cold weather and turbocharged cars

It's doesn't go anywhere? It does in here...

Moderator: Moderators

Post Reply
avriette
DCAWD Groupie
Posts: 1316
Joined: Sun Oct 01, 2006 3:48 pm
Location: Arlington, VA
Contact:

cold weather and turbocharged cars

Post by avriette »

Sandy is complaining that the car is "faster" than it was a little while ago. Yes, complaining. I haven't done anything to it, and the only thing I can think of is that the weather is 40F colder than the last time she took the car to work.

Before I moved out here, I was asking people if I needed to do anything to the Z in respect to the weather (from San Diego to Potomac, MD). The only response other than all weather tires (which I never found much use for) was "winter is great for turbocharged cars, it's like adding an intercooler!" (the 280ZXT had none). I never much noticed this in the Z, as taking it out in the winter was never such a good idea anyways. But more recently, I read an article by Honda Tuner about the Zex intercooler fogger kit. They recorded a 65-hp increase when using it on the dyno.

Now, liquid nitrous oxide is a lot colder than 29F. I am wondering whether it's possible she's noticing something like that. I personally don't get the car up to WOT that often, and when I do, it's hard to notice any objective difference (really f'n fast is just really f'n fast, most of the time). It's also possible I should cut back her crack intake.
rocket scientist
User avatar
sirwilliam
Resident Poop Expert
Posts: 7226
Joined: Mon Aug 01, 2005 1:27 pm
Location: The Wild Serengeti Suburbs

Post by sirwilliam »

It's just the cool air! Tell her to relax and enjoy it!
2004 SG Model A PearlBlackObsidian (RIP)
2008 SG Model D BlueRallyWorld

"When I get sad, I stop being sad and be awesome instead. True story." -Barney Stinson
"Nothing shuts my pie-hole but pie." -Shawn Spencer
User avatar
Sabre
DCAWD Founding Member
Posts: 21432
Joined: Wed Aug 11, 2004 8:00 pm
Location: Springfield, VA
Contact:

Post by Sabre »

Yep, cold air helps our cars a lot! People with UTEC's on their Subaru's notice it since the UTEC does not compensate for the colder air coming in. Conequently, they usually have a cold weather and a hot weather map.
Sabre (Julian)
Image
92.5% Stock 04 STI
Good choice putting $4,000 rims on your 1990 Honda Civic. That's like Betty White going out and getting her tits done.
avriette
DCAWD Groupie
Posts: 1316
Joined: Sun Oct 01, 2006 3:48 pm
Location: Arlington, VA
Contact:

Post by avriette »

Sabre wrote:Yep, cold air helps our cars a lot! People with UTEC's on their Subaru's notice it since the UTEC does not compensate for the colder air coming in. Conequently, they usually have a cold weather and a hot weather map.
Compensate? You mean the stock ECU actually changes its map based upon the temperature of the intake air? It would seem to me that a MAF just measures the amount of air (regardless of density) flowing through it. Or did I miss something?
rocket scientist
chicken n waffles
Moderator
Posts: 6314
Joined: Wed Oct 19, 2005 1:15 am
Location: Alexandria

Post by chicken n waffles »

colder air = denser air = more O2 molecules = more f4st4rrr
-Ben
Image
User avatar
drwrx
DCAWD Founding Member
Posts: 4382
Joined: Mon Sep 20, 2004 8:00 pm

Post by drwrx »

avriette wrote:Compensate? You mean the stock ECU actually changes its map based upon the temperature of the intake air? It would seem to me that a MAF just measures the amount of air (regardless of density) flowing through it. Or did I miss something?
Yes, the stock ECU does make adjustments for a colder/denser charge of air. It is very sesitive, but also pretty adaptive. Turbo cars will spool quicker and boost higher in cold air. The ECU can modify boost (adjust the wastegate), as well as pull timing and add fuel to compensate. This is why IC sprayers help so much during hot weather.
User avatar
Sabre
DCAWD Founding Member
Posts: 21432
Joined: Wed Aug 11, 2004 8:00 pm
Location: Springfield, VA
Contact:

Post by Sabre »

^^^ To add to what Darrin said, our MAF's are actually MAF's AND temperature sensors. My Hydra doesn't use the MAF reading, but it does use the intake temperature to compensate for the different intake temperatures.
Sabre (Julian)
Image
92.5% Stock 04 STI
Good choice putting $4,000 rims on your 1990 Honda Civic. That's like Betty White going out and getting her tits done.
Post Reply