It's amazing, that a piece of plastic tubing, can make such a big difference...
 

http://www.knfilters.com/instructions/57-3069_inst.pdf

I recently removed my K&N filter, & intake tube, for cleaning / maintenance.
What a difference...:skull1:
I lost my nice, crisp, around town, throttle response.

After putting just the K&N intake tube, back in place, my nice, & crisp,
throttle response, returned...:twothumbs:

I knew that the increased diameter, of the tubing, at the turbo end, removed
the choke point, the restriction, of the intake side of things, for HP gain.
But I didn't realize, how much of a difference, that it made, for low-speed,
around town, daily driving, throttle response...:smile:

I do remember, during testing, years ago, that it did reduce, the stock positive LTFTs of +8, to close to, if not, zero, LTFTs.
At that time, with all the changes that I was going thru, testing, with parts & programming, I didn't know that this simple piece of plastic tubing, was responsible, for such nice, & crisp, throttle response.

So, bottom line, anyone with a stock HHR SS, that is afraid of adding a 'tune',
to your buggy, you have got to try this simple, intake tubing.
It WILL 'tune' your buggy, by moving the pig-rich factory settings of +8 LTFTs, to close to zero, & at the same time, give you nice, crisp, around town, throttle response, + add appox: 9 HP.

It's an easy 10 minute switch, maybe 20 minutes the 1st time, & can easily, be swapped out for warranty work, if anyone still has a warranty.

Also, if you are tuned, & don't have any aftermarket intake, try this, you will be amazed...:twothumbs:

The intake tube likely has more to do with directing the airflow across the MAF than it has to do with an actual improvement in air flow. I have put a lot of MAFs on a flow bench and they all vary and you can dramatically change their reading if you change the inlet configuration leading up to the MAF. I built the reference out of 6 feet of 4" pipe with a Ford maf inserted 4' from the inlet. That's about enough room for the flow to get stable and give consistent results. You'll notice that most MASs are keyed so they only attach one way. If you remove that key and rotate them you'll probably see those number change.

Ira

The HHR SS intake tube, is after the MAF.
The air box itself, is located directly in front of the MAF

Cant wait to install my ZZP intake!

Time your install with retuning, as a new tune is a must,
With the ZZP intake.
I would even suggest adding a 'flow-straightener' to this.
http://www.southerncarparts.com/Inst/MAFscreen.pdf
http://www.treadstoneperformance.com...w+Straightener

Also, try this site Honeycomb for MAF I had use an air straightener on the intake for my 94 Impala SS just ahead of the card maf.

https://www.chevyhhr.net/gallery/fil...harger_web.jpg

It's JB welded in position just after the flex joint connection before the maf.

All the way back to the mid-90's I've had arguments with people regarding the factory MAF screen.

Every time I'd test it, removing the screen gave (maybe) a little more on the top end, but the bottom end, gas mileage, and drivability all suffered.

Unless you have the screen in there, the low RPM MAF readings the PCM has to base everything on are incorrect.

On two different 3800SFI powered vehicles I had, the gas mileage actually improved when driving in 3rd instead of O.D. (OD stock vs. OD with screen removed) I didn't have any way to actually test why, but always assumed that the higher RPM (and by default increased airflow over the MAP sensor) gave a better signal to the sensor.

No matter what, I still had the best gas mileage and drivability with the screen installed. I often wondered if a less dense screen (lower cell count like 2005HHRAuto suggested) wouldn't give the best of both worlds.

If the screen is removed you can see the effects when you log the MAF. Having the MAF close to a bend can cause the same thing. Also, it is RPM sensitive which makes sense when you think about it.

As you can see in the picture, the MAF is close to bend. Add to that is I'm boosting and changing the tube size as well, the honeycomb solved the problems I was seeing.

I felt a major difference when I changed the tube.....Thanks Dave......:twothumbs:

Would the K&N filter cause the "check engine" light to come on? My father just called me & told me the light showed up, & was planning on leaving work early to have some daylight to check it.