I've got a2005 Monte Calro LS with 3.4 engine .I am considering adding a 65mm MAF / throttle body. I was told by a reputable source that the mod would add 8 - 10 horsepower to my car.

Do you agree or not, and why?


Current mods

Stock air box delete for cone filter and smooth wall tube
cat back duals with turbo mufflers
U- bed delete, resonator delete
Milzy level 1 / stock programer

 

It can be that high with other mods, but I would only expect about 3-5 hp or so.

 

I wouldn't say that person is reputable.

The stock throttle body alone is more than large enough to support what you currently have done and would hold up very well for another 40+ H.P. before it becomes any kind of restriction.
Parts 2 of that is when you got larger in bore than what your motors requirements are, the velocity of air entering will slow and hamper the bottom end more than you could possibly gain up top.
MAF side, because of this air speed change coupled with the larger area of the MAF for air to enter, it WILL NOT see the correct amount of air entering without recalibrating throough a reprogramming. The 02's will be looking and asking for adjustments because the pre-read isn't close to being correct and it will more than likely throw performance MAF codes. On a long shot, it seeing less air because of what I just said, the OBD will dump in less fuel and you lean it up to a dangerous amount.

For a number of years 2 companies have been selling larger ended stock units with addes resistors that are suppose to aid in correcting the output voltage so the OBD isn't seeing skewed numbers and these are well known for creating leaner running engines. And thats were the gains come in they advertise. Leaner to a "point" is meaner in power making, but short term trims determine long term PE stages and that can lead to bad news.

Without reprogramming your current OBD, say no!!!

 

Ya, what he said!