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05 CTS V 07 ESCALADE
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Discussion Starter #1 (Edited)
After reading Trukks thread on the LPE CAI and tons of other threads, there is not a clear choice on CAIs for the V. Some say they are worthless, others say they are not cost effective. Still others say it's the tube not the box. So here I am looking at the stock V set up trying to decide what move to make. The Volant is pricey, the K&N looks pretty minimal and the LPE uses the stock tube. Which brings up a thought. Why is the stock tube split in 2 sections? I hardly believe it is cheaper than a straight tube, or that GM would spend extra money on a design that would deliver sub optimal performance. I would also think that there was some extensive flow testing on that set up for use with a OEM style flat filter. SO maybe it's the cone filter that delivers the performance in the aftermarket set ups??? As far as the metal tube "homegrown" setups, again I would think that this is the cheapest design GM could make for optimum performance but thay chose not to. BTW I heard metal tubes are a heat sync. So I'm taking the cowards way out and installing what looks the coolest (prettiest) because no one will ever get this CAI thing figured out. Who out there is happy with the CAI they're running now?
 

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Most of the performance 'mods' for our cars show minimal gains. A few hp from a cai, maybe 10hp from an exhaust system (it craks me up that most of them are the same diameter tubing that our factory systems are). On mine I just modified the stock airtube which is the obvious obstruction. I completely cut out that big ass divider and then used the material I cut out to cover up the holes I just made on the outside of the tube. You can't even tell from the outside when its in the car (which is good since I did a really ugly job with my epoxy). I just run that tube with a drop in K&N filter and enjoy the extra $200 I didn't spend.
 

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BANK OWNED!! CTSV & EXT
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The factory designs intake tubing with government standards in mind. Most factory inductions are way worse than ours. They have to meet certain noise level criteria, maybe our design was the smallest and most efficient way to make the car legal to sell. The factory isn't going for all out performance when they build a car, which is why the aftermarket exists.
 

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05 CTS V 07 ESCALADE
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Discussion Starter #6
I saw that stock split tube used on Katechs K series V package with a More airbox (looks like a LPE but I don't think they make it anymore)). Here are the guys who GM subcontracts with to build their race cars and they use the stock tube on the hotrod head and cam car package for sale to the public. I'm thinking that the tube isn't all that bad? Trukk said he got 8 or 9 RWHP on the LPE which is about as realistic as you could expect. Now we talk about heat sync which is another story:confused:. Decisions....decisions.....
 

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BANK OWNED!! CTSV & EXT
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Evidently Katech is leaving some power on the table. I'm pretty sure that a straight piece of pipe flows better than one with an odd shaped divider in it. Maybe I'm wrong though.

On the other hand I wouldn't say that its that bad since most don't get much improvement with aftermarket kits. Just a matter and what you're willing to do for every last little pony.
 

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2009 CTS-V
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Well, at least the LPE CAI looks serious. That's has to be worth 19hp, yeah right.
 

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05 CTS V 07 ESCALADE
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Discussion Starter #11
Ghd????
 

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2005 Cadillac CTS-V
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130 Posts
Evidently Katech is leaving some power on the table. I'm pretty sure that a straight piece of pipe flows better than one with an odd shaped divider in it. Maybe I'm wrong though.

On the other hand I wouldn't say that its that bad since most don't get much improvement with aftermarket kits. Just a matter and what you're willing to do for every last little pony.
The divider may prepare/create/stabilize turbulence for the bend into the intake at certain RPM, where the manufacturer may think most drivers will be. The goal being a design the provides the best (most evenly distributed) "one size fits all" airflow into the intake. It's kinda like the old carburated intake question... open plenum, or split? That depended on what RPM you intended to live in. One was better in town, the other at WOT.

I liked the GM airflow intake solution I had on my Chevelle SS (cowl induction) and 70 Hurst Olds. Air came though the traditional "snorkel" sucking in hot engine bay heat. But at WOT when the secondaries opened, there was an intake bypass on the top of the hood (scoops on the Hurst Olds) that actuated using the same vacuum as the secondaries. That allowed cooler outside air directly into the breather right above the carb bypassing engine bay plumbing.

Hmmmm... I wonder if there enough room under the V's hood for something like that. What we need is a 'backwards' intake, putting the opening at the rear so air can be drawn in where air vortexes at the base of the windshield (like the Chevelle SS design). That would eliminate a lot of plumbing and cooler air.

To the drawing board!
 

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Discussion Starter #15
Good point Fred. I also read on another site that the diameter and length are co dependent on each other for volumetric efficiency and the shorter the length, the smaller the diameter is required to keep up the speed of the air. Also the faster the speed the lower the pressure and the smaller the sound waves, which may mean that the split tube design was made to make it quieter as well. Who would think a hunk of tube would be so complicated?
 

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Discussion Starter #17
Besides the Katech big cube K series CTS V car using the stock tube, the boys at Lingenfelter claim they tried all the aftermarket CAIs and determined that the tube was not as restrictive as the box. Infact they also use the stock tube on their big cube motors as well. If this doesn't stir the pot!:stirpot:
 

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With the stock airbox and paper filter my V spun the tires from 4500 through 6500 yesterday while passing a car in 3rd gear.

That's pot stirring. :stirpot:
 

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Hmmmm... I wonder if there enough room under the V's hood for something like that. What we need is a 'backwards' intake, putting the opening at the rear so air can be drawn in where air vortexes at the base of the windshield (like the Chevelle SS design). That would eliminate a lot of plumbing and cooler air.

To the drawing board!
Well, as suspected, there isn't enough room to mount the intake manifold backwards. Just too close to the firewall. However, there may be enough room to fab a flat/oval intake at the base of the windshield and run it along the driver's side of the engine in order to capture cool air at the windshield base vortex. But the extra plumbing, 180 degree u-turn and distance through the warmed up engine compartment would rob any benefit.

I don't think it would be worth it anyway... unless you're counting one HP gains.

OK... think outside of the box... What's behind the radio? Make some room there, mount the intake on backwards and run an air tube into the cabin where the engine can breathe cooled (and low humidity) air from the AC!

OK, so I've too much rum this evening... :alchi:
 
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