I always see my fellow racers talking ****.Oh i got a cold air intake or i have a air intake. I understand what it does.But whitch one is truely better?Air intake or cold air intake.

 

Colder is always better.... However, cooler air verse more, but warmer, air... Hmmm...

Cold air intake boxes just seem so restrictive to me, but that's just me. I honestly don't know the flow characterists of all of them on the FD, never seen any tests. The only test I've seen was done on a Skyline, and even that data is very suspect.

Anyway, you can always build a heat shield for an open air intake if you like. The main time when warm air is an issue is when you are not moving (idling, sitting in traffic, etc).

 

cold air is bester because it takes air from the outside of the car... just an air intake would suck in the really hot air that is under the hood.
They are the same thing basically, except the cold air intake has a box around it to keep the engine bays hot air out of the intake

 

IMHO, if you have a good efficient FMIC, cold air intake is not needed, though every little bit of cold air helps I guess?

Timmy

 

cold intake matters a lot no matter if you have an efficient IC or not. Say ambient is 100F vs 50F, i doubt the intake charge would be the same because of the efficient IC. Colder air at the intake becomes a good starting point.

For hondas ( i know i know) the AEM brand always sells cold air intakes that install in the bumper. these have dyno proven to make more HP to the wheels than any other intake manufactuer simple because of the place they suck in air.

an open filter with good ducting and blocked off from the engine can yeild good results.

 

plus cooler air is more dense, therefore your turbos don't have to work as hard to make boost. probably has limited effect, but like someone said before, every little bit counts.

 

cold air all the way

 

not really related, but hey ryan, andy said you were gonna be up here sometime in the near future. are you and exactly when? be nice to see a 3rd gen again.

 

This kind of post always is a war Cold air vs non Cold air.

The way i look at it,a Cold air intake on a turbo car isnt going todo much.Im sure you all know by now how hot turbos get and how easy air heats up.So whats the point in a cold air intake then?Someone plz tell me.

 

my friend with a wrx has had both a normal intake and a cold air intake. he got the normal intake when he first got the car and saw some moderate improvment in his quarter mile times. then for his bday i got him the injen cai and his car became even faster. the turbo felt more responsive and you could here his stock bov quite clearly after that. i think that having a colder and denser intake charge is a big improvment on a turbo car. more air = faster car. i think its just that simple.

 

Yet you are sticking up for cold air intakes...which on an FD means a cold air intake box. These don't deliver more air to the turbos, they deliver cooler air. An "open" intake allows the turbos to injest "more" air.

From what I see on the forum, heavily modded FDs seem to have open intakes. Guys more lighted modded with mild bolt ons stick with the cold air boxes; not sure why though

 

Cold air is always better than warm/hot air, but the problem is that cold air intakes are also restrictive. Which cold air intakes are you looking at?

 

The only true cold air setups are:

Stock
Stock with Racing Beat
Knightsports

I took my car to my bro-in-laws best friend. He makes custom cars for a living. Makes over 6 figures a year. THis guy made a tiny bmx bike with a chain saw engine and disk brakes goes 60mph and is street legal. Has titanium welding equipment and made a Hot Rod out of Titanium (650hp).

Anyhow, showed him the M2 & tri-point boxes. He said the volume of air is too small and the cones are way too small and the restriction from that combo is way worse than my BLitz! He also mentioned jet planes use the same type of filters as the BLitz. Oh, HKS is now using metal filters.

 

There was a good thread on this in the past... search for it.

I think this discussion has been pretty on-target with the "colder air is always better" and "but there are other factors to consider" messages.

Cold air still matters on turbo cars with big intercoolers. Even if your IC will get the air down to the same temp (it won't, but it will be closer than the difference in intake temps) your turbo still has to pump more of the hot air than the cold air to get the same intake manifold boost+temp, so it makes more backpressure, which means less power.

On the other hand, if your intake is causing a 1 psi vacuum at the compressor inlet because it is so restrictive, the turbo will have to compress the air more (which makes it hotter and adds backpressure) which will work to offset the lower temps. However, I think the popular cold air intakes don't have this problem -- they flow enough.

One of the more practical considerations to weigh is that hot air kills the air pump. If you are running one, you might want to get a cold air intake, or work up a dedicated cold air intake for the air pump.

There aren't a lot of options for cold air intakes on a single turbo. I think this is the main reason you don't see cold air intakes on single turbo street cars. If you look at the drag scene in general and some of the faster RX-7s, though, you find some custom work to get cold air into the turbo. Don't be fooled into thinking cold air doesn't matter, it is just that other considerations sometimes take precence. It would be nice to have some dyno numbers, but I'm afraid those might be misleading as an open intake with the hood open is probably not so different from a cold-air intake. If you are looking for an intake for a stock-turbo car, I recommend a cold air solution.

-Max

 

Max, do you have any of the data that was passed around the big list about the M2/Tripoint intake? There was data on the opening size, and the surface area of the cone filters to prove there was more then enough air for the stock twins. I couldn't find any of it in the archives, and thought it would make for excellent discussion.

eric

 

I was told the box was too restrive/not enough volume and the cones were too smal! He would have done the test for me cpmaring Blitz vs Tri-point as well, but he charges $150/hr and it wasn't worth it for me. I was also told my money was better spent on a vented hood instead.

I would like to see some results. I don't beleive there would be any noticable gains on a M2 box vs Blitz intake system.

 

Goracer, I remember when I first saw the Tripoint box, I thought NO WAY is that little opening going to give enough air. But someone on the big list posted equations in regard to air volume/velocity and I was impressed. They proved that the boxes/intake cones were sufficient for the stock turbos. I'm not sure if all the data or the conclusions were correct. But it did make for interesting reading.

eric

 

That's the testing he would have done but I wasn't willing to pay for it. If someone has the results, please reply. If it also has some caprison against an open filter, it would make an excellent sticky post.

 

What about the M2? No good?

 

Cold air box do work but over hyped mainly because of the price. For the price for $495 M2's, I rather change a better radiator, lowering your engine temp, then look into a good efficient intercooler to lower the intake air temp, and lastly look into the cold air box.

I highly discourage buying a cold air box before radiator upgrade.

As for the WRX getting more power out of Injen Cai, that is because the stock i/c is an interheater, if he puts on a Blitz LM FMIC rather than the Injen CAI, I am willing to put money down that the power increase will be more than the Injen CAI.

Timmy

 

I'm not saying they are worthless, just misleading and expensive. They do draw colder air but it's not a true cold air nor a cold ram air system. Cold air comes from the front.

The stock system gets colder air than M2, RX7fashio or Tri-Point!!!

The racing beat opens up the path for more air and the KnightSports opens it up even more.

What I was told (and I consider him an expert) is that your money is better spent on cooling the engine. Buying the cold air box before that is worthless. SO buy a ventood hood insted.

I was going to have him custom fabricate my intakes in the space where the 2nd oil cooler goes but he told me to get a vented hood instead.

 

There is a relatively cheap test that you could do. Get a shop vac that flows about as much as the engine under full boost / high RPM (say 300-400 CFM) and hook it up the intake. Measure the vacuum with an accurate gauge and see if there is much difference between an open intake an a CAI. It would probably be a good idea to measure at least the CAI installed in a car to get accurate results -- I'm not sure if it would matter as much with the open intake.

The calcs I remember were of the opening size in the bottom of the CAI. The conclusion was that the hole was big enough to not be a significant restriction. K&N also has specs for filter element sizes that you could use to check their size. At 14.7 psi, the 13B is somewhat like a 5.2L NA piston engine (double because its rotary, double again at 2.0 pressure ratio).

-Max