ive been wondering about the effects of under hood ventalaition and how this might effect tunnign on itbs.

i see lots of people with the rear of the hood proped (for obvious reasons )
and its something i would like to do to help under hood temps.

now you guys think there would be any changes while, say cruising at 60mph.
with a good flow goign through the rad , over the motor andout the back of the hood interfear with the suction of the itbs.? if so what about making some sort of isolation sheild or some type of scoope/tube that runs air directly to the itbs (not a box that could be pressuerized) .

i had a talk with somone that had siad while on the hyway he noticed some lean conditions at low throttle angles , it crossed my mind that the ecu /tuner could not fix this issue since fans used on dynos were not flowing the same speed .

im bored at home , my car is under 5 feet of snow and this has been on my mind lol sorry if it makes no sence

 

anyone have any input

 

from this thread...
https://honda-tech.com/zero...age=8


Quote, originally posted by goforbroke »
Its proven to work, a close friend of mine took underhood temperatures with his hood "pop open" with the spacers. The temperatures were noticeable cooler. He also mentioned he could never get his car to fully warmup when he had his hood poped open. He said it would take damn near forever to actually warm up his car.



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by revolt_allmotor &raquo;</TD></TR><TR><TD CLASS="quote">

Really? That's funny. In a recent article of Hot Rod magazine, they took one of their Bonneville cars to the wind tunnel to test the aerodynamics, and while they were there, they interviewed the chief Aerodynamicist about common tricks that could help or hurt you, for the guys that can't afford to go to a wind tunnel.

He said that the base of the windshield is actually a high-pressure area, so air from the engine bay definitely does not exit through the back of the hood, in fact with a cowl induction hood (or a hood spaced up with washers) air will actually get forced IN to the engine bay through there. Might be helpful if you have ITBs but it definitely won't help get hot air out of the engine bay. And it causes drag. The point of the guy's statement was that making a really good seal between the back of the hood and the cowl/base of the windshield will make the car more 'slippery'.

Trust me I'm not trying to make fun of you, this was news to me too, I had my hood spaced up in the back for a couple years. Maybe your friend was taking the temps in the back parts of the bay, where parts were being cooled down by the air that was forced IN? I dunno.</TD></TR></TABLE>

 

called it! back in that JDM hoodspacers thread

 

cool , thanks again man ,

i thought for sure the suction wouls pull air away from the itbs , but that makes sence about the high presure area .

now to account for this on the road lol

 

there is no suction, and its easy to account for.. thats what map sensors are for... no need to worry with it

 

sweet , now on a itb tps/map tune , would it still account for it even though its tps(more then likely at those speeds) or would a quick street tune fix that up ?

 

I dont think it would hurt the suction of the ITBs. It might even help, like a cowl induction. There is a lot of pressure and turbulance where the windsheild is.

Julian

BTW - the propped up hood thing looks hideous.

 

it depends on how the program blends the tps/map .... idk about crome b/c it sucks for itb's so i never use it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">it depends on how the program blends the tps/map .... idk about crome b/c it sucks for itb's so i never use it</TD></TR></TABLE>

Really? I've heard several tuners say they like it for ITB's.

 

yea i had great luk with it to , but havent tried aem

 

the way crome does it makes it a little easier, but its not as good as you can get it with aem/motec/something real, there are some tricks to it, though.