Anyone tried these methods?
Basically, you make grooves in the cylinder head and/or throttle body to create more turbulent air, increasing power and, more importantly, torque. On older cars with no or 2-wire lambda sensors, a massive increase in fuel economy is said to have been found.
Check out the two documents on this page regarding throttle body grooving:
http://www.gadgetmangroove.com/getgroovedcheckout.php
and these pages for head grooving:
http://peswiki.com/index.php/Directo...ber_Turbulence
http://somender-singh.com/content/view/7/31/
(there's plenty more about the techniques out there and videos of how best to do it etc.)
I have a 48mm TB from a 1.6 Marea that fits nicely on my 1.2 punto and gives a nice top-end power increase but I loose bottom end pull. Rekon i'll give this a shot and see if it makes any kind of difference. Can't hurt!
If it does anything positive on the Punto i'll try it on the Bravo - it has a variable inlet system which restricts the inlet tract at low RPMs to increase torque and opens it up at higher RPMs to increase power. Alas, both of my current cars have 3 or 4 wire lambdas so the ECU will compensate and I prolly won't see much in the way of fuel gains.
...be interesting to see what happens with a Silvia!
In theory, head grooving should allow you to run more boost than is safe to do so now with std internals...]
EDIT: Have to say, the more I read about the "gadgetman groove" (throttle body one), the more it smells like bs and a rip off of the original squish groove idea (cylinder head one). The squish band groove might have some legs though...