cold air intake on 12a
 

how much horse power do u think i would get if I made a custom insulated cold air intake to my factory 12a??? If anyone has done this before can they tell me if they noticed a difference and if so what diffrince, thanks.

http://www.mazspeed.com/coldairintake.htm

Ive never done it, as I am running a dellorto, But they used to have a huge write up of a insulated CAI, on mazspeed.com but I cant find it any more!

Here is another link for the insulated CAI
http://www.ten15.net/Maz.tutorials

yeah thats what i was thinking of doing. I actually just printed that off, doesnt look as classy but it is insulated other than other where carl states that it will help quit a bit if insulated.

I did my own cold air intake a couple of years ago. It made quite a difference on the 'butt' dyno. I used a 4 inch aluminum hose and brought it through the passenger side rad bracket. I also used a slightly modified aluminum dryer vent as a scoop in front of the rad. Last year was my first real dyno where I got 101 hp at the wheel with a stock carb that has never been rebuilt or even adjusted. I'm sure that the RB header and presilencer helps too. ;) This year I'm gonna try and use a cone filter in front of the rad and run it through a smooth surface tubing straight into the carb to reduce turbulance.

Oh yeah... to fill in and smooth over the nooks and cranies in the scoop and the inside of the filter housing I used marine grade silicone. I also took of the warm air flap inside the snorkel and smoothed that over as well.

Why use 4 '' when you can use 6'' in the picture that is 6'' diamiter flexible plumbing tubing and 6'' plumbing bends. They also deleted the factory snorkle.

Ic, would u say insulating would be worth it??

DOes anyone have a dyno proven cold air that they can tell me about plz??

Ummm the thing is that you're sitting still on a dyno. the point of a cold air intak is the cool incoming air while at speed is colder than engine bay air. On a dyno most coldair only get air about 10* less than engine bay temps and that will hardley show anything on the dyno over a normal intake.

The difference would be so small it could not be measured. Under normal driving conditions the air temperature in the engine bay is little different from that of the air outside. It is marginally increased by passing through the radiator but the volume of that air is so great that there is little increase in temperature. I tried to measure it with an electronic probe and the variation was less than 2 degrees.

In terms of engine performance that is insignificant. Think of the situation when the engine starts, the radiator is cold so there is no air warming impact, but there is no increase in power.

Trying to get a dyno reading would be difficult as to get a valid reading you would need a very large fan to represent the cooling impact of air flow at speed.

I just got a front air dam,that has 2 holes for air ducts.I was thinking of using one of them to bring in air to my Delorto dhla,Looks like it might be a waste of time

So if a cold air intake is such a waste of time...then why do so many cars in so many racing ciruits use them? With heat being a major concern for the longevity of these engines coupled with the fact that stock, these engines put out a relatively low number of horsepower, having a faster, less restricted and 'slightly' lower temperature intake would be worth the extremely low cost and time of fabricating such a set up.

My install includes a standard GM IAT (Intake Air Temp) sensor as part of the EMS.The attached pic shows where the sensor is installed so it reads air temp immediately after it is filtered. On an 80F day I routinely see 130-135F IATs. I believe this is due to heated radiator air. A to-do on my fabrication list is provision to feed the TBs air from in front of the radiator. I've moved the battery so have plenty of room to place a tract through the driver's side of the radiator mounting plates/sheet metal.

-Mike

I had another look at my set-up (it's in storage behind several feet of snow) and it is in fact 6 inches (my first attempt was 4) and it's a single piece so there are no short/sharp 90 degree turns but rather a one long turn from where the snorkel was down to where my scoop is in front of the rad.

A well sorted cold air intake is a big benefit, the cooler the air the denser it is, try running a turbo without an intercooler and then adding one, the difference is huge. In an NA car it wont be so obvious but the cleaner the flow the better. Engine bay temps in an rotary are very high, our exhaust runs at the extreme levels of temps.

I will be experimenting with a cold air for my street and race car this spring. I am thinking of using a box style with a flat filter, and then running 6" hose.

Rotary7s, the holes in your airdam are for brake ducts, find a different inlet for your carb. Good brake cooling is very important for performance driving.

If you look at the competition manual it shows you how to make a cold ait intake if they are used in competitions then it must reflect on performance in some way.

I was just reading the PDF for it

my 2 CENTS

Yeah underhood temp while driving, is significantly different than if you were measuring the temp with the hood open. The fact is that the factory air box has its inlet on the side of the engine bay with the exhaust mainfold. That would be the hottest part of the engine bay under hard driving. You will never notice the difference I imagine unless you were driving very hard, for a long length of time.

For all of those that think a custom cold air intake will give 5 + horse power state that in the thread, and for all of those that think it will do little or nothing also state that in the thread. Plz give reasons. Thanks. Im basing these results on if i am going to make one on my 85 gsl 12a

You will need to test and tune to make your gains, its not that simple, denser air means more fuel to get the ideal fuel/air ratio, so you need to jet/adjust your carb to suit. 5 hp might be optimistic a 5% gain on an air box is ambitious but you should gain a few hp. The only real way to tell is to test it on track. use an accelerometer and try it back to back same track, same conditions.

Where is this tubing available from...Aussie boy living in Hicksville....lol

The engine bay gets hot when standing still due to the radiant heat of the engine. Once the car is moving the massive air flow through the engine bay helps everything keep cool and the impact of the heat transfer from the radiator is minimal. If you want to test the theory directly, just put a pipe through the firewall so there is engine bay air coming in while you drive, and have passenger measure the temperature.

Extending the air intake to in front of the radiator would cost nothing in production, if had a magical impact on power every manufacturer would design it into the layout.

My conclusion after detailed research was the power improvement was negligible, The air flow was far important in designing the FMIC and FMOC layout, even to backdating the radiator.

Add an extended air intake if you want, the cost and effort is small. At least it may look cooler in a ricer type way.

^^^

Rotary engines run hot, the radiator cools that by air flowing through the radiator, this air then moves into the engine bay, also the exhaust which can get hot enough to glow cherry is about 8 inches from the intake, there is a major heat issue involved with this.

Most modern cars do have cold air intakes, but they are flawed as always by cost, the bean counters and reducing the chances of water being dran into the intake, these are the reasons that most cars do not go all the way to having an air intake draw directly from the outside.

Check out a few race cars if you dont think this is so, most aftermarket and tested units draw air from outside the engine bay, I think these systems and companies have done a bit more testing than putting a tube through the fiewall.....Ever seen an open wheeled car, the air intake is huge and mounted right behind the drivers head.

I suggest you test at the intake with a meter not by trying to draw a little heat into the cabin by a tube.

Note this cold air intake, I beleive this little company thought it was worthwhile

http://www.geocities.com/MotorCity/G...9/f1black7.jpg

http://www.geocities.com/MotorCity/G...9/f1black6.jpg

Note: it is that bulge that runs from the roof down to the engine compartment.

What about this one, note the text on the two snorkels

http://www.geocities.com/MotorCity/G...9/f1black6.jpg

awsome, i need more opinions thanks a lot aussies and paulwitzsomethin, thats one for a lil increase and one for little next to nothing. Need more though