well at least your looking at the bright side^..but still you would sacrifice alot on looks imo

 

unless ur running ITB's propped hoods ftl

 

ITB's? I'm sorry I'm unfamiliar with that acronym.

 

individual throttle bodies

 

Alright well I found the article that was in Import Tuner on "JDM Hood Propping"
http://www.importtuner.com/tech/impp...rop/index.html

Summary:
Performed on a naturally aspirated Mazda
lowered engine bay temps 13.5 deg F all around during stop-and-go traffic; and intake air temperatures were found to be lowered as well (check out article bar graphs for specifics).

...But last night I broke down and bought a VIS Evo carbon fiber hood anyway. Hoping for good results!

 

13dg ..f wow it might be ugly but you cant turn your head away from performance
, maybe just a few washers so it is not that noticeable. who else has pictures of raked hood (stop with the jdm hood bs)

 

13* on a DD isn't going to do ANYTHING noticable for you. But you can look dumb with a propped hood, lack of A/C functionality, and a whole 13* cooler engine.

 

Well for my FI set up IATs kill me as a DD stand point because my EMS tunes off of the MAF which takes into account the IATs. Looking at the graph in the article at idle IATs were nearly 20deg cooler! That CAN make a difference especially in a DD because all of the stop and go traffic because high IATs forces the ECU to trim out fuel causing a lean condition where you have to hack tune/band aid towards a rich condition making first gear a pain from bogging and such cutting the reliability. It's an affordable alternative and some people like the look. I chose to just get a vented hood though for maximum cooling. It's all preference and what you can afford.

 

I would hope to god your tune is based off the MAF. lol

Obviously IAT's will count in a boosted car, 13-20* will help, but that 7* in between won't mean crap in reality. If you want a better cooled motor, go with a vented hood. If you want truly cooler IAT's with a boosted car, get a bigger intercooler.

 

You do understand that most EMS are based off a MAP, right? Which includes the FIC, Ultimate, Haltech, AEM EMS... I feel pretty safe to say that all EMS's tune based off a MAP using speed density and not the MAF other than the X1 speaking solely for the 2AZFE platform. And, a larger intercooler won't lower your intake air temps unless you're switching to a blow through set up and that could result in a larger amount of pressure loss. Bigger isn't always better.

 

unless ur heavily boosted a hood prop wont get you much in positive gains. Only purpose a hood prop would be functional is u have ITB's cause the more fresh air it can breathe in the better, also if you did a motor swap an need clearance, or if your boosting an insane amount, but if ur only boosting 7-8 psi on a small turbo as most boosted tc's do and ur having trouble with over heating hood prop obviously is not something you should be looking into.

 

People completely miss the physics of this. At highway speed this does not help an ITB get fresh air the way you think and it DOES help cool the engine bay. Faster air moving over an opening with slower air beneath causes a vacuum effect, pulling air OUT of the opening (not in) faster. In other words, this mod does what a vented hood does (help pull hot air up and out of the engine bay) only without soaking everything under the hood every time it rains. Close all your windows and turn off the recirc (with the fan off) and start driving and note how much air comes through the vents. Now.. open your sunroof and see how much more air is pulled through... same concept as a spaced hood.

Now... this will not have a huge performance effect on a DD and practically none on one that is not boosted or otherwise running high engine bay temps, but the above is how it works. IMO it is no uglier than a vented hood and I would not want either one withing a thoughts distance of my car for looks. But.. if I really needed lower underhood temps badly for performance purposes I would choose a spaced hood over a vented one simply to keep my engine dry ;)

 

Well I'm not speaking in positive gains from a power perspective. I'm just talking about the build up of engine temperatures during idle which makes IATs rise in effect. The engine is not over heating. It's just that the MAP sensor didn't take high intake temps into account with the FIC, but the X1 uses the MAF and inherently takes into account IATs requiring the control of engine temperatures; dissipation being one of the options.

 

well thats what i was saying obviously you wouldnt be sucking air from the hood prop you would be venting. as the way airflow goes is through the mouth of the bumper and into the crossframe while propping the hood would allow a faster air recirculation.

 

It does "suck" air out when you are driving. Once the air moving over the top of the hood is moving faster than the air under the hood you have a low pressure area over that hood opening. The air under the hood then starts moving out faster due to this suction effect. The radiator and engine components prevent the air under the hood from moving as fast as the air moving over the hood.

 

i dont get if ur agreeing or disagreeing.. or teaching me physics.

 

Just clarifying

The word "suck" ... is kind of a loosely used term most every time it is used (well... outside of dating....). What is actually happening, even with a vacuum cleaner, is you are creating a lower pressure zone that the outside air rushes into because it is at a higher pressure. But in the regular use of the word, the hood lift does suck air out of the engine bay.

 

i got you.

but ya the way i see hood propping is 98% of people who do it, do it for looks and a increase in butt dyno while the other 2% actually use it for functionality.

 

Well of course. That is true of most mods 95% of them dont do anything, and most times the other 5% are not used for the right reasons. I cant see why anyone would think a raised hood looks good at all...