TKOPerformance wrote:

Once you read about a thousand dyno tests these trends become obvious, BUT these tests are also all done on a dyno with unlimited hood clearance.  In the real world where an engine needs to fit into a car, and most of us don't want to run cowl hoods, scoops, etc. you can only get a spacer that's so tall under the carb and still close the hood.

One thing they don't talk about is what kind of air cleaner is on top of the carb.  If you run a 2" tall spacer, but it necessitates a drop base air cleaner you probably negated any gain from the spacer by restricting airflow. 

Ultimately spacers are tuning aids like anything else.  You think the bottom end is soggy, put a 4 hole spacer on it.  Want a little more top end, put an open spacer on it.  A spacer is also a way to crutch a bad manifold by increasing plenum volume, or improving low speed flow.  There are engines where I've seen them pick up 20HP with the right spacer, but that was a 500HP engine that probably would have benefited from a different/modified intake as well.  Gains on a street engine making 250HP aren't going to be anywhere near that drastic. 

One thing I can say is those Wilson spacers are super sexy, but you ain't gonna like the price. 

Thanks TKO! You appear to have a way more detailed knowledge on engine performance than I do, so I appreciate the post.
I still have the stock standard 4-hole spacer on my engine. I have known about the theory behind taller spacers for some time, but I've not known the intrinsic performance stats like the article touched on.
What is the school of thought or rule of thumb on spacers for a street car with a little "pep" in mind. I have not measured my spacer, but maybe it is the best one for my set up? Again, I am not thinking crazy here and trying to magically gain horsepower with a spacer. I am interested in optimizing what I have and if I should be running a better spacer then I would be interested in knowing what options I have.
Does this make sense, or are these stupid posts?

Motortrend TV did a very nice segment just on carb spacers, its a good video to watch. One thing they point out is you will most likely be rejetting after adding the height under the carb. That is something I didnt know.

We all can agree a spacer is just a crutch for the worng size/shape/type of intake.
Like TKO said..."they are pricey".
Wilson...FunnelWeb....and others use a lot of slick ads in the car mags to justify the hefty price (and help pay for their testing!)
I THINK  the $$$ spent on a 1" spacer (when a 2" is what you really need butt won't fit under the hood)..........shoulld be applied to the cost of an Alum. hi Rise intake like the Edelbrock Performer RPM  or Wiend equivelant. It will fit better......and give a noticeable boost in power and torque especially in the old "butt-o-meter" dyno....in addition to the weight you just reduced on the front half of your car. Your back will thank you too when replacing it.
IMHO
6sal6

50vert wrote:

As it says at the top of every page ... THERE ARE NO DUMB QUESTIONS!!!!!
Knowing you don't know is half the battle.

Sometimes they feel like dumb questions...

Yes, that's the intake. 

The Performer RPM is intended for engines running in the 1,500-6,500RPM range.  A hydraulic cam 289 is done at 5,000.  The Performer by contrast is idle-5,500RPM.  The Performer RPM is a mismatch for a mostly stock engine.  If you're going to swap the cam, heads, etc. its worth it, but if not stick with the Performer. 

I've read a  lot of places where they claim the Performer is the same as an iron stocker.  I can tell you I've had them side by side and its simply not true.  The performer is taller for one thing, and the angle of the runners where they meet the carb flange is different (better).  How much more power?  I'm not going to say its a ton, but its something and you trade nothing in low speed torque (might actually gain a bit).  I can tell you this too, its a lot lighter than the iron intake.