Which catch can for boost, MM "Race" or MM "Draft"
This is from the MightyMouse website,
1. Black "Race" Can
- This is a no nonsense can for BECAUSE RACE CAR. Two dirty -AN inlets in 6,8,10 or 3/8 -1/2" barb and a wide open breather to let it all fly (except the oil).
- Use this can when you do not have need or want to put a vacuum draw on the crank case, or circulate fresh air in / dirty out.
2. Black "Draft" Can
- This is one step toward the environment; Hook between your engine and low pressure S/C or TURBO Filtered inlet with your choice of -AN or barb fittings on either side. This can has a ONE WAY BREATHER so it will scavenge crankcase fumes, while venting any blow by you can hum its direction. Guaranteed not to transfer oil.
-Use this can when you want to avoid fumes or oil mist in the engine bay, and want some vacuum draw on the crank case, but do not want to circulate fresh air in / dirty out, OR IN FACTORY SYSTEMS THAT DO NOT USE A PCV VALVE.
If anyone has had any problems out the Holley valve covers let me know so I can cancel it. The only review I've seen was on amazon and they said the baffling isnt great and the catch can was filling up withing 50 miles. I took that with a grain of salt because that could be user error or engine problem.
My other question is. On MMs instructions it says to run a dirty line from valve cover to CC, then clean line from CC to turbo or intake depending on if you're boosted or NA. But I've seen a lot of pictures of guys running it that way plus another line going from valve cover to throttle body. So which way is it. Makes me wonder if that extra line is supposed to be there but not in the instructions because it might be implied or something.





