striker
New Member
The one thing i haven't seen awnsered yet (think the question was asked though in some form)
to get the peak hp RPM higher up in the rev range the runners go shorter, but where did erol's 50mm diameter throttle valve come from?
we're obviously trying to make the effective diamater of the intake bigger to undo the boudary layer fenomenon making it smaller than it is is that the definitive reason?
the practical side of this.
is it the 50mm making it able to reach 500+hp CFM
and the short length of the runner decides where in the rev range peak HP comes?
from what i know/think (no expert by any means, just lots off theory and maths done)
I have the lower manifold but only a very small part of it, runners are now about 6cm long from plenum chamber into the head port. but the diameter of the part retained is stock,
what this will do is shift the peak rpm point upwards, and being able to flow a little better because the boudary layer effect increases dramticly in longer tubes. also the intake tract from the plenum to the valve has now only got 1 angle (from port to valve) instead of 3. in corners/angles flow choke is a very big factor.
How did you get the angle of entry into the head port that steep erol by welding up the lower part of the port? and have you been able to fully eliminate the curve/angle into the valve throat?
@ jibby, I hear you on the experts vs hobby man debate, but all of ou keep it nice please, here's one for you.
warning: "low cost tech approach DIY research and tune project)
get 2 pieces of 8mm alloy plate make those into intake manifold flanges, 8 peices of tube about 10cm long 40mm in diameter, or fabricate from sheet tapper from 40 to 45mm ID, 2 stes of hayabusa or R1 throttle bodies from ebay, mount everthing together and put it where your stock manifold now is. make an airbox to cover the intake trumpets, run a tube the size of you AFM/MAF outlet from the box towards that sensor leave you cone filter attached, and start to play with the length of the trumpets and if possible the length of the runners.
Very low cost, no need to inmediatly convert to programmable manegment, easily sold on if no succes. Nice learning curve and practical stuff like that beats calculting till you see purple while still not having put anything together.
I actually did this on my old 16v T-vis 4age in my striker once throttle response was through the roof compared to stock, and torque kept on about 1400rpm higher than stock, result extra BHP from the RPM. did require a little higher fuel presure but was controlled by the stock 4age ECU, I've never tried on MAP version but if a canister is used for vacuum I think it coulb be possible,
back to topic
Grtz Thomas (not scottish btw)
to get the peak hp RPM higher up in the rev range the runners go shorter, but where did erol's 50mm diameter throttle valve come from?
we're obviously trying to make the effective diamater of the intake bigger to undo the boudary layer fenomenon making it smaller than it is is that the definitive reason?
the practical side of this.
is it the 50mm making it able to reach 500+hp CFM
and the short length of the runner decides where in the rev range peak HP comes?
from what i know/think (no expert by any means, just lots off theory and maths done)
I have the lower manifold but only a very small part of it, runners are now about 6cm long from plenum chamber into the head port. but the diameter of the part retained is stock,
what this will do is shift the peak rpm point upwards, and being able to flow a little better because the boudary layer effect increases dramticly in longer tubes. also the intake tract from the plenum to the valve has now only got 1 angle (from port to valve) instead of 3. in corners/angles flow choke is a very big factor.
How did you get the angle of entry into the head port that steep erol by welding up the lower part of the port? and have you been able to fully eliminate the curve/angle into the valve throat?
@ jibby, I hear you on the experts vs hobby man debate, but all of ou keep it nice please, here's one for you.
warning: "low cost tech approach DIY research and tune project)
get 2 pieces of 8mm alloy plate make those into intake manifold flanges, 8 peices of tube about 10cm long 40mm in diameter, or fabricate from sheet tapper from 40 to 45mm ID, 2 stes of hayabusa or R1 throttle bodies from ebay, mount everthing together and put it where your stock manifold now is. make an airbox to cover the intake trumpets, run a tube the size of you AFM/MAF outlet from the box towards that sensor leave you cone filter attached, and start to play with the length of the trumpets and if possible the length of the runners.
Very low cost, no need to inmediatly convert to programmable manegment, easily sold on if no succes. Nice learning curve and practical stuff like that beats calculting till you see purple while still not having put anything together.
I actually did this on my old 16v T-vis 4age in my striker once throttle response was through the roof compared to stock, and torque kept on about 1400rpm higher than stock, result extra BHP from the RPM. did require a little higher fuel presure but was controlled by the stock 4age ECU, I've never tried on MAP version but if a canister is used for vacuum I think it coulb be possible,
back to topic
Grtz Thomas (not scottish btw)
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