Hey guys...

I discovered that I have the dreaded 'flat spot' from a K&N panel filter when I fitted it to my 2003 TJ AWD. When I swapped across the filter from my wifes TJ exec, the flat spot went away. I didn't notice it first time I installed the K&N because the old filter was that badly clogged the K&N made a good improvement.

The weirdest thing is that the executive doesn't suffer from this problem. Oh well. Low end acceleration has improved again, and partial throttle response is also restored.

Anyone else experience this? I suppose since people have dyno'ed against K&N, Stock and No Filter with no difference, spose it doesn't matter. It is quieter with stock filter as well...

Cheers
Heath Young

Does the CPU need to adjust to the k&n filter? How long does this take?

Mine definetly revs out easier with the new filter, but I havent seemed to notice any flat spots yet. There was a flat spot before the filter though.

Im happy with mine overall.

Have a read of this thread Heath. Its to do with flatspots with Pods and panels..

Maybe its the design of the core in the panel and pod that causes issues?

http://www.aussiemagna.com/forums/showthread.php?t=12089

Im happy with mine overall.

you better be!!! hahaha

yes, you need to wait for the ecu to adj, heath

I suppose since people have dyno'ed against K&N, Stock and No Filter with no difference, spose it doesn't matter.


Personally I dynoed a NEW Stock panel VS the K&N Panel and gained 3Whp. The dynos were done 5 minutes apart. I would say they are surely worth the money. I never noticed a flat spot either. :confused:

For once and for all: the problem is not with the 3.5L engines (not very much anyway). Sometimes I wish the 3.5L brigade would just stop saying 'I don't have a flat spot" - of course you don't you have an extra half-litre capacity!

It is the 3.0L 6G72's that this is happening to. Manuals are coming off worse than the Autos.

I have confirmed it with a learned Mitsu dealer technician who also works on a AWD rally car. He has the same (but lesser due to engine capacity) problem.

He said the 3.0L is definitely worse. Manuals are worse again as they actually have a different fuel map than autos. The autos are set to run richer, so when the air is flowing through the filter easier however more turbulent, the autos have the extra fuel in the curve to compensate. It leans out, but not like the manuals do.

And yes, the manuals had 2x different fuel curves from '96 (TE) to '99-'00 (TH). The factory manual curve was alwasy set, but if the customer had any problems with this sort of thing, the dealer would flash in the second fuel curve with the MMAL handheld ECU thingy (I saw one once!). Apparently there was some drivability problems while the choke was on and the engine running while cold -mainly coughing and spluttering, losing power on takeoff. The new fuel curve was designed to fix this.

Same tech said he had to use a RRFPR, crank it up to 46psi, plus go for extra engine management and richen the fuel curve in the area of the flat spot. He also said that flowing the throttle body helps to keep the airflow nice and clean, hence able to be metered effectively by the MAS.

Most suprising thing he told me was that 95/98 octane fuel actually made it worse in most cases, and if I was running 98 octane, to go back to standard unlead and see how she went.

I find 95 octane seems to give the best in my particular car. On 98 it runs like a pig when cold, but I am sure some timing advance would help that, not to mention peak power and torque!

For once and for all: the problem is not with the 3.5L engines (not very much anyway). Sometimes I wish the 3.5L brigade would just stop saying 'I don't have a flat spot" - of course you don't you have an extra half-litre capacity!

It is the 3.0L 6G72's that this is happening to. Manuals are coming off worse than the Autos.
I know you mean well, and it's interesting and all, but you did read how heathyoung got flat spots when he fitted the K&N panel to his 2003 AWD, right?

No I didn't, but the most of the cars doing it really badly are 3.0L TF manuals. 3.0L autos can suffer from it pretty bad too, i know one auto that was worse than mine (non-amc).

as I said, 3.5L engines have been known to experience it but not to the degree of the 3.0L. As I said, this Mitsu dealer tech had the problem on the 3.5L but only slightly. Bearing in mind that it was a rally car and power delivery must be spot on.

Is it worth going to the K&N with no other mods? Although at the moment I've got the OE intake snorkel off, strangely I seem to have picked up some fuel economy.

Most suprising thing he told me was that 95/98 octane fuel actually made it worse in most cases, and if I was running 98 octane, to go back to standard unlead and see how she went.

I find 95 octane seems to give the best in my particular car. On 98 it runs like a pig when cold, but I am sure some timing advance would help that, not to mention peak power and torque!

I got no probs with the BP ultimate. In fact my car doesn't idle as rough and it drives smoother than standard unleaded.

I'd agree that the intake snorkel is a bit restrictive. Try running some sort of piping to a clocation that can get some much colder air, asy in front of the bumper somewhere, but not in the engine bay. See the power go up a bit &/or fuel economy go up.

I've only got the panel, but soon to have sports exhaust & flowed throttle body from EzBoy.
I think that then the extractors would be required. Makes sense to do all the inlet & outlet sides of the breathing.

Just remember that after a couple of air filters, you've paid for it. Last time I checked for a standard air filter (Valvoline) from Supercheap Auto it was over $30! :shock:

Standing starts get a bit bogged down, but once you are moving, you'll give most cars a slight scare.

I got no probs with the BP ultimate. In fact my car doesn't idle as rough and it drives smoother than standard unleaded.
Good to hear. Mine does as well, just not when it is cold and not in the 1500-2500 rpm area. Again, I think the choke is playing silly buggers with the fuel curve while it is trying to warm up the engine up to temp, but hey, it happens.

Could be also something to do with the timing at those revs...... never actually checked that

i got the flat spot and it ****s me, especially when i first start the car, its terrible when its cold, its got nothig up until 3000rpm and the it just goes bang and shes off, and once its warmed up its only mildly annoying, id change back to the stock filter but my induction noise is just soo damn good :D