Why the bludge on Silvia(S13) hood?

[Jhay]

I've noticed alot of people who have done Silvia front end conversions that the hood doesnt seem to be flush with the fenders...theres always that buldge or gap near the windshield....what are some remedies on DIY fixes on flushing it up? Rubber hammer? :(

[cdlong]

some people put washers under the hood hinges to creat a gap for air to escape. it's a JDM trend. i've heard that it doesn't work and i've heard that it does so it's just style.

[Bbandit]

are you talking about lifted hood? If so, they did it on purpose... supposedly, It will release the pressure and heat thats building up inside of the engine bay.

[Jhay]

I know about the washer technique but I've heard some people complain about the flushness when they just did the conversion..for example Nekopunch..

[bkfill]

same thing as a cowl hood on the american cars
air gos in from the bottom/front of the car and heat exits thru the top of the hood
i think the air would vent better
(spacers)

[xVaporx]

not to mention the air traveling over top of the hood creates a negative pressure area right over the windshield cowl, thus drawing it out. Simple science really.

[bkfill]

not to mention the air traveling over top of the hood creates a negative pressure area right over the windshield cowl, thus drawing it out. Simple science really.
wasn't sure how to say it so i left it out

<3 cowl

[iamwesley]

I know what you mean. I just installed my silvia conversion on my hatch. The hood seems to come up alittle more about 5 cm's and I didnt use washers.

[KA24DESOneThree]

Mine's lifted with spacers and I can see the heat radiating out of the engine compartment while the car's sitting still. I don't think it looks ghetto... of course, I am a proponent of function over form.

[brianglawson]

no no no no no he is talking about where as our 240sx hoods, and 180sx hoods, sink down in the middle section of the hood, the silvia hood actually rises up....and i suppose it is to further differentiate the 2 models from each other, he isnt talking about that fugly lifted hood crap

[Strategos]

so he means like the opposite of a kouki 97-97 s14 hood how it has two lines running down it as where the silvia s13 hood has two lines as well although there is a rise. Am I right?

[brianglawson]

yeah at the 2 lines it rises instead of sinks like on the pop up front end

[sykikchimp]

not to mention the air traveling over top of the hood creates a negative pressure area right over the windshield cowl, thus drawing it out. Simple science really.

There is low pressure above the hood, but right at the bas of the windshield where the hood meets it is high pressure. If it wasn't air would be sucked out of the cabin when you turn the "vent" on.

On old school cowl induction hoods this high pressure created a "Ram air" effect in the intake/carb for increased horsepower.

[thx247]

I was going to say...High pressure at the base of the hood. Air flow INTO the engine bay.

[bkfill]

There is low pressure above the hood, but right at the bas of the windshield where the hood meets it is high pressure. If it wasn't air would be sucked out of the cabin when you turn the "vent" on.

On old school cowl induction hoods this high pressure created a "Ram air" effect in the intake/carb for increased horsepower.

but on our cars it'll ram air thru the intercooler

[sykikchimp]

what?? raising the back of the hood will do no such thing.

[bkfill]

what?? raising the back of the hood will do no such thing.
why woudn't it

[sykikchimp]

how would it? the intercooler is in the front of the car in front of the radiater, and it see's very high pressure on the front side. the slight increase of pressure by the back of the motor will have no effect on the intercooler.

[bkfill]

slight? K! well in MY opinion it'll scoop up air better + removing more heat out of the motor

[thx247]

I want some of what he's smoking!

[bkfill]

I want some of what he's smoking!
same crap thats under your hood

[thx247]

slight? K! well in MY opinion it'll scoop up air better + removing more heat out of the motor

Luckily for us, your opinion means nothing.

Air from a hood scoop would exit under the car, the same place that air entering at the base of the hood exits.

WHY THE FUCK you would have a hood scoop for cooling is beyond me though.

Try a larger radiator. More efficient ++

[Jhay]

Wow this is getting out of proportion..lol
This is more of what I mean
Pics from Nekos homepage..

fresh install this was...this is what I mean guys..
http://northwestnissans.com/donations/nekopunch/neko/nekosil06-04.jpg
http://northwestnissans.com/donations/nekopunch/neko/nekosil06-05.jpg

[s14slide]

There is low pressure above the hood, but right at the bas of the windshield where the hood meets it is high pressure. If it wasn't air would be sucked out of the cabin when you turn the "vent" on.

On old school cowl induction hoods this high pressure created a "Ram air" effect in the intake/carb for increased horsepower.

Isn't part of the reason for the high pressure in this area also because of the windshield wiper being there. The back of the hood doen't cover the wipers, so I'm guessing that the air would pile up in that area, thus having a higher pressure than the faster moving air going over the hood. And then raising the back end would still leave the wipers exposed and still creating a high pressure point, thus forcing the hot air to go out frumunda the car, where it would of gone anyway, because (stock) the backside of the hood is sealed.

On another note, if you want to improve airflow through your engine bay, get a cold air intake or box off your open element and provide high pressure ducting to it, then install electric fans on the back of your radiator and box the back of it off, cept the top, where it would meet a vent where the low pressure air rushing by the hood would actually suck the hot air out, and if your turbo, naca duct just forwarad of the turbo and a vent just to the back side. That should be more than plenty. That's what I plan to do once I get my FRP hood. And for those of you who don't know, you don't need to be flying at freeway speeds to get a good airflow effect on something w/ as much surface area as a hood.

[bkfill]

Luckily for us, your opinion means nothing.

Air from a hood scoop would exit under the car, the same place that air entering at the base of the hood exits.

WHY THE FUCK you would have a hood scoop for cooling is beyond me though.

Try a larger radiator. More efficient ++
let me say this again, look under your hood

[s14slide]

let me say this again, look under your hood

If your refferring to your engine itself, the cooling effect of the air going around the engine is so minimal that it's not even a factor. Maybe getting good flow around a set of headers or mani/turbo would reduce overall engine bay temps, but if the engine designers wanted to cool the engine using air around the block, they would have designed cooling fins instead of spending many design hours on water jackets.

[KiDyNomiTe]

get a water sprayer for your radiator :), you'll actually see an improvement. The whole hood thing I have yet to see proved, it seems like a lot of it is in peoples heads.

[sykikchimp]

I think it could lower under hood temps.. especially with an aftermarket turbo setup that would set near that area..

I think it's absurd for someone to believe that this will create more flow through the intercooler. Raising the hood at the back will increase underhood pressure. REDUCING the pressure gradient from the front to back of the intercooler. The larger the pressure gradient, the faster air will flow (vacuum). Reducing it will DECREASE the flow through the intercooler and radiator. (albeit, I would guess it to be a marginal change at best.)

[NekoPunch]

Wow this is getting out of proportion..lol
This is more of what I mean
Pics from Nekos homepage..

fresh install this was...this is what I mean guys..

Keep in mind that was when I had just bolted everything on for the first time. The reason it didn't flush up at first was because the hood, fenders, etc. had sustained damage from the junkyard, shipping, etc. But with a little TLC, everything fit and lined up just fine.

[Jhay]

Ah thanks for clearing that up Neko...