut on the second turbo at lower rpm ,will this cause an issue to the valves and valve seats ?
3:What are your thoughts on an inlet manifolt with a similar aproach ? with 8 separate inlet ports ? will this be a benefit or too much hastle for nothing ?
Thanks in advance !
Mike.
I would like to ask some questions based on Lancias Abarth triflux ecv2 engine with the sequential twin turbo engine . I am sure that most of us are familiar with this engine !
I am thinking of a twin turbo project on the Lancia 16v turbo engine with a twin turbo sequential set up with max turbo response and high rpm power and i would like your thoughts on this very complicated idea !
My Engine current spec:
Bore 85mm
stroke: 86mm
inlet vlave diameter :35.5mm flow:173,5cfm @.55 inch lift @10"
ex valve diameter:30mm 147cfm @.55 inch lift @10"
camshaft spec:
inlet:valve lift = 11,75mm duration @ .1mm= 280 inlet:duration@ 1mm =244 lift@ tdc 2,8mm set @110degr full lift
exhaust: valve lift = 11.05mm duration @ .1mm= 262 inlet:duration@ 1mm =234 lift@ tdc 1.4mm set @115degr full lift
power : 720hp flywheel @ 9120rpm @28psi
torque: 58kgm flywheel @ 5800rpm @28psi
There are two options of doing this .
Option A.
Fabricate two exhaust manifolds 4 into 1 design with 28mm internal diameter, and each manifold will use 1 exhaust port per cylinder isolated from the other ex port ....this will require a minor welding at the end of the ex ports close to the manifold flange !
2:Each ex manifold will direct the ex flow to its small turbocharger with a max capacity of 360hp at 30psi of boost.
3:Turbocharger number one will use all the available ex gas from the engine ,to spool as quickly as possible! when the max boost of 28-30psi is reached an external waistegate valve will direct the excess of ex gas to the turbine inlet of the turbo number two.
3:Turbocharger number two will be fitted with a turbine outlet valve being shut( after the turbine housing on the ex downpipe) that will control the ex gas flow for this turbo, starting to open at around 4,500rpm and 28-30psi of boost . On the compressor side of turbo number2, a one way reed valve will direct the air flow to the intercooler inlet pipe during the 1st stage (waistgate gases of turbo1 to tubine inlet of turbo2 ) and then at higher rpm when the turbo2 has reached a higher boost 28-30psi a throttle valve will be used to direct the flow to the intercooler inlet .
Option number 2:
Fabricate one exsaust manifolt with 4 into 1 into 2 design with 40mm internal diameter and attahed both turbos with a Y joint !
All other parameters and valves on the systems will be working same as option A.
My questions are :
1:Will option A benefit a significant turbo spool (at least 500-800rpm sooner )at lower rpm due to the fact that all ex gases will have to pass from the smaller diameter exsaust valves , ports and exsaust pipes ?How much the exsaust gas velocity will affect turbo response?
And if yes will this affect the cylinder ex scavage in a positive way (at lower rpm) since only one ex valve will be used to scavage the ex gases up to 4500 rpm(bearing in mind that we are using a long duration cam wiht lots of overlap)?
2:On a high duration turbo cam ,during overlap some of the fresh air-fuel mixture will probably escape from the exast valve ...giving additional cooling to the ex valve ! Keeping the flow shut on the second turbo at lower rpm ,will this cause an issue to the valves and valve seats ?
3:What are your thoughts on an inlet manifolt with a similar aproach ? with 8 separate inlet ports ? will this be a benefit or too much hastle for nothing ?
Thanks in advance !
Mike.