I currently have a 27x7x2.5 intercooler and was wondering if a 29x9x3 intercooler would make any difference (on a 400whp B18C setup) or should I just keep the 27x7x2.5? I have not been getting "heat soak", etc. because I do not stay in boost for too long lol. Both intercoolers are the CX Racing brand and I gettin a pretty good deal on the bigger one ($40 - 3 mos old) so this is why I ask

Turbo is a GT35R btw.

 

Almost 200 views no answer lol - bumpy for meee

 

The CX racing is a lower rate bar & plate intercooler. For 400whp, what you have will barely keep that power without heat soak on most B series and D-series setups. If you can upgrade to a slightly taller and wider one with more exposed area, you should be fine. But for now, you're at the limits for 400whp with what you're proposing.