As it gets hotter outside...What does the engine do to adapt?
Thread Starter
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
As it gets hotter outside...What does the engine do to adapt? Well its very ******* hot outside.
Now thats out of the way. My IAT is showing 112 degrees and the coolant is showing 202 degrees. Normally the coolant is around 196 degrees under cooler conditions. The motor seems to be running perfectly fine without the slightes issue. I am just curious about what the engine does to adapt when its hot out? Do the timing curves and the A/F change?
Thanks.
Now thats out of the way. My IAT is showing 112 degrees and the coolant is showing 202 degrees. Normally the coolant is around 196 degrees under cooler conditions. The motor seems to be running perfectly fine without the slightes issue. I am just curious about what the engine does to adapt when its hot out? Do the timing curves and the A/F change?
Thanks.
TECH Fanatic
Joined: Feb 2006
Posts: 1,025
Likes: 1
From: CT/NJ
Timing drops like a rock on a stock tune as the IATs go up. Fueling is decreased proportionally as (basically) the air density drops.
Be happy your coolant temp is only up a few degrees. Some less well designed cars will overheat in this weather.
Be happy your coolant temp is only up a few degrees. Some less well designed cars will overheat in this weather.
Thread Starter
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
I dont have problems. It aint overheating. It runs friggin awesome. All is good.
The question was what does the motor do to adapt to these hot conditions. I was merely curoious as to what the PCM does under these conditions. Thanks to 05hd for the informative response.
air charge heats up, timing lowers, detonation occurs easier, motor pulls more timing, coolant temps raise, timing retards, fuel leans, fuel also richens.
That's the gist.
Too many variables to tell you exactly what it's doing specifically in your case, but the tune takes iat, map, timing, afr, and more into account to adjust.
That's the gist.
Too many variables to tell you exactly what it's doing specifically in your case, but the tune takes iat, map, timing, afr, and more into account to adjust.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
For somebody with no clue posting this topic you shouldn't insult someone who gives you factual answers.
How about a stock GM tune that says I'm right:
Take a look at the %change to AFR vs coolant temps. As it gets warm it leans out and when it gets really hot it richens.
When it's really cold out and that coolant comes from the radiator to the block you are getting a 4 tenth richer mixture. When it heats back up it leans out. Then when it hits 240 it richens up again.
Gee whiz who's right?
I've spent a decent amount of time looking at the LT1 tune.
Now, I also said it depends on too many variables as to what YOU WILL SEE.
So cool the douchebag BS.
How about a stock GM tune that says I'm right:
Take a look at the %change to AFR vs coolant temps. As it gets warm it leans out and when it gets really hot it richens.
When it's really cold out and that coolant comes from the radiator to the block you are getting a 4 tenth richer mixture. When it heats back up it leans out. Then when it hits 240 it richens up again.
Gee whiz who's right?
I've spent a decent amount of time looking at the LT1 tune.
Now, I also said it depends on too many variables as to what YOU WILL SEE.
So cool the douchebag BS.
Last edited by LSWHO; Jun 9, 2011 at 11:38 PM.
Staging Lane
Joined: Aug 2010
Posts: 49
Likes: 0
Heat soak and the IAT equal crappy performance. That alone will take up to 3 degrees of ignition advance away. On a speed density, the IAT and coolant temprature sensor are key in creating tables when the engine is at open loop. The cooler the IAT on start-up, the 'better' the A/F mixture.
I have relocated mine inside my SLP filter at the front of the radiator. Hot starts are no longer a problem. Car performs as if the engine is cool. It's also great for hot laps at the track.
I have relocated mine inside my SLP filter at the front of the radiator. Hot starts are no longer a problem. Car performs as if the engine is cool. It's also great for hot laps at the track.
Launching!
Joined: Oct 2009
Posts: 247
Likes: 0
Heat soak and the IAT equal crappy performance. That alone will take up to 3 degrees of ignition advance away. On a speed density, the IAT and coolant temprature sensor are key in creating tables when the engine is at open loop. The cooler the IAT on start-up, the 'better' the A/F mixture.
I have relocated mine inside my SLP filter at the front of the radiator. Hot starts are no longer a problem. Car performs as if the engine is cool. It's also great for hot laps at the track.
I have relocated mine inside my SLP filter at the front of the radiator. Hot starts are no longer a problem. Car performs as if the engine is cool. It's also great for hot laps at the track.
https://ls1tech.com/forums/lt1-lt4-m...at-sensor.html
I am just curious about what the engine does to adapt when its hot out?
Staging Lane
Joined: Aug 2010
Posts: 49
Likes: 0
Puting the sensor inside the SLP filter that sits out front of the radiator gave the ECM a better repensentation of the actual air temp and helped with hot start performance.
TECH Apprentice
Joined: Feb 2011
Posts: 301
Likes: 0
This is the same answer that I gave someone else
" I had this same issue with my first modded truck (TPI in a 1997 4X4) the only way to fix it is to wrap (insulate) the CAI plumbing, to eliminate the heat soaking of the plumbing, IE eliminating the heat transfer into your incoming air supply. that is the real issue, not the sensor"
" I had this same issue with my first modded truck (TPI in a 1997 4X4) the only way to fix it is to wrap (insulate) the CAI plumbing, to eliminate the heat soaking of the plumbing, IE eliminating the heat transfer into your incoming air supply. that is the real issue, not the sensor"
Thread Starter
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
For somebody with no clue posting this topic you shouldn't insult someone who gives you factual answers.
How about a stock GM tune that says I'm right:
Take a look at the %change to AFR vs coolant temps. As it gets warm it leans out and when it gets really hot it richens.
When it's really cold out and that coolant comes from the radiator to the block you are getting a 4 tenth richer mixture. When it heats back up it leans out. Then when it hits 240 it richens up again.
Gee whiz who's right?
I've spent a decent amount of time looking at the LT1 tune.
Now, I also said it depends on too many variables as to what YOU WILL SEE.
So cool the douchebag BS.
How about a stock GM tune that says I'm right:
Take a look at the %change to AFR vs coolant temps. As it gets warm it leans out and when it gets really hot it richens.
When it's really cold out and that coolant comes from the radiator to the block you are getting a 4 tenth richer mixture. When it heats back up it leans out. Then when it hits 240 it richens up again.
Gee whiz who's right?
I've spent a decent amount of time looking at the LT1 tune.
Now, I also said it depends on too many variables as to what YOU WILL SEE.
So cool the douchebag BS.
Thread Starter
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
The comment was in jest and I see no pissing match cause I had nothing to add and added nothing. Both of you cheer up, its Friday.
Last edited by wrd1972; Jun 10, 2011 at 08:51 AM.
