will a large street port (race port) kill my stock twins?
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here's the only compressor map on the twins that i have found. as you can see it is incomplete as to scale.
we can back into the X scale.... it takes 1.92 cubic feet of air to produce one rotary rear wheel hp. let's assume that the motor is making 385. two turbos so 385/2= 193 rwhp per turbo.
193 X 1.92= 371 CFM/14.471= 25.6 lbs/minute. that sounds about right to me re total air delivery on the X scale.
as far as porting...
the relationship between the exhaust and intake ports can have a major effect on the point at which a compressor cavitates. the amount of overlap can effect the output side force against the compressor.
when considering ports on a rotary there really is alot of confusion.. if you really want to understand what's going on you should study piston engine valve timing/camshaft dynamics.
that all said, messing w the stock turbosystem is putting lipstick on a pig. lots of EBP will cause high egts and kaboom. throw some AI at it please.
hc
we can back into the X scale.... it takes 1.92 cubic feet of air to produce one rotary rear wheel hp. let's assume that the motor is making 385. two turbos so 385/2= 193 rwhp per turbo.
193 X 1.92= 371 CFM/14.471= 25.6 lbs/minute. that sounds about right to me re total air delivery on the X scale.
as far as porting...
the relationship between the exhaust and intake ports can have a major effect on the point at which a compressor cavitates. the amount of overlap can effect the output side force against the compressor.
when considering ports on a rotary there really is alot of confusion.. if you really want to understand what's going on you should study piston engine valve timing/camshaft dynamics.
that all said, messing w the stock turbosystem is putting lipstick on a pig. lots of EBP will cause high egts and kaboom. throw some AI at it please.
hc
when you do your calculations as to the CFM/turbo .. is this flow from the turbos into the engine or through the exhaust .... are they the same ... ?related via a certain ratio?
thx ....
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