K&N air flow filter

[Paul325ITouring]

Hi iam looking at changing my air filter set up with a k&n filter Ive seen,on you tube a heat pannel they do in the USA. Which sits along side the k&n filter stopping,heat from getting to the filter has any one eles seen this at all.

[danbear]

I think you're better off with the standard air box, but with a K&N panel filter tbh

[beemerbird]

Are you talking about a K and N cone filter with a heat shield? Whilst these might look a bit more 'tuned' and sound better (if you like that kind of thing), the received wisdom is that the standard air box with a standard filter works best for the E30.

I'm sure if you google K and N heat sheild you'll find something to help you, as I definitely have looked at this to go with my K and N cone

[Paul325ITouring]

Thanks if standard is best for the car il keep with that don't want to spend alot of cash and find out I have to change it back again

[B4UR]

Cone filters make a nice noise but can actualy reduce hp instead of increase

[daimlerman]

I fitted a K&N cone filter when I was new to E30's,just swapped it back to the stock airbox with a K&N panel filter....no results yet as the car is still in the workshop...but it sounds better!

[Messenjah]

an open cone filter will probably loose hp but a proper cone filter in a sealed airbox with a cold air feed will almost certainly work bette rthen the standard panel filter in bmw airbox

[m_jermyn]

Messenjah...

Someone on here has done exactly what you just said, that is a cone filter that is sealed from the engine bay and has a direct cold air feed..........

They dynoed it before the KN and then after well the results might surprise you..... With the KN it actually developed something like 2HP more right at the top end, it also developed a massive flat spot at around 3000rpm...

So all that money and time to get 2hp right at the top where no one drives anyway but they got a big flat spot in the rev range..

If memory serves me correct it developed more torque with the standard filter..

Mike

[benji471]

The cone filter will almost defiantly reduce the power and fuel consumption, or it seamed to as mine came with one. I changed back to the standard box with a k&n panel filter and also cut out some of the slot in the grill by the feed pipe on the air box works a treat. I honestly cant see the benefit of the cone filter you don’t even really get the noise because of the AFM. An enclosed induction kit would do the same as the standard air box with a good feed but maybe look better too some people under the bonnet and another thing to add to the list for kudos.

[m_jermyn]

Here you go some great reading......... It explains it all


http://www.e30zone.net/modules.php?name ... light=cone

[murran]

hmmmm..... just read that.
not that i know much about rollers but i thought they could calculate the transmission losses by pressing the clutch at down at the end of the run and letting the drive and transmission slow down from 60-80mph (what ever the speed was at the end of the run) on the rollers?

[m_jermyn]

Forget about the transmission loss, look at the loss of power and torque the KN filter gives.... Thats what you started the thread about...

Dont get me wrong I want a KN filter to because of the induction noise, I love it... However power comes before asthetics

Mike