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Old 10-27-2008, 07:46 AM   #1
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Default cold weather tuning

I had a tough time this weekend getting a good tune on my v-spec. It was probably 8 degrees celcius. I had to use my heat gun to get the engine up to a reasonable temp to get it to fire...that's no big deal but I had a tough time getting it to run smooth on the track. The temps were quite a bit below normal.

Tips, advice??
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Old 10-27-2008, 07:56 AM   #2
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The temps, as in engine or outside air temps? Typically, you run an engine richer (more fuel) in cooler situations. The colder the air the thicker, so to get a good tune in the cold you run it richer. When it is hot outside you lean (less fuel) because the outside air is thinner. Humidity can make this tricky. Moisture in the air displaces oxygen, but this is not too hard to figure out if you understand the basics mentioned above. Really watch the temps. I have seen more hot engines in cold weather than in hot weather.

Hope this helps
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Old 10-27-2008, 08:00 AM   #3
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thats approx 46 degrees F, so pretty cool. When temps get low here I'll usually wrap the head so that it will hold temp up for you. When the engine runs it needs to be a certani temp, since it's cold you can't lean it out to make it run hotter. I go to walmart and get a pack of heavy duty black socks, calf high's. I'll cut the band off of them and double fold it and put it over the cooling head. The elastic holds the sock on nice and tight and it keeps temps up near normal.
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Old 10-27-2008, 08:59 AM   #4
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haha, WHAT! Why cant you lean it up in colder weather???

The principals dont change because the temp does. The window of prime tune moves is all. When it gets colder, you will richen the motor, but only to the point of prime tune again. The motor makes more power in cooler weather as well. Dont you u guys watch the NHRA Top Fuel, look at there numbers in cooler conditions, the track is better, and the air.

As the temp comes down you will start to richen, but its not a RADICAL adjustment, at most maybe 3-4 hours and thats if its a big change in temp.
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Old 10-27-2008, 09:01 AM   #5
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you can still get a motor to over 300 degrees no matter what the air temp is, it might take a little more time, but like posted above, ive seen hotter motors in cooler temps as well.
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Old 10-27-2008, 09:22 AM   #6
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I usually switch to a hotter plug in cold weather
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Old 10-27-2008, 10:05 AM   #7
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Quote:
Originally Posted by motoclay View Post
haha, WHAT! Why cant you lean it up in colder weather???

The principals dont change because the temp does. The window of prime tune moves is all. When it gets colder, you will richen the motor, but only to the point of prime tune again. The motor makes more power in cooler weather as well. Dont you u guys watch the NHRA Top Fuel, look at there numbers in cooler conditions, the track is better, and the air.

As the temp comes down you will start to richen, but its not a RADICAL adjustment, at most maybe 3-4 hours and thats if its a big change in temp.

I was just giving him the basic principles (theory) of what is going on, so he better understands why he is doing something. I don't think I told him to make "RADICAL" changes. I have no idea what temp changes he is talking about.
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Old 10-27-2008, 10:16 AM   #8
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for the record, that post was not directed at you. It was more for the guy running a sock on the cooling head. and im not insulting ne one, or trying to ne way, its just that engines are affected by weather, but the tuning can still be done for optimum performance, i guess in EXTREME sub zero conditions, it might be extra difficult to get it done, that i dunno, have no experience with any engine below freezin, i live in TEXAS hahah
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Old 10-27-2008, 10:19 AM   #9
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Run a hotter plug. It makes a BIG difference. If you have already been running super hot plugs even in warm weather then you will have to do something else. Maybe try higher nitro.
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Old 10-27-2008, 10:22 AM   #10
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Quote:
Originally Posted by mracer View Post
The temps, as in engine or outside air temps? Typically, you run an engine richer (more fuel) in cooler situations. The colder the air the thicker, so to get a good tune in the cold you run it richer. When it is hot outside you lean (less fuel) because the outside air is thinner. Humidity can make this tricky. Moisture in the air displaces oxygen, but this is not too hard to figure out if you understand the basics mentioned above. Really watch the temps. I have seen more hot engines in cold weather than in hot weather.

Hope this helps
in fact, i wasnt dissin on you at all, you are EXACTLY correct,
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Old 10-27-2008, 10:51 AM   #11
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Anyone tried running a magnesium head in the winter? They don't seem to cool quite as well in the summer,.. maybe thats the ticket for winter. Just wondering....

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Old 10-27-2008, 02:37 PM   #12
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Ok...I was leaning it out to try to get it better but it didn't work. I have a P3 plug in the motor. I thought that a cooler plug would make sense, but I guess I had it backwards.

Thx
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Old 10-27-2008, 03:17 PM   #13
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moto, let me see if I can explain this better. What I meant is if your engine is tuned properly it just may not hold enough heat due to the cold air hitting the head. so if it is already tuned the correct way but it is just to cold you can not just lean it out to bring temps up.

I race the indoor events and it will be 15 degrees farienheit and this works well. I think Adam Drake showed me this a couple years ago.

Almost like breaking in a engine...you need it to be a certain temp but sometimes if it's to cool you have to wrap the head to get the temps up. YOu can;t just lean it out there to make it hotter. You starve it of fuel in return starving it of oil and lube.
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Old 10-27-2008, 03:53 PM   #14
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what temps should u be at? I know some engines run at 260 and some 190?
my trinity extech ran this summer from 188-198?
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Old 10-27-2008, 05:05 PM   #15
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Well, on my GRP tuned .21 it runs about 190 when tuned properly. so of course it can vary with weather but if I take the engine and tune it while running in very cold weather the temps will be very low maybe like 130-40, so with wrapping the head or doing the sock I'll have the same temps as I do running in the summer. Keep in mind the motor's internal parts have to be a certain temp before the expand. This has worked very well for me.

But like mentioned before you will have to tune with drastic variations in the weather(HOT/COLD).
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