i am making one for my 1990 prelude and wondering if there is a specific location for the filter to be towards the front or the back of the engine ? also how low ?
Towards the front and the lower and farther away from the engine the better.( That means the front corners of the engine bay, or fenderwall). The name of the game is keeping engine heat out, and bringing more cold air in. If you put in in back the heat from the motor is going to travel back when your moving forward, and there is more stuff in the way of air traveling through the engine compartment. As for height you need to keep it lower to keep it away from heat, remember how heat rises. Also the bigger the filter the better, KN cone filters work the best. A good idea is to keep it behind a head light(thats probably where the stock intake is anyways), there are three reasons for this, 1) theres more air flow there, 2) you have room to work with since the stock airbox was probably there, 3) if you ever go to the drag strip you can take out that headlight to increase air flow, and yes that does work really good. Also it is a good idea to minimize bends in the intake tube, the more bends the worse the airflow is. Theres my two cents, Good Luck!
I would bet that your 1990 Prelude already has a factory installed cold air intake. In the mid 1980s, to lower emissions, most automobile makers began installing cold air induction at the factory. Most of those breath air from between the inner fender panel and the fender liner. A great many naive young people rip that factory cold air induction system out and replace it with an aftermarket product that is no better than the factory setup, and a lot of times an aftermarket product that is not even as good as the factory setup.
Well if you're making a cold air intake, you might as well do it right. The air around your engine will probably be warm, which means it is less dense, negating the effect of the intake in the first place. Usually cold air intakes draw in air from inside the wheel well, where air is usually the coldest. Rule of thumb is to get it as far away from the engine as possible. However, the real gain in power is probably negligible. Until you couple it with a better exhaust system and possibly a chip that will increase your fuel intake. The focus is to get more fuel and air into the engine and more out. Also, just a hint for automotive tuning. You want to start with your brakes and suspension before you even think about doing power modifications. Not only will this prevent you from getting killed, but it will greatly improve the handling and overall performance of your vehicle. Unless you turbocharge your engine or something, you really won't notice much of a difference. Except possibly a cooler sound out of your muffler. haha
