Cold Air Intake

[jbenington86]

I was curious what kinda of preformace increase we might see from a cold air intake?

I have never modded a car and I am not sure what the 128i would get out of it.

[Artmasterx]

I can't say for sure, but you can bet it will be minimal. Almost certainly not enough to make a noticeable difference while driving.

To get something noticeable, I would bet you would have to do CAI + freer-flowing exhaust... and I'm not even sure that would do much.

Maybe a little ECU tuning could help too. People with more experience on this can likely give you a more definitive answer.

[jbenington86]

I have been reading a little and some people are saying that cold air intake does more for a N/A car than FI car.....I just wanna know because I am deciding what mod im doing first.

[1er junkie]

Originally Posted by jbenington86

I have been reading a little and some people are saying that cold air intake does more for a N/A car than FI car.....I just wanna know because I am deciding what mod im doing first.

100% false. F/I motors always benefit more from cold air intakes.

[jbenington86]

i was just reading some stuff from FI people lol

[1er junkie]

lol, I was like....wtf?!?!

[JohnnyTT]

NA cars gain more from a cold air intake. This has been explained tons of times over. Do some searching on these and the e90 forums and you'll see why.

[1er junkie]

Same here

[JohnnyTT]

I'll find the posts a little later. Runnin out.

But the jist of it is that when you have turbos on a car, they get very hot, and no matter what the temp of the intake air, it will always get extremely heated b4 passing into the engine.

An NA car takes the air directly, therefore there is no stage for that air to be heated up b4 entering.

[jbenington86]

thats what i was thinking...all i know is on all these random site turbo cars put them on for the better intake noise

[Brandon26pdx]

Originally Posted by jbenington86

I have been reading a little and some people are saying that cold air intake does more for a N/A car than FI car.

Not really. Intake and exhaust mods that help the car "breath" better will almost always show more impressive gains on turbo/supercharged engines, which move higher CFM's to begin with compared to N/A engines. Factory turbocharged engines are usually tuned very conseratively compared to N/A engines also, allowing intake/exhuast mod's to provide more of a "bang" compared to those same mods on a N/A motor.

I think the (misguided) point someone was trying to make about cold air intakes doing "more" for N/A engines was in regard to the temperature of the intake air, which is a different measurement than the volume (CFM) of air entering the engine. Drawing significantly hotter air into an N/A engine will almost certainly wreck more havoc on power and drivability than the gains provided by sneaking in a few extra CFM's with an open-style "hot air" filter. The idea with the CAI on a N/A motor is to get more air but also cooler air into the engine (or at least air that's not any hotter than what comes into the OEM intake system). This usually shows some reliable power gains on a N/A engine. Whether it's worth the money and hassle is of course the owner's discretion.

[jbenington86]

Originally Posted by Brandon26pdx

Not really. Intake and exhaust mods that help the car "breath" better will almost always show more impressive gains on turbo/supercharged engines, which move higher CFM's to begin with compared to N/A engines. Factory turbocharged engines are usually tuned very conseratively compared to N/A engines also, allowing intake/exhuast mod's to provide more of a "bang" compared to those same mods on a N/A motor.

I think the (misguided) point someone was trying to make about cold air intakes doing "more" for N/A engines was in regard to the temperature of the intake air, which is a different measurement than the volume (CFM) of air entering the engine. Drawing significantly hotter air into an N/A engine will almost certainly wreck more havoc on power and drivability than the gains provided by sneaking in a few extra CFM's with an open-style "hot air" filter. The idea with the CAI on a N/A motor is to get more air but also cooler air into the engine (or at least air that's not any hotter than what comes into the OEM intake system). This usually shows some reliable power gains on a N/A engine. Whether it's worth the money and hassle is of course the owner's discretion.

I completly understand where you are coming from but still dont understand....I have read 4-5 websites that say if you have a turbo car CAI will do next to nothing. Why would they feed false information on there own cars? With or w/o a turbo it is still letting the car breath just as easy...in a turbo car air is forced into the cylinder and on a N/A motor the piston sucks the air in...even with the turbo forcing air in if you want more cfm's in the cyliner raising PSI is how you do that...maybe i need to take physics again

[Brandon26pdx]

Originally Posted by jbenington86

I completly understand where you are coming from but still dont understand....I have read 4-5 websites that say if you have a turbo car CAI will do next to nothing. Why would they feed false information on there own cars? With or w/o a turbo it is still letting the car breath just as easy...in a turbo car air is forced into the cylinder and on a N/A motor the piston sucks the air in...even with the turbo forcing air in if you want more cfm's in the cyliner raising PSI is how you do that...maybe i need to take physics again

Both the 128i and 135i have "cold air intakes" right from the factory...ambient air enters the system through the two front kidney grills. Besides adding a K&N drop in filter to increase the CFM's a bit, you'd be hard pressed to design an intake for a 128i that both flowed as well, and kept intake air temps as cool as the stock system. (The only reason they don't use K&N's stock is because they don't filter as well as paper, but they do flow better.)

[jbenington86]

What about BMW's CAI that they designed? specifically for the 128i

[Dan@UnitedBMW]

BMW released the CAI to be purchased but we haven't gotten one in stock yet. If anyone wants to try it out, I'll sell it for the cost that I pay to buy it from BMW + shipping

[AussieRacer]

Not voting either way, but when people say CAI do nothing on Turbo cars, was that measured on a dyno or on the road? If just on a dyno, unless the dyno is sitting in a wind tunnel, it really doesn't tell you anything about how the CAI is performing.

[jbenington86]

most people that do real dyno test put a giant powerful blower infront of the car to get that effect...doing a dyno on a powerful engine w/o using it can cause problems

[1er junkie]

Originally Posted by Brandon26pdx

Not really. Intake and exhaust mods that help the car "breath" better will almost always show more impressive gains on turbo/supercharged engines, which move higher CFM's to begin with compared to N/A engines. Factory turbocharged engines are usually tuned very conseratively compared to N/A engines also, allowing intake/exhuast mod's to provide more of a "bang" compared to those same mods on a N/A motor.

I think the (misguided) point someone was trying to make about cold air intakes doing "more" for N/A engines was in regard to the temperature of the intake air, which is a different measurement than the volume (CFM) of air entering the engine. Drawing significantly hotter air into an N/A engine will almost certainly wreck more havoc on power and drivability than the gains provided by sneaking in a few extra CFM's with an open-style "hot air" filter. The idea with the CAI on a N/A motor is to get more air but also cooler air into the engine (or at least air that's not any hotter than what comes into the OEM intake system). This usually shows some reliable power gains on a N/A engine. Whether it's worth the money and hassle is of course the owner's discretion.

This is the information that I have thought was true for the past 3 or so years, but I didnt feel like getting flamed

[Brandon26pdx]

Originally Posted by 1er junkie

This is the information that I have thought was true for the past 3 or so years, but I didnt feel like getting flamed

all the flamers are over in the 135i forum arguing about which tune won't void their warranty or blow their car up.

[ModBargains.com]

Originally Posted by jbenington86

I was curious what kinda of preformace increase we might see from a cold air intake?

I have never modded a car and I am not sure what the 128i would get out of it.

You will probably get a slight improvement in throttle response and power, but it won't be significant. Although it will probably make your car sound mean

It'd be an okay place to start modification on the 128i

[sndprssr]

You cannot compare the benefit of a CAI on an N/A car vs. an FI car. The benefits are always vehicle specific. An AEM intake for a Hyundai Tiburon will net 18+ HP but an AEM on a Civic will net 5 - 7 HP. I'm sure there are cars that can post better numbers and worse numbers. So which numbers do you use to compare to any random FI vehicle? Which FI vehicle numbers do you compare the other numbers to? Neither side of the argument is right or wrong, you can't compare apples to oranges to be a little cliche...

[Xyloft]

Originally Posted by 1er junkie

100% false. F/I motors always benefit more from cold air intakes.

unless that car happens to be an WRX or STI and then its pretty much worthless without a tune. and even with a tune it didnt do much of anything.

it really depends on the motor and how restrictive the stock intake system is. my 2003 hyundai tiburon got 13 whp from its Cold air. (on end user dyno's) but my 1996 NA eagle talon was only supposed to gain 7 or so.

keep in mind though, that the mods won't stack. dyno numbers for an exhaust alone may give you 8hp, and a cai 10, but together you may get 11 or 12.

I'd assume the bmw intake system is designed well.