[jfaubion]

>Say what?  There is no way to get 20 more hp from a 4 cyl engine 
>(the 2.5L injected "slant-four" from Chrysler, right?) with 
>induction mods unless you add a turbo.  

Being a long time nitrous oxide racer, my first question would be for 
how long? If you only need the power for short bursts (say 5-20 
seconds) at a time, use nitrous oxide injection. This should provide 
a reliable 20-30 hp. Especially if used in conjunction with a few 
pressure switches and a throttle position switch. This will allow you 
to use the nitrous at full throttle only and shut it down if oil or 
fuel pressure is lost. This works great for passing and merging with 
traffic.

If you need the power for a longer period then I'd recommend 
turbocharging. Works great, lasts long time, and is a relatively easy 
DIY project. Is is just as dangerous to the life of the engine as 
nitrous but power can be used for longer periods.


>speeds if you manage to design a very good forced system, but that 
>will really only have an effect at speeds of 50+ mph.  You can get a 
>couple more ponies just by making a better, higher-flowing airbox, 
>or cooling the air coming in (or keeping it cool, once it is cool), 
>but the forced-air idea is not going to yield that kind of power 
<increase.  

I think by "forced induction" he meant mechanically forced through a 
turbo or supercharger.

John