Temp changes and tunes?
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,204
Likes: 14
From: Savannah Ga
Temp changes and tunes?
I got my car tuned in FL at 96 degrees and 25% humidity. Pulled 591 rwhp on a dynojet.
I recently did a dyno pull on a dynamics dyno, because it was free, and did 598 rwhp at 77 degrees and 50% humidity. The guy on the DD dyno said my car was pulling timing.
What worries me is that the temps are very sporadic around here in Savannah. During the winter months it often goes from 40 degrees in the morning to 70 in the afternoon. While some days just stay 30ish all day. Should I be worried about the tune on my car?
My friend said I have nothing to worry about and that the computer will compensate for the change in temperature, but I was worried that a 50-60 degree change (96 to 40 and below) would cause something very bad to happen with my car.
Thoughts/opinions?
Thanks,
Brett
I recently did a dyno pull on a dynamics dyno, because it was free, and did 598 rwhp at 77 degrees and 50% humidity. The guy on the DD dyno said my car was pulling timing.
What worries me is that the temps are very sporadic around here in Savannah. During the winter months it often goes from 40 degrees in the morning to 70 in the afternoon. While some days just stay 30ish all day. Should I be worried about the tune on my car?
My friend said I have nothing to worry about and that the computer will compensate for the change in temperature, but I was worried that a 50-60 degree change (96 to 40 and below) would cause something very bad to happen with my car.
Thoughts/opinions?
Thanks,
Brett
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
There are some tables that will help with temperature compensation with fuel and timing. The only problem is the tuner tuned it at that one temperature and most likely left the temperature modifiers stock since he had no way to tune at different temps. You might wait until it gets as cold as it's going to get and change those temperature compensation tables only and fill in the values in the temperatures in between. Was it pulling timing due to knock or something else?
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,204
Likes: 14
From: Savannah Ga
There are some tables that will help with temperature compensation with fuel and timing. The only problem is the tuner tuned it at that one temperature and most likely left the temperature modifiers stock since he had no way to tune at different temps. You might wait until it gets as cold as it's going to get and change those temperature compensation tables only and fill in the values in the temperatures in between. Was it pulling timing due to knock or something else?
The guy that tuned my car (Tony) also tuned Joe's Ford GT TT if you know who I'm talking about.
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,204
Likes: 14
From: Savannah Ga
A friend of mine and I had a "arguement" about temps and detonation last night and I decided to post to see what everyone else though.
Really don't want to blow my motor just because I want to drive it during the winter.
Drifting
Joined: Sep 2008
Posts: 1,389
Likes: 3
From: somewhere shooting my assault rifles
Even with the computer adjusting for colder temps your tune to run a little leaner ESPECIALLY if your area has "winterized" gasoline (more ethanol in it in the winter months and will make it .5 leaner afr's WOT).
I load a winter tune and summer tune here in Cal on my car because of the crap winter gas with 10% ethanol in it (and the gas I had tested actually had 12% ethanol in it which was even worse).
I load a winter tune and summer tune here in Cal on my car because of the crap winter gas with 10% ethanol in it (and the gas I had tested actually had 12% ethanol in it which was even worse).
Last edited by Z06supercharged; Oct 16, 2009 at 11:25 AM.
Melting Slicks
Joined: Feb 2006
Posts: 2,163
Likes: 5
From: Houston
Even with the computer adjusting for colder temps your tune to run a little leaner ESPECIALLY if your area has "winterized" gasoline (more ethanol in it in the winter months and will make it .5 leaner afr's WOT).
I load a winter tune and summer tune here in Cal on my car because of the crap winter gas with 10% ethanol in it.
I load a winter tune and summer tune here in Cal on my car because of the crap winter gas with 10% ethanol in it.
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Drifting
Joined: Sep 2008
Posts: 1,389
Likes: 3
From: somewhere shooting my assault rifles
The Metro areas in Texas have ethanol in the gas as I saw a sticker on a Shell pump in Dallas last month stating it. Texas applied for a Ethanol waiver and they were denied it in 2008. Yes even Texas has fallen to the political environmentalist crap...
Last edited by Z06supercharged; Oct 16, 2009 at 11:29 AM.
Melting Slicks
Joined: Feb 2006
Posts: 2,163
Likes: 5
From: Houston
Drifting
Joined: Sep 2008
Posts: 1,389
Likes: 3
From: somewhere shooting my assault rifles
10% ethanol (E10) runs leaner than non oxygenated gasoline and it will reflect a .5 leaner afr because of it, It has a stoich of 14.1 and not 14.7 like regular gasoline. Do the math...A tuner should know this and adjust the tune for 10% ethanol in the stoich table input. Most dont though....
It was night and day noticeable on my tune when they switched over to winter gas here. Same exact thing to date as last year to me as well.
Do a google on stoich for E10 cause there is lots of reading out there on its affects on tunes.
Last edited by Z06supercharged; Oct 16, 2009 at 11:39 AM.
Melting Slicks
Joined: Feb 2006
Posts: 2,163
Likes: 5
From: Houston
You wanna bet on that?
10% ethanol (E10) runs leaner than non oxygenated gasoline and it will reflect a .5 leaner afr because of it, It has a stoich of 14.1 and not 14.7 like regular gasoline. Do the math...A tuner should know this and adjust the tune for 10% ethanol in the stoich table input. Most dont though....
It was night and day noticeable on my tune when they switched over to winter gas here. Same exact thing to date as last year to me as well.
Do a google on stoich for E10 cause there is lots of reading out there on its affects on tunes.
10% ethanol (E10) runs leaner than non oxygenated gasoline and it will reflect a .5 leaner afr because of it, It has a stoich of 14.1 and not 14.7 like regular gasoline. Do the math...A tuner should know this and adjust the tune for 10% ethanol in the stoich table input. Most dont though....
It was night and day noticeable on my tune when they switched over to winter gas here. Same exact thing to date as last year to me as well.
Do a google on stoich for E10 cause there is lots of reading out there on its affects on tunes.
