I realize a turbo car would have probably the best performance in cool weather, but how about really cold weather? Say, 25-30 degrees Fahrenheit? If the car is up to normal operating temp would the turbo be even more effective, thus creating higher performance? Or is there a certain temperature where it drops off? For example would 50 degrees be better than 25?

 

the colder the better the car will run. I live in Al, but all i have expericed its about 32 degrees F. The car pulls so much harder, it seems that the car runs like **** on a 75 degree F day.

 

I went out last night it was 16 degrees out,car ran like a absolute beast,big difference between 16 and 30 degrees.

 

yeah quit braggin....us down here in FL live for it to drop below 60.....at least our cars do.

 

Yeah there is --- be careful though
Watch your gauges

 

watch what gauges? boost in case of overboosting? or temp?

 

Its easier to for boost to spike in cold weather. My car got slower when it got cold out and was running pig rich. The temperature correction maps must be off.

 

It is very important to watch your gauges when the weather is very cold, and very hot as well. The reason your car feels like a beast when it is colder outside is that the lower ambient air temp is giving you intake air temps that are much cooler as well. The colder air is denser, more molecules of O2 are being ingested into your engine.. as a result you NEED to have a corresponding increase in fuel delivery.. ECU's have temp correction compensation built into them, but you never know what could happen with a modified car. If your fuel system is topping out at say 12psi for example in 60 degree weather, and now you are running out at 12psi in 20 degree weather you run a good chance of popping the motor.

Matt

 

It was 15 deg here in Indiana yesterday and I hit 17lbs on my stock twins, not good!. Make sure you give the IC a chance to warm up a little. I know that sounds stupid but if your IC is 15 deg you intake temps are going to be REALLY low the first time you do a good pull, probobly too low, even if the car is up to temp.

 

The thing that most people are missing here is the physics are still alive and well in cold weather - this is both good and bad. There are three areas of interest here.

The obvious good is more power generally. The colder the air, the denser the air. There is a limit to the air density though. Around 32 degrees and the big gains are gone as the expanded water is quite dense at that point leaving more room for the other air (namely oxygen). You will find it does improve power going down to even 0 degrees - past 0 degrees and the gains are minute.

The other area is boost. The more air, the more boost. Your turbo will not have to work as hard, however, this will really test your boost controller and supporting systems. Therefore, as said in previous posts, really look at those gauges, namely the boost gauge the first time you hit the "go switch". It is quite easy to get boost creep in cold weather. Watch it as the gas is still running the same octane, however, the a/f is colder and less prone to detonation .... anyways.... you get the idea.

Lastly, the air/fuel (a/f) ratio is quite important. Make sure you monitor this will a EGT or a/f meter/gauge. You can go very lean if the computer is not or cannot quite compensate for the possibly drastic change is charge density.

It is best to know your car and how it is running. Got to remember the RX-7 is a balancing act. All systems must act in harmony to make the car its perfect whole. Think of the RX-7 as the Ying and Yang of the car world. Balance is essential to survival - no balance, doom is inevitable.

regards

Rick
1993 RX-7
403 rwhp T04E
2001 911 Turbo
445 hp and more coming
2002 Tony Kart Mitox 125cc Shifter (Vortex powered!)
42 hp and 125 mph down front straight of SOW
2001 Lexus LX-470
2000 Acura TL

 

wow, very good information indeed! I guess I will be careful when i get my TII. And what exactly is boost spike? is that when it suddenly increases unexpectedly?

 

Excellent post carcrazy - you're right on!

 

Yup,I hit 100% duty cycle at about 15 1bs today!

Getting some 1600,s

C.