JamesH

iTrader: (21)

If a Cossie with T34, greens etc was mapped with a boost spike of almost 2BAR and the AFR on boost is 11.8:1, would fitting an air filter heat shield make it run lean (as it can't take in so much, all be it, hot air)

Therefore would it miss on high boost then? Or impossible to say?

Anonymous

Impossible to say, simply check the AFR again to know one way or the other.

11.8 sounds about right in principle though, assuming EGT's are ok.

JamesH

iTrader: (21)

Thought as much Chip

I was just wondering if fitting such a thing could cause it to misfire at high boost because it can't take in as much air, thus making it run too lean

Or does the filter get a VERY high percentage of its air intake from the front?

Anonymous

IF you have a filter and it breathes through the whole filter and then you cover up half of it, then providing its a large filter it will just flow almost exactly the same amount of air anyway.

Restricting the filter though would make the turbo work slightly harder, this would mean the exhaust side of the turbo showed more restrition, which would mean that the engine became less volumetrically efficient which could potentially see it running more RICH as a result if the same amount of fuel is still supplied because the MAP sensor still reads the same.

CHECK IT!

JamesH

iTrader: (21)

Will do

JamesH

iTrader: (21)

Well, I don't know if it makes it run lean or not, but it DOES cause it to misfire @ 4.5k-5k (25psi at that point)

big_wig_074

what plugs and gaps you using?could it not be the spark being blown out?

JamesH

iTrader: (21)

The car runs C57 Champions gapped at 25thou.

Karl said this was perfectly fine, so when the plugs do need changing, I will be getting C57's once again

The car runs absolutely perfectly without the shield on again

big_wig_074

cool,soz,i had probs with 57s at high boost and had to swap to 59s hence the question!glad its sorted

Staffi

iTrader: (1)

Well there`s your answer :leave the shield off

abdr500

iTrader: (1)

smidsy
no will not make it misfire at all

JamesH

iTrader: (21)

Well even after a long run, the car is now running PERFECT again (without the shield), just like the day it was brought back from Karl's