How can a CAI produce this 20hp & 23 torque for the srt's? Will it make that much with the stock TB or would I have to get the 90mm TB? Because that is pretty sick for an intake imo.
Mopar CAI,Magnaflow cat-back,180 t-stat,Predator,245/40-275/40/20,demolded
Hemi Registery #1333 http://www.lxforums.com/board/f76/6-1l-hemi-registry-1333-blue-bullet-srt-215368/
1. Decent amount of taperand diameter. This means the "choke point", or smallest cross section is bigger than the TB, and short, which enables a higher air speed without the associated pumping loss.
2. "Cobra head" style elbow. This acts as a mini plenum, giving the TB a sort of reservoir, instead of just a regular 90° pipe bend. This enhances the air speed profile around the perimeter of the TB, resulting in a higher average air speed for a given max. It is the maximum air speed that limits how much air can be moved without "choking". The more even your "velocity profile" is, the more air you can flow without crossing the velocity threshold. The cobra head elbow allows the TB to pull from all 360°.
You gotta keep in mind that moving air faster gets more in the engine, but it takes energy to move it. There is a certain air speed that makes the most power. Slower, and you loose power from lack of airflow. Higher, and all the power the extra air makes is simply wasted on accelerating the air, itself. It's all a matter of finding the majical spot in the middle.
Hope this helps.
Last edited by dacaman12; 06-12-2010 at 03:11 PM.
I did this comparison of a cobra head vs. a 90* elbow a while ago.
Mod List: http://www.lxforums.com/board/showth...35#post2353135
Thanx guys those 2 post did help.
Interesting that the C&L intake tube forms a cobra head also...always wondered why go through the expense.
"I dunno. Is that a real sponsor? I'm gettin' stupid loose..."
2006 Inferno Red Charger SRT8
SHR trans|Wavetrac&3.23s|DSS shafts
Built by Cam
Tuned by Sohfast94
*Car sold, and missed, September 2013*
Cobra head elbows are not expensive. Check out the vendor below:
IME the cost/benefit of the Arrington CAI lies in the tapered carbon fiber intake tube which resists the transfer of excess heat from the engine bay while producing a ram air (compression and acceleration) effect as noted in the other posts.
Below 3.5 K there was no difference in RWHP. However, above 3.5 K RPM there was a consistent a 18 - 20 RWHP advantage with the cobra head elbow. Due to the increase in air flow, fuel delivery above 3.5 K RPM will need to be adjusted to mitigate any lean-out conditions at WOT.
Bottom-line: By itself the ram-air CAI with a cobra head elbow makes a difference in air flow. However, the results will vary depending on all the engine and drivetrain mods of the vehicle. In other words, results may vary.
Last edited by richierevs; 06-13-2010 at 11:32 AM.
Very cool...thanks, Rich!
Again interesting. I lost 15 RWHP on the dyno recently with a straight 90 degree tube. Pulling it off restored the HP.