I think he means a tapped nitrous dry/wet nozzle in the TMIC... I've run it on several other cars, but not this one.. don't really plan to.
You really wont find many Subarus running nitrous. Most guys wont hesitate to put on meth or alcohol injection but will hate on nitrous users all day long. I know the meth kits tap into the topmount but I'm not quite sure what the difference would be with using nitrous. I'd say do it but datalog it a lot and start with a small shot and work your way up to a 75 or 100 shot. I've said before that in a couple of years when I can afford to blow my motor or transmission I'd love to play around with a 75 shot to see how the Subaru will take it.
I would say on the exit side of the topmount right before the throttle body would be fine. Just make sure your WOT switch is on there and test it before running it. I see no reason why nitrous would not be fine with our cars. If you look at a lot of the REALLY fast subarus with hot 1/4 mile times, a lot of them are running a little shot of nitrous.
Don't some people use nitrous or co2 just to spray on the intercooler. Just like the sti water spray except actually cold?
They do, but only get minimal gains. I've never seen one of those systems give more than 2-3whp. I've never seen one on a top mount, but I assume it would be similar to an fmic.
Spraying on the IC is only beneficial mostly for HIGH temp areas and for people that have HUGE turbos and little dinky IC's that can't dissipate the heat well IMO. If you want to cool that air, either spray NOS into the engine or go meth injection.
wouldnt it be cheaper to spray co2 instead of n2o? on the intercooler not in the intercooler of course
Of course! Much cheaper to get refills of the C02. I think you can get a 10 lb bottle filled for around $15 of C02 vs $50 for N02.