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Discussion Starter · #1 ·
Got a 2014 ST about a week ago, coming from owning other turbo cars, I have been trying to get more of the BOV sound out of my ST, I read about the green filter and removing the top lid of the intake....... Since I had aftermarket filters laying around, I put one on my car and took the lid off. I noticed that after long drives the car lost power. I haven't datalog the temperature readings while driving, but I did a test at idle.

Test was like this:

Warm car for 15min with A/C ON and open windows (keep the compressor and fans working) before datalogging.
All the tests were with the hood 100% closed and it took about 6 seconds to open the hood, put or remove the cover and closed back.
test lasted 12min, every 3min I put or removed the top lid cover as fast as I could.

It was interesting seen how quickly the temps went down or up once I changed the top lid.

GREEN line is the post intercooler temp, I put it there just in case, the PURPLE line is the RPM, and the BLUE line is the Intake (filter) Temp.

I myself got a twisted motion BOV adapter so I now have the BOV sound I wanted and after doing this test, I will be putting back the top lid of the intake until I make my own insulated CAI or raise a wall between the filter and engine :D

Text Line Blue Wave Plot

Vehicle Car Engine Auto part Hood
 

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Discussion Starter · #3 ·
I agree with keeping the lid on. However your loss of power could be if you have the stock intercooler. Those are known to heat soak badly.
Yeap, last night I was datalogging the temps and I saw 149F on the post intercooler sensor on a 89F weather, way to high for any car. I just ordered a new intercooler today lol.
 

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Discussion Starter · #6 ·
The flaw with this is you're not moving. There is no where for the hot air to go sitting there idling. Your results will be very different if you do this test again going for a drive.
I couldn't not helped and did a quick datalogging cruising at 40mph........ first drive was with the LID OFF then with the LID ON, third logging pictured was a full pull to see the intercooler temps, it reached 157.7F NOT GOOD, intercooler is already ordered. About 130F starting 3rd gear....no no no, I have never had a turbo car passing 115F on 90F weather. This stock intercooler is pure pure pure poop.

TOP LID OFF 40mph cruising
83.1F Ambient
111.2F Air Intake
103.4F Post Intercooler

TOP LID ON 40mph cruising
82.4F Ambient
98.2F Air Intake
88.6F Post Intercooler

I'm guessing the % of people just using the green filter or similar with the lid off is minimal, many have CAI already with a wall blocking the engine/fan heat. But for those running with the lid off and have datalooging capabilities give it a try, I prefer not hearing the BOV than running those temps, specially here in FL weather right now. :D

AND YES, with the top lid ON: The car feels stronger pull after pull, not like before when after the first pull, it felt slower or it took more time to reach redline.

Third data logging testing the intercooler efficiency NOT GOOD at all.
Text Green Line Slope Plot
 

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Hate to say it but it doesnt matter man. Your numbers even show it. Your highest temps are from heat soak on the stock intercooler not at the filter. Which varied by +- 1 or so degrees. I use to run a cut open lid. Last week i traded it to a stock st for his closed lid since he wanted to hear his bpv more. Ive only seen a +-1 degree difference since then.
 

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I will say in the end you run it however you feel more comfortable. Thanks for taking your time on it. These cars run notoriously hot especially the face lift model. As for the charge temps you werw getting. Those will go down once that fmic gets upgraded. I just ordered my son of the beast today.
 

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Discussion Starter · #9 ·
Hate to say it but it doesnt matter man. Your numbers even show it. Your highest temps are from heat soak on the stock intercooler not at the filter. Which varied by +- 1 or so degrees. I use to run a cut open lid. Last week i traded it to a stock st for his closed lid since he wanted to hear his bpv more. Ive only seen a +-1 degree difference since then.
Actually cruising at 40mph the difference is 13degrees in the intake and about 15F post intercooler, but I hope to see improvement once I get my intercooler in......... Come FEDEX hurry up :D

TOP LID OFF 40mph cruising
83.1F Ambient
111.2F Air Intake
103.4F Post Intercooler

TOP LID ON 40mph cruising
82.4F Ambient
98.2F Air Intake
88.6F Post Intercooler
 

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Air box lid off and hood liner off. Turbo noises are beautiful and I didn't feel any difference vs with it on
And before anyone says it it's been driven through many storms with no issues at all.
 
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Discussion Starter · #12 ·
Having the lid off isn't the issue. The RS has an open lid style box. I'm betting it's heat soak due to the itty-bitty stock unit.
The RS has a open design but it does has a rubber seal around, it blocks the hot air from the engine bay and fans, but on this turbo cars you wont notice any "butt dyno" difference, the car can adjust to the hotter temps quickly but it sacrifices timing=power, but I notice that after cruising around if I step on the gas the pull is harder when the top lid is on and the air is cooler, and the pull isn't as strong with the lid off.................... having the lid off will make the stock intercooler heat soak faster. Everyone with a COBB or SCT tuner can datalog and see for themselves.

The test that I did CRUISING at 40mph and not under boost, I had 10F-15F hotter intake/charge temps with the intake lid off. UNDER BOOST after 3-5 seconds the temps will be very similar to having the lid on or off, but on those 3-5 seconds the engine is dealing with hot intake temps and the pull on my tests were not that great, plus as soon I reached a stop light the temps went very high quickly, with the lid ON the temps were very low and raised very slowly.

Either way, if having the top lid off works for you, great :D , I do miss the intake sound on mine, but I will be making a laser cut ABS wall for the factory box today with a rubber seal and see how it performs.
 

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The RS has a open design but it does has a rubber seal around, it blocks the hot air from the engine bay and fans, but on this turbo cars you wont notice any "butt dyno" difference, the car can adjust to the hotter temps quickly but it sacrifices timing=power, but I notice that after cruising around if I step on the gas the pull is harder when the top lid is on and the air is cooler, and the pull isn't as strong with the lid off.................... having the lid off will make the stock intercooler heat soak faster. Everyone with a COBB or SCT tuner can datalog and see for themselves.

The test that I did CRUISING at 40mph and not under boost, I had 10F-15F hotter intake/charge temps with the intake lid off. UNDER BOOST after 3-5 seconds the temps will be very similar to having the lid on or off, but on those 3-5 seconds the engine is dealing with hot intake temps and the pull on my tests were not that great, plus as soon I reached a stop light the temps went very high quickly, with the lid ON the temps were very low and raised very slowly.

Either way, if having the top lid off works for you, great :D , I do miss the intake sound on mine, but I will be making a laser cut ABS wall for the factory box today with a rubber seal and see how it performs.
FWIW- I have the RS box on my ST, due to me breaking the bottom portion of the stock airbox. I notice absolutely zero difference in either noise nor performance. I actually put the top from the stock box back on. I would have purchased the stock ST box had it not been +3 times the price of the RS box.
 

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Discussion Starter · #14 ·
I will be testing a laser cut heatshield that I just designed and see how it performs. This is a prototype pictured made from high impact ABS 1/16" I still need to modify the design to fill the front gap, extended the rear heatshield wall all the way to the back and add the rubber seal, probably raise the heatshield wall too to make sure it seals with the hood. final version will be made from 1/8" ABS.

I will recreate the 12min test and see if it helps

STOCK BOX NO HEAT SHIELD
Vehicle Car Engine Auto part Hood


HEAT SHIELD INSTALLED
Vehicle Car Motor vehicle Auto part Automotive exterior

Automotive exterior Vehicle Auto part Car Hood

Auto part Engine Automotive exterior Vehicle Machine
 

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Discussion Starter · #15 ·
Here is the updated heatshield design, so far I like it....... I warmed up the car around the neighborhood and let the car idle for 10min while I datalogged and the max temp reached in the 10min idle was 121F at the intake with the lid off and the custom heatshield installed, without the heatshield I got 139F yesterday. The nice intake sound is back but the temps are way lower. :) I need to find a nice rubber seal to put on the edge of the heatshield. Still uses both factory air ducts and stock box.

Vehicle Car Engine Auto part Automotive exterior

Vehicle Car Engine Auto part Luxury vehicle
 
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Focus on the intercooler and getting cool air through that. Radiator Grille Automotive exterior Bumper Technology
. I run cool coolant, oil and intake temps both pre and post intercooler my oil temps are at 179 and coolant about the same in 85° weather cruising most speeds. Charge air temps stay about 1-5 degrees warmer than ambient. Iat doesn't matter too much with a good efficient intercooler and proper ducting.
 
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check out that new one from fswerks...only $199! $249 for thermostatic...i would have saved myself $250 and bought that before the mishimoto...
 
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