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Old Jun 14, 2011 | 11:11 AM
  #12 (permalink)  
XXxx_Totmacher_xxXX's Avatar
XXxx_Totmacher_xxXX
Joined: Feb 2009
Posts: 108
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From: Mission Viejo, CA
Default Re: FS: ~~~ BDJ Duel Intake - $300 OBO ~~~

Truthfully this thread really isnt worth the time it would take to properly lay down the proof. I'm not arguing anything in regards to the lengths of the pipe. I would argue the inside diameter of the pipe and Bernoulli's equation, but really I doub't it matters signafacantly.

Bottom line, the inlet air temp difference between any intakes at the throttle Body at max is maybe 15-20 degrees. Then next look at the temp across the S/C and the resulting heat transfer to the charged air there. This heat transfer is easily going to absorb a huge portion of the initial temperature difference. The resulting Air maybe is 5-10 degrees warmer. Then we move on to the next step, the air to water, now here is where almost all playing fields are leveled. Why? Because thats the intercoolers job! Any discrepency left by the dieviet in inlet air temp is going to be damn near zeroed out once it transfers the remaining latent heat to the intercooler. Now lets get to the bottom where the power really plays in. Timing. Have you looked at Charge Air vs. Timing modifiers for typical turbo/SC cars? Even in a hard core protective tune the difference of 4-5 degrees Charged air temp is going to be a swing of maybe 1/2 a degree timing And thats worst case.


It's pretty simple, in the end it's like saying my car performs like a Dog when it's 85 out but runs like a beast when it's 70 out with my Cold Air Intake. And thats simply not the case. A 15 degree delta in ambient temps is no difference in comparison to a 15 degree delta between a cold air intake and a short ram intake. Both will be properly absorbed.

Bottom line, if you are going to make the claim that a CAI is that much better for performance on this platform then a SRI you also must make the claim that the factory heat exchanger / intercooler (stock boost levels) is inefficient and can not do it's job.



Relating story... On the 900 HP 8 second car we Drag race we used to run a open turbo mounted transversly behind the engine by the firewall. No piping, no nothing, just open turbo. With an extremely efficient intercooler, even at 55 pounds of boost we still only see about 120 degrees charge air temps of the nitrous and about 90 degrees on the juicy. After we swaped the head around and hung the snail off the front of the motor with the turbo pulling air from directly in front of the bumper, guess what. No change in charge air temps outside a measurable amount. Why? Because between the super efficient heat exchanger and the Nitrous they do there job and absorb any changes in charge air temps. thats why they are there. Same as on a stock crossfire.