[Z28_302]

Anyone using one of the K&N X Stream air cleaner toppers or assemblies? I'm looking for more power - anyone feel strongly one way or another?

[DjD]

Not a part I would be looking for more power from... Looks cool when the hood is up though.

[dyno jonn]

Those give you less power, unless your lid is smashed down on the top of your carburetor. You'll look faster at the drive in though, and you'll be out some cash you could have used better elsewhere.

[bilodeaulynn]

Not a big fan of K&N. Most of the air filter products do flow more air, but at the cost of less filtering.

[Z28_302]

wow... why will it make less horsepower? Thought more flow was better as long as the fuel/air mixture was adjusted correctly.

[bigblockragtop]

Originally Posted by Z28_302

wow... why will it make less horsepower? Thought more flow was better as long as the fuel/air mixture was adjusted correctly.

I wonder why also. I used the topper, I am not sure it helped(never did side by side comparison). I can not see how it would not help. I also think K&N does flow better than stock. I added a procharger and it came with a K&N...

[Eric Kammerer]

Search for tests. One or more of the magazines did testing and the filter top made more power.

http://www.superchevy.com/technical/..._filter_tests/

[DjD]

Originally Posted by Eric Kammerer

Search for tests. One or more of the magazines did testing and the filter top made more power.

http://www.superchevy.com/technical/..._filter_tests/

But not enough to amount to a noticeable change in power on the street. Close the hood and that improvement might just go away because the hood is too close to the lid for it to be efficient. They said a 4" filter wouldn't allow the hood to close so they switched to a 3" filter... That's leaving less than an inch of clearance above the lid...

[Fred Ficarra]

I've one installed at this moment. It'll be comparison tested this season but that won't be until April. Also, it sits on a K&N 4" that's a replacement for a worn K&N. (Yep, a freebie from Summit) The entire assembly fits up and in my standard ducted hood.
OK, I admit it. It's there just to see if it works. I'll swap it out for the original during test and tune.
More thoughts; Air flow. It's not what it's cracked up to be. Example; A couple years ago after going too quick because of a new Lunati SR, I had to slow from an 11.30 ET. I had one chance to get it right or go to jail. So, what to do? Knowing about the 80-20 rule was the key. With engines as most everything else in our world, the rule says an engine will produce 80% of its maximum power at 20% throttle opening. So after backing off the throttle rod so that the plates were just seen to open, (mechanical linkage, non-progressive to the secondaries) I took a chance. Success! I slowed to 11.54. Just over the 11.50 cutoff for no roll bar. 20% = -3 tenths. Whew.
I might have a topper available this spring if anyone wants the 'look'.

[Z28_302]

so if you were going to go with either the topper and a 4" filter or a 1" carb spacer, which would you go with the generate more low-end power?

[Fred Ficarra]

You just have to compare on a good dyno. All anyone can give you before hand are theory's. In either case you wouldn't notice much difference if any.

[bigblockragtop]

Carb spacer would lower the low end torque. Like a tunnel ram better higher end power. Although if the spacer is a 4 hole it may help with low rpm, either way I do not think the difference would be drastic. The spacer if not made of metal can keep some of the heat off the carb and cool fuel equals better power. Have fun

[chevysrule454]

Aparently they state that a flow through top changes the dynamic of a carb needing the air to flow across the top, not straight down.

[scblucam]

You know this introduces a possible new issue. I began having fuel problems when they went to the 10% ethanol with the carb evaporating after a couple of weeks of not being started. Coincidently is was about the time I put on the X-stream.??? I'm changing to FI now but I wonder if the exposed top caused the evaporation. Either way hate the E10.

[Eric Kammerer]

Any testing of any "minor" (or low buck, bolt-on, whatever you want to call it) engine modification such as a spacer of any type or height or something like this "extra" filter area done by any of the more reputable publications almost always explains, either in a table or chart or text, exactly how much tuning had to be done and how power/torque output was affected by a given modification.

I did not intend the link to Super Chevy testing the Xtreme lid to be anything remotely definitive... Just to illustrate what you can find with some simple googling.

You can't just throw some simple bolt on at an engine and see significant gains without tuning. Now in the case of something like a plastic spacer, maybe some gains can be seen just because of the spacer's insulation properties (increasing the density of the fuel/air charge, curing a "problem" the user did not know he or she had). But again, most all different bolt-ons get tested by reputable publications and/or websites, and information is out there to find and review.

I have an old drag racing buddy who was great at this. someone he knew would buy some new bolt-on like a carb, or lifters, or headers, just plop stuff on their car, and go slower. He'd buy the parts that didn't "work" cheap, and because he understood how to tune, he'd be out on the track soon after, and things worked.

So, as Dennis pointed out, just because somebody with a Chevelle saw some power gain with that Xtreme lid doesn't mean everybody will.

I personally would not run one. I don't like the look, and intuitively I feel that much filter area and letting air in from sides AND top would affect air velocity and fuel atomization. Clearly you could try to tune/change components to make it work. But...