Topic: DIY Cold air intake not working right

[Arabas]

My car with the BIG wheel when is started it and is cold it sounds really weird.
Once it settles and goes below 1K RPM it is just like any other OEM K04.

off topic but i 'll have to second that about the big wheel upgrade and the sound when cold... you should have told me that earlier... i was always hearing the turbo and thinking to myself : "this sounds weird, this sounds weird.."
But Kagem's sound is not the same, it sounds as if the engine is missing a breath now and then

[Carbon Sky]

I think someone already mentioned it, but a key part is that the cross sectional area at the MAF must be the same diameter.  Perhaps initially, boost went down because parameters were off due to the different cross sectional area.  After the key cycle engine went back into "learn" mode, and readjusted. Just a thought.

[shabby]

I think someone already mentioned it, but a key part is that the cross sectional area at the MAF must be the same diameter.  Perhaps initially, boost went down because parameters were off due to the different cross sectional area.  After the key cycle engine went back into "learn" mode, and readjusted. Just a thought.

That's true, also the maf has to be as close to the air filter as possible just like with the oem airbox and gmpp intake... and not have a bend that affects flow.

[Kagem]

Last night i went for a ride, at my way there the boost was up to 15 psi, and at my way back home the boost was only up to 1,5 psi, almost no boost at all. Before the intake the boost was 25 psi in almost all rpm range. Have to test every single part as to see what exactly is that which causes this situation. Regarding the friend's car, he has no trifecta but is tuned from a local tuner, first i'm going to test his maf on my car, if the problem still occurs i'm going to test his dejon filter, and if it is still there i'll put all of his dejon intake on the car like elff said and i hope there it will be ok, because if not oh then ''supercalafragilisticexpialidocious''....

[LatinVenom]

Kagem.
Both my self and Shabby have pointed out the location of the MAF is not ideal.
Please look at the placement of the MAF on the GM GMPP CAI and you will see what we are saying.

[Carbon Sky]

If your car is running that poorly, it's gotta be throwing codes.  Have you gotten them read?  What were they?

In my humble opinion (take it for what it's worth), I don't think it is the proximity to the bends that is causing the issue.  If you look at the stock intake, there is not a lot of straight section before or after the MAF.



I know the picture above does not have stock intercooler piping, but the intake/filter is stock, and you'll notice just ahead of the MAF sensor is the top of the filter element.  I'm sure there is atleast as much turbulence in that design as there is in yours, if not definitely more.

And there is a bend right behind the sensor on the stock setup, so bends just before and after the sensor should not be causing these serious driveability issues.

Now, looking at that same picture, it's impossible to tell whether the inner diameter is the same on the stock setup or yours, but if it is not the exact same diameter on both, you definitely will have issues.  My guess is, your diameter is larger, and therefore, it is detecting less air than it is ingesting.  Which is confusing the ish out of your car, causing the driveability issues.

Secondly, you must also make sure that mounting depth of the MAF sensor is the same.  If it is not as far into the stream, it would again detect less flow than actual.

Just my thoughts, hope it helps.

Also, didn't the Injen intake cause driveability issues because it too had a different diameter for the piping where the MAF sensor was mounted as well?

[Graywolf]

Agree with Carbon Sky, larger diameter tube or smaller will effect MAF sensor reading. Larger tube=slower velocity which I believe is what the sensor is actually reading.

[Carbon Sky]

A MAF sensor is basically a well tuned heating element/filament. It is heated, and as air is drawn across it, density, temperature, humidity, etc, all vary the amount of air/oxygen that is actually being consumed is calculated by the change in resistance (and temperature) of the heating element/filament.

So if the diameter at that given point is different, it's definitely going to throw things off.  And similarly if the filament isn't at the same mounting depth.

[Carbon Sky]

Agree with Carbon Sky, larger diameter tube or smaller will effect MAF sensor reading. Larger tube=slower velocity which I believe is what the sensor is actually reading.

Perhaps, although at those high velocities, interesting physics (fluid dynamics) begin to produce unusual results at times.  For example, at slower speeds, the ratio of air passing in the open section will be more generous towards passing in the open section.  However, as air velocities increase, this difference will begin to reduce, and the ratio will begin to lean towards less air passing in the open section.  This will begin to happen in the 2000-3000rpm range, and with the valve timing change the most in that range, who knows what other factors will come into play without at least a well designed simulation.

[tazz]

I would agree mostly with the statement above but in addition as also stated that the MAF will need to be closer to the air filter and as close to a straight shot as possible from the filter.  In both the stock & GMPP setup the MAF is located less than 4" after the filter with a straight shot from the filter before any bends takes place.  I do agree that the diameter probably has alot to do with your issues since I remember other CAI's having similar issues with idling.  Even the RAM Air hood that Norm makes will affect the drivability of the vehicle because of the increased airflow ramming effect of the hood.  Also position of the MAF does play a role as a few people over at HPT forum have learned.  Not sure if it's a larger issue than the diameter of the pipe probably not but still an issue and that's what Shabby was getting at I think.
The MAF frequency and fuel trims are very touchy to flow.  Ive monitor the fuels trims constantly with both the stock intake with a K&N filter and the GMPP intake and the less restricted flow alters the trims by 8% on my vehicle but still is fine with the stock MAF settings.  When I had the Catless DP it really changed the flow to the point I needed to change the setting for the MAF frequency and increase  by 4% almost across the board to get it to run better.  Seemed like it was pulling timing due to the trims being farther off than with the GMPP intake so I was loosing power.

[Graywolf]

I just read a bunch of articles on MAF sensors to make sure my comments are correct. Our membrane sensors read at the front of the sensor and at the back of the sensor[both read differently] The velocity of the air flow is the problem with his set up or dirty sensor/faulty sensor.  Also laminar flow is important according to one article which makes sense. Bigger isn't always better.

[scoobyless]

How thick is that MAF plate?  Is the sensor far enough in the pipe?

Also, having the sensor so close to the reduction could be an issue.  I don't believe your having issues being too far or too close to the intake and I also don't think that there is too much air turbulence in that area unless it is caused by the reduction.

[Kagem]

Thank you guys for the help and information! Yesterday went for a ride to check what the situation is, and while cruising i felt the power reducing and there was a check engine light, scanned it and it showed p0101. Turned off the car, turned it on again and the boost was back, hitting 25 psi. Cleared the code, and some hours later the boost dropped again to 1,5 psi. It will drive me nuts, cannot understand why. Carbon Sky said it pretty right, that's what i am assuming too, that the diameter of the tube between the maf and the filter is too large. I have a long way to go on that now, i must try all these exchanges with the other car, so we know what exactly is that which is responsible. The maf plate is almost as thick as the one of dejon, we checked last night. Graywolf's statement ''bigger isn't always better'' is correct, and that is not my fault. I went to that local tuner with photos of the typhoon filter as individual and as placed in our car, more specifically i went there with those photos....
http://www.knfilters.com/images/l/69-8433TTK.jpg
http://www.knfilters.com/images/press/69-8433TTK-engine.jpg
And that is what he made for me....
http://img190.imageshack.us/img190/1280/dsc06557k.jpg
http://img196.imageshack.us/img196/3864/dsc06565on.jpg

Tazz you said about trims and maf frequency when changing the dp with a catless one, this is what i did too the same day. I first put the catless dp and went to the other local tuner about 5 miles away to put the filter. On the way there the sound was great and the car performed just fine! After the intake some hours later when they installed it to the car and i left, i noticed all these issues with boost. I will contact the tuner who made the tube intake and ask for a new tube the same diameter as stock, any other suggestion please feel free to drop! Good day to all....

[Arabas]

did you get a revised tune for the catless dp ?????

[Kelu]

Did you logged all these behaviors? What Vince said about your logs?

Another suggestion even I don't think you should go through this path until you don't have a straight answer from Vince:

[attachment=1]

HoneyComb MAF Mass Air Meter Airflow Straightener. These small additions to any cold air intake, turbo inlet pipe or anywhere a MAF sensor is located, will greatly improve the MAF readings "fuel trims" that the ECU sees. No more erratic MAF readings, fix lean or rich spikes, increase throttle response, fix idle, all of these can be improved with this $20 upgrade!
-Available in 3", 3.5" and 4" diameters.
-Slides right into pipe before MAF sensor
-Can be glued, braised, or epoxy'd in

[Helios]

If your car is running that poorly, it's gotta be throwing codes.  Have you gotten them read?  What were they?

In my humble opinion (take it for what it's worth), I don't think it is the proximity to the bends that is causing the issue.  If you look at the stock intake, there is not a lot of straight section before or after the MAF.



I know the picture above does not have stock intercooler piping, but the intake/filter is stock, and you'll notice just ahead of the MAF sensor is the top of the filter element.  I'm sure there is atleast as much turbulence in that design as there is in yours, if not definitely more.

And there is a bend right behind the sensor on the stock setup, so bends just before and after the sensor should not be causing these serious driveability issues.

Now, looking at that same picture, it's impossible to tell whether the inner diameter is the same on the stock setup or yours, but if it is not the exact same diameter on both, you definitely will have issues.  My guess is, your diameter is larger, and therefore, it is detecting less air than it is ingesting.  Which is confusing the ish out of your car, causing the driveability issues.

Secondly, you must also make sure that mounting depth of the MAF sensor is the same.  If it is not as far into the stream, it would again detect less flow than actual.

Just my thoughts, hope it helps.

Also, didn't the Injen intake cause driveability issues because it too had a different diameter for the piping where the MAF sensor was mounted as well?

After the MAF won't account for anything since the hole in the MAF is on the side facing the filter. Still in stock form the small section of tube is straight. Therefore, less turbulence. On his DIY setup the bend in the pipe could be causing a significant amount more turbulence since the airflow has to straighten out after rounding the bend. The air does not have to do that in the stock setup.

[Arabas]

first thing to be answered is whether kagem has got a catless tune with his new catless dp.

[Kagem]

I did not get a revised tune for the catless, Vince told me once i do not need updates for that kind of mods, moreover the catless worked fine, the intake messed up. Vince has not answered yet, still waiting. I will send a reminder, and i'm gonna put the dejon's tube which is straight and has the proper diameter with the typhoon filter and see how it reacts. If it works fine i'll have the tuner make me the same tube....

[Arabas]

for the de-cat you certainly need a tune AFAI.
maybe this is the problem or maybe a combination of these two...since you added both the de-cat and the intake at the same day with only a couple of miles and minutes difference...

[JimVonBaden]

I did not get a revised tune for the catless, Vince told me once i do not need updates for that kind of mods, moreover the catless worked fine, the intake messed up. Vince has not answered yet, still waiting. I will send a reminder, and i'm gonna put the dejon's tube which is straight and has the proper diameter with the typhoon filter and see how it reacts. If it works fine i'll have the tuner make me the same tube....

I think you, or he, misunderstood. For all exhaust mods EXCEPT a cat delete, you are good with no tune update. Removing the cat dramatically changes the exhaust flow necessitating a retune.

Jim

[Kagem]

George i left the exhaust tuner, went to Hercules and he told me to go back in an hour, so i left from there, went home, and then back to Hercules parts. This means 2 hours and 12 miles. During that except from the sound that changed a bit and became more aggressive, i noticed no other difference, neither in boost nor in performance. I can tell it gained some torque due to the catless. After the installation of the intake everything started, maybe you're right and the combination of that two in the same day was not a good idea, but i still believe the tube is made wrong and this is what it should be different. I contacted Hercules parts and he assured me that he'll make another tube for the typhoon filter free of charge, so now i have to decide the design of the tube and i'll have to be sure of it because there's not gonna be a third time, only Kelu's suggestion with HoneyComb MAF Straightener after that. Any suggestion of the new tube design is welcomed, thank you for your help everyone....

[Arabas]

Kagem, i understand you make your own decision and after all, this is what modding is all about! experimenting and gaining or loosing...

but for what is worth as my final suggestion, this is my pov:

get a tune for decat. As Jim says, Vince meant no tune update is needed for exhaust, dp, intake etc. certainly he didn;t mean catless dp. you certainly will get a cel for going catless w/out the proper tune.

get rid of your custom intake tube. IMHO, as stated from day 1, the design is random and not simulated in any kind of simulation program or ever tested on the road.

get a branded, original and tested CAI i.e. K&N typhoon from ebay, Dejon, or DDM when they release it.


i rest my case!
hope you figure this out buddy!!

[Kagem]

I've sent Vince a mail since Friday, logged and e-mailed him, it's up to him, i never said i won't flash with another tune if he sends me, i know you and Jim and all the others are right. Just thinking that until he does send me a tune for these mods i can drive the car, and not let it in the parking lot waiting for Vince to find some free time to deal with my case, i use it as a daily driver....

[Graywolf]

Several years ago when I purchased a BSR tune from Hahn they warned me about changing the intake set up. They said they had problems with the cars performance with some intakes other than stock. They did not mention which ones did not work well or why. I would not get a tune until you change the intake[expensive]. Tune if Vince suggests since he is the expert!

[SKY888]

while waiting for a response from Vince, avoid hammering the car for safety purposes.  Your car might be experiencing tons of knock at WOT.

you can drive it normally....as a daily driver....and it will be fine though.....

better be safe than sorry.....

I'm not familiar with trifecta gadget....so I'm not sure if everytime you "log", you can see the parameters or not.     

With HPT, everytime I log, I can see the parameters including KRs.....

good luck and hang in there