Can a drop in filter and a smooth intake pipe make as much power as an intake system that utilizes a larger intake pipe which will lean out the AFR? It seems like the several available intake pipes that work with drop in filters use the same diameter pipe as stock and therefore utilize the same MAF sensor reading. I will assume that this cannot make as much power as leaning out the mixture and changing the timing as with the larger MAF pipe in some intake systems.

If you are not going to tune, I would think that the larger pipe like what is found on the AEM is a better choice. Once a tune is done, it is possible that there will be no difference as the benefits of the leaner condition with the larger intake pipe will be lost in the tune. Can someone confirm this? The larger pipe can flow more air, so wont the ecu be able to take advantage of this?

Would there ever be a reason to get rid of a larger intake pipe system like the AEM and put back the stock box with a drop in filter and new intake pipe like from someone like Cobb prior to getting a tune? This is not a money issue, but only a performance question. Thanks for your comments.

 

this topic is covered about twice a week.

searching is your best option.

Edit: You did actually ask one enw question regarding the AEM pipe flowing more air after the tune. You are correct in your assumption that it can flow more air even after a tune, a large pipe can flow more air. But what is not being taken into account is how much air can be pulled through the turbo efficiently and if this larger pipe is actually needed, and if the pipe will make any additional power.

The answer to that question is: No. The stock intake system is actually very effcient and will not produce more power with the addition of the larger diameter pipe after a tune. The only real restrictive peace on the stock intake system is the elbow between turbo and MAFS...and Nesei as well as Cobb make a solution to replace this accordian style tube with something smooth.

Will you notice a power increase by adding the smooth intake elbow (cobb or nisei)? Nope. But you can rest assured knowing you have a very efficient/highflowing intake system that will easily be able to keep up with most all power levels you desire..... Stock intake system will probably continue to flow great into power levels of 400-500hp

 

Thanks for your comments. I have read all the threads on this topic of intakes as well as the hood scoop thread which shows that the stock hood contour allows just as much air to enter the stock air snorkle as does the carbon fiber unit, so we know there is no more power from that.

This thread is not to recommend any particular manufacturer (as those threads already exist), but to discuss the merrits of the different systems and their advantages/disadvantages if any.

Give your argument regarding the larger pipe, it appears that there is no advantage in terms of additional air flow with or without a tune. And the smoother intake pipe will provide a better less disrutptive power curve, not necessarily more peak power.

As for the filter, both a drop in and a cone will flow similar and therefore no obserable gains there, except for the possible fouling of the MAF sensor with some oiled filter if not careful.

I think we can all agree that a protected filter (housing or cover) is better than an unprotected filter in keeping out additional engine bay; air turbulence which can effect idle, unwanted heat which can reduce power by increasing air intake temps, and possible water from rain and the road.

So what are the differences between all these systems? Well, given the comments above if they prove to be correct, the only difference in these systems is the larger intake pipe vs a stock diameter pipe. The larger pipe tricks the MAF into leaning out the AFR and changing the timing. The stock diameter pipe keeps the factory values.

Here is my own conclusion and I encourage other opinions:

The larger smooth aftermarket pipe will make more power than a stock diameter smooth aftermarket pipe. I believe it will make up to twice as much power as the stock diameter pipe given its effect on the stock ecu. This is for a stock tuned ecu.

As for a tuned ecu, if you are correct in that the larger pipe cannot take advantage of the additional air flow, and the tune will adjust the AFR's and timing anyway, then the larger pipe has no real advantage other than making the tune easier as the AFR values and timing have already been pushed towards wanted values.

Another question to ask would be: Although there appears to be an advantage to running a larger pipe without a tune, is there any disadvantage to the larger pipe with a tune? Should it be removed and a stock diameter smooth pipe installed with or without a drop in vs. already existing cone filter?

These questions are not really answered or discussed in detail in the other threads and that is why I wanted to start a new one being impartial to all manufacturers. Thanks for your responses.

 

I think the disadvantage to the larger pipe with no tune is that unless you are correctly monitoring your car (logging ect...) you can not be sure how far you are leaning out your car and if adverse effects are being put onto the engine. The large companies (AEM for instance) probably took quite a long time to develop their intake to make sure that it leaned out the AFR on a consistent basis on many cars before they released it to the public.

As for a disadvantage with running the pipe with a tune, I wouldn't say there is a large disadvantage, the only one i can think of is the fact that there would be slightly less clarity from the MAFS, but in all actuality i don't see a large disadvantage except the extra cash from your pocket.

 

Might want to think in terms of air velocity then in terms of volume. A smaller diameter tube will have high velocity earlier but will be restricted in volume in the high end..A larger intake will have slower airspeed down low and flow more volume up top.. So, its all about what you want to achieve and where you want to acheive it in the power band. Each option has its advantages, but with those adv something needs to be given up in another area (in most cases) and I dont think the stock intake is ribbed on the inside---so not much af a restriction.

 

I don't think it's twice as much .. but its more than stock

not true ..with a larger pipe .. it seems you're running leaner even with a tune .. so you need a retune to allow for more fuel .. meaning more power ..

Sorry no idea .. but if you have both .. it would be a serviceif you can help test them out and pacify some of the uninformed here ..

 

I've actually tested & tuned with drop ins and larger diameter MAF pipes. As far as I can tell, the larger diameter MAF pipe doesn't give you any extra power if both are tuned correctly. Of course if you wanna run 600+ WHP, then I'm sure the stock diameter pipe would become a restriction compared to a larger one.

So far with the AMS intake, I see the loads shift anywhere from 5-20% when compared to drop ins. This does not only affect AFR & Timing but any map that depends on load such as mivec and boost correction. I think alot of tuners don't like larger diameter pipes because it affects so many maps that it's a pain in the butt to adjust. Not all tuners may adjust for the larger MAF pipe since it's only 1 cell, but I'm kinda picky so I would adjust for it.

 

This is good information. Meckert, I like the velocity argument. I am only interested in high rpm power, above 5000 for road course work mainly in 3,4,5 gear. It would seem if you are correct, that the larger intake would therefore have more velocity and a proper tune would accomodate the extra movement of air. As for the stock pipe being ribbed, it is, as I have seen it off my car when installing the AEM.

gunzo and SiC, I think you both are saying the same thing. If your ecu tuner is willing to play with all the parameter affected by the larger pipe and subsequent altered MAF reading, you will have a better tune with the larger pipe.

J5isalive2. On the dyno, the leanest I saw was 11.5/1 which should be a safe range.

 

Correct me if I'm wrong but, if you can think of it as arterioles radius with blood flow and blood pressure. As you have a larger diameter radius (larger intake), your blood flow (air flow) would be increased but your blood pressure (velocity) would be decreased. With a more smaller intake, an increase in velocity and decrease in airflow would be observed. I guess there is a direct corrleation with size of the intake and air flow and there is an inverse relationship between intake size and velocity.

 

You are correct, when the MAF housing is larger the MAF sensor cannot determine the correct amount of air flow. This is due to the fact that the air flowing thru the MAF (velocity) will be decrease although the actual flow (air flow) is increased by the larger diameter.
By doing this the ECU thinks there is less air flowing than there actually is. This will make the vehicle run lower load cells within the maps. Lower load cells have higher IGN timing, leaner AFR, and more aggressive mivec degrees.

Also, I don't know if anyone noticed, but the stock MAF housing is actually around 76 mm but if you look inside, it is tapered right around the MAF sensor to about 70 mm (goes from 76mm to 70mm back to 76mm). I believe this may be giving the air flow a venturi type effect which increases the air speed right where the MAF sensor is located.