wrd1972

iTrader: (12)

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.

05HD

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.

gregrob

iTrader: (8)

Takes off all its clothes

pillarpod

take the hood off, **** can it on an open highway, top it out, pop it in N and cost and enjoy

wrd1972

iTrader: (12)

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.

LSWHO

iTrader: (1)

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.

wrd1972

iTrader: (12)

Fuel leans and fuel richens.
Rrrrrrrrrright.

Wicked94Z

iTrader: (26)

fail.

tbag_skywalker

One of LS1Tech's finest moments here.

LSWHO

iTrader: (1)

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.

Fly on the wall

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.

5_LTR_ETR

ok now im confused

https://ls1tech.com/forums/lt1-lt4-m...at-sensor.html

cam

iTrader: (9)

Well you see first it grows a fresh new beard because more hair = more cooling and well.... while its at it it also grows a new coolant blow off valve that whistles "WHEEEEEEEEEEEWEEEEEEEEEEEEEEEEEEEEEEEEE" which means I'm hot so you know add some 20 weight ball bearings to your next oil change and put a couple of GM pucks in the coolant after you rid that DexGoo **** and your good to go

Fly on the wall

I have a '93 vette(I should have mentioned that). The stock location for the IAT is in front of the TB and above the water pump. The IAT has hit 200 degrees during the summer after a drive. That is not a very good repensentation of the outside air. So when I start the car, the IAT was telling the ECM the temp is 200 degrees. That would remove timing and lean out my mixture, causing the car to run like a turd. This false heat causes a power loss because the engine control system uses the intake air temperature in its detonation control strategy.

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.

cam

iTrader: (9)

awww common that was funny. Blah carry on

NewOrleansLT1

There is some good info in here...

Tinbender59

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"

wrd1972

iTrader: (12)

The above detailed explanation is much more useful than simply stating "fuel leans, fuel richens" in the same statement without expanding just a bit. Dont you agree?

pillarpod

could of just ask him to be more elaborate, but hey if you wish to have a pissing match with him, have fun

wrd1972

iTrader: (12)

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.