adam c

iTrader: (2)

The best intake for the FD is a modified stock airbox, with 2 sources of cool air: The original source, and a source for cool air from under the airbox. No aftermarket cold air intake (that I have seen) offers this. The only problem with the stock airbox is that it won't work with a very big intercooler.

If only someone made some sort of a kit to modify a stock airbox ......................

airborne

Is there anyone currently selling new box style intakes? i know the store doesn't have any.

ehos

Once you figure out how to make the stock airbox SMALLER and fit IC's (as you saidyourself), you'll be a millionaire

ronbros3

very simple! back in 98 I put a water to air intercooler system in my FD, A radiator made from a Cadillac heater core, a pump from a boat catalog, A resiviour tank from a Summit catalog, and a intercooler from Turbonetics, put it all togther, and works fine, come on guys. does it work?? if you dont turn on the switch for the pump, On the dyno it will run, almost a full A/F ratio richer, it leans out when you use the cold air ,YES it works, at least on the Hiway and drag racing at night, I dont road race on courses much!

dradon03

iTrader: (2)

I have a heatsheild that is open to the now removed bottom side of the foam it's not the best but I think it is better than not having one.

Wouldn't the best intake be to have a sealed box with tubing to the mouth of the front bumper?

Alex

FDZero

iTrader: (10)

I was looking into the Rotary Extreme intake box to later accomodate my future ASP or Vmount IC since it was completely aluminum-made but their business has halted (hopefully not indefinitely!).

You can buy it elsewhere here but with the intakes only: http://www.shaneracing.com/sr93intk.html
The RE version appeared to be completely aluminum wheras this one the sides aren't but top is? All intake boxes I've ever seen are same design though.

ronbros3

very simple! back in 98 I put a water to air intercooler system in my FD, A radiator made from a Cadillac heater core, a pump from a boat catalog, A resiviour tank from a Summit catalog, and a intercooler from Turbonetics, put it all togther, and works fine, come on guys. does it work?? if you dont turn on the switch for the pump, On the dyno it will run, almost a full A/F ratio richer, it leans out when you use the cold air ,YES it works, at least on the Hiway and drag racing at night, I dont road race on courses much!

ptrhahn

iTrader: (9)

I think the deal is this: Cold air is great, MORE air is better. That's a simple way of saying cold air IS what you want and DOES make a difference, but shouldn't be acheived at the expense of good flow... so if you've only got a 1" x 8" opening of fresh cold air and that's it, that's not going to work better than an open, less restricted "hot" air intake.

What we don't all know is at what point those two competing factors meet in in a compromise. Is a little restriction OK for a LOT of cold air? ... or a LOT less restriction worth a hotter charge? I don't think anyone has a definitive answer.l

GoodfellaFD3S

iTrader: (213)

I agree with ya Peter.

I have a 'hot air' intake. K&N filters with minimal piping.....the front turbo filter clamps right onto the small black 90 degree bend piece off of the compressor, and the rear turbo filter clamps onto a custom mandrel bent pipe that I bought from chuck westbrook. Here is a pic:



I decided to delete the hard pipe kit and go this route after my experience with a friend's FD. He owned it for about 6 years out in Texas and ran the same intake configuration. His car always boosted well, ran strong, and his intake temps (on the pfc commander) never were any higher than mine.

I've never had any problems, plus I can hear my turbos spool up much better now, hehe. I am sure some in the 'Ice Cold Air' camp will take potshots at me, so here is something to aim at ------>

iceman4357

iTrader: (2)

Im glad all you have twins still For my single im going to have to fab up a cold air intake because having the K&N on the turbo itself next to the engine isnt helping much.

7racer

I've always wondered if the Odula hoods would help cold air boxes.

The look of the scoop isn't that great...but I could imagine removing the top of a M2 or rx7fashion box and have foam placed around it to create a tight seal to this hood scoop.



http://www.odula.com/page/frame.htm

rynberg

The box that SR Motorsports sells is the rx7fashion box. It's all aluminum. I run mine with the top removed -- I gained 5 rwhp on back-to-back runs on the dyno with the top removed and no other changes. I don't think having the top removed hurts much from a "sucking hot air from under the hood perspective", but I could be wrong.

7racer

Rynberg,

did you have the hood open during the runs?? It may not represent real life conditions as the car is static.

And DamonB, what got your panties all in a wad to start this thread!

rynberg

True, but I think it's safe to say that more air will hit the filter with the lid off than on, under any conditions.

He's got a newborn, enough said...

Damon, congratulations on the new addition to the family, BTW.

renkenkyo

iTrader: (6)

From a thermodyamic stand point, the cooler the air coming into the compressor, the less work (equating to horse power used in the turbine) to compressor the air and push it. This is of course purely textbook so I don't know how true that holds to real life results.

Does, anyone know what cold air boxs will fit with a small v-mount? Does the pfs fit with the rotary extreme normal vmount?

Thanks,
Josh

samiralfey

How about mating the A/C with the IC? Cooling the air inside the IC instead of cooling the inside of the car? I remember reading about a concept Mustang with this system.

matty

anyone who thinks hot is better than cold is an idiot. go drive your car on a cool night then come talk to me. YEP!

My buddy and i did alittle testing comign back from the track one night. we both have smic;s but he has hot and i have cold air intake. the intake temps as measured by the power fc were dramatcally cooler in my car. i cant remeber exactly what they were as it was a few yrs ago but there was a big difference.

Shinobi-X

How much of this change in power is attributed to cold air flowing through the intercooler (which will vary based on type), rather than ambient temps reaching the filtered intake, which is super-heated anyway after compression? Also, what method was used to test and verify your conclusion?

Would you say a more efficient component of the intake system can make up for the shortcommings of another? Say for example, the greater flow point that ptrhahn raised, as opposed to a colder but more restricted setup.

I more than agree with the logic concerning the efficiency of the turbo, as we've all experienced sharper boost response, but what happens afterwards tends to be a rather large debate as well, and is responsible for making or breaking a lot of power. I can't help but think this is a large(er) part of why we make more power on those cold nights.

DamonB

The only debate comes from those who don't know what they are talking about; people can't see the forest for the trees. I have not said a hot air intake won't work, will hurt your engine, blah blah blah I'm saying a hot air intake is losing you power and I don't care what kind of intercooler you're running or what the weather is.

For example some say that the cool air is making more power not due to temperature at the intake but because the intercooler works more efficiently in the cool air. Let's look at the flip side of that coin. Let's say that it's a hot day and the intercooler therefore is less efficient. Wouldn't you want to do everything possible to get cool air into the turbo and keep intake temps down since the intercooler now can't contribute as much? Of course you would!!! But this is also true in every situation! This doesn't somehow magically change just because you have a bigger intercooler or it's a cool day!

DaveW

I agree completely! Logic rules!

Dave

Monkman33

iTrader: (28)

Ok, so the intake air temps have either 2 or 3 temperature changes to go throgh:
Cold Air Intake: Air enters the Intake Piping at X degrees (where X is outside air temps). The air then enters the turbochargers and is compressed. The air temps are then raised Y percentage degrees based on turbocharger adiabatic efficiency (my spelling may suck, sorry) at whichever boost point you are running. This air is then pushed through an intercooler where it is cooled Z percentage degrees (depending again on which point of the efficiency range it is running, which will depend on OAT's, IAT's, Boost Level, and Airflow). So this actually gives us an equation that if given the values of each variable, we can determine the ending IAT (notated by I) at the throttle body. For the equation to work, all percentages must be noted in an additive fashion, meaning to see a %10 increase, X must be multiplied by 1.10)
I = X * (1+Y) * (1-Z)
Hot air would add one variable to this equation. The percentage increase determined by Air movement in the engine and heating of the air underhood. This term will be represented by H.
I = X * (1+H) * (1+Y) * (1-Z)

Any increase at any point in the equation will result in higher ending IAT's.

Another thing to factor in the equation: Intake Air Flow restriction of a cold air, versus a Hot Air. With turbocharged vehicles, it really means that it would take just a little longer to reach boost if there is any noticable restriction. Since the turbos will spool to a certain point above atmospheric, which will not be affected.

I honestly believe filter design will play a more important role in restriction that cold air intakes or hot air intakes.

Shinobi-X

I understand the importance of cold air on turbo function, but what I'm refering to is the importance of the intercooler, and if it has greater effect, nullifying effects of cold air entering pre-turbo. Heat soak is a problem, so I figure that because of this, the effects on the intercoolers ability to alter air temp before it hits the manifold, is now more dramatic, and thus requires more concern.

Putting it another way, is there any consistent evidence out there which shows that colder air hitting before the turbo, provides substantially more power, even with a heat-soaked intercooler?

DaveW,
I believe this mimics what you stated ealier. "The ability of the IC to cool the air after the turbos compress it. That is also directly related to the temperature of the air passing through it, and may have an even bigger effect than the intake air temperature."

Any input?

matty

u guys are reading too much into this. It really is very simple, on a cool day the car performs better. why cause starting ambient is cooler. The cooler u start with the much much better off u are.

Kento

Yes...the fact that every OEM production turbo application has an intake that draws air from outside the car, not the engine bay.

Kento

You're making the subject of heat-soaked ICs the issue here, not intake air temps before the turbo, which is what this thread is about.