I built and fitted a maf amp over 10 years ago to out terrano, still going strong.

I was on the receiving end of his rants too over fitting a lift kit. He couldn't accept the car was safe and road worthy after I fitted it.
Kept going on about being really really careful as the car would fly out of control or topple over at any moment.
Once he got a notion in his head it didn't matter if you could prove beyond doubt he was wrong he wouldn't accept it, then would get aggressive and nasty.
We're better off without him.

Thanks for the info guys!

Asshole or not, the MAFAM design he posted looks great.
I just managed to put mine together after all. I dialed in the variabale resistors, bench tested with different voltages and the outputs are perfect 1.1 gain across the whole range.
Will see what kind of difference will it make on a car.

Good tho hear yours have been serving you well Dave.
Has anyone else tried that or similar DIY design?