spacer for air cleaner
#25
#27
+1 on that. You'd never get a 3 inch filter in a truck (without a body lift) with a flat base. I'm not sure when you got the horsepower loss theory because I've been told for years that a drop base tends to create a velocity stack effect at certain rpms. I remember the Moroso rep discussing it at a tech seminar. In fact they showed dyno charts that showed how much improvement could be gained over a flat base air cleaner. Now I know this is back in the day of carburetors...but we're still flowing air.
Wow! Moroso still has the pictures after almost 28 years! Check it out!
http://www.moroso.com/catalog/catego...?catcode=34003
Wow! Moroso still has the pictures after almost 28 years! Check it out!
http://www.moroso.com/catalog/catego...?catcode=34003
That pic from Moroso is crude but correct. A slight bulge in the bottom of the air hat flows air better. The main purpose of the "riser" in the air hat is to get rid of the 90* bend that the intake air would have to take to enter the TB. That 90* bend causes a low pressure zone on the inner lip and a high pressure zone on the far edge. Those two competing pressure zones cause turbulence in the air stream. It's the same thought process you try to use when porting the intake runners in heads. The more you can smooth out the bends in the runners, the better it flows.
It's the same reason that RM_Indy has a Turtle in the bottom of the M1. It does reduce the amount of room in the bottom of the M1 for air to occupy, but that is more than overcome by the efficiency at which it redirects the air into the runners and keeps a "dead zone" from forming in the middle of the intake.
Also keep in mind that it all depends on the most restrictive element in the intake system. Most of the time it's the heads. If it isn't, you're really loosing power.
I'm currently wondering if I have the correct TB for my setup. Might need to bump it up to the 52mm. not sure though, might just need a new cam.
Last edited by aim4squirrels; 05-01-2009 at 10:44 PM.
#28
#29