Cold Air Intakes, compatibilities and why not?

I've heard varying opinions on this mod. I recently had my cone filter get busted up (don't ask). I have the oportunity of picking up a CAI from a 1.8T. First of all is the MAF the same diameter as the TDI where the piping for the CAI would attach.

Second, would there be anything in the engine bay around the battery on a TDI that would prevent me from running the piping between the battery case and the wheel well area that a 1.8T doesn't have?

Finaly I wanted to know why so many people say this mod is a waste of money, by reason I mean a decent explanation as to why there is no benefit? Not just simply telling me not to do it.. By the way this would only be for the summer months and the OEM air box goes in for the winter..

Thanks to those who respond..

The MAF diameter is the same between the TDI and the 1.8. Second I don't think there is anything in the way left of the battery, and third. Why not, for every 10 degrees cooler the air is 1 extra horsepower.

Troy

Dyno testing and seat-of-pants testing and pressure drop measurement testing all agree on one thing: no significant difference between this and OEM. That's why it's considered not worth spending money on.

The stock intake on an A4-chassis is already a "cold air intake" from the top of the grill ... and that's a much better place in terms of resisting water ingestion than where a lot of aftermarket setups have it.

The only issue with the stock setup is the snow screen, and that's easily dealt with - cut it out and keep an eye on your air filter afterward (which you have to do with any air filtering system anyway).

Installing a cold-air-intake won't break anything unless you either over-oil it (MAF ...) or have the intake in a location where water ingestion could be a problem (bye-bye engine). But it won't accomplish much, if anything. If you want one, go right ahead ... just be aware that it's not accomplishing much.

why not spend the money on bigger injectors that you can keep in year round?? Youll get more of an increase and it wont look modded.

GoFaster. Would you say the stock air box and de-screened snorkle is enough to support the air needed by a chipped TDI thats obviously generating more boost and thus putting greater demand on air flow? I find that snorkle to be amazingly narrow as it approaches the area where the screen should be.

No Rest Till : I would LOVE to do injectors. But being chipped and reading some of the posts on the performance forum I'm nervouse about taking the engine too far for something that I use as a daily driver. Not to mention the fact that I will definitly take it too far for what the clutch can handle..

Thanks for the replies so far.

didnt know you were chipped, thats the same thing i thought about, I think im going to do injectors first and then see about a chip.

If you are chipped you will need to replace the clutch sooner or later...be ready,,,be very ready

No Rest Till : Yeah, I am currently running UPSOLUTE. I love it as far as power, still would like to know if increased boost which means increased air requierments is sufficiently met by the OEM stock airbox or if I should go CAI or another cone.

TdiDog : Yeah, I figure the clutch will eventualy go, but to be honest I've had the UP for +30K Km ( 19K Miles) and even this harsh winter with temps around -15 F I had no slip. Either way injectors + clutch will fit in the budget, however, injectors + clutch + labour on clutch install.. out of budget and I am still concerend about perhaps a combo of chip + injectors being too much on the engine for a daily driver.

Can't say I have any more power.

GoFaster. Would you say the stock air box and de-screened snorkle is enough to support the air needed by a chipped TDI thats obviously generating more boost and thus putting greater demand on air flow? I find that snorkle to be amazingly narrow as it approaches the area where the screen should be.

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My TDI is chipped and I find that the OEM airbox and paper filter, descreened, is sufficient. I don't notice any smoke unless I'm really driving her hard or bogging it at a very low rpm to accelerate.

I used to have a cone filter and I found no performance difference between it and the OEM setup.

The OEM setup is actually very good and I don't see the need to spend 200-300$ on a air intake.

same here, I have accutally dyno'd with stock airbox, K&N drop filter (HIGH performance supposedly) & a CAI snorkle ....

power was lost @ all aftermarket air intake modifications. Stock is the way to go for me, as the dyno proved it to me.




--marco

below are the results

Dyno Results:

3/15/03 - Temp: 82° F.:
1. 111.8HP / 193.9ft-lbs torque - stock
2. 110.9HP / 186.1ft-lbs torque - K&N filter
3. 111.2HP / 176.8ft-lbs torque - snorkle CAI

Would you say the stock air box and de-screened snorkle is enough to support the air needed by a chipped TDI thats obviously generating more boost and thus putting greater demand on air flow? I find that snorkle to be amazingly narrow as it approaches the area where the screen should be.

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Wouldn't the presence or absence of soot behind the car give a good idea of whether you're getting enough air? If there's no soot, there's enough air, right?

The stock intake on an A4-chassis is already a "cold air intake" from the top of the grill ... and that's a much better place in terms of resisting water ingestion than where a lot of aftermarket setups have it.

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The B4s also benefit from a similar cold air induction system directly from the factory.

Can't say I have any more power.

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Man, I did the same thing... No fancy cap on the intake, but the same thing none the less.

The “fancy cap” is a plastic gutter down spout.

Wouldn't the presence or absence of soot behind the car give a good idea of whether you're getting enough air? If there's no soot, there's enough air, right?

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If you see a decrease in smoke after installing an oiled air filter on a TDI, more than likely you just contaminated the MAF sensor. Smoke behind the car is a good indicator that the MAF is seeing ALL of the air going into the engine. Soot output simply shows that you need to make an adjustment to either the timing or the IQ. As summer heats up smoke output will increase for a variety of reasons.

Routing an air intake down low is asking for trouble for several reasons, FOD (Road debris ingestion) water ingestion as well as higher air temps due to road heating in the summer.

VW designed the intake to MAXIMUM air flow under all conditions again this directly reflects upon the SEVERE limits a TDI must comply with. The airbox on our TDI's will outflow even an Audi A6 2.7T twin turbo engine...So ask yourself if increasing the air filter is going to do anything for you...the answer is simply no.

DB

I think I'll throw in just a little disagreement with the "general" nature of the comments here.. I'm not sure that a New Beetle will get the fresh air flow (thru the fender well intake) that a Jetta/Golf can get... The New Beetle might be an exception to this thread. But then, you have to figure out how to get fresh air into the New Beetle intake.

There is a modification from www.bugmod.com that will allow you to use the stock airbox with some added hosing that brings fresh air directly to the airbox.. This may require modification of the turnsignals depending on the model of New Beetle you have.

Just something else to think about.

Gary M

So far I appreciate everyones input, and it seems for the most part, short of the new beetle, you all agree that the stock OEM air box is sufficient to meet the needs of the TDI. I assume this also means that even a chipped TDI producing more boost gets sufficient flow.

Wouldn't the presence or absence of soot behind the car give a good idea of whether you're getting enough air? If there's no soot, there's enough air, right?

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I was actualy concerned that perhaps the turbo on chipped car was labouring to meet the requiered air needs, and thus wasn't simply relying on the absence of smoke as a sign that I wasn't putting even more stress on it with perhaps a restrictive OEM setup. I know, if I am concerned about the turbo why did I chip?

So now I have money to throw at injectors and a clutch. I will be having my timing belt done come the end of summer. Would this be a good time to also take on the clutch replacement and incure some costs saving or are these two basicaly so unrelated that it doesn't matter?

Last question, I promise. Whats the reccomended cleaning/cleaner for the MAF to get oil and grim off the element. I've thought of using "rubbing alcohol"/ Isopropyl. Is there a far more effective product. Maybe an electronics cleaner??

Thank you.

Whats the reccomended cleaning/cleaner for the MAF to get oil and grim off the element. I've thought of using "rubbing alcohol"/ Isopropyl. Is there a far more effective product. Maybe an electronics cleaner??

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I was actualy concerned that perhaps the turbo on chipped car was labouring to meet the requiered air needs, and thus wasn't simply relying on the absence of smoke as a sign that I wasn't putting even more stress on it with perhaps a restrictive OEM setup.

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The stress on the turbo is not occuring on the suction side of the compressor. The stress comes from the engine itself in that it cannot digest the huge volume of air the turbo is pumping out when running a chip. Restriction on the front end of the turbo in fact can decrease the likelyhood of surge to a VERY small degree, in other words restriction can in fact be a good thing in a VNT application. However you will need to get about 40,000-60,000 miles on an OEM filter before you can even get a measurable amount of restriction EVEN when running a chip at 1.23bar . The total area of the OEM filter has more than 6 times the exposed surface area of any foam filter, this is simply because of the depth of the pleats as well as the number of rows: 85 rows x 2 inches deep x 2 sides x 7inches wide = LOTS of flow under any situation EVEN when dirty.

The turbo is designed to be a very efficient air pump, just make sure that the turbo is not trying to pump air into the engine at times when the motor cannot breathe in the volume being produced, ie below 2,000 rpm.

As for the Beetle, Gary would be the one to talk to about the intake and air flow in that application.

Denatured alcohol is the best cleaner for the MAF if you get contamination. With the OEM setup try not to open the airbox anymore that required to retain the original seal of the filter. Think of the seal as a one time use seal that will not filter as effectively if the filter is opened. Most of the problems with after market filters are because they fall apart because the seals cannot stand up to the environment of the engine compartment. Cracking and delamination from the element surface are the norm with certain elements Sand is a bad thing to let into your turbo...

DBW I agree with all but one thing, alcohol for removing oil. Having spent many years working in optical-electronics I can tell you alcohol will not remove oil film from optic's or electronic parts and will in fact leave a film residue on said parts.

Now to the lighter side of things, I have vented the I/C on the NB through the fender liner by instaling the cutout section of fender liner from 1.8T vent section of fender liner.

I have always been able to fell the power loss when it gets warm in the summer, so I thought this might help some.

I wanna say thanks to everyone for their help and replies to this post. I have contacted KERMA and am gonna probably scoop those 520's if there are any left. I am probably gonna need to find someone in Ontario to help me install these for a few bones! Thanks again to all.