Quote:
Originally Posted by AW M3
From everything I've read, a drop in filter is pretty much as good as anything. Not sure about the hp and torque #'s you're quoting though. I didn't think they were that high.
I got the aFe Stage 1 (filter and charge pipe) installed at the same time as my exhaust and didn't notice anything from it, either increased sound or performance. I understand given it was done at the same time as the exhaust, it would be hard to notice ... just sayin.
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Look at the dyno here:
It's pretty impressive from just an intake. A filter replacement would help with the airflow, but the stock one is already pretty large and "good enough". The real benefit with these Cold Air Intakes is that they make the air COLDER. And this is where the performance gains come from. Looking at the temperature readings
here and doing some simple physics calculations (ideal gas law, otto cycle), you get a thermal efficiency increase of 1.3% just from 8 degrees lower intake temperature. Coupled with improvement airflow (more than double, link
here) you can get close to 5% more power. So it's not surprising you can see gains of +18hp or more. If you want to do the calculations yourself, go
here or if you're not physically inclined, use
this calculator for relative horsepower calculations.
The question, is it noticeable? Ok a 5% increase by itself might not be. But add in a tune, exhaust and pulley and they'll all add up. Literally, say best case, 18+10+22+20 =
70 hp increase at the wheels, that's 85 hp at the flywheel, you're bound to feel that. Maybe with the incremental increases it won't be noticeable with each upgrade, but drive in a stock M3 for a while and you'll quickly appreciate your mods. At this point you might even think of a supercharger, but they run the engine harder and I wouldn't do it until the car is out of warranty. They do provide one of the best $/hp increases though. Note that I haven't done any of this yet, I'm just assuming this will be the case based on the dynos I've seen and information I've read here and elsewhere.
If I bought a used M3, I'd consider supercharging it. I don't think there are any Dinan dealers in Vancouver, are there? So the road of intake, exhaust, pulley, and tuning is what I'm doing to make the car more efficient and... faster. Anyway, enough of the rant... I wish the Akra Evo exhaust wasn't so expensive!!!
