Ian Howell sent me this article way before it went to press

My first initial comment to him was:

"Was the same throttle body used on the Area Six / Jenvey manifold?"

Answer "no"

Area 6 was 65mm
Jenvey was 60mm (thats all you can use on the feed pipe that was used although there is a 70mm version out now)

Thats why there is a differnce in the BHP figure all be it very marginal

As for the inlet design

Both inlets use the same head flange (jenvey), inlet runner length, bore and the same 19mm cast jenvey air horns

The only real difference here is the plenum design

At that boost pressure (0.7bar) the results are going to be very similar due to the relativly low air speed through the plenum.

You change the throttle body size on the Jenvey item and start upping the boost and then you might start to see the real difference between the two. (say at 2 bar positive boost)

Look at the swedish inlet everyone was raving about a few years ago for the YB, it was end fed and produced good numbers but not as much as the new hart plenum everyone is using now. Why is that? because at high boost the swedish plenum fires the air straight into trumpet number 1 slowing it down and creating losses.

The hart plenum fires the air along the whole length of the plenum like the Jenvey item and it is not effected by the trumpet being in the way to slow the air down.

Mad Rod has experienced this on his YB after dyno runs camparing both inlets.

Inlet runner length, bore size, taper and bell mouth radius also play a role too but in this test they were the same on both manifolds

I have tested several design with Andy Nichols 800whp rover drag car on the dyno using longer runners, my plenums and billet bell mouths with interesting results, we have compred end feed, my own, AMS and jenvey manifolds to date.

The rover lump uses virtually the same bore and stroke as the zetec so a comparable result TBH

Dont get me wrong, Ian is a very good friend of mine and the quality of his work is A1.

His inlet is very good, and well worth the money

If you are looking for a 500bhp motor get his inlet, but IMO if you want to squeeze every little last drop of HP out of your engine then other options need to looked at.

The problem is for the relativly low increase in power this will give you your inlet doubles in price.