Need advice : CAI extension for CP-e

[Sebas007]

Hi guys,

I want your input on the routing I choose for my CAI.

First of all, I'm going to relocate the battery in the trunk. I bought this kit with my new Optima RedTop 34/78 battery
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DG1231%2DK&N=700+4294925143+400304+115&autoview=sku
And kill switch
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D830050&N=700+0&autoview=sku


With this done...it will gives me some extra space. I will cut a part of the stock battery base (under the plastic tray) because I'm planning to pass not directly to the driver corner (like Tacti) because I'll use 3.5" and will not fit directly. If I do would have to use 3.0" and go back to 3.5" to join it to the CP-e pipe. I will pass near the radiator but not in front of it.

Here a pic of the situation. Using a 45 degrees silicone elbow from the CP-e to route it like the red lines...the little left red lines is the limit of the radiator vent. After that it is 90 degrees elbow down and an other 90 elbow toward driver side fog where filter will sit there (a lot of space there !)

I'll use silicone angle elbow...a bit more flexible than aluminum...if I need to gain some fraction of an inch of cleareance.

My questions are...


Do I have to avoid this absolutely because air from radiator can increase air temp by heating up a bit the aluminum tubing ? Does the difference would be negligeable ? Or I would have to find a way to pass directly by the corner like Tacti ??

Do a little custom heat shield to deviate the air from the radiator would be enough to solve this issue ??

Does it would be better using 3" pipe all the way thru or keep 3.5" all the way thru or mixing 3" with 3.5" ? What is the effect on air flow ?



Thanks for any effort answering my questions !

[theprodigy79]

I can't really offer you solid answers, but a few concerns peak to me:

#1 90 degree bends are pretty sharp, and may cause a lot of restriction (especially if you have multiple as you're planning). Especially if they aren't bent properly and are crimped any...

#2 3.5" to 3" to 3.5" piping will cause additional turbulence, and will substantially reduce the efficiency of the setup... Also, while I don't believe it should effect it, but there [may] be a chance it would mess with the MAFci piggyback calculations if you mix the sizes?

#3 It does seem that placing the intake directly behind the radiator would take in substantially warmer air...

With those three potential issues above, the straight up SRI would probably offer you more...

If you're able to maintain 3.5" diameter the entire way, not use such sharp bends and get it into a corner away from the radiator or any other heat sources, THEN you may see a benefit.

Good luck dude, I'm curious to see this...

-James

[Sebas007]

Thanks !

I ask my friend hardcore engineer...say that the proximity of the CAI pipe form the radiator is not a big deal at all, since air is a good isolating. He will calculate also the air flow in my setup with the same program he use to calculate all the force he need to calculate do to stuff here (hydro-turbine)...but from what I heard from him 90 degrees should be that restrictive. you were right with the 3.0" to 3.5" the turbulences would be not good in there. The interogation point is what is the temp difference between the air I will bring inside the TB with my CAI and the air that come from the SRI at 60 MPH...there is the real question. We gotta measure it...but I've already bought everything ! haha Should be an improving but I doubt it worth every dollars invested.

[Sebas007]

Well...an other friend of mine told me he has a "wireless" thermometer. You install the sensor somewhere...and you get the result on a little display screen. I'll measure the temp in the "behind driver fog" area VS CrispMongo filter area...just to see if the potential is there or not. I need at least 20F diff at 60 MPH to make it efficient...I just doubt about it now !

You probably right on the final answer : CAI, at least in Gen 2, doesn't worth it. But let's measure the potential before...I'll let you know guys.

[PXLpainter]

Let us know what you find out Sebas - I was going to go the same route but if it's not effective, then I may forget all the hassle!

[tacti]

First of all good luck with your project.
it will be hard to put the 3.5" pipe thru though...
how do you think about cutting off the base for the battery.
it won't affect the structure, and it will give much more space once you remove that part.

just a thought...

Tact

[Sebas007]

First of all good luck with your project.
it will be hard to put the 3.5" pipe thru though...
how do you think about cutting off the base for the battery.
it won't affect the structure, and it will give much more space once you remove that part.

just a thought...

Tact

Funny...I wrote it in my first post...but maybe not in a good english way !! haha


I wrote it that way...
"I will cut a part of the stock battery base (under the plastic tray) "

I would be obligated to do it that way ! Like you said...not enough space without cutting it.

[PXLpainter]

Sebas - I'd make sure to take that blue rag out of your intake before you add the CAI tubing!

[Sebas007]

It is just to block the sewer rat entering the pipe !!

[Sebas007]

Day temp = 78.8
Temp are in F and Speed in MPH (just for you...Americans ! I first make it in metric...I copy it and had the formula to get in US)


S1 = Sensor 1 located in the fog light area
S2 = Sensor 2 located in the CP-e SRI area
S3 = Sensor 3 located in front of the battery

Code: Select all

Speed = 0 MPH (Idle)
    Time (sec)   S1       S2       S3     S2-S1   S2-S3
Test 01   040   81.68   114.08   101.66   32.40   12.42
Test 02   080   84.20   115.34   098.42   31.14   16.92
Test 03   120   84.92   116.78   095.90   31.86   20.88
Test 04   160   86.18   117.68   094.82   31.50   22.86
Test 05   200   87.26   119.30   094.64   32.04   24.66
Test 06   240   88.52   121.82   094.46   33.30   27.36
Test 07   280   90.14   122.00   094.64   31.86   27.36
Average   000   00.00   000.00   000.00   32.01   21.78
                                                                   

Speed = 37 MPH (60KM/H)
    Time (sec)   S1       S2       S3     S2-S1   S2-S3
Test 01   040   84.56   109.76   101.66   25.20   08.10
Test 02   080   82.22   121.28   098.42   39.06   22.86
Test 03   120   81.86   121.28   095.90   39.42   25.38
Test 04   160   81.86   120.92   094.82   39.06   26.10
Test 05   200   81.86   120.20   093.74   38.34   26.46
Test 06   240   81.86   120.02   093.02   38.16   27.00
Average   000   00.00   000.00   000.00   36.54   22.65



Speed = 62 MPH (100KM/H)
    Time (sec)   S1       S2       S3     S2-S1   S2-S3
Test 01   040   86.00   113.72   092.30   27.72   21.42
Test 02   080   81.86   112.82   091.22   30.96   21.60
Test 03   120   79.70   117.86   090.50   38.16   27.36
Test 04   160   79.88   115.88   089.78   36.00   26.10
Test 05   200   79.70   114.62   089.24   34.92   25.38
Test 06   240   79.70   113.72   088.70   34.02   25.02
Test 07   280   79.70   113.18   088.70   33.48   24.48
Test 08   320   79.52   112.64   088.52   33.12   24.12
Test 09   360   79.52   112.64   087.26   33.12   25.38
Test 10   400   79.34   112.46   086.72   33.12   25.74
Test 11   440   79.52   112.64   086.00   33.12   26.64
Test 12   480   79.34   112.46   085.82   33.12   26.64
Test 13   520   79.52   112.28   085.64   32.76   26.64
Test 14   560   79.34   112.64   085.46   33.30   27.18
Average   000   00.00   000.00   000.00   33.35   25.26


Speed = 75 MPH (120KM/H)
    Time (sec)   S1       S2     S2-S1
Test 01   040   80.06   111.20   31.14
Test 02   080   80.24   112.28   32.04
Test 03   120   80.60   111.92   31.32
Test 04   160   81.14   111.20   30.06
Test 05   200   80.96   109.94   28.98
Test 06   240   80.60   108.68   28.08
Test 07   280   80.24   107.60   27.36
Average   000   00.00   000.00   29.85


Bottom line
- More you go faster less the difference between the CP-e SRI area air temp and fog area temp is big. Same tihng with the front of battery area. The average is fu'cked because of the Test 1 at 37 MPH. Air flow is strong eliminating more hot air.

- The potential gain is always bigger in the fog area but remains way more complicated and more restrictive to reach then the front battery area.

- Front of battery area seems to have a good potential and is very easy to reach. It would surely help installing some heat shield and air deflector in the fog area (it would be a bit better).

- Relative humdity is not such a big parameter...was always the same for all the test (fog were always twice %humidity then the CP-e SRI area was)

- Thumb rule : for each 5F diff you got 1% more air dendity. 4% air density = 3% more power (hp).

http://www.hardtail.com/techtips/airdensity.html

Roughly...

Fog area temp potential give around 4.95% more power (hp)
Average of the 3 average (37, 62, 75 MPH) = 33F diff
(33/5) = 6.6% more air density
6.6/ ?? = 4/3
(6.6*3)/4 = 4.95% more power


Front battery area temp potential give around 3.75% more power (hp)
Average of the 2 average (37, 62 MPH (ignoring test 1)) = 25F diff
(25/5) = 5% more air density
5/ ?? = 4/3
(5*3)/4 = 3.75% more power


In my case I evalute I have around 240 hp
CAI in fog area could give around 12 hp at peak but would improve all the RPM band power.
240*0.0495=11.88 hp

CAI in front of the battery area could give around 9 hp at peak but would improve also all the RPM band power
240*0.0375=9 hp

Last thing to check...restriction of the CAI tubing itself. Need to get calculation of my friend engineer...but for many purpose (complexity, restriction, unfriendly install/uninstall) I think to make it like a Long SRI ! Will get colder air and be very easy to make, install and everything.

[Midias]

Stick with 3.5 or go bigger going from big to small increases air velocity small to big is no good.

[theprodigy79]

So it makes a substantial difference. Hmmm..

[solaraheno]

definitly let us know how it goes, i wanna go it too

[Down2TheC]

With the 3.5" pipe, you don't want turbulence on the outter edges where the MAF is reading. But other than that, as long as you don't move it, the volume calculations are the same. So you can start bigger/same/smaller without an issue.

[PXLpainter]

Sebas - thanks so much for the test results!

I think I'll have JP help me with my CAI once we get done with the headers/Y-pipe testing. He is a big believer in air flow in + air flow out.