Don't hurt me for asking, but...

Rahob

Member
Thinking ahead here on a project that I have yet to start. (I'm coming out of a few years of hibernation) But trying to debate this over on my head, and I know... it's a topic that's been beat to death over the years, and one I'm probably way overthinking. Cold air intake routed behind the headlights vs. open element under the hood. I already know about the argument of added length of tubing and bends of cold air intake equal more restriction but for cooler denser air, which equals more air as it enters into the engine heating up and expanding.

Now for what I've been wondering, debating and contemplating, looking at it from the under the hood open element point of view. Less friction from a short intake tube and less bends equals more air through the system... essentially being the same amount of volume.. Or more? amount of air that would be coming from the cooler condensed air once into the engine? (If all other variables were exactly the same, filter size, ambient temperature, etc.)

I've read about every article I've found on the subject, watched the video "chasing air molecules" with Richard Clark, and read all the debates in the forums, and I haven't got a clear answer (and I'm not sure there might even be one). I'm sure I'm overthinking this GREATLY given I have no plans to be on the tracks every weekend, just a Sunday driver and some occasional fun on a back road. I just want to squeak out the greatest potential with the littlest modifications. (Like Richard Clark said "3% here, 3% there, adds up").

Also, on top of that, I've read about adding the MAF in the up-pipe, but I don't believe that would effect flow? According to the article the vehicle performed better, I just feel leery putting the MAF sensor right before the intake.. It feels like with my luck the element would break off the sensor then get sucked into the engine and then I'd have to replace an entire engine instead of just a turbo, if it were to happen on the MAF tube. And while speaking of flow, I've read about turbulence in the MAF pipe after the filter which might cause issues for the MAF sensor.. So is it better not to mount a MAF sensor directly after a air filter, but to add a little tubing then the sensor? Or would it be fine after the air filter as long as the MAF screen is not removed? ALSO could be TOO BIG of an intake pipe???? From what I've read, since a larger pipe has less velocity (specifically idle and regular driving) it could give bad readings on the MAF sensor? Has anyone done any testing on this? I'm asking because I'd like to go from stock MAF to 4" pipe with LS1 sensor. So far before my GN went into hibernation, I changed the stock intercooler for a duttweiler neck stock. RJC power plate, and blocked off the throttle body heater lines. (Just with those improvements I noticed a seat of the pants difference in power)

My next plans and what I'm halfway saved for is RJC 3" downpipe along with their 3" exhaust. Over the future I plan on doing more things when money is good which would justify a bigger MAF pipe. MAF intake being the next upgrade after exhaust.

If you made it this far, thank you for taking your time, you all earn 5 horsepower per question answered I know there are many questions I asked, I appreciate any opinions and hard data results! Thanks!

-Rob
 

Jerryl

Tall Chinese Guy
Reducing the restriction before the compressor is worth HP, and that's not an opinion. Of course, the HP depends on how much is removed. Reducing the drive pressure is a good area to focus on as well. After all that, there is more HP available in tuning percentage wise, if the combo is correct.
 

Rahob

Member
Reducing the restriction before the compressor is worth HP, and that's not an opinion. Of course, the HP depends on how much is removed. Reducing the drive pressure is a good area to focus on as well. After all that, there is more HP available in tuning percentage wise, if the combo is correct.

Thank you, just trying to understand it better because of contradicting statements (although common sense tells me the bigger the intake pipe the easier the turbo breaths). But does it effect the MAF sensor wire in a negative way? What I'm getting at is since a MAF detects how much air the engine is getting, by how fast it cools. So given everything is equal from the turbo back, a less diameter pipe will have a stronger velocity of air flow going over the MAF sensor, cooling it faster, whereas, a larger diameter pipe will more easily suck in the same volume of air, but easier and at a much slower velocity, which would cause the MAF sensor to cool at a slower rate, which would tell the computer to get less fuel to the cylinders causing a leaner condition? OR since the diameter of the MAF sensor stays the same regardless of pipe size, does the velocity of the air coming in, still stay the same as it passes over the sensor as it would with a smaller diameter pipe ?
 

Jerryl

Tall Chinese Guy
. . . OR since the diameter of the MAF sensor stays the same regardless of pipe size, does the velocity of the air coming in, still stay the same as it passes over the sensor as it would with a smaller diameter pipe ?
Your understanding is correct. For additional clarification; If a blade sensor is used in a 4" pipe, it will read different than a 5" pipe. The translator is calibrated to the 4" pipe. The MAF sensor will read the lowest mass flow in a system. It can't read higher flow than the highest restriction as the same restriction dictates max mass flow.

Make sure to get a real DELCO MAF sensor if you decide to go aftermarket. Hope that helps.
 

Jerryl

Tall Chinese Guy
Some info from a while back.

 

grass doctor

Dream Catcher
there is a video from RC comparing stock air box to nothing at all and it is not that much of a difference in CFM's ill try and find it , but the cooler air is such a difference , I can tell driving my car in my so called winter months versus the hotter than a four balled tomcat days here normally , I have never seen a maf put on an up pipe , but who knows
 

grass doctor

Dream Catcher
the old kenne bell air intake that came form a port cut out of front air dam is the way to go for cold air , don't know why this set up fell by the way side
 

Grumpy

Thread killer
the old kenne bell air intake that came form a port cut out of front air dam is the way to go for cold air , don't know why this set up fell by the way side

why ???? BECAUSE IT DIDN'T WORK. Bought one when it came out . I was looking for the 3 tenths that Jim Bell claimed youd get.. Didn't happen. Sold the kit a week later. Guy asked why I was selling it. Told him it didn't work. Still bought it. Maf pipe with the AC on the end in the hot engine bay WORKED the best. Matter of fact we just tried it in Melissa's car. Nice smooth bends out to the frot grill. NO GAIN an this is a 9.1 car.
 

Nigel

Active Member
345537


This is a pipe flow formula. The friction factor determines the loss assuming you are at a low fraction of sonic velocity. If the friction loss is low enough and the angle you hit the compressor is not adverse you will recover the velocity. If you use an aluminum intake pipe with a good inside diameter finish the loss will be negligible. If there was no friction between the air and the pipe as long as the velocity remained roughly 40% of sonic the diameter would not matter as a reference example. You would have to be moving a shit ton of air to need more than a 3 inch aluminum intake. The MAF will be a different story because of the screens and internals.

Also, it is a misnomer that alky lowers air temps. It cools the charge on the compression stroke. It violates the laws of physics to think it cools the intake air temps prior to entering the cylinder so long as you have a decent intercooler. The reason the IAT reads lower is because the sensor is being sprayed with liiquid meth. The air cannot drop below the saturation temp of the meth. On a hot air you can lower temps but an intercooled car likely has exit air temp below the saturation temp of the meth which means it cannot provide cooling.
 

grass doctor

Dream Catcher
I just got a 3 inch maf pipe from earl and did a lt1 maf and used stock elbow, because I'm cheap and can plug air temp sensor into something even though not need with Erics chips into a 4 inch K&N cone sits in wheel well facing down and works great , but really not that much difference from stock air box , just wanted better maf and chip for idle and use of newer shittier gas
 

rodruckus

Taking out the Euro trash
I installed a 4" MAF pipe and built my own 4" MAF with a LS7 blade MAF inside. Short run, open element style, no numbers, just personal preference. But I have noticed an improved, more responsive throttle and quicker spool up from a dig or roll.

My set-up includes 14" cone filter with 4" outlet(9" works, too), Spectre 9705 4" MAF housing, AC Delco LS7 MAF, and RJC 4" MAF pipe. I took a measurement of the system, then had a muffler shop cut my MAF pipe to its desired length. In my opinion, it's a lot easier to just buy the MAF housing, than to attempt to cut the MAF pipe and weld in a bung for the LS7 MAF. Why deal with the hassle?

There are some things you'll want to be aware of. First, you'll need an IAC angle boss(purchased from RJC) to run any MAF pipe larger than 3". You'll need a special pig tail adapter in order to connect the LS7 MAF to the Translator. Like Jerryl mentioned, beware of chinese, counterfeit junk MAFs. Make sure to buy from a dealership or parts dealer. Don't buy the cheap ones off the internet. They're spot on, right down to the packaging, but are still fake as hell.

Now, running the 4" MAF, I went straight to the air filter. However, several people told me I'd have to install a piece of pipe(answers varied on length of) between the two. I guess I was just lucky? But we all know no two cars run exactly alike, so a piece of pipe may be required for your set-up. I did not install any of the cups from the Spectre kit or have to put any sort of honeycomb/mesh screen into the MAF housing, it's completely open. Also, there are no instructions as to the orientation of the MAF in the intake system. But I found it optimal at the 6 o'clock position, blade straight up. For the air temperature sensor, I drilled a hole into the neck of the air filter just before where the MAF housing rests. But some guys just leave it hanging somewhere. Again, personal preference.
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grass doctor

Dream Catcher
very nice set up there rodrukus !!
but if you want ice cold air, I know where an ATR liquid intercooler is for sale and you can put in ice and little old Milwaukee for flavor and alky and your ready for a good PULL :p
 

rodruckus

Taking out the Euro trash
Not trying to high jack...but if you look again, I already have an ATR liquid intercooler installed. For its reservoir, I have a Metco tank where the spare used to be in the trunk. You're not kidding about adding ice. I've measured the temp in the reservoir as cool as 23° without adding very much ice(compared to what my buddy adds to his twin turbo Stage car). The ass dyno measures a 30-50hp gain when ice is added to it. Shit goes from crazy to insane. Without ice, I still run cooler than ambient temp.
 

grass doctor

Dream Catcher
Not trying to high jack...but if you look again, I already have an ATR liquid intercooler installed. For its reservoir, I have a Metco tank where the spare used to be in the trunk. You're not kidding about adding ice. I've measured the temp in the reservoir as cool as 23° without adding very much ice(compared to what my buddy adds to his twin turbo Stage car). The ass dyno measures a 30-50hp gain when ice is added to it. Shit goes from crazy to insane. Without ice, I still run cooler than ambient temp.
ha I didn't even pay attention to that , damn maybe ill keep that baby !!! for something I just found
 

Rahob

Member
I have read over all this info provided a few times and it's starting to make some sense, I don't have the educational levels as you all in regards to this, so it will take some time to understand. I'm getting quite tired and will reread this tomorrow and see if makes more sense
Thank you all for the info.
Grass doctor that's the video I was referring to in my OP, I would have been there for hours trying different filters, turns and tubes, it's great that it was documented like that! Here are the articles I read about the MAF sensor in the up pipe
and
 
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