The "FYI" on K&N

[dwysywd]

FROM THE K&N BOOTH AT SEMA 2004 -

K&N Rep says to me: "Don't bother running a cold air induction (CAI) on your GT, the computer will automatically adjust the your air flow to accomodate for the forced air. CAI is best used on naturally aspirated engines. My suggestion is to use a standard K&N and route a straight pipe from the lower facia of your car into your OEM airbox."

Wow, how is that for a lesson! I was shocked. I was at SEMA as a registered buyer (jobber) and he could have sold me anything. I was suprised by his understanding of it all. Kudos to K&N. Hope this helps.

[Cal Cruzer]

quote:Originally posted by dwysywd

FROM THE K&N BOOTH AT SEMA 2004 -

K&N Rep says to me: "Don't bother running a cold air induction (CAI) on your GT, the computer will automatically adjust the your air flow to accomodate for the forced air. CAI is best used on naturally aspirated engines. My suggestion is to use a standard K&N and route a straight pipe from the lower facia of your car into your OEM airbox."

Wow, how is that for a lesson! I was shocked. I was at SEMA as a registered buyer (jobber) and he could have sold me anything. I was suprised by his understanding of it all. Kudos to K&N. Hope this helps.

Professional races accross the country (heck, around the world) would dissagree with him.

[grantwildbill]

at long lsst a correct answer on downpipes pcm controls engine. any increase in power is very little.

[Mr.Blonde]

hmm, well... it worked for me.. with my BTG CAI and my mopar/borla exhaust, i have a 14.7 sec stage 0 PT . and those are the ONLY performance mods i have done.

[grantwildbill]

what did u run before?

[Dalite]

quote:Originally posted by dwysywd

FROM THE K&N BOOTH AT SEMA 2004 -

K&N Rep says to me: "Don't bother running a cold air induction (CAI) on your GT, the computer will automatically adjust the your air flow to accomodate for the forced air. CAI is best used on naturally aspirated engines. My suggestion is to use a standard K&N and route a straight pipe from the lower facia of your car into your OEM airbox."

It is good to see the honesty and verification of what has been discussed on the forum for the past 2 years.

However, the PCM also adjusts boost for temp changes to give the same power out; no matter what the temp of the incoming air.

The big hint here, even if the PCM didn't do this, is that one byproduct of the turbo compressing the air is heat.

FWIW, if you remote your temp sensor that feeds the overhead console to the input of the stock airbox, you will find that there is a 5 degree (or less) difference between under hood air temp and outside air temp - provide there is forward motion.

Remoting the air pickup will do nothing to improve performance.

[Cal Cruzer]

quote:
FWIW, if you remote your temp sensor that feeds the overhead console to the input of the stock airbox, you will find that there is a 5 degree (or less) difference between under hood air temp and outside air temp - provide there is forward motion.

I did this and my findings were that there was a HUGE difference. I have mounted it in various locations thoughout the engine bay, with and without a rear seal and in and out of the air box with an airaid. Even in the air box temps got very high. That is why I plumbed air to it.

Even the seat-of-the-pants dyno tells me that hot air in = less power. The intercooler will only do so much. If the air going into the intake is 30-50 degrees higher, it will be higher coming out of the intercooler. Again, you will have a hard time convicing race car builders to junk the idea of getting the coolest charge possible into the engine but you are welcome to campaign the point with them. Let us know how it goes. They don't do this without research and proven success.

[Dalite]

Even the seat-of-the-pants dyno tells me that hot air in = less power. The intercooler will only do so much. If the air going into the intake is 30-50 degrees higher, it will be higher coming out of the intercooler. Again, you will have a hard time convicing race car builders to junk the idea of getting the coolest charge possible into the engine but you are welcome to campaign the point with them. Let us know how it goes. They don't do this without research and proven success.

A walk back through memory lane will find this confirmed by3barboost and one of the import car mags that featured the PT Turbo engine.

The engineering paper on the engine that I paid $AE to download goes into further detail.

This has been discussed in detail here, and even Mopar Performance pulled it's proposed CAI product from production for the same reason.

It uses torque-based turbo management. Boost is increased under higher ambnient temperatures to provide the same torque at the same throttle position.

I won't have a hard time convincing racecar builders anything; I'm not trying to. I dont go to the car parts store to by salad either.

There is nothing in common with old-time technology and the approach that DCX took with the Next Generation PCM used on the PT Tubo.

I have been trying to chronicle this since early 2003, but apparently haven't been very effective.

[Dalite]

quote:Originally posted by Cal Cruzer
[br

I did this and my findings were that there was a HUGE difference. I have mounted it in various locations thoughout the engine bay, with and without a rear seal and in and out of the air box with an airaid. Even in the air box temps got very high. That is why I plumbed air to it.[/quote]

I consistently see less than 5 degrees differential; as long as there is forward motion. The input to the stock airbox is already oriented in a position to receive the coolest air, as long as there is forward motion.

If you will look back where I outlined the mod, and the logic of the module in the overhead console, you will see that DCX used an abortion of a logic application to keep the temp from updating until either 2 minutes of motion was detected or motion was verified by 2 compass direction changes. This is from the service manual set that I bought to try to see what was actually going on under the hood.

For this reason, the temperature will remain at what ever the last heat soaked measurement was when the car is idling at a traffic light, or is restarted after being parked for a short differnece.

It tops out at 140 degrees. You will see a rise from near ambient temp to a max of 140 degrees whenever there is no motion.

No motion = no air flow. In the absence of air flow, ambient underhood temperatures increase.

In spite of this, if you nail it after sitting at a traffic light, the PCM measures air in 3 different places, from airbox output to intercooler output to determine the correct amount of boost needed for the torque demand, determined by throttle position.

This is hard to accept. I am a 51 year old gearhead that is having to unlearn everything I though was sacred. It is not an easy process, but I promise there is no agenda here other than trying to provide awareness and dispell rumors.

[mvandale]

Here's a question (from an admittedly ignorant tinkerer):
If the computer compensates for warmer air (i.e., less dense air) by increasing boost, could a person theoretically place the temperature sensor near a warmer engine source to try to "trick" the computer into thinking the temperature is warmer, thereby increasing boost?

Just a thought.