peadya100 wrote:Can someone please tell me once and for all whether or not there is a performance gain with after market top mounts?
Simply - yes but gains would start on a scale of not even being noticeable to significant based on size of turbo and boost you are running.
You would get an aftermarket TMIC because:
a) You want to run high boost which not only generates more heat (and needs more cooling) but tests the strength of the stock IC which is not designed for high boost,
b) You run a larger than stock turbo and want increased airflow (aftermarket typically have a larger core which means increased flow capacity without sacrificing cooling).
Just remember that the bigger the IC, the longer it takes to reach peak boost as there is extra space to fill between blower and IM so actually reduced not improved response - same concept as larger aftermarket headers and up-pipes introducing lag as it takes longer for pressure to build behind turbine. The benefit is when you are on boost you will get improved air flow (assuming your IC was a restriction in the first place which wouldn't be the case with a little VF46 and stock IC) and improved intake charge temps = more power for a given airflow (which should be of minor benefit even with stock turbs but moreso if running higher in efficiency range - more boost as the extra heat generated will be dealt with better. Whether any of this is noticeable (good or bad) to the driver without high boost and bigger turbo is hard to say unless you have one
.
If I upgrade to a VF52 @19psi and I find one for the right price I think it would be worthwhile but shame they aren't more affordable.