As a little side project I've made phenolic spacers.
These serve as thermal barriers shielding the cast aluminum intake manifolds from the hot cylinder heads.
The real life effects on a graph:
test conducted by hondata on a inline engine.
Quick summary of the effect:
10 degrees C drop = 3% power increase
Fact: For every 3.3 °C (5° F) rise in intake temperature, air density drops 1%. The hotter the air, the less fuel the computer injects to compensate for reduced oxygen. Datalogging software has enabled us to measure intake air temperature under varied driving conditions.
Around town, testing has shown an average drop of around 10 degrees C which is good for around 3 percent power increase.
NOTE: this testing was conducted on a inline engine, a V engine has added heat due to the manifolds being in-between two cylinder banks
We have these thermal spacer kits ready for machining:
Maserati BiTurbo - $125 - €95
Maserati 4200GT & Quattroporte (4.2) - $155 - €120
Available on request:
Ferrari V8 (Dino & F/M)
Ferrari V12 Other sports cars, please contact us
Kit includes the spacer plates and gaskets.