It was even colder this morning....30 degrees....too bad there's not a track nearby on days like this!!!!

 

Dodge4SRT,

that makes sense... I had just never heard 59 deg. F being the "magic number"... rock on!

 

Good post, guys.

I have noticed the cold bringing out the beast in my car as well. One thing, It might feel quicker partially because the tires have less traction in the cold and they seem to be struggling more to bite.

I have to clock the car in a couple of low temp. runs to see if there really is a difference.

 

I'll have to agree with 4SRT, the "magic" number is somewhere between 50 and 60 degrees. I've had three intercooled turbo cars (my SRT the third), and you notice drastic changes both below 50 and above 60 degrees.

 

Same here, this is my third intercooled tubo as well, my Shelby Z's being the first and second.

 

Wow I never knew that.. GREAT info!!
[sm=interesting.gif]

 

this is a great link too http://not2fast.wryday.com/turbo/glo...rbo_calc.shtml
i've been using it to figure out my low budget path to 300+ hp... for my 04

right now i'm planning on:
-1-down pipw w/e-cutout (keeps the stock exhaust) and durring WOT, well lets say it will be loud (this should elimate the 7lbs of back presure from the stock exhaust) and max out the capablity of the stock turbo (which if i'm reading the map's right is 325hp)
-2-a couple of those spring mods for the stock WGA
-3-i'll work on the MAP clamp, i don't like the zener diode--- thought i would go with a simple voltage follower (with an adjustable clamp ~4.7v), not sure about the part, but something like a lm385 should do the trick.
-4-still have to figure out the BOV part of this, & diy Manual Boost stuff
-5-new intercooler, hmmm-- guess this is a TBD.. if you play around with the above url a lot of HP can be made from cooling the air, plus the added benefit of less presure drop across the intercooler- (unfortunatly i don't have the $20 catch can, can wait to pull the intercooler off an look inside)
-6-since i'm doing #1, i was going to add a wideband just to make sure i don't burn anything -- the options here are feed it into the stock ECU, or piggy back.. leaning towards using the stock ecu, and durring WOT modifing the wideband to narrow band input to the stock ECU..

ah well..sorry for going off ... i'm still trying to work this out...
i could spend the $$$ on an AGP or S3, but thats $3k.

 

Normal Sea level Pressure is 29.92 inHg.

0 expansion is 68f or 20c

Optimal for a standard combustion engine is high 50's

But you also have to remember that turbos heat intake air to 300+.

So outside temps don't mean anything when it comes to an intercooled turbo engine. You have to measure temps in the manifold to start thinking about the "optimal" temp to test out your toy.

 

A very good point - I thought of this after I entered my response as well. So if 50ish is ideal, what outside temp would acheive this after passing through all of the heating going on in the turbo/manifold?

I would assume that Sub freezing outside temp's would be better than 50's in the case of our cars.

So if that is the case, then , you would be faster at 0 degrees, than at 50, right?

 

Ambient air temperature is most critical for intercooler efficiency. Since your turbo is going to heat the hell out of the air whether it's 20, 30, 59 or 110, it doesn't matter as much as it does on an NA engine. What really matters is the air across the intercooler, so the colder the better. The SRT-4 also backs off the boost a bit on colder days for just this reason.