Modified Stock:
   Once upon a time, IMSA hosted the RX3SP RS series. Those cars were ported 12A engines with modified open plenum intake manifolds (I know someone who's got one but we'll never get it) and a modified Nikki 4bbl. They made well over 200HP. The main carb mods were the larger venturies (but there were other minor things). With the classification of the Rx7 in SCCA Production racing, we may see the return of modified Nikki carbs. There are a few souls out there that still remember this stuff - I was just a HS kid then, and busy racing motocross. I have since done my best duplication of that manifold from a '79 12A piece, but have yet to play with it.

Holley:
   The Holley 4bbl is a nice setup, but Holley carbs are, in my opinion, a finicky contraption, and are prone to icing much like the sidedrafts. The manifold is a Racing Beat piece, and is nicely made. There are many folks out there that can do very neat things to a Holley, but I am not one of them, nor do I closely know anyone that is. For those reasons, that intake has never been an option for me. You, and others, may be different. As far as I know, Holley/Racing Beat is still making these kits.

Webers:
   There are three setups I am aware of. The first is a progressive setup that actually has a primary and secondary for each rotor in a two carb design. These are no longer available to my knowledge. The second is the downdraft IDA setup. These are proven HP makers, and for rotary use they come in two flavors, 48mm and 51mm. These are also no longer available, as far as I know. Lastly, the 45mm DCOE setup is still alive. I have never used nor tuned one, so I can offer little on it, but I suspect it is not much different than the Mikuni PHH or the Dellorto.

Dellorto:
   This is a pretty nice sidedraft setup. I have limited experience with them, but they are a nice carb and come with Racing Beat manifold castings. Icing abounds, but so does power. These are no longer available.

Mikuni:
   My favorite - I have used these on a whole lot of cars. The single Mikuni 44PHH setup performs nicely also. Unfortunately, this setup also is no longer available. Icing problems live here also.

EFI:
   You can duplicate a DCOE, IDA or even a Holley style intake via the appropriate manifold, ECU, throttlebody, and injectors/fuel delivery system that will outperform any of the above intakes. The drawback is cost, but the pro is the almost   infinite adjustability. There are some details on EFI options on my webpage at .

Hope this sheds a little light on the options.