A Corvette business that sells all types of Corvette parts requested I test a modified MAF, halltech airbridge and ends that they sell.
They wanted to know if these mods really increase performance or not and if installed would the PCM be required to be tuned.

I do not know what all the mods would cost but could see the carbon fiber airbridge alone had a price tag of $330 !

You notice the big buck airbridge does not have the wings on it to properly mount it to radiator shroud and end that connects to throttle body has no give to handle engine torque movement and thus over time airbridge can slip off or have air leaks :



As seen the modified MAF has the center support used to smooth air out, half of it cut out :



For the high cost of this airbridge they just give you junks of rubber ends that do not fit and your forced to cut both ends to make it fit and even then it does not sit low enough to prevent hood from closing on it. MAF end is really nothing more then coolent hose and neither end is easy to cut

I have seen one of these cracked due to slamming of hood and then broken carbon pieces being sucked into intake :



Here is the condition of the PCM calibration and what the performance numbers were at on the day before mods were installed.
Notice no knock and the HP and torque values.
Notice LTFTs about perfect:



How the HP and torque curve looked like before mods added:



How calibration per fuel trims looked:

Part 2 :

After mods were installed, no PCM calibrations made shows these mods cannot be used on their own for LTFTs were quite lean by 11% so tune 1 was required and here is the results:



20 mile test drive, PCM being recorded, no performnace gain, less torque :



Via PCM tuning, only MAF table used to reduce the 11% lean problem, 2nd tune, LTFYs close to zero, Over 500 knocks in just 20 miles ! :



2nd PCM tune, even though LTFTS was MAF table tuned to average around zero, had to adjust injector flow to solve high knock count :



HP and torque after knock was taken out :



Bottom line, after much work to make the mods fit, tune the PCM, the performance is no better then before the high cost of these modes.



I'll do further testing but all I see is the PCM calibration had to be done differently then before these mods but gave no positives at all to spend that kind of money which I assume would be about $600 dollars plus another $600 to have PCM custom tuned, thus a $1200 no performance gain.

John,
Curious about the state of tune before you started the test. All fuel trims running slightly lean, with knock. Why?

Al the slight knock was from bouncing off the rev limiter and dyno drums causing braking down the speed so it was false knock as you can see the WOI timing was 27 degrees and knock average was zero.