I think it depends on your cam. Doing that is fooling the engine thinking it has a single plane intake on it..L88 comes to mind.

 

Interesting to note the Weiand Stealth has no divider and it has the largest plenum.
The RPM has approx. a 1/2" removed from its divider out of the box.

 

Chris, If you can gets your hands on a Stealth, maybe just bolt one on see how you like it.

 

Not really apples to apples comparing the Stealth with an RPM and cut divider. The Stealth has much more plenum and runner volume than the RPM.

 

try 1/2 inch open spacer

 

I like the non obvious mods

Dan..just sold a Stealth..running the factory LS6 intake at the moment.

 

I have a oval Stealth for a 049 headed 496 that will go for sale. I did not think twice about selecting it for that motor. Wish I could keep that motor, but no car to go into.

 

I have a Holley 300-36 street dominator on my 355
Cutting the divider down 1" and radius the edges was worth 11rwhp and 14rwtq, and about 1.5mph.

Aaron

 

great info Aaron..thanks for sharing :thumbsup:

 

I really think it has more to do with the combination than anything.

This is on a small 180cc headed motor with a rather large 231/239 @ .050 hyd roller and almost .600 lift.

I also had a 1" open carb spacer on the intake before the radius and after.
Last year I fixed the leaking intake gasket, threw another 1" this time 4 hole on top of the open, and picked up 44rwhp and 5mph

Before divider cut
Avg 104-105mph

After avg 107mph

After additional spacer
Avg 111-112 mph. (as day gets hotter, car gets faster, even hot lapping).

This year I'd like to unstack the spacer now that I'm back auto again and really see what each thing does.