Cold Air Intake

[Alfred1]

I was just reading a thread on the other board where a guy installed one of these CAI's in his 914 and claims he feels a seat-of-the-pants improvement in acceleration. How much hp, if any, do you think you'd get by installing one of these in a good running, stock 2.0L? I used to think that CAI's were gimmicks until I read an article that compared various CAI's installed on a 12V, 2.8L VR6 motor from a 2001 GTI and some of them gave an increase of 9 whp which is about 10 flywheel hp. If that increase applied to the old flat-four motors, that might be equal to 10hp*(91hp/174hp) = ~ 5hp gain in a 2.0L.

Eurotuner p.64

Eurotuner p.72

Eurotuner p.74

[mike mueller]

big difference in the intake designs for a 2.0 914 and the VR6 engine....the VR6 design engineers had to take noise from the intake system much seriously than before.

the factory could easily make the newer cars flow more easily on the intake side, but increased noise will the result of the freer breathing system...

[Alfred1]

Would a stock 2.0L get any benefit from a ram effect if you ducted cooler air from the outside directly to the throttle body and kept the intake air temperature sensor and increased the fuel pressure somewhat?

[mike mueller]

yes, that would work, some factory Trans-Ams or some other big 'ol american cars did just that.....

now how to do it on a 914 and have it still look "normal" might be the bigger challange...also, the ROI might not be worth it.....

[Dave at Pelican Parts]

I believe that Demick did a similar modification to his 2.0 once. He claimed it gave a "just noticeable seat of the pants improvement".

Note that the CAI in the above link still draws heated air from inside the engine bay. All the kit really does is replace the stock air cleaner box with a K&N, and add a heat shield that looks at first glance to be of dubious benefit. Oh, and the K&N will be able to suck in rain, which probably won't help your power.

You would probably see a slightly larger gain if you drew air from outside the engine bay, as there is often a 30dF or greater difference between the outside air and the air in the engine bay.

But I wouldn't count on it for anywhere near 5 HP under any circumstance, frankly...

--DD

[Alfred1]

Here's the link to Demick's CAI info.

http://members.rennlist.com/demick/coldair.html

If you could get 4 more hp by adding his CAI to a stock 2.0L plus a good header that may take you to a total of over 100hp, no? I ran a couple of simulations with Drag Racing Analyzer and for a stock 2.0L I got 0 - 60mph in 9.6s and 1/4 mile in 17.2s. Increasing the hp and torque by ~ 10% to 100hp and 115tq I get 0- 60mph in 8.7s and the 1/4 mile in 16.7s so a CAI and header may be useful upgrades for someone who doesn't want to tear down their motor.

[Bleyseng]

The biggest improvement on any stock 2.0l is improving the exhaust with a header.
Even the great 2.0l heads have poor exhaust flow due to the 90 degree turn after the valve.
I am going to try a Jake cam to see if that fixes the problem some.

All this intake crap is just that crap. A engine is a air pump and if the air going out is too restricted then trying to force more intake in won't work unless its a turbo.

I am sure running a snorkle for a cold air intake will help somewhat.


Geoff

[Alfred1]

Originally posted by Bleyseng


All this intake crap is just that crap. A engine is a air pump and if the air going out is too restricted then trying to force more intake in won't work unless its a turbo.


Geoff

It's not crap. Look at the Eurotuner links above plus Demick's info. He even got a measureable increase in acceleration from his CAI setup. Cooler air is denser which means more mass per volume of air stuffed in the cylinder so if you can meter out more fuel (the computer should do this based on the intake air temp. sensor input) to match the greater mass of air, you get a bigger explosion and more power.

[Bleyseng]

Demick is using cold intake air to gain hp which works.
Open throttle body vs a stock air cleaner box with a new filter netted a big 1/2hp on the dyno when I did it.
The dyno says no....

Geoff