Throttle sluggish when hot

[Roe Racing]

The manufacturer's are protecting our investments and of course theirs during warranty especially.

100% correct.
However, reducing the perceived IAT by the PCM has nothing to do with the knock sensors or the strategy of how much timing is removed once knock has been seen.
Ultimately, this modification is a simple "low buck" mod to help keep the stock PCM from going into a table where it starts aggressively removing ignition advance due to temperature.
You should only notice the difference on an 85+ degree day.
It can also be achieved through a reflash, but that costs more than 20 cents.

Regards,
Sean

 

[VIPER HP]

Sean, you are so correct. I'm running the 10k resistor now and on a hot day it is great. As I've said, I did my own Paxton install about 1 year ago and have the BG Paxton flash. I always have thought the sluggish when hot problem has to be more than just hot air. This problem has bugged the crap out of me.
I CANNOT THANK YOU ENOUGH for defining the problem and THEN offering the fix.

 

[rottenronnie]

100% correct.
However, reducing the perceived IAT by the PCM has nothing to do with the knock sensors or the strategy of how much timing is removed once knock has been seen.


Regards,
Sean

Thanks Sean,

Chris (DC Performance) let me know that the resistor mod would compromise the program if used with the stage 2 flash and that is the info I was passing along in a previous post, shortly after this thread began.

Just to clarify your information above- The AMOUNT of the reduction isn't altered but when the engine begins to ping, the knock sensor is triggered and that is what ultimately pulls timing...correct? I was just a little concerned when you said reducing the perceived Intake Air Temperature has nothing to do with the knock sensors or the strategy of how much timing is removed..

 

[Roe Racing]

Uh...., correct?
I really don't know why you're talking about knock sensors
This has nothing to do with them, their function or what the PCM does when it sees knock. Knock sensors aren't part of this subject in any way, at all.
This is only about where the ignition table goes when the IAT gets over 95F on a stock program.
This is not a mod to increase timing advance. It is a mod to keep the advance closer to optimum. It still reduces the advance, just not as much.

 

[rottenronnie]

Uh...., correct?
I really don't know why you're talking about knock sensors
This has nothing to do with them, their function or what the PCM does when it sees knock. Knock sensors aren't part of this subject in any way, at all.
This is only about where the ignition table goes when the IAT gets over 95F on a stock program.
This is not a mod to increase timing advance. It is a mod to keep the advance closer to optimum. It still reduces the advance, just not as much.

Well, I didn't start by talking about knock sensors, I just assumed that is what was pulling the timing out.

So, the data is hard coded into the e.c.u. that if the Air Intake Temperature exceeds a certain value (95F.), the e.c.u. pulls back timing, correct?

And all this occurs PRIOR to a knock sensor controlling timing? So the knock sensor must be the very last line of defense in the chain.

If the A.I.T. is that hot, wouldn't the knock sensor be very nearly ready to operate anyway; especially during competition (i.e. drag racing)?

Thanks for the clarification.
Ron

 

[Roe Racing]

So, the data is hard coded into the e.c.u. that if the Air Intake Temperature exceeds a certain value (95F.), the e.c.u. pulls back timing, correct?

Correct

 

[azpyroguy]

Correct

Well.. heck.. that has to be my problem also... during the summer months here in AZ there is NOT a single day here that goes by that the temperature is less than 110 degrees... even with the chiller unit my intake air temps hover around 105 derees, and in the cooler months (now), they are around 100 or so... I can definatley feel a difference in the performance of the truck when my air temps reach 100 and above.....

Wonder if this fix will help alleviate my issue...

 

[Prof]

Scott if you will allow a non-professional opinion...you have lots of problems and this fix will only address one of them...of course having been in health care for so many years I am a little warped....

 

[azpyroguy]

Scott if you will allow a non-professional opinion...you have lots of problems and this fix will only address one of them...of course having been in health care for so many years I am a little warped....

Hey... I work in healthcare also...so that must mean that I am also warped...:nurse:

 

[Prof]

Exactly! I noticed your certifications...and was pulling your chain...but then you can probably heal yourself...I was just an administrator who screwed things up over and over.

 

[azpyroguy]

Exactly! I noticed your certifications...and was pulling your chain...but then you can probably heal yourself...I was just an administrator who screwed things up over and over.

I knew that... I was just playing into it... :rock:

I work in the information security area of the hospital... basically my job is to keep the hackers out...

 

[eddie102870]

got my resistor's in today went ahead and fixed it up to splice into the wire when i get home this afternoon.

 

[76574srt10]

here's possibly a stupid question. can this mod be seen by the dealership doing a system scan?

 

[davo19]

i wonder how it would act on a mopar performance pcm???

 

[LitemUp]

Wouldn't water/meth injection also do the same thing in fooling the IAT sensor?

 

[Prof]

The water meth only activates under load...the IAT is reading constantly...if you are hot lapping at a track, heat soak will be noted by the IAT and the timing will be pulled, but I don't know when the pcm leans the mixture after the IAT senses a lower temp. The IAT mod just makes the IAT tell the pcm that it is 30 degrees cooler than it actually is...all the time.

 

[msdnga]

Here is a quadcab's stock table for ECT and ACT. Just to give you an idea of how much is pulled and why Dodge guys run cooler t stats and relocated IAT sensors for years.
Now subtract that from the stock SRT10 timing table pict#2.

 

[VIPR PWR]

So would this be a benifit or not

 

[msdnga]

On a non tuned truck, yes, SCT or Custom flashed, no. It's already changed in those.

 

[VIPR PWR]

Thanks Marty ,,,That was my next question hahahaha