Hi Maxdax,

i too have a cosworth rush though mines the 4wd variant. what vintage is yours?

great to see your intercooler testing, though as someone said in an earlier post on this thread, the cosworth 4wd intercooler may not be big enough. i think it has good charge air flow (low restriction) because its very deep with wide tubes but not a lot of frontal area. also in the rush, its positioning means that it gets heat soak from the rad below it when you are at the traffic lights. sevens also typically dont evacuate the hot air in the bonnet area very well.

about 20 years ago Dax supplied a thing they called a 'splitter' which divided the air coming through the nose cone between the engine rad and the intercooler. they also provided a curved upswept fibreglass thing which was meant to deflect the air exiting the intercooler upwards. it didnt work because the air pressure over the nose cone was greater than the pressure exiting the intercooler.

its difficult to measure inlet air temps in a yb (at least it is when the yb is in a 7) because of heat soak. over the last year ive done some data logging and measurirng of IAT's however and i believe that an air water intercooler is the most effective solution for a road going 7 though clearly its more complex.

as soon as i saw the picture you posted of your manifold i thought 'that wont fit in a rush!' due to the external waste gate which i see you've cut off. did you get the manifold custom made?

i think the turbo you have will be better than the larger 7163 for road use. i put a 7163 on mine and it makes loads of power from 37 psi @ 5000 onwards but substantially less lower down than the dyno plots show for the other efr turbos. for this reason ive now bought a 7064!

borg warner have a marvelous program called matchbot which you can download. you tell it info like engine size, boost pressure required at what rpm, intercooler details etc and it will calculate what efr turbine wheel and compmressor wheel you require to get your objectives.