bboyclo

which is a better hood, for cooling the engine bay or a better hood in general



or

Omixeo

iTrader: (1)

Who makes the top one?

JanusRN

I really like the 1st one. However as far as your question goes, it depends on whether you are using the stock top mounted intercooler or have a front mounted intercooler / plan to get a front mount. The hood scoop for a stock hood and the 1st hood you have shown does not work well with a front mount. So if you have a front mount or plan to get one soon, I'd suggest the 2nd one for better cooling.

MidnightOwl

Bah, stock aluminum TII hood ownz. That scoop looks like it's dead center on the top one too, which isn't gonna cut it with a TMIC. I'd imagine that the second hood would work well for pulling air through, however you'd have to run a front mount.

Evil Aviator

Unless your car has an aftermarket cone-type or similar air filter that is sucking in air from the engine bay, "cooling the engine bay" will not matter a hill of beans. Those hoods are mostly for looks, so just get the one you like. If you intend to make the hood ducts fully functional, you need to install custom duct work between the hood and the heat exchanger (radiator, oil cooler, intercooler, etc.).

bboyclo

i think the first one is made by b magic not sure, and one more question, does it matter if the engine bay gets wet when it rains and stuff?

87rx7girl

ya. i agree. stock aluminum hood really does a great job.
if you had to get a CF hood. i'd say stick as close to the stock design as posible.
the 2nd one is mostly made for if y ou have a V mount intercooler and radiator. and y ou need your under tray or to make a new baffle to help direct air the way it should. or else that 2nd hood would most likely be useless and kinda ugly IMO.
stick with stock looking hoods they go best with FC style
engine bay wet?
depends on what is getting wet. you wouldnt want water getting in making your manafolds dirty. your throtle body springs dont like water, the'll rust. the only things that CANT get wet are the electronic stuff like tps, alternator, coils. those shouldnt get wet. so....
to answer that question...
some water=ok
constant water = bad

you'll get **** failing like my tps did and my BACV. also my alternator failed aswell since i put on the TII hood with out a top mount intercooler there to stop the water.

CarzArKoo1

get the turbo 2 cf hood, its from vis racing too. no don't worry about water going in. im using it, im fine with it.

SLOASFK

iTrader: (5)

So FCs don't have the extremely high underhood temp problems that FDs have? Obviously FD engine bays are smaller and have a second terbo shoehorned in, but I was under the impression that FCs had just as many problems as FDs underhood temps.

SpooledupRacing

I love the 1st hood

TehMonkay

iTrader: (-1)

The 2nd hood would work well, also it would be a good hood for a v-mount setup if you wanted to do that. It helps with heat soak because instead of the air being trapped under there or radiating from under the car it leaves out the top (warm air rises remember).

And regardless if you want good intake air temps you should have a cold air box for your filter.

phoenix7

The TRUE D-MAX hood ( the VIS hood is a copy) helps bring temps down by almost 15-20* celcius(49.X*C with it and ~60-something*C without it, according to the testers in the RX7magazine from Jp) so My vote is for VIS (assuming it's an exact copy of the D-MAX hood).


the top hood would be awesome in you have the ARC top mount upgrade otherwise you're wasting money on looks.


I just saw your signature. Say no to crack and Superstreet.

Evil Aviator

Besides the vacuum lines getting a bit crusty after 10 years, what underhood temperature problems did you encounter with the FD?

classicauto

iTrader: (3)

Not exactly. We only have one oven (for the turbo guys) not two oven's

Its as much of a *problem* on an FC as it is with any car that has a hot engine stuffed under its hood.....not as bad as the FD's though.

phoenix7

i think the heating issues you two are talking about stem from the AST failing, the plastic pieces in radiator which can lead to failure and the IC straps failing under high boost. If you're not talking about these please explain what other issues you guys have seen. Those are all the heating related problems I can think of and it has nothing to do with the flow of air in the engine bay or HOODS.

phoenix7

BTW, from what I see the VIS does NOT have the rear vents (at least not in the pic you posted) near the windshield and I recall the test hood having them. I'm not sure if the VIS hood is an exact replica but not having those vents will not yield the same venting benefits as the D-Max hood.

classicauto

iTrader: (3)

AST and end tank failure.....yes those too. But mostly the BAKING that goes on under an FD bonnet from the massive arrangment of turbocrahgers that are roughly equvialent to 1/2 the size of the engine sitting under/in/around a nest of delicate plastic lines. Thats the under hood temp trouble I'm talking about

alexdimen

iTrader: (13)

I've seen FD owners at auto-crosses use a rag to open their hood it's so hot. I've never seen an FC owner afraid to touch the hood.

If you ever take a REW apart you will understand why. It's mainly due to the amount of cast iron with 1000+ deg. exhaust gasses forced through it. That **** retains heat like crazy. Not to mention that it's clumped together closely and has very little air flowing around it.

There is also a piece of **** catalytic converter (AKA the nuclear reactor) alomost fully inside the FD engine bay. Do the math, they get hot as ****.

phoenix7

I'm under the impression that all the hot air leaves by the tranny well due to the underbelly tray. I'm not arguing against vented hoods at all, I just don't know if the amount HEAT that is actually generated in the FD engine bay is enough to be considered a heating "problem" that mazda did not take into consideration.

feel free to ignore me also, I just like to argue about everything.

Evil Aviator

I'm with you on this one. I have owned NA FB, NA FC, and TurboII RX-7's for 19 years, and have never run into any under-hood heating problems, even when autocrossing in the Florida heat. I have crewed for NA FB and TurboII cars at Sebring and they had no under-hood heating problems. My brother owned an FD and he had no under-hood heating problems, although he had just about every other problem, lol. None of my friends who have owned stock or modified FD's have had any under-hood heating problems. I think that the "under-hood heating problem" is a sales scam for over-priced designer hoods. What is so wrong about buying something simply to make your car look good?

Soma

how about something like this...
could prove to be beneficial while maintaing the sleek lines of the stock hood.
I haven't seen anyone doing this on an FC.

bboyclo

that looks pretty sick, but wouldnt the alternator get soaked if it rains? I live in seattle so raining is an issue over here

classicauto

iTrader: (3)

Sure, its an angle that a hood company would work....but you've obviously never owned a car with a vented hood. I've seen a reduction in under hood temps from over 130 degrees in my turbo FC, to a hair over 90. Measured as an average between both shock towers during track days in the summer.

Sure, an FD's engine bay is not so hot as to make a problem worthy of REQUIRING a vented hood...but does a vented hood decrease the load on the already taxed cooling system? Yes.

And all I was originally pointing out is that an FD's bay IS hotter then an FC's. Measure a stock vs. stock the next time you have a chance if you don't believe me......

ericgrau

iTrader: (1)

Yeah only point of dropping underhood temps is to make your rubber parts last longer or if you don't have a cold air intake sucking in air from outside the engine compartment. But a cold air intake is much cheaper than a vented hood. Plus that carbon fiber doesn't save much weight compared to aluminum and it costs a fortune. One of Ferrari's latest and greatest cars is all aluminum. No carbon fiber, hardly any steel. That should tell you something.